Sludge dewatering and treatment may cost as much as the wastewater treatment.Usually large proportion of the pollutants in wastewater is organic.They are attacked by saprophytic microorganisms,i.e.organisms that feed ...Sludge dewatering and treatment may cost as much as the wastewater treatment.Usually large proportion of the pollutants in wastewater is organic.They are attacked by saprophytic microorganisms,i.e.organisms that feed upon dead organic matter.Activity of organisms causes decomposition of organic matter and destroys them,where the bacteria convert the organic matter or other constituents in the wastewater to new cells,water,gases and other products.Demolition activities,including renovation/remodeling works and complete or selective removal/demolishing of existing structures either by man-made processes or by natural disasters,create an extensive amount of wastes.These demolition wastes are characterized as heterogeneous mixtures of building materials that are usually contaminated with chemicals and dirt.In developing countries, it is estimated that demolition wastes comprise 20%to 30%of the total annual solid wastes.In Egypt,the daily quantity of construction and demolition(C&D) waste has been estimated as 10 000 tones.That is equivalent to one third of the total daily municipal solid wastes generated per day in Egypt.The zabbaliin have since expanded their activities and now take the waste they collect back to their garbage villages where it is sorted into recyclable components:paper,plastics, rags,glass,metal and food.The food waste is fed to pigs and the other items are sold to recycling centers.This paper summarizes the wastewater and solid wastes management in Egypt now and future.展开更多
Food Waste(FW)is a pressing environmental concern that affects every country globally.About one-third of the food that is produced ends up as waste,contributing to the carbon footprint.Hence,the FW must be properly tr...Food Waste(FW)is a pressing environmental concern that affects every country globally.About one-third of the food that is produced ends up as waste,contributing to the carbon footprint.Hence,the FW must be properly treated to reduce environmental pollution.This study evaluates a few available Food Waste Treatment(FWT)technologies,such as anaerobic digestion,composting,landfill,and incineration,which are widely used.A Bipolar Picture Fuzzy Set(BPFS)is proposed to deal with the ambiguity and uncertainty that arise when converting a real-world problem to a mathematical model.A novel Criteria Importance Through Intercriteria Correlation-Stable Preference Ordering Towards Ideal Solution(CRITIC-SPOTIS)approach is developed to objectively analyze FWT selection based on thirteen criteria covering the industry’s technical,environmental,and entrepreneurial aspects.The CRITIC method is used for the objective analysis of the importance of each criterion in FWT selection.The SPOTIS method is adopted to rank the alternative hassle-free,following the criteria.The proposed model offers a rank reversal-free model,i.e.,the rank of the alternatives remains unaffected even after the addition or removal of an alternative.In addition,comparative and sensitivity analyses are performed to ensure the reliability and robustness of the proposed model and to validate the proposed result.展开更多
The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sou...The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.展开更多
This research explores strategies to enhance the efficiency of secondary treatment in Vertical Flow Constructed Wetlands (CW) in Montenegro. The focus is on selecting appropriate primary treatment methods alongside th...This research explores strategies to enhance the efficiency of secondary treatment in Vertical Flow Constructed Wetlands (CW) in Montenegro. The focus is on selecting appropriate primary treatment methods alongside three distinct substrate types to improve wastewater treatment efficacy. The study examines the combination of two primary treatments with different substrate types in constructed wetlands (CW1, CW2, and CW3). The primary treatments include the existing wastewater treatment plant (WWTP) in Podgorica, involving coarse material removal through screens, inert material separation in aerated sand traps, and sediment and suspended matter removal in primary sedimentation tanks. The Extreme Separator (ExSep) was employed to evaluate its efficacy as a primary treatment method. The research demonstrates that the efficiency of CW can be significantly enhanced by selecting suitable primary treatment methods and substrates in Podgorica’s conditions. The most promising results were achieved by combining ExSep as a primary treatment with secondary treatment in CW-3. The removal efficiencies after CW3 for COD, BOD, and TSS exceeded 89%, 93%, and 91%, respectively. The outcomes underscore the significance of primary treatment in mitigating pollutant loads before discharge into the constructed wetlands, emphasizing potential areas for further optimization in wastewater treatment practices to enhance environmental sustainability and water quality management.展开更多
Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wast...Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of roads.This review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes:industrial solid waste,infrastructure solid waste,and municipal life solid waste.Industrial solid wastes suitable for road engineering generally include coal gangue,fly ash,blast furnace slag,silica fume,and steel slag,etc.Infrastructure solid wastes recycled in road engineering primarily consist of construction&demolition waste,reclaimed asphalt pavements,and recycled cement concrete.Furthermore,recent exploration has extended to the utilization of municipal life solid wastes,such as incinerated bottom ash,glass waste,electronics waste,plastic waste,and rubber waste in road engineering applications.These recycled solid wastes are categorized into solid waste aggregates,solid waste cements,and solid waste fillers,each playing distinct roles in road infrastructure.Roles of solid waste acting aggregates,cements,and fillers in road infrastructures were fully investigated,including their pozzolanic properties,integration effects to virgin materials,modification or enhancement solutions,engineering performances.Utilization of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure development.However,challenges such as variability in material properties,environmental impact mitigation,secondary pollution to environment by leaching,and concerns regarding long-term performance need to be further addressed.Despite these challenges,the recycled solid wastes hold immense potential in revolutionizing road construction practices and fostering environmental stewardship.This review delves into a bird’seye view of the utilization of recycled solid wastes in road engineering,highlighting advances,benefits,challenges,and future prospects.展开更多
The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the coll...The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the collection of wastewater samples. Their analysis revealed specific pollutant loads, including loads of BOD5 3.6966 kgO<sub>2</sub>/day and COD of 12.8775 kgO<sub>2</sub>/day, which were central to the design phase. Following a rigorous assessment of the existing sanitation infrastructure, constructed wetland (CWs) emerged as the most appropriate ecological solution. This system, valued for its ability to effectively remove contaminants, was tailored to the specific needs of the site. Consequently, the final design of the filter extends over 217.16 m<sup>2</sup>, divided into two cells of 108.58 m<sup>2</sup> each, with dimensions of 12.77 m in length and 8.5 m in width. The depth of the filtering medium is approximately 0.60 m, meeting the standards while ensuring maximized purification. Typha, an indigenous and prolific plant known for its purification abilities, was selected as the filtering agent. Concurrently, non-crushed gravel was chosen for its proven filtration capacity. This study is the result of a combination of scientific rigor and design expertise. It provides a holistic view of sanitation for Ndiebene Gandiol. The technical specifications and dimensions of the constructed wetland filter embody an approach that marries indepth analysis and practical application, all aimed at delivering an effective and long-lasting solution to the local sanitation challenges. By integrating precise scientific data with sanitation design expertise, this study delivers a holistic solution for Ndiebene Gandiol. The detailed dimensions and specifications of the constructed wetland filter reflect a methodology that combines meticulous analysis with practical adaptation, aiming to provide an effective and sustainable response to the challenges of rural and school sanitation in the northern region of Senegal.展开更多
The study conducted at Ndiebene Gandiol 1 school in Senegal has unveiled serious environmental and public health challenges. The wastewater analysis revealed high levels of Biochemical Oxygen Demand (BOD5), Chemical O...The study conducted at Ndiebene Gandiol 1 school in Senegal has unveiled serious environmental and public health challenges. The wastewater analysis revealed high levels of Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and fecal coliforms, signaling potential risks to the well-being of students and staff. This situation mirrors a wider issue in rural educational settings, where inadequate sanitation persists. Intensive wastewater treatment options are known for their effectiveness against high pollutant loads but are resource-intensive in both energy and cost. Conversely, extensive treatment systems, while requiring more land, provide a sustainable alternative by harnessing natural processes for pollutant removal. The research suggests a hybrid treatment approach could serve the school’s needs, balancing the robust capabilities of intensive methods with the ecological benefits of extensive systems. Such a solution would need to be tailored to the specific environmental, financial, and logistical context of the school, based on comprehensive feasibility studies and stakeholder engagement. This study’s findings underscore the urgency of addressing sanitation in schools, as it is intrinsically linked to the health and academic success of students. Quick, effective, and long-term strategies are vital to secure a healthier and more prosperous future for the youth. With proper implementation, the school can transform its sanitation facilities, setting a precedent for rural educational institutions in Senegal and similar contexts globally.展开更多
The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domai...The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift.展开更多
Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typ...Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.展开更多
The overarching goal of this study is to offer an effective and sustainable solution to the challenges of sanitation in rural and school settings in the northern region of Senegal. The study explores a wastewater trea...The overarching goal of this study is to offer an effective and sustainable solution to the challenges of sanitation in rural and school settings in the northern region of Senegal. The study explores a wastewater treatment approach based on phytoremediation, with a particular focus on the use of horizontally-flowing reed bed filters. Furthermore, it aims to adapt and optimize these systems for the specific needs of Senegal, focusing on wastewater in school environments. Thus, we constructed a horizontally-flowing reed bed filter, planted with Typha, at the Ndiébène Gandiol school in Senegal. We will investigate the efficiency of wastewater treatment by this horizontally-flowing reed bed filter, emphasizing the role of the plant used: Typha. The filter is described in detail, specifying its dimensions, its composition of flint gravel, and the choice of plants, namely Typha. The experimental protocol is detailed, describing the sampling at the entrance and exit of the filter to evaluate water quality. The parameters analyzed include Chemical Oxygen Demand (COD), Biochemical Oxygen Demand over 5 days (BOD5), suspended solids, ammonium, nitrates, phosphates, pH, conductivity, and fecal coliforms. The results indicate a significant improvement in water quality after treatment. COD, BOD5, suspended solids, and fecal coliforms are greatly reduced, thus demonstrating the efficacy of the Typha filter. However, nitrate concentrations remain relatively stable, suggesting room for improvement in their elimination. A perspective of reuse of the treated water is considered, showing that the effluents from the planted filter meet Senegalese and international standards for irrigation. The findings suggest that these waters could be used for a variety of crops, thereby reducing the pressure on freshwater resources. In conclusion, the Typha-based filtration system shows promising results for improving water quality in this region of Senegal. However, adjustments are necessary for more effective nitrate removal. This study paves the way for sustainable use of treated wastewater for irrigation, thus contributing to food security and the preservation of water resources.展开更多
Confronted with the challenge of wastewater management, particularly in the school environment of Senegal, our study set out to achieve multiple objectives. Following field surveys, laboratory analyses of wastewater s...Confronted with the challenge of wastewater management, particularly in the school environment of Senegal, our study set out to achieve multiple objectives. Following field surveys, laboratory analyses of wastewater samples were carried out, revealing a significant pollutant load. In the community of Gandiol, near Saint-Louis (Senegal), the school of Ndiebene Gandiol 1 faces significant sanitation challenges. Our study aimed to address this issue by using a constructed filter composed of two filtering bed cells measuring 12 × 8.5 m, preceded by a septic tank. We particularly focused on the influence of Vetiver;a plant chosen for its purification potential. Our analyses showed remarkable efficiency of the filter. Elimination rates reached 95% for 5-Day Biochemical Oxygen Demand (BOD5), 91% for Chemical Oxygen Demand (COD), and 92% for SS, far exceeding the Senegalese standards set at 50 mg/L, 200 mg/L, and 40 mg/L, respectively. Furthermore, the concentration of fecal coliforms was reduced to 176 FCU/100mL, well below the Senegalese threshold of 2000 FCU/100mL and close to the World Health Organization’s (WHO) recommendation of 1000 FCU/100mL. However, despite these promising results, some parameters, particularly the concentration of certain pollutants, approached the thresholds defined by European legislation. For example, for Suspended Solids (SS), the post-treatment level of 3 mg/L was well below the Senegalese standard but edged close to the European minimum of 10 mg/L. In conclusion, the Vetiver filter demonstrated a remarkable ability to treat school wastewater, offering high pollutant elimination percentages. These results suggest significant opportunities for the reuse of treated water, potentially in areas such as irrigation, though some adjustments may be necessary to meet the strictest standards such as those of the European union (EU).展开更多
Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation techniques.This review article provides a detailed examinat...Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation techniques.This review article provides a detailed examination of magnesium oxide(MgO)nanoparticles as an innovative nanoadsorbent for wastewater treatment,with a specific focus on heavy metal and dye removal.The review comprehensively explores various aspects of MgO nanoparticles,including their structural characteristics and synthesis techniques.The article delves into the morphology and crystallographic arrangement of MgO nanoparticles,offering insights into their structural attributes.Given the complexity of adsorption processes,the review identifies and analyzes parameters influencing the adsorption efficiency of MgO nanoparticles,such as temperature,pH,contact time,initial concentration,and co-existing ions.The interplay between these parameters and the adsorption capability of MgO nanoparticles emphasizes the importance of optimizing operational conditions.Furthermore,the review assesses various synthesis methods for MgO nanoparticles,including sol-gel,hydrothermal,precipitation,green synthesis,solvothermal,and template-assisted techniques.It discusses the advantages,limitations,and resulting nanoparticle characteristics of each method,enabling readers to grasp the implications of synthesis processes on adsorption efficiency.This comprehensive review consolidates current insights into the effectiveness of MgO nanoparticles as a potent nanoadsorbent for removing heavy metals and dyes from wastewater covering a wide spectrum of aspects related to MgO nanoparticles.Moreover,there is a need to investigate the use of MgO in the treatment of actual wastewater or river water,in order to leverage its cost-effectiveness and high efficiency for practical water treatment applications in real-time.展开更多
The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled ...The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.展开更多
The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising sol...The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising solution.Here,we introduce an ML technique based on multimodal strategies,focusing specifically on intelligent aeration control in wastewater treatment plants(WWTPs).The generalization of the multimodal strategy is demonstrated on eight ML models.The results demonstrate that this multimodal strategy significantly enhances model indicators for ML in environmental science and the efficiency of aeration control,exhibiting exceptional performance and interpretability.Integrating random forest with visual models achieves the highest accuracy in forecasting aeration quantity in multimodal models,with a mean absolute percentage error of 4.4%and a coefficient of determination of 0.948.Practical testing in a full-scale plant reveals that the multimodal model can reduce operation costs by 19.8%compared to traditional fuzzy control methods.The potential application of these strategies in critical water science domains is discussed.To foster accessibility and promote widespread adoption,the multimodal ML models are freely available on GitHub,thereby eliminating technical barriers and encouraging the application of artificial intelligence in urban wastewater treatment.展开更多
Wastewater treatment plants(WWTPs)are important and energy-intensive municipal infrastructures.High energy consumption and relatively low operating performance are major challenges from the perspective of carbon neutr...Wastewater treatment plants(WWTPs)are important and energy-intensive municipal infrastructures.High energy consumption and relatively low operating performance are major challenges from the perspective of carbon neutrality.However,water-energy nexus analysis and models for WWTPs have rarely been reported to date.In this study,a cloud-model-based energy consumption analysis(CMECA)of a WWTP was conducted to explore the relationship between influent and energy consumption by clustering its influent’s parameters.The principal component analysis(PCA)and K-means clustering were applied to classify the influent condition using water quality and volume data.The energy consumption of the WWTP is divided into five standard evaluation levels,and its cloud digital characteristics(CDCs)were extracted according to bilateral constraints and golden ratio methods.Our results showed that the energy consumption distribution gradually dispersed and deviated from the Gaussian distribution with decreased water concentration and quantity.The days with high energy efficiency were extracted via the clustering method from the influent category of excessive energy consumption,represented by a compact-type energy consumption distribution curve to identify the influent conditions that affect the steady distribution of energy consumption.The local WWTP has high energy consumption with 0.3613 kW·h·m^(-3)despite low influent concentration and volumes,across four consumption levels from low(I)to relatively high(IV),showing an unsatisfactory operation and management level.The average oxygenation capacity,internal reflux ratio,and external reflux ratio during high energy efficiency days recognized by further clustering were obtained(0.2924-0.3703 kg O_(2)·m^(-3),1.9576-2.4787,and 0.6603-0.8361,respectively),which could be used as a guide for the days with low energy efficiency.Consequently,this study offers a water-energy nexus analysis method to identify influent conditions with operational management anomalies and can be used as an empirical reference for the optimized operation of WWTPs.展开更多
This study presents an assessment of wastewater ecological treatment processes utilizing a horizontal flow bio-reactor at the Ndiebene Gandiol 1 school. It primarily aims to juxtapose the filtration efficacy of two di...This study presents an assessment of wastewater ecological treatment processes utilizing a horizontal flow bio-reactor at the Ndiebene Gandiol 1 school. It primarily aims to juxtapose the filtration efficacy of two distinct vegetative cells, Vetiver and Typha, in the pursuit of sustainable wastewater management strategies for rural scholastic institutions. A synergistic approach was employed, integrating on-site surveys for site-specific insights and laboratory analyses to quantify the pollutant loads pre- and post-treatment. Our findings indicate that both Vetiver and Typha-infused filter beds significantly reduce most contaminants, with particular success in diminishing chemical oxygen demand (COD) and biological oxygen demand (BOD5). Vetiver was notable for its superior reduction of COD, achieving an average effluent concentration of 74 mg/L, in contrast to Typha’s 155 mg/L. Conversely, Typha excelled in suspended solids removal, registering 1 mg/L against Vetiver’s 3 mg/L. While both systems notably surpassed the target metrics across several indicators, including fecal coliform reduction, our results pinpoint the need for refinement in phosphate remediation. Conclusively, the study underscores the efficacy of both Vetiver and Typha systems in rural wastewater treatment contexts, with their integrative application potentially paving the way for enhanced system robustness and efficiency. The outcomes herein highlight the imperative for continued research to further hone these ecological treatment modalities, especially concerning phosphate elimination.展开更多
The status of utilization and disposal of the building wastes are introduced on the basis of analysis of its compositions, genera- tion and effects on urban environment. The basic framework of the integrated building ...The status of utilization and disposal of the building wastes are introduced on the basis of analysis of its compositions, genera- tion and effects on urban environment. The basic framework of the integrated building waste management, including control of the sources, reduction of the integrated process and final disposal, are proposed in view of the problems existing in recovery of the building wastes and the experiences from the developed countries.展开更多
This paper describes the wastewater treatment of 3 liters per second of capacity of discharges of capacity,from the avocado washed,as well as the production of avocado sauce.Effluents were pretreated with a grease and...This paper describes the wastewater treatment of 3 liters per second of capacity of discharges of capacity,from the avocado washed,as well as the production of avocado sauce.Effluents were pretreated with a grease and oil trap and contained small amounts of oil and grease,dissolved and total solids,organic matter and trace of organic and inorganic compounds from the vitamins and minerals of avocado.The treatment train is located in an small surface and the train is integrated with coagulation in line with alumina in a static mixer,rapid filtration in two steps,double advanced oxidation with ozone and heterocyclic photocatalysis with a nanofilm of zinc oxide as,photocatalyzer and final adsorption of refractory compounds with activated charcoal.The treated wastewater meets the environmental regulation to urban sewerage discharges of the city,according to the results of a Mexican Certified Laboratory.展开更多
The strategies of coordination between production activities of alcohol and the comprehensive utilization of its by products was discussed in this paper. It can be concluded from the study that guided by the principl...The strategies of coordination between production activities of alcohol and the comprehensive utilization of its by products was discussed in this paper. It can be concluded from the study that guided by the principles of ecological engineering the purposes of both environment protecting and higher profits gaining can be realized simultaneously with less input than other engineering forms. Within this case, the by products, CO 2,wastewater, distillers' grain, navel and mixed oil were treated as resources for certain purpose such as using as raw materials to produce fuel, forage and fertilizer. The rings earlier broken or given up by human behaviors were connected properly or added, and some high efficient rings were re added. The economic benefits getting from the treatment of by products occupy 10.39% of the total output or 1.17 times of the net output without environmental impacts.展开更多
Tannery industries generate wastewater containing high concentrations of sulfur. Most of wastes are liquid (effluent). The river section and tanning are the source of most tannery waste. Dehairing is a process of sepa...Tannery industries generate wastewater containing high concentrations of sulfur. Most of wastes are liquid (effluent). The river section and tanning are the source of most tannery waste. Dehairing is a process of separation of hair and epidermis. Lime and sulfides are used for this process. Thus, sulfur in wastewater dehairing occurs as sulfide. Today, catalysis is at the centre of major societal concerns about energy, environment and sustainable development. The discovery of new catalytic processes and the improvement of existing ones are also critically important for improving the quality of life while simultaneously reducing the adverse impact of human activities on the environment. With a substitution approach of a catalyst MnSO4 by multiple wastes from tannery and the metallurgical sector, this study investigated the recycle of waste from dehairing process and waste from metallurgical industry. The results indicated 32% of oxidized sulfur for the first waste derived from process of depilation and 30% for the second waste from metallurgical process industry. A preliminary cost analysis demonstrated that the proposed solution is much cheaper than the discharging of waste and wastewater in a WWTP;however, the sustainability of the proposed solution provided a second alternative, to alleviate the operational costs of installations wastewater from tanneries, without significantly impacting the environment.展开更多
基金Supported by a grant from Sanko Company for EM Production and its produetsa grant from JICA Agency.OIC.Okmawa.Japan
文摘Sludge dewatering and treatment may cost as much as the wastewater treatment.Usually large proportion of the pollutants in wastewater is organic.They are attacked by saprophytic microorganisms,i.e.organisms that feed upon dead organic matter.Activity of organisms causes decomposition of organic matter and destroys them,where the bacteria convert the organic matter or other constituents in the wastewater to new cells,water,gases and other products.Demolition activities,including renovation/remodeling works and complete or selective removal/demolishing of existing structures either by man-made processes or by natural disasters,create an extensive amount of wastes.These demolition wastes are characterized as heterogeneous mixtures of building materials that are usually contaminated with chemicals and dirt.In developing countries, it is estimated that demolition wastes comprise 20%to 30%of the total annual solid wastes.In Egypt,the daily quantity of construction and demolition(C&D) waste has been estimated as 10 000 tones.That is equivalent to one third of the total daily municipal solid wastes generated per day in Egypt.The zabbaliin have since expanded their activities and now take the waste they collect back to their garbage villages where it is sorted into recyclable components:paper,plastics, rags,glass,metal and food.The food waste is fed to pigs and the other items are sold to recycling centers.This paper summarizes the wastewater and solid wastes management in Egypt now and future.
文摘Food Waste(FW)is a pressing environmental concern that affects every country globally.About one-third of the food that is produced ends up as waste,contributing to the carbon footprint.Hence,the FW must be properly treated to reduce environmental pollution.This study evaluates a few available Food Waste Treatment(FWT)technologies,such as anaerobic digestion,composting,landfill,and incineration,which are widely used.A Bipolar Picture Fuzzy Set(BPFS)is proposed to deal with the ambiguity and uncertainty that arise when converting a real-world problem to a mathematical model.A novel Criteria Importance Through Intercriteria Correlation-Stable Preference Ordering Towards Ideal Solution(CRITIC-SPOTIS)approach is developed to objectively analyze FWT selection based on thirteen criteria covering the industry’s technical,environmental,and entrepreneurial aspects.The CRITIC method is used for the objective analysis of the importance of each criterion in FWT selection.The SPOTIS method is adopted to rank the alternative hassle-free,following the criteria.The proposed model offers a rank reversal-free model,i.e.,the rank of the alternatives remains unaffected even after the addition or removal of an alternative.In addition,comparative and sensitivity analyses are performed to ensure the reliability and robustness of the proposed model and to validate the proposed result.
文摘The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.
文摘This research explores strategies to enhance the efficiency of secondary treatment in Vertical Flow Constructed Wetlands (CW) in Montenegro. The focus is on selecting appropriate primary treatment methods alongside three distinct substrate types to improve wastewater treatment efficacy. The study examines the combination of two primary treatments with different substrate types in constructed wetlands (CW1, CW2, and CW3). The primary treatments include the existing wastewater treatment plant (WWTP) in Podgorica, involving coarse material removal through screens, inert material separation in aerated sand traps, and sediment and suspended matter removal in primary sedimentation tanks. The Extreme Separator (ExSep) was employed to evaluate its efficacy as a primary treatment method. The research demonstrates that the efficiency of CW can be significantly enhanced by selecting suitable primary treatment methods and substrates in Podgorica’s conditions. The most promising results were achieved by combining ExSep as a primary treatment with secondary treatment in CW-3. The removal efficiencies after CW3 for COD, BOD, and TSS exceeded 89%, 93%, and 91%, respectively. The outcomes underscore the significance of primary treatment in mitigating pollutant loads before discharge into the constructed wetlands, emphasizing potential areas for further optimization in wastewater treatment practices to enhance environmental sustainability and water quality management.
基金A number of financial funding including the National Natural Science Foundation of China(Nos.52278455,52268068,52078018,52208434)National Key R&D Program of China(2022YFE0137300)+5 种基金the ShuGuang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.21SG24)China Postdoctoral Science Foundation(No.2022M711079)Provincial Natural Science Foundation/Postdoctoral Research Grant/Science and Technology Project(Nos.222300420142,202103107,192102310229)have to be acknowledged for supporting this manuscript.As well,some university's funding including Chang'an University(No.CHD300102213507)Changsha University of Science and Technology(No.KFJ230206)Henan University of Technology(No.21420156)are also appreciated.Meanwhile,the strong supports from the Editor Office of Journal of Road Engineering have to be highly acknowledged for their kindly inviting,guiding,assisting,and improving on the manuscript of current review.
文摘Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory structures.The utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of roads.This review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes:industrial solid waste,infrastructure solid waste,and municipal life solid waste.Industrial solid wastes suitable for road engineering generally include coal gangue,fly ash,blast furnace slag,silica fume,and steel slag,etc.Infrastructure solid wastes recycled in road engineering primarily consist of construction&demolition waste,reclaimed asphalt pavements,and recycled cement concrete.Furthermore,recent exploration has extended to the utilization of municipal life solid wastes,such as incinerated bottom ash,glass waste,electronics waste,plastic waste,and rubber waste in road engineering applications.These recycled solid wastes are categorized into solid waste aggregates,solid waste cements,and solid waste fillers,each playing distinct roles in road infrastructure.Roles of solid waste acting aggregates,cements,and fillers in road infrastructures were fully investigated,including their pozzolanic properties,integration effects to virgin materials,modification or enhancement solutions,engineering performances.Utilization of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure development.However,challenges such as variability in material properties,environmental impact mitigation,secondary pollution to environment by leaching,and concerns regarding long-term performance need to be further addressed.Despite these challenges,the recycled solid wastes hold immense potential in revolutionizing road construction practices and fostering environmental stewardship.This review delves into a bird’seye view of the utilization of recycled solid wastes in road engineering,highlighting advances,benefits,challenges,and future prospects.
文摘The primary objective of this study was to design and size a sustainable sanitation solution for the Ndiebene Gandiol 1 school located in the eponymous commune in northern Senegal. Field investigations led to the collection of wastewater samples. Their analysis revealed specific pollutant loads, including loads of BOD5 3.6966 kgO<sub>2</sub>/day and COD of 12.8775 kgO<sub>2</sub>/day, which were central to the design phase. Following a rigorous assessment of the existing sanitation infrastructure, constructed wetland (CWs) emerged as the most appropriate ecological solution. This system, valued for its ability to effectively remove contaminants, was tailored to the specific needs of the site. Consequently, the final design of the filter extends over 217.16 m<sup>2</sup>, divided into two cells of 108.58 m<sup>2</sup> each, with dimensions of 12.77 m in length and 8.5 m in width. The depth of the filtering medium is approximately 0.60 m, meeting the standards while ensuring maximized purification. Typha, an indigenous and prolific plant known for its purification abilities, was selected as the filtering agent. Concurrently, non-crushed gravel was chosen for its proven filtration capacity. This study is the result of a combination of scientific rigor and design expertise. It provides a holistic view of sanitation for Ndiebene Gandiol. The technical specifications and dimensions of the constructed wetland filter embody an approach that marries indepth analysis and practical application, all aimed at delivering an effective and long-lasting solution to the local sanitation challenges. By integrating precise scientific data with sanitation design expertise, this study delivers a holistic solution for Ndiebene Gandiol. The detailed dimensions and specifications of the constructed wetland filter reflect a methodology that combines meticulous analysis with practical adaptation, aiming to provide an effective and sustainable response to the challenges of rural and school sanitation in the northern region of Senegal.
文摘The study conducted at Ndiebene Gandiol 1 school in Senegal has unveiled serious environmental and public health challenges. The wastewater analysis revealed high levels of Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and fecal coliforms, signaling potential risks to the well-being of students and staff. This situation mirrors a wider issue in rural educational settings, where inadequate sanitation persists. Intensive wastewater treatment options are known for their effectiveness against high pollutant loads but are resource-intensive in both energy and cost. Conversely, extensive treatment systems, while requiring more land, provide a sustainable alternative by harnessing natural processes for pollutant removal. The research suggests a hybrid treatment approach could serve the school’s needs, balancing the robust capabilities of intensive methods with the ecological benefits of extensive systems. Such a solution would need to be tailored to the specific environmental, financial, and logistical context of the school, based on comprehensive feasibility studies and stakeholder engagement. This study’s findings underscore the urgency of addressing sanitation in schools, as it is intrinsically linked to the health and academic success of students. Quick, effective, and long-term strategies are vital to secure a healthier and more prosperous future for the youth. With proper implementation, the school can transform its sanitation facilities, setting a precedent for rural educational institutions in Senegal and similar contexts globally.
基金supported by the National Natural Science Foundation of China(52321005,52293443,and 52230004)the Shenzhen Science and Technology Program(KQTD20190929172630447)+1 种基金the Shenzhen Key Research Project(GXWD20220817145054002)the Talent Recruitment Project of Guandong(2021QN020106).
文摘The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift.
基金support was received the Science&Technology Foundation of RIPP(PR20230092,PR20230259)the National Natural Science Foundation of China(22278419)the Key Core Technology Research(Social Development)Foundation of Suzhou(2023ss06).
文摘Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.
文摘The overarching goal of this study is to offer an effective and sustainable solution to the challenges of sanitation in rural and school settings in the northern region of Senegal. The study explores a wastewater treatment approach based on phytoremediation, with a particular focus on the use of horizontally-flowing reed bed filters. Furthermore, it aims to adapt and optimize these systems for the specific needs of Senegal, focusing on wastewater in school environments. Thus, we constructed a horizontally-flowing reed bed filter, planted with Typha, at the Ndiébène Gandiol school in Senegal. We will investigate the efficiency of wastewater treatment by this horizontally-flowing reed bed filter, emphasizing the role of the plant used: Typha. The filter is described in detail, specifying its dimensions, its composition of flint gravel, and the choice of plants, namely Typha. The experimental protocol is detailed, describing the sampling at the entrance and exit of the filter to evaluate water quality. The parameters analyzed include Chemical Oxygen Demand (COD), Biochemical Oxygen Demand over 5 days (BOD5), suspended solids, ammonium, nitrates, phosphates, pH, conductivity, and fecal coliforms. The results indicate a significant improvement in water quality after treatment. COD, BOD5, suspended solids, and fecal coliforms are greatly reduced, thus demonstrating the efficacy of the Typha filter. However, nitrate concentrations remain relatively stable, suggesting room for improvement in their elimination. A perspective of reuse of the treated water is considered, showing that the effluents from the planted filter meet Senegalese and international standards for irrigation. The findings suggest that these waters could be used for a variety of crops, thereby reducing the pressure on freshwater resources. In conclusion, the Typha-based filtration system shows promising results for improving water quality in this region of Senegal. However, adjustments are necessary for more effective nitrate removal. This study paves the way for sustainable use of treated wastewater for irrigation, thus contributing to food security and the preservation of water resources.
文摘Confronted with the challenge of wastewater management, particularly in the school environment of Senegal, our study set out to achieve multiple objectives. Following field surveys, laboratory analyses of wastewater samples were carried out, revealing a significant pollutant load. In the community of Gandiol, near Saint-Louis (Senegal), the school of Ndiebene Gandiol 1 faces significant sanitation challenges. Our study aimed to address this issue by using a constructed filter composed of two filtering bed cells measuring 12 × 8.5 m, preceded by a septic tank. We particularly focused on the influence of Vetiver;a plant chosen for its purification potential. Our analyses showed remarkable efficiency of the filter. Elimination rates reached 95% for 5-Day Biochemical Oxygen Demand (BOD5), 91% for Chemical Oxygen Demand (COD), and 92% for SS, far exceeding the Senegalese standards set at 50 mg/L, 200 mg/L, and 40 mg/L, respectively. Furthermore, the concentration of fecal coliforms was reduced to 176 FCU/100mL, well below the Senegalese threshold of 2000 FCU/100mL and close to the World Health Organization’s (WHO) recommendation of 1000 FCU/100mL. However, despite these promising results, some parameters, particularly the concentration of certain pollutants, approached the thresholds defined by European legislation. For example, for Suspended Solids (SS), the post-treatment level of 3 mg/L was well below the Senegalese standard but edged close to the European minimum of 10 mg/L. In conclusion, the Vetiver filter demonstrated a remarkable ability to treat school wastewater, offering high pollutant elimination percentages. These results suggest significant opportunities for the reuse of treated water, potentially in areas such as irrigation, though some adjustments may be necessary to meet the strictest standards such as those of the European union (EU).
基金the support of the Khalifa University internal funding CIRA-2021-071(8474000416),Khalifa University,UAEthe financial support from the Science batch of 1976-1980 of the University of Peradeniya,Sri Lanka。
文摘Wastewater contamination by heavy metals and synthetic dyes presents a significant environmental challenge,necessitating effective and sustainable separation techniques.This review article provides a detailed examination of magnesium oxide(MgO)nanoparticles as an innovative nanoadsorbent for wastewater treatment,with a specific focus on heavy metal and dye removal.The review comprehensively explores various aspects of MgO nanoparticles,including their structural characteristics and synthesis techniques.The article delves into the morphology and crystallographic arrangement of MgO nanoparticles,offering insights into their structural attributes.Given the complexity of adsorption processes,the review identifies and analyzes parameters influencing the adsorption efficiency of MgO nanoparticles,such as temperature,pH,contact time,initial concentration,and co-existing ions.The interplay between these parameters and the adsorption capability of MgO nanoparticles emphasizes the importance of optimizing operational conditions.Furthermore,the review assesses various synthesis methods for MgO nanoparticles,including sol-gel,hydrothermal,precipitation,green synthesis,solvothermal,and template-assisted techniques.It discusses the advantages,limitations,and resulting nanoparticle characteristics of each method,enabling readers to grasp the implications of synthesis processes on adsorption efficiency.This comprehensive review consolidates current insights into the effectiveness of MgO nanoparticles as a potent nanoadsorbent for removing heavy metals and dyes from wastewater covering a wide spectrum of aspects related to MgO nanoparticles.Moreover,there is a need to investigate the use of MgO in the treatment of actual wastewater or river water,in order to leverage its cost-effectiveness and high efficiency for practical water treatment applications in real-time.
基金financially sponsored by Qing Lan Project in Jiangsu Province of China(2023)Scientific Research Project of Taizhou Polytechnic College(TZYKY-22-4).
文摘The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.
基金the financial support by the National Natural Science Foundation of China(52230004 and 52293445)the Key Research and Development Project of Shandong Province(2020CXGC011202-005)the Shenzhen Science and Technology Program(KCXFZ20211020163404007 and KQTD20190929172630447).
文摘The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising solution.Here,we introduce an ML technique based on multimodal strategies,focusing specifically on intelligent aeration control in wastewater treatment plants(WWTPs).The generalization of the multimodal strategy is demonstrated on eight ML models.The results demonstrate that this multimodal strategy significantly enhances model indicators for ML in environmental science and the efficiency of aeration control,exhibiting exceptional performance and interpretability.Integrating random forest with visual models achieves the highest accuracy in forecasting aeration quantity in multimodal models,with a mean absolute percentage error of 4.4%and a coefficient of determination of 0.948.Practical testing in a full-scale plant reveals that the multimodal model can reduce operation costs by 19.8%compared to traditional fuzzy control methods.The potential application of these strategies in critical water science domains is discussed.To foster accessibility and promote widespread adoption,the multimodal ML models are freely available on GitHub,thereby eliminating technical barriers and encouraging the application of artificial intelligence in urban wastewater treatment.
基金the financial support from the National Key Research and Development Program of China(2019YFD1100204)the National Natural Science Foundation of China(52091545)+2 种基金the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(2021TS03)The Important Projects in the Scientific Innovation of CECEP(cecep-zdkj-2020-009)the Open Project of Key Laboratory of Environmental Biotechnology,Chinese Academy of Sciences(kf2018002).
文摘Wastewater treatment plants(WWTPs)are important and energy-intensive municipal infrastructures.High energy consumption and relatively low operating performance are major challenges from the perspective of carbon neutrality.However,water-energy nexus analysis and models for WWTPs have rarely been reported to date.In this study,a cloud-model-based energy consumption analysis(CMECA)of a WWTP was conducted to explore the relationship between influent and energy consumption by clustering its influent’s parameters.The principal component analysis(PCA)and K-means clustering were applied to classify the influent condition using water quality and volume data.The energy consumption of the WWTP is divided into five standard evaluation levels,and its cloud digital characteristics(CDCs)were extracted according to bilateral constraints and golden ratio methods.Our results showed that the energy consumption distribution gradually dispersed and deviated from the Gaussian distribution with decreased water concentration and quantity.The days with high energy efficiency were extracted via the clustering method from the influent category of excessive energy consumption,represented by a compact-type energy consumption distribution curve to identify the influent conditions that affect the steady distribution of energy consumption.The local WWTP has high energy consumption with 0.3613 kW·h·m^(-3)despite low influent concentration and volumes,across four consumption levels from low(I)to relatively high(IV),showing an unsatisfactory operation and management level.The average oxygenation capacity,internal reflux ratio,and external reflux ratio during high energy efficiency days recognized by further clustering were obtained(0.2924-0.3703 kg O_(2)·m^(-3),1.9576-2.4787,and 0.6603-0.8361,respectively),which could be used as a guide for the days with low energy efficiency.Consequently,this study offers a water-energy nexus analysis method to identify influent conditions with operational management anomalies and can be used as an empirical reference for the optimized operation of WWTPs.
文摘This study presents an assessment of wastewater ecological treatment processes utilizing a horizontal flow bio-reactor at the Ndiebene Gandiol 1 school. It primarily aims to juxtapose the filtration efficacy of two distinct vegetative cells, Vetiver and Typha, in the pursuit of sustainable wastewater management strategies for rural scholastic institutions. A synergistic approach was employed, integrating on-site surveys for site-specific insights and laboratory analyses to quantify the pollutant loads pre- and post-treatment. Our findings indicate that both Vetiver and Typha-infused filter beds significantly reduce most contaminants, with particular success in diminishing chemical oxygen demand (COD) and biological oxygen demand (BOD5). Vetiver was notable for its superior reduction of COD, achieving an average effluent concentration of 74 mg/L, in contrast to Typha’s 155 mg/L. Conversely, Typha excelled in suspended solids removal, registering 1 mg/L against Vetiver’s 3 mg/L. While both systems notably surpassed the target metrics across several indicators, including fecal coliform reduction, our results pinpoint the need for refinement in phosphate remediation. Conclusively, the study underscores the efficacy of both Vetiver and Typha systems in rural wastewater treatment contexts, with their integrative application potentially paving the way for enhanced system robustness and efficiency. The outcomes herein highlight the imperative for continued research to further hone these ecological treatment modalities, especially concerning phosphate elimination.
文摘The status of utilization and disposal of the building wastes are introduced on the basis of analysis of its compositions, genera- tion and effects on urban environment. The basic framework of the integrated building waste management, including control of the sources, reduction of the integrated process and final disposal, are proposed in view of the problems existing in recovery of the building wastes and the experiences from the developed countries.
文摘This paper describes the wastewater treatment of 3 liters per second of capacity of discharges of capacity,from the avocado washed,as well as the production of avocado sauce.Effluents were pretreated with a grease and oil trap and contained small amounts of oil and grease,dissolved and total solids,organic matter and trace of organic and inorganic compounds from the vitamins and minerals of avocado.The treatment train is located in an small surface and the train is integrated with coagulation in line with alumina in a static mixer,rapid filtration in two steps,double advanced oxidation with ozone and heterocyclic photocatalysis with a nanofilm of zinc oxide as,photocatalyzer and final adsorption of refractory compounds with activated charcoal.The treated wastewater meets the environmental regulation to urban sewerage discharges of the city,according to the results of a Mexican Certified Laboratory.
文摘The strategies of coordination between production activities of alcohol and the comprehensive utilization of its by products was discussed in this paper. It can be concluded from the study that guided by the principles of ecological engineering the purposes of both environment protecting and higher profits gaining can be realized simultaneously with less input than other engineering forms. Within this case, the by products, CO 2,wastewater, distillers' grain, navel and mixed oil were treated as resources for certain purpose such as using as raw materials to produce fuel, forage and fertilizer. The rings earlier broken or given up by human behaviors were connected properly or added, and some high efficient rings were re added. The economic benefits getting from the treatment of by products occupy 10.39% of the total output or 1.17 times of the net output without environmental impacts.
文摘Tannery industries generate wastewater containing high concentrations of sulfur. Most of wastes are liquid (effluent). The river section and tanning are the source of most tannery waste. Dehairing is a process of separation of hair and epidermis. Lime and sulfides are used for this process. Thus, sulfur in wastewater dehairing occurs as sulfide. Today, catalysis is at the centre of major societal concerns about energy, environment and sustainable development. The discovery of new catalytic processes and the improvement of existing ones are also critically important for improving the quality of life while simultaneously reducing the adverse impact of human activities on the environment. With a substitution approach of a catalyst MnSO4 by multiple wastes from tannery and the metallurgical sector, this study investigated the recycle of waste from dehairing process and waste from metallurgical industry. The results indicated 32% of oxidized sulfur for the first waste derived from process of depilation and 30% for the second waste from metallurgical process industry. A preliminary cost analysis demonstrated that the proposed solution is much cheaper than the discharging of waste and wastewater in a WWTP;however, the sustainability of the proposed solution provided a second alternative, to alleviate the operational costs of installations wastewater from tanneries, without significantly impacting the environment.