Surface flow constructed wetland with composite plant bed for pretreatment of micro-polluted Yellow River raw water in China

In order to investigate the feasibility of pretreating the micro-polluted Yellow River raw water by constructed wetland, an experiment was conducted using a surface flow constructed wetland with composite plant bed. The contamination removal efficiency and their trends in the wetland treatment system were studied under different hydraulic loading rates(HLR). The contamination removal efficiencies were compared according to the seasonal change under optimum HLR. The result shows that in the same season, under different hydraulic loadings ranging from 2 to 6 m3/(m2·d) at the same period, the best HLR is 4 m3/(m2·d) in the experimental system. The average removal rates of COD, TN, ammoniacal nitrogen(NH4+-N), and TP in the constructed wetland are 38.37%, 45.97%, 39.86% and 41.69%, respectively. According to China Standard for Surface Water Resources (GB3838-2002), mean effluent of COD, TN, NH4+-N and TP can nearly reach Grade Ⅲ, GradeⅤ, GradeⅠand GradeⅠ, respectively. Furthermore, treatment efficiency of the system in summer is obvious higher than that in other seasons. The expenditure of constructing the constructed wetland with the average treating capacity of 176 m3/d and lifetime of 20 years is 17075.00 RMB. The average disposal cost is summed up to 0.17 RMB/m3, which shows that the pretreatment of the micro-polluted Yellow River raw water by constructed wetland is feasible.

Performance of a Horizontal Flow Constructed Reed Bed Filter for Municipal Wastewater Treatment: The Case Study of the Prototype Installed at Gaston Berger University, Saint-Louis, Senegal

In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.

Comparison of Pb,Cd Adsorption to Surface Coatings Developed in Natural Waters with that in Plant Effluents

The comparative studies of Pb and Cd adsorption to the surface coatings(Fe, Mn, Al oxides, organic materials, and associated minerals), which were developed on glass slides in five natural and two technical waters(plant effluents), were carried out under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25 ℃ and pH 6 0). The classical Langmuir adsorption isotherm was applied to estimating the equilibrium coefficients of Pb and Cd adsorption to the surface coatings. The results show that the maximum adsorption of Pb and Cd to the surface coatings mentioned above varied widely. There was a systemic increase in the maximum adsorption of Pb and Cd to the surface coatings with increasing the contents of Mn and Fe oxides in the surface coatings in significant correlation, respectively, not only highlighting the relative importance of the metal oxide fraction for Pb and Cd adsorption to the surface coatings developed in natural and technical water samples, but also implying the same adsorption mechanisms of Pb and Cd to the surface coatings developed both in natural and technical water samples.

Emergency management of reservoirs and water treatment plants in typhoon season:a case study of Ningbo

Coastal cities represented by Ningbo are directly or indirectly affected by typhoons each year. By analyzing the past three typical typhoons landing in Ningbo from 2013 to 2016, it was found that before and after the typhoon transit, reservoir and water treatment plant would be made by the destructive impact, including the increasing water level, water volume in a short time, and the deteriorating water quality. Among those, the water quality caused by typhoons increased the water treatment process load, the amount of water purification agents increased significantly,and the emergency response put a great pressure on the inventory of water plants. Based on the statistics and analysis of the basic parameters of the reservoir and water treatment plant during the typhoon season, the emergency management of the typhoon was divided into three situations, namely, pre-typhoon, typhoon period and post-typhoon. Thus, it is effective for the relevant practitioners of the reservoir and water plant to ensure the safe water supply during typhoon season.

Physico-Chemical and Bacterial Characteristics of Groundwater and Surface Water Quality in the Lagbe Town: Treatment Essays with <i>Moringa oleifera</i>Seeds

The river water and groundwater from Lagbe town in Benin Republic were collected and analyzed for physical, chemical and microbiological parameters. The surface water samples were treated with alum, Moringa oleifera seeds powder and the combination of alum and Moringa oleifera seeds. The jar-test essays were carried out with two water samples at initial turbidities 7.2 NTU and 14.4 NTU. The water samples analyzed are fairly mineralized (conductivity varies between 166 and 687 μS/cm), enough soft and contain the nitrate (104 mg/L for W4 sample). They are greatly polluted by pathogenic microorganisms such as Escherichia coli, Klebsiella, Enterococcus, Vibrio, Serratia. The optimal dosages of Moringa are 96 mg/L and 80 mg/L respectively. We have observed a reduction of 60% of turbidity and a substantial remove of all pathogenic microorganisms after water treatment with Moringa oleifera seeds. For the combination treatment, 93% of initial turbidity and 92% of initial concentration of organic matter in the sample E2 were eliminated. The pH remained almost constant during the treatment.

Performance Simulation of H-TDS Unit of Fajr Industrial Wastewater Treatment Plant Using a Combination of Neural Network and Principal Component Analysis

Nowadays, with regard to environmental issues, proper operation of wastewater treatment plants is of particular importance that in the case of inappropriate utilization, they will cause serious problems. Processes that exist in environmental systems and environmental engineers are dealing with them mostly have two major characteristics: they are dependent on many variables;and there are complex relationships between its components which make them very difficult to analyze. Being familiar with characteristics of industrial town effluents from various wastewater treatment units, which have high qualitative and quantitative variations and more uncertainties compared to urban wastewaters, plays very effective role in governing them. In order to achieve a better and efficient control over the operation of an industrial wastewater treatment plant, powerful mathematical tool can be used that is based on recorded data from some basic parameters of wastewater during a period of treatment plant operation. In this study, the multilayer perceptron (MLP) feed forward neural network with a hidden layer and stop training method was used to predict quality parameters of the industrial effluent. Data of this study are related to the Fajr Industrial Wastewater Treatment Plant located in Mahshahr—Iran that qualitative and quantitative characteristics of its units were used for training, calibration and evaluation of the neural model. Also, Principal Component Analysis technique was applied to modify and improve performance of generated models of neural networks. The results of this model showed good accuracy of the model in estimating qualitative pro- file of wastewater. This model facilitates evaluating the performance of each treatment plant units through comparing the results of prediction model with the standard amount of output.

Surface treatment technology of downhole water cut sensor

Based on the structure,working principle,and working conditions of conductance water cut sensor,it is revealed that the early failure of the metal electrode of the sensor is due to the comprehensive influence of well fluid erosion,electrochemical corrosion,and oil pollution during its long-term service in the downhole.A technology for electrode surface treatment is proposed using boron-doped diamond(BDD)films to improve the service performance of the modified electrode.The hot wire chemical vapor deposition method was adopted to fabricate BDD film,the boron doping concentration and deposition time were optimized,and fluorination treatment was applied to improve the wear resistance,electrochemical corrosion resistance,and oleophobic property of the BDD film comprehensively.The results showed that BDD film with boron doping concentration of 6×10^(-3) exhibited high wear resistance and good electrochemical corrosion resistance,and endowed the modified electrode with superior erosion resistance and corrosion resistance.The friction coefficient and wear rate of BDD modified electrode were 92%and 78%lower than those of Invar alloy,also,the low-frequency impedance modulus value of the modified electrode was higher than 1×10^(4) Ω·cm^(2).The BDD film prepared with a deposition time of 8 h had a favorable micro-nano structure owing to small grain size and uniform distribution.Such morphology was conducive to enhancing the oleophobic performance of the modified electrode,and its contact angle in the simulated well fluid was high to 102°.The engineering applicability of BDD film modified electrode under simulated working conditions indicated that,the modified electrode had excellent comprehensive performances of erosion resistance,electrochemical corrosion resistance and oil adhesion resistance,and can realize the long-term stable operation of the conductance water cut sensor under harsh downhole conditions.

High Pressure Water-Jet Technology for the Surface Treatment of Al-Si Alloys and Repercussion on Tribological Properties

Recent developments in high pressure water-jet technology have brought the process to the forefront as a means of surface treatment. Water jet technology offers cleaning, cutting, processing as well as potential refinement of surface properties. By adapting the process parameters the surface characteristics can be changed while the profile remains the same. In the present study, water-jet technology was used for the surface treatment of Al-Si alloy to investigate its effect on tribological properties. Dry sliding wear behavior was investigated against AISI 52100 bearing steel ball using a reciprocating ball-on-flat configuration. Optical microscopy examination reveals that ploughing of grains, transgranular and intergranular propagation of cracks;are the mechanisms by which material is removed during water jet treatment. While, on the other hand, SEM observation of the wear track reveals that plastic deformation and delamination are the dominant wear mechanism during the wear process. Water jet treatment was compared to hot isostatic pressing in terms of its effects on wear resistance and surface porosity of Al-Si alloy. It was found that, hot isostatic pressing reduces the total amount of porosity at the expanse of hardness while water jet treatment produces a compressed surface having higher hardness and compressive residual stress, which ultimately increases wear resistance.

Investigation of the Effects of Radio Frequency Water Treatment on Some Characteristics of Growth in Pepper (<i>Capsicum annuum</i>) Plants

The aim of the present study was to investigate the effect of electromagnetic radio frequency treatment of water on the growth of pepper (Capsicum annuum) plants. For this experiment, one hundred one-week old plants were divided into two groups. The first group of plants was watered with water subjected to radio frequency electromagnetic radiation from an internet router for one hour a day, while the other group was watered with tap water (control). The overall results showed changes of growth characters of plant watered with electromagnetic water. The length of pepper plants is significantly affected by the treated water, where the length of shoot was lower in plants grown under the effect of treated water (22.43 ± 7.17 cm) than those grown without treated water (28.11 ± 8.57 cm). The results revealed that the stem diameter of control plants (1.74 ± 0.39 cm) was significantly higher than that of the treated plants (1.66 ± 0.35 cm). In addition, the root length was lower in plants grown under the effect of treated water than those grown without treated water. Pepper plants watered with electromagnetic treated water exhibited marked decreases in health index, fresh and dry weight, relative water content, number of flowers and fruits/plant as well as number of seeds/fruit. In addition, the current experiment showed a significant decrease in the number of leaves, branch and flower per plant when watered with electromagnetic treated water. The results revealed that the first flowering time for plants in treated group was remarkably decelerated when compared to other plants in control group.

C-Language Programming for Development of Conventional Water Treatment Plants Decision Support System

Water-Decision Support System (DSS) tools enhance decision-makings towards improved water supply in a given region. The rigours of manual design of the conventional water treatment plants are easily eliminated with the use of softwares as in the case of DSS. Therefore, this paper focuses on the development of a Water-DSS for design of treatment plant in Karkala Town, Udupi District of India. A four-decade population projection was made using the baseline data of 1971 till date. The manual computation for water demand, unit operations and adjoining facilities was carried out and later coded in C-programming language for development of a DSS for easier design and process selection. Data validation was done and results from the two approaches were compared. With the C-programming technique, a decision support tool for design and process selection of drinking water treatment plant using conventional method has been developed and named Water-DSS1. The designed tool is simple, accurate, flexible, efficient and universal, easily adaptable to any similar conventional treatment plant. Water-DSS1 is thus recommended for general use in ultimately alleviating water supply challenges.

Engineering of Self-Supported Electrocatalysts on a Three-Dimensional Nickel Foam Platform for Efficient Water Electrolysis

Economical water electrolysis requires highly active non-noble electrocatalysts to overcome the sluggish kinetics of the two half-cell reactions,oxygen evolution reaction,and hydrogen evolution reaction.Although intensive efforts have been committed to achieve a hydrogen economy,the expensive noble metal-based catalysts remain under consideration.Therefore,the engineering of self-supported electrocatalysts prepared using a direct growth strategy on three-dimensional(3D)nickel foam(NF)as a conductive substrate has garnered significant interest.This is due to the large active surface area and 3D porous network offered by these electrocatalysts,which can enhance the synergistic eff ect between the catalyst and the substrate,as well as improve electrocatalytic performance.Hydrothermal-assisted growth,microwave heating,electrodeposition,and other physical methods(i.e.,chemical vapor deposition and plasma treatment)have been applied to NF to fabricate competitive electrocatalysts with low overpotential and high stability.In this review,recent advancements in the development of self-supported electrocatalysts on 3D NF are described.Finally,we provide future perspectives of self-supported electrode platforms in electrochemical water splitting.

Stable Isotopic Signatures of NO3 in Waste Water Effluent and Los Angeles River

A metropolitan city such as Los Angeles (LA) is an ideal study site with a very high population density, and it houses at least 3 treatment plants where sewage is treated preliminarily and then progressing to tertiary treatment before discharging into the LA River. We will gain a better understanding of the water quality in the LA River and the nitrate load in the watershed system by examining the influence of waste water treatment plants (WWTPs). The goal of this study is to pinpoint the exact source of nitrate in the LA River using the isotope signatures. We have selected sampling locations both upstream and downstream of the WWTP. This serves to monitor nitrate levels, aiding in the assessment of treatment plant effectiveness, pinpointing nitrate pollution sources, and ensuring compliance with environmental regulations. The research explores the isotopic composition of NO3 in relation to atmospheric nitrogen and Vienna Standard Mean Ocean Water, shedding light on the contributions from various sources such as manure, sewage, soil organic nitrogen, and nitrogen fertilizers. Specifically, there is a change in the δ15NAir value between the dry and wet seasons. The isotope values in the Tillman WWTP sample changed between dry and wet seasons. Notably, the presence of nitrate originating from manure and sewage is consistent across seasons, emphasizing the significant impact of anthropogenic and agricultural activities on water quality. This investigation contributes to the broader understanding of nitrogen cycling in urban water bodies, particularly in the context of wastewater effluent discharge. The findings hold implications for water quality management and highlight the need for targeted interventions to mitigate the impact of nitrogen-containing compounds on aquatic ecosystems. Overall, the study provides a valuable framework for future research and environmental stewardship efforts aimed at preserving the health and sustainability of urban water resources. This data informs decisions regarding additional treatment or mitigation actions to safeguard downstream water quality and ecosystem health.

Evaluation of copper removal efficiency using water treatment sludge

Large quantities of sludge are produced during water treatment processes. Recently, sludge has been treated as waste and disposed of in landfills, which increases the environmental burdens and the operational cost. Therefore, sludge reuse has become a significant environmental issue. In this study, adsorption of copper ions (Cu^2+) onto calcined sludge was investigated under various operational conditions (with varying temperature, Cu^2+ initial concentration, pH, and sludge dosage). The prepared sludge material was characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS), and Brunauer-Emmett-Teller (BET) surface area. The sorption capacity of sludge was directly proportional to the initial Cu^2+ concentration and inversely proportional to the sludge dosage. The optimum operational pH and solution temperature were 6.6 and 80℃, respectively. The experimental results followed a Langmuir isotherm and pseudo-first-order adsorption kinetics. Thermodynamic parameters such as activation energy, change in free energy, enthalpy, and entropy were calculated. Thermodynamic analyses indicated that the sorption of copper ions onto the calcined sludge was driven by a physical adsorption process. The prepared sludge was proven to be an excellent adsorbent material for the removal of Cu^2+ from an aqueous solution under optimum conditions.

Performance Analysis of Automated Control System for Condenser Water Treatment Unit

The air conditioning system in the Umm Al-Qura University (Albdiya Campus) was conceived to be a district cooling by a remote chilled water plant. Recently, there are two chilled water plants in the university installed strategically to provide chilled water to all the academic and administrative buildings of the university through distribution network with total capacity approximately of 12,000 tons of refrigeration. The plants were built based on cooling towers with open water cycle as heat rejection system. Water treatment chemicals has been used to protect the cooling systems from corrosion, scaling and microbiological fouling accompanied with dissolved and suspended water impurities. Different methods are being used to determine and control the treatment chemical concentrations and system performance indicators. Traditional chemical controller has drawback of indirect measurements and set points. The purpose of this paper is to present a solution to overcome the problems of traditional and conventional chemical treatment and control sys-tems. Central cooling plant number (1) assigned to perform experimental setup using new chemical treatment technology. Advanced automatic chemical treatment controller installed on condensers (1, 2 and 3), and certain key performance indicators were selected and monitored such as chemical and water consumption, power, energy saving, and maintaining system integrity and efficiency. Satisfactory results were obtained in terms of performance and cost of operation.

Filtering Surface Water with a Polyurethane-based Hollow Fiber Membrane: Effects of Operating Pressure on Membrane Fouling

Membrane fouling seriously restricts applications of membrane technology. A novel strategy was applied in this study to retard membrane fouling by changing operating pressure with the pressure responsibility membrane. A polyurethane-based hollow fiber membrane was used to treat surface water for evaluating the effect of operating pressure on membrane fouling. Some bench-scale tests in dead-end mode were carried out. In the experiments without backwashing, as operating pressure increased, severe membrane fouling occurred on membrane surface, while the permeate quality was improved obviously, which is considered to be due to shrinkage deformation. The total resistance, irreversible resistance and reversible resistance under different backwash pressures were determined in filtration/backwashing test. With the increase of backwash pressure, the total resistance decreased, and more importantly, the irreversible resistance also decreased, which implies that small particles deposited inside membrane pores and cake layers on membrane surface are effectively removed. Similar results could be obtained in mass balance tests. The results of the present study indicate that the application of pressure responsibility membrane in surface water treatment may be an effective strategy for reducing membrane fouling.

Decomposition of oil cleaning agents from nuclear power plants by supercritical water oxidation

Oil cleaning agents generated from nuclear power plants(NPPs)are radioactive organic liquid wastes.To date,because there are no satisfactory industrial treatment measures,these wastes can only be stored for a long time.In this work,the optimization for the supercritical water oxidation(SCWO)of the spent organic solvent was investigated.The main process parameters of DURSET(oil cleaning agent)SCWO,such as temperature,reaction time,and excess oxygen coefficient,were optimized using response surface methodology,and a quadratic polynomial model was obtained.The determination coefficient(R^(2))of the model is 0.9812,indicating that the model is reliable.The optimized process conditions were at 515 C,66 s,and an excess oxygen coefficient of 211%.Under these conditions,the chemical oxygen demand removal of organic matter could reach 99.5%.The temperature was found to be the main factor affecting the SCWO process.Ketones and benzene-based compounds may be the main intermediates in DURSET SCWO.This work provides basic data for the industrialization of the degradation of spent organic solvents from NPP using SCWO technology.

Water Analyses, Eco-Balance and Socio-Demographic Analyses as Prerequisites for Solutions of the Sewage Treatment Problems in Rural Areas

The implementation of the EU-water framework directive (EU-WFD) demands a financeable and adaptable sewage treatment, creating a need for action especially in rural areas, where the “good ecological status” is often not reached even though the sewage works fulfill the legal minimum requirements. Therefore the construction of new, more efficient wastewater treatment plants is advisable. Due to the precarious financial situation in most rural areas, many municipalities can however not master the necessary funds for an improved waste water infrastructure. A large part of the costs would have to be shouldered by the local population in the form of additional sewage levies, leading to massive socio-economic strain. Hence, different solutions, which are tailored to the socio-economic, demographic and environmental characteristics of rural areas and fulfill the legal requirements, need to be developed. One possible approach is presented in the form of the Dirlammen case study (municipality Lautertal, Hesse, Germany). It consists of 1) biological and physicochemical analyses of the waste waters, 2) a modified eco-balance for the construction of a new sewage works and 3) socio-economic and demographic analyses of the population. It serves as a tool for the assessment of the influencing ecological, socio-economic and demographic factors on the sewage problems in rural areas. These findings can easily be transferred to other rural areas with a similar configuration and thus deliver the basis for a generally applicable approach to these problems. The results of the comprehensive analysis have shown for the municipality Dirlammen/Lautertal that the continued operation of the existing pond sewage plant is, with regards to the ecological, socio-economic and demographic points of view, preferable to the construction of a new waste water treatment plant. With regard to the sustainability principles of the sewage treatment and the objectives of the EU-WFD, existing sewage works should be operated for as long as the sewage treatment is feasible within technical and legal boundaries. With the construction of new facilities on the other hand, the expected improvement of the water quality has to be weighed against the ecological impairments caused by the construction itself. Rural waste water plans have to be developed for the long-term, taking not only the ecology into account but also the demographic change. Possible approaches in this regard could be a shift towards a decentralized waste water treatment concept and–even more important–improvements of the river morphology. But also the reduction of the diffuse pollution from agricultural sources should be considered for the development of strategies for the improvement of the ecological state. Short-term optimization measures in the existing sewage works might also improve the water quality until the long-term development plans can be implemented. In particular the challenges of the demographic change and linked with that the changing requirements for the rural waste water treatment must be addressed by any future plans. Only with the help of such a comprehensive approach the dangers of bad planning and unacceptable socio-economic burdens can be minimized.

A Case Study on the Utilization of Wind Energy Potential on Remote and Isolated Small Wastewater Plants

Small WWTP （wastewater treatment plants） are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. This paper describes a case study which is a step by step procedure concerning the evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, on the utilization of the potential wind energy in Magoito WWTP. The adopted methodology comprised the collection of one year of in-situ wind data and its validation by comparison with historical data of more than 10 years of a nearby anemometric station. The data provided by the two anemometric stations was statistically treated and allowed the analysis of the results from the two stations. These results are promising in terms of wind availability and velocity. Finally, the study comprised the simulation of the local wind conditions for a considerable larger area in order to find the best site for locating a wind turbine.

Overview coking plant & Lurgi gasifier plant waste water treatment

The paper described the coking plant and Lurgi gasifier plant waste water types and characteristics , comparing the COD and ammonia-N level in different source of waste water in the plant.The currently maturity coking plant waste water treatment method was statement in the paper and analyzed the pros and cons of each method.The primary cost analysis of each type of waste water treatment was also completed in the paper.According to these analyses , recommendation was prepared for coking plant and Lurgi gasifier plant waste water treatment.

Operation Characteristics of Treating Surface Water with Polyvinylchloride Hollow Fiber Ultrafiltration Membrane

A pilot plant study on a polyvinylchloride hollow fiber ultrafiltration membrane process was conducted for treating surface water. The membrane system was operated in the dead-end filtration mode under different constant permeate fluxes. The results show that the optimized operation (transmembrane pressure≤0.1 MPa, filtration time≤30 min) with a hydraulic cleaning (30 s) and a chemical cleaning (30 min, the chemical cleaning was performed after 16 cycles of filtration ) ensures a quite steady flux (1 100 L/(m^2·h·MPa)) and good permeate quality (turbidity<0.1 NTU). A full-scale plant can be suggested to operate with a mixed strategy of constant permeate flux mode (transmembrane pressure≤0.1 MPa) and constant transmembrane pressure mode. When the temperature of raw water becomes below 5 ℃, a constant transmembrane pressure mode should be used; otherwise a constant permeate flux mode (transmembrane pressure≤0.1 MPa) can be operated. In this way, irreversible fouling of ultrafiltration membrane can be minimized to keep a stable flux and make the life of membrane longer.