Treatment of coke plant wastewater by SND fixed biofilm hybrid system

In this article, coke plant wastewater was treated by a simultaneous nitrifying and denitrifying （SND） fixed biofilm hybrid system. The results showed that suitable parameters of the system were important for the performance of the bio-degradation system. The chemical oxygen demand （COD） removal efficiency in this system was satisfactory, higher than 94%, and ammonia nitrogen was higher than 95%. The effluent COD concentration could meet the discharge standard, except for very few situations. The results showed that a sufficient carbon source was important for making ammonia nitrogen concentration meet the discharge standard. Then the TiN removal efficiency in this system can be brought higher than 94%. Dissolved oxygen （DO） is very important to the performance of the SND bio-degradation system, and the suitable DO is about 3.5-4.0 mg/L at the forepart of reactor. In addition, the performance of the system was almost not affected by pH value. The results show that the system is feasible to treat coke plant wastewater.

Decomposition of Organic Compounds in Coke Plant Wastewater by Ultrasonic Irradiation and Its Combined Process

The paper deals with the degradation of the organic compounds in the coke plant wastewater by the combined process of ultrasonic irradiation and activated sludge. The influence factors of the ultrasonic degradation effect such as air atmosphere, initial concentration, ultrasonic power density and the category and consumption of catalyst were investigated. A water quality model was used to explain the degradation of different kinds of organic compounds in the coke plant wastewater by ultrasonic irradiation. After the wastewater was treated by the combined process of ultrasonic irradiation and activated sludge, the COD degradation efficiency was 95.74%, which is 63.49% higher than that by the process of activated sludge alone.

Cloud-Model-Based Feature Engineering to Analyze the Energy-Water Nexus of a Full-Scale Wastewater Treatment Plant

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.

Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants

Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight （dw）, with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs （World Health Organization-Toxic Equivalents） of the sludge were lower than 1 pg /g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra- CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.

Optimum municipal wastewater treatment plant design with consideration of uncertainty

A newly developed model for the optimum municipal wastewater treatment plant(MWTP) design is presented. Through introducing the interval variables, the model attempts to consider the effects of uncertainties caused by the fluctuation of the wastewater quality and quantity during the design of MWTP. The model solution procedure is illustrated in detail, and a numerical example is given to verify the feasibility and advantage of the model. Furthermore, the possibility of the model application is briefly outlined.

Advanced Treatment of Wastewater Treatment Plant Effluent by Using Biofilms on Filamentous Bamboo

[ Objective ] The study aimed at treating wastewater treatment plant （WWTP） effluent by using bio-film reactor with filamentous bamboo as bio-carrier. [ Method] With the aid of a continuous flow reactor, a bio-film reactor using filamentous bamboo as bio-carrier was used to treat WWTP effluent with low C/N ratio, and the removal effects of CODc,, TN （total nitrogen）, and NO3--N in the wastewater were analyzed.[ Result ] The average removal rates of CODcr, TN, and NO3- -N reached 47.7%, 23.6% and 34.5% when the C/N ratio of influent was around 2. In addi- tion, a stable bio-film was formed very well in the secondary effluent with low C/N ratio and hardly degradable organic pollutants. The pollutants could be removed effectively because of the excellent surface characteristics and compositions of filamentous bamboo. [ Conclusion] The research provides a new method to treat WWTP effluent with low C/N ratio.

The Effect of Wastewater Treatment Plants on Retainment of Plastic Microparticles to Enhance Water Quality—A Review

Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in wastewater treatment and briefly highlights novel developments in the removal of microplastics from aqueous systems.

Notice on a Case Study on the Utilization of Wind Energy Potential on a Remote and Isolated Small Wastewater Treatment Plant

Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environmental sensible zones, and due to tourism activity of these sites, seasonal effects related with population size fluctuation can occur, which can originate certain inefficiencies concerning WWTP design and energy supply. The objective of this paper is to describe a step by step procedure for evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, a case study on the utilization of the potential wind energy in Magoito WWTP (5000 p.e.). The employed methodology comprised the collection of one year of in-situ wind data and its validation by comparison with historical data of about 10 years of a nearby anemometric station. The data provided by the two anemometric stations was statistically treated. It allowed the analysis of the results from the two stations are promissory in terms of wind availability and velocity. Finally, it 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.

Phosphorus Recovery as Struvite from the Supernatant of Anaerobic Digestion in Wastewater Treatment Plant

Phosphorus is an irreplaceable and depletable element. Furthermore, it has an almost one-way circulation on earth, so it is necessary to close the phosphorus cycle loop. Phosphorus could be recovered as struvite, which is a good slow-released fertilizer for agriculture. The supernatant of anaerobic digestion used to treat sludge from wastewater treatment plant is one main source from which phosphorus can be recovered. Studies have proven that phosphorus recovery from digester supematant is a feasible choice to preserve phosphorus rock technically and economically. A modified ＂PHOSNIX＂ P-recovery process was applied under the operating conditions of a 9.0 pH value and a 1.8 mg： P ratio with the influent of the centrate coming from the sludge centrifuge of the Songjiang Wastewater Treatment Plant in Shanghai. More than 80% influent phosphorus was recovered as struvite. Crystal products with good purity and low heavy metal content were gained. The largest crystal had a length of up to 0.26 mm. It was found in our study that the reaction time did not play an important role in crystal growth. Therefore, the optimization of the reaction condition for crystal growth should be examined in future study.

Effectiveness of Centralized Wastewater Treatment Plant in Removing Emerging Contaminants: A Case Study at Kuching, Malaysia

Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewater had polluted Sarawak river, which is regulated and cannot discharge freely into the South China Sea. The polluted Sarawak river has endangered human health, river water quality, and aquatic ecosystems. Hence, the KCWTSP1 commissioned in 2015 serves the purpose of removing pollutants from wastewater before it is discharged into natural waterways. However, the effectiveness of KCWTPP1 is unknown. This paper is aimed to discuss and review the effectiveness of KCWTPP1 in treating wastewater since its inception in 2015. From 2017 to 2020, KCWTPP1 has treated an average of 4,200,000 m3 of wastewater per year. Generally, most of the discharge effluent met Environmental Quality Act (1974) Standard A criteria, except for the oil and grease parameter. Initially, the plant could not treat suspended solids and total phosphorus, but this was greatly improved in subsequent years. Therefore, some improvements are required to treat oil and grease parameters effectively and efficiently to ensure that only Standard A effluent is discharged into the Sarawak River in the future.

Environmental Assessment of AI-Hilla City Wastewater Treatment Plants

Iraq is one of the countries that is suffering from water shortage problems and, for this reason, wastewater treatment plants become a necessity to minimize this problem. In this study, the impact of A1-Hilla WWTP （wastewater treatment plant） on the environment has been studied. This was achieved using SimaPro software package. This software is a powerful tool for analyzing the environmental impact on products during their whole life cycle. A huge amount of knowledge about the environment is built into the program and database, enabling to analyze a product with a minimum of specialized knowledge. The results of LCA （life cycle assessment） showed that the impact and damage on the environment by A1-Hilla WWTP was 41 bad points for each 1 m3 of treated wastewater. The most environmental impacts potentially were global warming, respiratory inorganics and non-renewable energy. The study also showed that most of the effects were the result of the use of cement, steel and electricity consumption.

Occurrences of Glucocorticoids in Aquatic Environment and Their Removal during Wastewater Treatment

Glucocorticoids(GCs) are a group of endocrine-disrupting compounds(EDCs) frequently prescribed against various medical conditions.Recently,GCs have been shown to be effective in managing septic shock in patients infected with the 2019 novel coronavirus(COVID-19).Due to colossal consumption and potential risks to aquatic organisms,GCs have immensely attracted the focus of the scientific research community as a water pollutant.Therefore,the aim of this paper is to review the current knowledge on the occurrence of various GCs in the aquatic environment and their removal during wastewater treatment.A variety of GCs are ubiquitous in surface water,hospital wastewater,and sewage water worldwide.And the minimum concentration in volume is below 0.01 ng/L,and the maximum one is 10 000 ng/L,and enter the environment through hospital and urban wastewater discharging.Compared with natural GCs,higher risks to aquatic environments could be induced by synthetic GCs.The current activated sludge processes used in wastewater treatment plants(WWTPs) are not fully effective in eliminating GCs,some of which may further increase the risk of GC in the environment.In comparison with the aerobic process in WWTPs,the anaerobic and anoxic processes were found to be more efficient for GC degradation.Of the studied GCs,fluticasone propionate,clobetasol propionate,fluocinolone acetonide,and triamcinolone acetonide need more attention due to their low removal efficiencies and strong toxicity.Among the advanced treatment processes,reverse osmosis,ultraviolet irradiation,CaO_(2),and plasma could achieve significant GC activity removal while micro/ultra-filtration,chlorination,and ozonation were less efficient.

Stability and Removal of Commonly Used Drugs in Environmental Water and Wastewater

Introduction:Pharmaceuticals are regarded as emerging contaminants in the environment.In recent years,their destiny and removal have piqued people’s interest.Methods:Examine how well conventional wastewater treatment facilities and cutting-edge technologies(ultrafiltration and reverse osmosis)can remove specific pharmaceutical compounds from water,with a focus on the compounds'environmental status,their origin,deterioration,metabolites,and the capacities of these facilities.Results and discussion:the ability and efficacy of sophisticated treatment technologies such as membrane separation,adsorption,and AOPs(Advanced Oxidation Processes)in eliminating chosen commonly used drugs from water are explored.Batch adsorption experiments were integrated with appropriate adsorption isotherms and appropriate kinetic models to predict the final extent of pollutant removal by this method.Continuous filtration mode was also investigated.Combining filtration(using AC(Activated Carbon)and micelle-clay granule complexes)with AOPs improves the economy of treating wastewater,which contains recalcitrant PhACs(Pharmaceutical Compounds).

Impact of wastewater treatment plant effluent discharge on the antibiotic resistome in downstream aquatic environments:a mini review

Antimicrobial resistance(AMR)has emerged as a significant challenge in human health.Wastewater treatment plants(WWTPs),acting as a link between human activities and the environment,create ideal conditions for the selection and spread of antibiotic resistance genes(ARGs)and antibioticresistant bacteria(ARB).Unfortunately,current treatment processes are ineffective in removing ARGs,resulting in the release of large quantities of ARB and ARGs into the aquatic environment through WWTP effluents.This,in turn,leads to their dispersion and potential transmission to human through water and the food chain.To safeguard human and environmental health,it is crucial to comprehend the mechanisms by which WWTP effluent discharge influences the distribution and diffusion of ARGs in downstream waterbodies.In this study,we examine the latest researches on the antibiotic resistome in various waterbodies that have been exposed to WWTP effluent,highlighting the key influencing mechanisms.Furthermore,recommendations for future research and management strategies to control the dissemination of ARGs from WWTPs to the environment are provided,with the aim to achieve the“One Health”objective.

A global perspective on microbial risk factors in effluents of wastewater treatment plants

Effective monitoring and management of microbial risk factors in wastewater treatment plants(WWTPs)effluents require a comprehensive investigation of these risks.A global survey on microbial risk factors in WWTP effluents could reveal important insights into their risk features.This study aims to explore the abundance and types of antibiotic resistance genes(ARGs),virulence factor genes(VFGs),the vector of ARG/VFG,and dominant pathogens in global WWTP effluents.We collected 113 metagenomes of WWTP effluents from the Sequence Read Archive of the National Center for Biotechnology Information and characterized the microbial risk factors.Our results showed that multidrug resistance was the dominant ARG type,while offensive virulence factors were the most abundant type of VFGs.The most dominant types of ARGs in the vector of plasmid and phage were both aminoglycoside resistance,which is concerning as aminoglycosides are often a last resort for treating multi-resistant infections.Acinetobacter baumannii was the most dominant pathogen,rather than Escherichia coli,and a weak negative correlation between Escherichia coli and two other dominant pathogens(Acinetobacter baumannii and Bacteroides uniformis)suggests that using Escherichia coli as a biological indicator for all pathogens in WWTP effluents may not be appropriate.The Getah virus was the most dominant virus found in global WWTP effluents.Our study presents a comprehensive global-scale investigation of microbial risk factors in WWTP effluents,providing valuable insights into the potential risks associated with WWTP effluents and contributing to the monitoring and control of these risks.

Methane and nitrous oxide emissions from municipal wastewater treatment plants in China:A plant-level and technology-specific study

Wastewater treatment is an important source of greenhouse gases(GHGs).Yet large uncertainties remain in the quantification of GHG emissions from municipal wastewater treatment plants(MWWTPs)in China.A high-resolution and technology-specific emission inventory is still lacking to support mitigation strategies of MWWTPs.Here we develop a plant-level and technology-based MWWTP emission inventory for China covering 8703 plants and 19 treatment technology categories by compiling and harmonizing the most up-to-date facility-level databases.China's methane(CH_(4))and nitrous oxide(N_(2)O)emissions from MWWTPs in 2020 are estimated to be 150.6 Gg and 22.0 Gg,respectively,with the uncertainty range of-30%to 37%and-30%to 26%at 95%confidence interval.We find an emission inequality across cities,with the richest cities emitting two times more CH_(4)and N_(2)O per capita from municipal wastewater treatment than the poorest cities.The emitted CH_(4)and N_(2)O are dominated by Anaerobic/Anoxic/Oxic-,Sequencing Batch Reactor-,Oxidation Ditch-,and Anoxic/Oxic-based MWWTPs of less than 20 years old.Considering the relatively young age structure of China's MWWTPs,the committed emissions highlight the importance of reducing on-site GHG emissions by optimization of operating conditions and innovation management.The emission differences among our estimates,previous studies,and the Intergovernmental Panel on Climate Change guidelines are largely attributed to the uncertainties in emission factors,implying the urgent need for more plant-integrated measurements to improve the accuracy of emission accounting.

Changes of composition and antibiotic resistance of fecal coliform bacteria in municipal wastewater treatment plant

The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria(FCB)in a typical wastewater treatment plant(WWTP)were investigated concerning the seasonal changes.Results showed that WWTP could remove the FCB concentration by 3∼5 logs within the effluent of 10^(4)∼10^(5)CFU/L,but the antibiotic resistant rate of FCB species increased significantly after WWTP.The dominant FCB changed from Escherichia coli in the influent(∼73.0%)to Klebsiella pneumoniae in the effluent(∼53.3%)after WWTP,where the Escherichia coli was removed the most,while Klebsiella pneumoniae was the most persistent.The secondary tank removed the most of FCB(by 3∼4 logs)compared to other processes,but increased all the concerned antibiotic resistant rate.The potential super bugs of FCB community showing resistance to all the target antibiotics were selected in the biological treatment unit of WWTP.The FCB showed the highest multiple antibiotic resistance(92.9%)in total which even increased to 100%in the effluent.Klebsiella has the highest antibiotic resistant rate in FCB,with a multiple antibiotic resistance rate of 98.4%.These indicated that the Klebsiella pneumoniae not just Escherichia coli should be specially emphasized after WWTP concerning the health risk associated with FCB community.

Community analysis of ammonia-oxidizing bacteria in activated sludge of eight wastewater treatment systems

We investigated the communities of ammonia-oxidizing bacteria （AOB） in activated sludge collected from eight wastewater treatment systems using polymerase chain reaction （PCR） followed by terminal restriction fragment length polymorphism （T-RFLP）, cloning, and sequencing of the α-subunit of the ammonia monooxygenase gene （amoA）. The T-RFLP fingerprint analyses showed that different wastewater treatment systems harbored distinct AOB communities. However, there was no remarkable difference among the AOB T- RFLP profiles from different parts of the same system. The T-RFLP fingerprints showed that a full-scale wastewater treatment plant （WWTP） contained a larger number of dominant AOB species than a pilot-scale reactor. The source of influent affected the AOB community, and the WWTPs treating domestic wastewater contained a higher AOB diversity than those receiving mixed domestic and industrial wastewater. However, the AOB community structure was little affected by the treatment process in this study. Phylogenetic analysis of the cloned amoA genes clearly indicated that all the dominant AOB in the systems was closely related to Nitrosomonas spp. not to Nitrosospira spp. Members of the Nitrosomonas oligotropha and Nitrosomonas communis clusters were found in all samples, while members of Nitrosomonas europaea cluster occurred in some systems.

Advances in Research of Characteristics and Removal of Microplastics in Sewage Treatment Plants

Microplastic pollution has become a worldwide issue.The discharge of sewage treatment plants(STPs)or wastewater treatment plant(WWTPs)is an important way for microplastics to enter the environment.This study reviewed the sources and occurrence characteristics(type,size,color and components)of microplastics in domestic and foreign sewage plants.It elaborated the removal principles of microplastics by primary,secondary and tertiary treatments.In addition,the removal effects of various treatment units and different processes on microplastics were summarized.In the future,the removal mechanism of microplastics in sewage treatment plants should be discussed in more depth,so as to further improve the removal rate of microplastics by optimizing and transforming traditional sewage treatment processes.Therefore,it is necessary to develop new technologies/processes specifically for the removal of microplastics and promote them to practical applications.

Why Should We Bother on Measurement in Wastewater Treatment Operation?

The question of wastewater treatment and control is reflected from a very specific viewpoint: the low priority given to accurate and useful measurements within wastewater treatment. The matter is discussed from four various perspectives, that may be labelled “Legal understanding”;“Needs for accurate measurement results already in the planning and design stage”;“The measurement problem and human behaviour”;“The understanding of the short term and long term dynamics and changes in pollution and flow loads on a wastewater treatment plant (WWTP)”. All these aspects bring about much improved needs for an accurate and frequent measurement scheme both for pollutants and flows entering a WWTP. The conclusion is stated as follows: A far more and well elaborated on-line measurement system at the plants would become a needed tool for improved water environment protection at lower costs.