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Antibiotics are a large group of emerging organic pollutants with low concentration levels in the water. The presence of antibiotics will affect the ecological environment and human health. The removal of trace organic compounds by graphene oxide (GO) membranes has attracted extensive attention. This study investigated the removal of three differently charged antibiotics by GO membranes and the influence of water quality on the removal of antibiotics. It showed that a crosslinked ethylenediamine-GO (EDA-GO) membrane had better stability and higher antibiotic removal performance than a non-crosslinked GO membrane. Among the three antibiotics, penicillin (PNC) was negatively charged and had the highest removal efficiency due to steric effect and electrostatic repulsion. A low concentration (10 mmol L−1) of Na+ in water could increase the membrane flux but had no significant effect on the removal of antibiotics. Ca2+ could reduce the membrane flux and improve the removal of chloramphenicol (CAP) and PNC. The removal efficiencies of low-concentration antibiotics (500 μg L−1) were higher than those of high-concentration antibiotics (10 mg L−1). Furthermore, the removal of antibiotics under the condition of actual wastewater quality was higher than those in solutions prepared with ultrapure water. The EDA-GO membrane has great potential in the removal of antibiotics in wastewater. HIGHLIGHTS The removal of three differently charged antibiotics by GO membranes was studied.; Crosslinked EDA-GO membrane had higher removal performance and better stability.; The removal of PNC with a negative charge was higher than CAP and ERY.; Ca2+ could reduce the membrane flux and increase the removal of antibiotics.; The removal of antibiotics under the condition of actual wastewater quality was higher.;

The issue tending toward alternative water resources tremendously becomes important for supplying the increasing water demand all over the world. It may be a good option to evaluate industrial effluents for agricultural irrigation. However, industrial effluent must be cleansed from the factors such as salt, toxic compounds, and microbial load that possibly cause negative effects on soil during agricultural irrigation. In this study, microbiological qualities and toxicity conditions of water sources such as membrane bioreactor (MBR) influent, MBR effluent, and mixture of MBR effluent and reverse osmosis (RO) permeate (MBR:RO = 2:1) were analyzed and evaluated according to irrigation standards. Total aerobic heterotrophic bacteria (TAHB), total coliforms (TC), fecal coliforms (FC), fecal streptococci (FS), and Clostridium spp. were screened and enumerated as indicator microbial groups for the microbial quality of water samples. Analyses of indicator microorganisms showed that loads of different bacterial groups decreased by 5.2 and 6.66 log units at maximum levels in MBR and MBR + RO system at the end of treatment. Also, evaluation of the toxicity effects of MBR effluent and MBR + RO permeate waters on Vibrio fischeri and Daphnia magna was investigated. None of the samples showed any acute toxic effect on D. magna after 48 h and V. fischeri in 5 min and 15 min. From the outputs of this study, it can be said that industrial effluents treated by advanced filtration technologies may provide a significant source of water for agricultural irrigation. This option can have positive impacts on both environmental and economic factors. [ABSTRACT FROM AUTHOR]

The application of ultraviolet (UV) disinfection systems in water and wastewater treatment plants is highly recommended due to their high inactivation efficiency and absence of disinfection byproducts. UV light-emitting diodes (UV-LEDs) are alternatives for UV mercury lamps due to its longer lifetime, improved efficiency, robustness, lesser start-up time, and environment-friendly. In this research study, the log inactivation of total coliform, fecal coliform, Escherichia coli (E. coli), and fecal streptococci were determined in biologically treated sewage using AlGaN-based UVC-LED reactor system operated at a wavelength of 275 nm. A novel reactor system with a baffled arrangement of UV-LEDs was developed and evaluated to improve the inactivation efficiency. The performance of the laboratory-scale UVC-LED reactor was evaluated under batch mode. AlGaN-based UVC-LED reactor yields high log inactivation in terms of coliform removal, even in the biologically treated sewage of heterogeneous character. The experimental results showed that the log inactivation of total coliform, fecal coliform, E. coli, and fecal streptococci was 5.25, 5.45, 5.00, and 4.70 log, respectively. With improved reactor design, increased output power, and reduced cost, AlGaN-based UVC-LEDs could be scaled-up for full-scale application in sewage treatment plants. [ABSTRACT FROM AUTHOR]

BACKGROUND: Increased water demand caused by population growth has forced the reuse of wastewater after treatment. Safflower is a salt‐tolerant plant that can be irrigated with moderately saline water. Cultivation of safflower plant can be achieved by irrigation with membrane bioreactor (MBR)‐treated wastewater and further utilized in oil and then biodiesel production according to standard (TS EN 14214). Irrigation water quality can impact oil and biodiesel yield and content. RESULTS: In this study, safflower plants were cultivated using different irrigation strategies in a field next to a wastewater treatment plant in Menderes‐Izmir, Turkey. These strategies were: irrigation weekly with MBR‐treated wastewater or with tap water; with MBR‐treated wastewater just three times during phenological periods; and without irrigation. Oil yields for seeds of the plants irrigated by these strategies were 103.8, 98.7, 63.7 and 57.4 (kg oil daa−1), respectively. Oil yield was found to be highest following weekly irrigation with MBR‐treated wastewater that has a high salinity of 4 mS cm−1. Safflower oil methyl ester (SOME) contents of biodiesel were 94.6 and 94.5% (g SOME:g biodiesel), and ester yields of biodiesel were 71.3 and 81.4% (g biodiesel:g oil–1) for safflower irrigated weekly with MBR‐treated wastewater and tap water, respectively. CONCLUSION: It is concluded that SOME yields and contents of safflowers irrigated with MBR‐treated wastewater and tap water weekly are so close. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Bioelectrochemical systems (BES) are a newly emerged technology for energy-efficient water and wastewater treatment. Much effort as well as significant progress has been made in advancing this technology towards practical applications treating various types of waste. However, BES application for agriculture has not been well explored. Herein, studies of BES related to agriculture are reviewed and the potential applications of BES for promoting sustainable agriculture are discussed. BES may be applied to treat the waste/wastewater from agricultural production, minimizing contaminants, producing bioenergy, and recovering useful nutrients. BES can also be used to supply irrigation water via desalinating brackish water or producing reclaimed water from wastewater. The energy generated in BES can be used as a power source for wireless sensors monitoring the key parameters for agricultural activities. The importance of BES to sustainable agriculture should be recognized, and future development of this technology should identify proper application niches with technological advancement.

Multiple-barriers are widely employed for managing microbial risks in water reuse, in which different types of wastewater treatment units (biological treatment, disinfection, etc.) and health protection measures (use of personal protective gear, vegetable washing, etc.) are combined to achieve a performance target value of log 10 reduction (LR) of viruses. The LR virus target value needs to be calculated based on the data obtained from monitoring the viruses of concern and the water reuse scheme in the context of the countries/regions where water reuse is implemented. In this study, we calculated the virus LR target values under two exposure scenarios for reclaimed wastewater irrigation in Japan, using the concentrations of indigenous viruses in untreated wastewater and a defined tolerable annual disease burden (10 −4 or 10 −6 disability-adjusted life years per person per year (DALY pppy )). Three genogroups of norovirus (norovirus genogroup I (NoV GI), geogroup II (NoV GII), and genogroup IV (NoV GIV)) in untreated wastewater were quantified as model viruses using reverse transcription-microfluidic quantitative PCR, and only NoV GII was present in quantifiable concentration. The probabilistic distribution of NoV GII concentration in untreated wastewater was then estimated from its concentration dataset, and used to calculate the LR target values of NoV GII for wastewater treatment. When an accidental ingestion of reclaimed wastewater by Japanese farmers was assumed, the NoV GII LR target values corresponding to the tolerable annual disease burden of 10 −6 DALY pppy were 3.2, 4.4, and 5.7 at 95, 99, and 99.9%tile, respectively. These percentile values, defined as “reliability,” represent the cumulative probability of NoV GII concentration distribution in untreated wastewater below the corresponding tolerable annual disease burden after wastewater reclamation. An approximate 1-log 10 difference of LR target values was observed between 10 −4 and 10 −6 DALY pppy . The LR target values were influenced mostly by the change in the logarithmic standard deviation (SD) values of NoV GII concentration in untreated wastewater and the reliability values, which highlights the importance of accurately determining the probabilistic distribution of reference virus concentrations in source water for water reuse. [ABSTRACT FROM AUTHOR]

The multiple-barrier concept is widely employed in international and domestic guidelines for wastewater reclamation and reuse for microbiological risk management, in which a wastewater reclamation system is designed to achieve guideline values of the performance target of microbe reduction. Enteric viruses are one of the pathogens for which the target reduction values are stipulated in guidelines, but frequent monitoring to validate human virus removal efficacy is challenging in a daily operation due to the cumbersome procedures for virus quantification in wastewater. Bacteriophages have been the first choice surrogate for this task, because of the well-characterized nature of strains and the presence of established protocols for quantification. Here, we performed a meta-analysis to calculate the average log 10 reduction values (LRVs) of somatic coliphages, F-specific phages, MS2 coliphage and T4 phage by membrane bioreactor, activated sludge, constructed wetlands, pond systems, microfiltration and ultrafiltration. The calculated LRVs of bacteriophages were then compared with reported human enteric virus LRVs. MS2 coliphage LRVs in MBR processes were shown to be lower than those of norovirus GII and enterovirus, suggesting it as a possible validation and operational monitoring tool. The other bacteriophages provided higher LRVs compared to human viruses. The data sets on LRVs of human viruses and bacteriophages are scarce except for MBR and conventional activated sludge processes, which highlights the necessity of investigating LRVs of human viruses and bacteriophages in multiple treatment unit processes. [ABSTRACT FROM AUTHOR]

A down-flow hanging sponge (DHS) reactor has been developed as a cost-effective wastewater treatment system that is adaptable to local conditions in low-income countries. A pilot-scale DHS reactor previously demonstrated stable reduction efficiencies for chemical oxygen demand (COD) and ammonium nitrogen over a year at ambient temperature, but the pathogen reduction efficiency of the DHS reactor has yet to be investigated. In the present study, the reduction efficiency of a pilot-scale DHS reactor fed with municipal wastewater was investigated for 10 types of human pathogenic viruses (norovirus GI, GII and GIV, aichivirus, astrovirus, enterovirus, hepatitis A and E viruses, rotavirus, and sapovirus). DHS influent and effluent were collected weekly or biweekly for 337 days, and concentrations of viral genomes were determined by microfluidic quantitative PCR. Aichivirus, norovirus GI and GII, enterovirus, and sapovirus were frequently detected in DHS influent, and the log 10 reduction (LR) of these viruses ranged from 1.5 to 3.7. The LR values for aichivirus and norovirus GII were also calculated using a Bayesian estimation model, and the average LR (±standard deviation) values for aichivirus and norovirus GII were estimated to be 1.4 (±1.5) and 1.8 (±2.5), respectively. Quantitative microbial risk assessment was conducted to calculate a threshold reduction level for norovirus GII that would be required for the use of DHS effluent for agricultural irrigation, and it was found that LRs of 2.6 and 3.7 for norovirus GII in the DHS effluent were required in order to not exceed the tolerable burden of disease at 10 −4 and 10 −6 disability-adjusted life years loss per person per year, respectively, for 95% of the exposed population during wastewater reuse for irrigation. [ABSTRACT FROM AUTHOR]

The virus reduction efficiency of each unit process is commonly determined based on the ratio of virus concentration in influent to that in effluent of a unit, but the virus concentration in wastewater has often fallen below the analytical quantification limit, which does not allow us to calculate the concentration ratio at each sampling event. In this study, left-censored datasets of norovirus (genogroup I and II), and adenovirus were used to calculate the virus reduction efficiency in unit processes of secondary biological treatment and chlorine disinfection. Virus concentration in influent, effluent from the secondary treatment, and chlorine-disinfected effluent of four municipal wastewater treatment plants were analyzed by a quantitative polymerase chain reaction (PCR) approach, and the probabilistic distributions of log reduction (LR) were estimated by a Bayesian estimation algorithm. The mean values of LR in the secondary treatment units ranged from 0.9 and 2.2, whereas those in the free chlorine disinfection units were from - 0.1 and 0.5. The LR value in the secondary treatment was virus type and unit process dependent, which raised the importance for accumulating the data of virus LR values applicable to the multiple-barrier system, which is a global concept of microbial risk management in wastewater reclamation and reuse. [ABSTRACT FROM AUTHOR]

The study reported and analyzed the current state of wastewater treatment plants (WWTPs) in urban China from the perspective of treatment technologies, pollutant removals, operating load and effluent discharge standards. By the end of 2013, 3508 WWTPs have been built in 31 provinces and cities in China with a total treatment capacity of 1.48 × 10 8 m 3 /d. The uneven population distribution between China's east and west regions has resulted in notably different economic development outcomes. The technologies mostly used in WWTPs are AAO and oxidation ditch, which account for over 50% of the existing WWTPs. According to statistics, the efficiencies of COD and NH 3 –N removal are good in 656 WWTPs in 70 cities. The overall average COD removal is over 88% with few regional differences. The average removal efficiency of NH 3 –N is up to 80%. Large differences exist between the operating loads applied in different WWTPs. The average operating loading rate is approximately 83%, and 52% of WWTPs operate at loadings of < 80%, treating up to 40% of the wastewater generated. The implementation of discharge standards has been low. Approximately 28% of WWTPs that achieved the Grade I-A Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918–2002) were constructed after 2010. The sludge treatment and recycling rates are only 25%, and approximately 15% of wastewater is inefficiently treated. Approximately 60% of WWTPs have capacities of 1 × 10 4 m 3 /d–5 × 10 4 m 3 /d. Relatively high energy consumption is required for small-scale processing, and the utilization rate of recycled wastewater is low. The challenges of WWTPs are discussed with the aim of developing rational criteria and appropriate technologies for water recycling. Suggestions regarding potential technical and administrative measures are provided. [ABSTRACT FROM AUTHOR]

Nitrogen pollution in river-based artificial groundwater recharge using reclaimed municipal wastewater poses a major threat to groundwater drinking water supplies in Beijing, China. Laboratory leaching column experiments simulating recharge were conducted to study nitrogen transformation, transport and leaching. Representative soil vadose zone media from three parts of the ChaoBai River were used as filler for the three columns. The media consisted mainly of waterpermeable gravel sand, fine sand and less-permeable silty clay, which are the typical streambed in the Huabei plain. The results showed that the attenuation of total nitrogen (TN) was in the order of silty clay column > fine sand column > gravel sand column, which followed the first-order kinetics. The TN attenuation mass was 6.36, 2.05 and 1.33 mg 100 g-1, respectively. The TN decay rate constants were 2.1, 1.7 and 1.6 m-1, respectively. The NO3--N attenuation mass was 7.68, 1.76 and 1.17 mg 100 g-1, respectively. The denitrification rate constants were 6.5, 3.5 and 2.6 m-1, respectively. The inflection points of TN concentration at different depths were 0.4, 0.5 and 0.8 m, respectively. The same trend was observed in NO3-. The content of NH4+-N was in the range of 0-4 mg L-1 in the early experimental period, while NH4+ was not detected after 15 d. Nitrogen transformation was affected by water temperature; when the temperature was below 5°C, the conversion of nitrogen did not change significantly with depth and time. Groundwater nitrogen pollution was related to the adsorption and degradation capacity of the soil vadose zone media. To avoid or minimize possible nitrogen contamination of groundwater in artificial groundwater recharge areas, the amount of TN in treated reclaimed municipal wastewater has to be determined and minimized by optimizing reclaimed water treatments and enhancing the ecological purification function of rivers. [ABSTRACT FROM AUTHOR]

Ozonation has been widely applied in advanced wastewater treatment. In this study, the effect of ozonation on assimilable organic carbon (AOC) levels in secondary effluents was investigated, and AOC variation of different molecular weight (MW) organic components was analyzed. Although the removal efficiencies were 47%-76% and 94%-100% for UV254 and color at ozone dosage of 10 mg/L, dissolved organic carbon (DOC) in secondary effluents was hardly removed by ozonation. The AOC levels increased by 70%-780% at an ozone dosage range of 1-10 mg/L. AOC increased significantly in the instantaneous ozone demand phase, and the increase in AOC was correlated to the decrease in UV254 during ozonation. The results of MW distribution showed that, ozonation led to the transformation of larger molecules into smaller ones, but the increase in low MW (< 1 kDa) fraction did not contribute much to AOC production. The change of high MW (> 100 kDa and 10-100 kDa) fractions itself during ozonation was the main reason for the increase of AOC levels. Furthermore, the oxidation of organic matters with high MWs (> 100 kDa and 10-100 kDa) resulted in more AOC production than those with low MWs (1-10 kDa and < 1 kDa). The results indicated that removing large molecules in secondary effluents could limit the increase of AOC during ozonation. [ABSTRACT FROM AUTHOR]

To tackle current water insecurity concerns, wastewater reclamation and reuse have appeared as a promising candidate to conserve the valuable fresh water sources while increasing the efficiency of material utilization. Climate change, nevertheless, poses both opportunities and threats to the wastewater reclamation industry. Whereas it elevates the social perception on water-related issues and fosters an emerging water-reuse market, climate change simultaneously presents adverse impacts on the water reclamation scheme, either directly or indirectly. These effects were studied fragmentally in separate realms. Hence, this paper aims to link these studies for providing a thorough understanding about the consequences of the climate change on the wastewater reclamation and reuse. It initially summarizes contemporary treatment processes and their reuse purposes before carrying out a systematic analysis of available findings. [ABSTRACT FROM AUTHOR]

It is an essential task to remove the residual organic pollutants (ROP) from secondary effluent of a Wastewater Treatment Plant (WWTP) in wastewater reclamation and reuse processes. Four different compared flow schemes would be achieved for further purification of the secondary effluent by switching of different valves. In order to mainly remove non-biodegradable residual organic pollutants under various operating conditions, the optimum technology and economic process was obtained in the advanced purification flow scheme at a flow of 3200 m³/d in Harbin Wenchang WWTP. Conclusions under a lot of experiments show that: choosing the coagulation-settler plus biofilm filter for advanced purification process is reasonable; during the stable operation phase, this process showed good performance in removing the COD, BOD5, TP, NH3-N and SS; the removal rates are 50%, 39%, 67%, 50%, 80% respectively. The effluent is able to excel the requirements for wastewater reuse standards. The unit cost of the water is 0.542 yuan/m³, which is far below the fee paid for supply water, long-distance transfer water or seawater desalination through economic analysis. [ABSTRACT FROM AUTHOR]

Abstract: A model-based estimation of the wastewater reclamation and reuse potential in a European context is presented, and the effects of different water management scenarios on the appraisal are quantified. The impact of climate change on water availability and variation in the demand pattern and water use of considered countries is the modifying variable in these scenarios. The simulation demonstrates that there is a significant potential for an increased utilisation of reclaimed wastewater in many European countries, specifically in the Mediterranean region. Aspects related to the factors that will definitely drive or slow down the development are addressed. [Copyright &y& Elsevier]

Groundwater recharge with reclaimed municipal wastewater presents a wide spectrum of technical and health challenges that must be carefully evaluated prior to undertaking a project. This review will provide a discussion of groundwater recharge and its management with special reference to health and regulatory aspects of groundwater recharge with reclaimed municipal wastewater. At present, some uncertainties with respect to health risk considerations have limited expanding use of reclaimed municipal wastewater for groundwater recharge, especially when a large portion of the groundwater contains reclaimed wastewater that may affect the domestic water supply.The proposed State of California criteria for groundwater recharge are discussed as an illustration of a cautious approach. In addition, a summary is provided of the methodology used in developing the World Health Organization''s Guidelines for Drinking Water Quality to illustrate how numerical guideline values are generated for contaminants that may be applicable to groundwater recharge. [Copyright &y& Elsevier]

With the ever-increasing urban population and economic activities, water usage and demand are continuously increasing. Hence, finding/re-creating adequate water supply and fully utilizing wastewater become important issues in sustainable urban development and environmental benign aspect. Considering Hong Kong’s situation, e.g., lack of natural fresh water, domination of municipal wastewater, etc., developing wastewater reclamation and reuse system is of specific significance to exploit new water resource and save natural fresh water supplied from Mainland China. We propose and have carried out some preliminary studies on the potential of categorizing municipal wastewater, developing grey and storm water recycling system in public housing estate, investigating the feasibility and potential of using reclaimed grey water, etc. Since there is very limited experience in grey water recycling, such initial studies can help to understand and increase knowledge in utilizing grey water, to foresee the feasibility of developing new water resource, to estimate the cost-effectiveness of reclaiming grey water in metropolitan city. [Copyright &y& Elsevier]

Strong wastewater from the animal breeding industry threatens the environmental and human health, while the widely used anaerobic digestion treatment is insufficient. To achieve the reclamation and reuse of the effluent containing an excessively high amount of nutrients (N, P and K) and a certain extent of biochemical oxygen demand (BOD), an original CO 2 -enhanced natural treatment system was put forward, which was composed of trickling filter and soil-plant units installed inside an elaborate greenhouse with an elevated CO 2 concentration. On the basis of previous feasibility studies, an investigation on the system's limitations and potential were carried out for further optimisation, in which red ball earth-Kentucky bluegrass column tests were conducted at the recommended CO 2 concentration of 1,400 ppm for two specific scenarios, i.e. high BOD concentration and increasing hydraulic and nutrient loading rates. N is the most critical factor determining the effect and efficiency of the system, and results confirmed that, to establish a satisfactory nitrification function in the soil for N removal, adequate BOD reduction prior to land application was indispensable. Optimal operational strategies and parameters, as well as design information for scale-up, are also discussed. By means of nutrient balance approximation, the system's significant capabilities of removing and recovering waterborne nutrients are further presented, specifically complete removal of both N and P, and 8%, 18% and 18% recovery rates for N, P and K, respectively. Meanwhile, carbon balance analysis reveals its potential for substantially reducing greenhouse gas emission, as 9% of the input waterborne C is sequestrated for establishing plant biomass and maintaining greenhouse CO 2 concentration at the designated level. More importantly, the above are realised in a highly profitable manner, as the value of the high-quality turf product can be an order of magnitude higher than the cost for system operation and maintenance. This original system provides an innovative way for rural communities worldwide to achieve sustainable development via wastewater reclamation and reuse. Image 1 • An innovative CO 2 -enhanced natural treatment system was proposed and developed. • Ensuring sound nitrification in the soil for N removal was the most critical issue. • Significant nutrient removal and recovery and CO 2 emission reduction were achieved. • Optimal operating conditions and design information for scale-up are discussed. • The profitable system is applicable to reclamation and reuse of strong wastewater. [ABSTRACT FROM AUTHOR]

Ozonation has been widely applied in advanced wastewater treatment. In this study, the effect of ozonation on assimilable organic carbon (AOC) levels in secondary effluents was investigated, and AOC variation of different molecular weight (MW) organic components was analyzed. Although the removal efficiencies were 47%-76% and 94%-100% for UV254 and color at ozone dosage of 10mg/L, dissolved organic carbon (DOC) in secondary effluents was hardly removed by ozonation. The AOC levels increased by 70%-780% at an ozone dosage range of 1-10mg/L. AOC increased significantly in the instantaneous ozone demand phase, and the increase in AOC was correlated to the decrease in UV254 during ozonation. The results of MW distribution showed that, ozonation led to the transformation of larger molecules into smaller ones, but the increase in low MW (<1kDa) fraction did not contribute much to AOC production. The change of high MW (>100kDa and 10-100kDa) fractions itself during ozonation was the main reason for the increase of AOC levels. Furthermore, the oxidation of organic matters with high MWs (>100kDa and 10-100kDa) resulted in more AOC production than those with low MWs (1-10kDa and <1kDa). The results indicated that removing large molecules in secondary effluents could limit the increase of AOC during ozonation., (Copyright © 2014. Published by Elsevier B.V.)

To tackle current water insecurity concerns, wastewater reclamation and reuse have appeared as a promising candidate to conserve the valuable fresh water sources while increasing the efficiency of material utilization. Climate change, nevertheless, poses both opportunities and threats to the wastewater reclamation industry. Whereas it elevates the social perception on water-related issues and fosters an emerging water-reuse market, climate change simultaneously presents adverse impacts on the water reclamation scheme, either directly or indirectly. These effects were studied fragmentally in separate realms. Hence, this paper aims to link these studies for providing a thorough understanding about the consequences of the climate change on the wastewater reclamation and reuse. It initially summarizes contemporary treatment processes and their reuse purposes before carrying out a systematic analysis of available findings., (Copyright © 2014 Elsevier B.V. All rights reserved.)