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Water contamination is a major global threat, which requires effective treatment methodologies and monitoring to preserve precious resources of water. In comparison to other sides of environmental sanitation, grey water has traditionally received less attention. Kitchen grey water (KGW) is one of the largest wastewater discharged into the water bodies directly. The present study investigated the ability of waste ceramic filtration for the treatment of KGW. The treatment system was designed with ceramic wastes that are used in household applications. Response surface methodology (RSM) was employed to optimize the hydraulic retention time (HRT) and ceramic particle size. Total organic carbon (TOC), chemical oxygen demand (COD), total suspended solids (TSS) and turbidity were reduced effectively by ceramic filter media. The maximum percentage removal of TOC, COD, TSS and turbidity were 66, 60, 70 and 72%, respectively, for the 120 min HRT and 0.25 mm particle size.

Microbial fuel cells (MFC) provide a breakthrough development for wastewater treatment combined with electricity production. Though, MFC applications are restricted in laboratory scale level. Present study an effort has been made to employ the electroplating industrial wastewater as feedstock in dual chambered anaerobic microbial fuel cell for organic content removal as well as energy production. The ultimate goal of this research is to analyze the effect of organic load (OL) on removal of organic matter and power production. The maximum removal efficiency of total, soluble oxygen demands (TCOD, SCOD) and total suspended solids (TSS) of about 87%, 79% and 72% respectively was obtained at the OL of 1.5 gCOD/L. The maximum power and current density of about 260 mW/m2 (6.2 W/m3) and 364 mA/m2 was also recorded at a same OL of 1.5 gCOD/L. From the above findings proposed that utilization of high strength organic wastewater in MFC could pave the way to handle the problem of electroplating industries as well as minimize a small portion of energy demand.

In order to monitor the ecological status of the largest Egyptian northern drains, an environmental comparison is performed between Bahr El Baqar Drain and Hadous Drain based on water quality and the community composition of their phytoplankton groups to assess the environmental hazard impacts on Lake Manzala. From both drains during the period 2015–2020 (5 years average), fourteen parameters were seasonally recorded; Hydrogen Ion, biological oxygen demand, chemical oxygen demand, electric conductivity, total suspended solids, total dissolved solids, bicarbonates, cations and anions (nitrates, sulfates, Calcium, Sodium, Potassium, Magnesium and Chloride), as well as seven heavy metal parameters (Copper, Iron, Manganese, Nickel, Lead, Boron, and Zinc). Statistically, phytoplankton seasonal dominance and abundance, diversity indices, species richness, evenness, Shannon and Simpson indices, and Pearson correlation were statistically calculated. The results showed that the average values of pH, HCO3, BOD, COD, EC, TSS, TDS, NO3, anions and cations in Bahr El Baqar Drain were higher than those in Hadous Drain. Phytoplankton groups in both drains belonged to five major groups with a descending order of dominance; Cyanophyta > Chlorophyta > Bacillariophyta > Euglenophyta > Dinophyta. Bicarbonates positively correlated with Chlorophyceae (evenness = 0.871, Shannon = 2.029), Cyanophyceae (1.964, 0.853), Euglenophycea (0.857, 1.535), and Dinophyceae (0.836, 0.918). BOD and COD positively correlated with Nitzschia sp., Euglena velata, and Peridinium volzii, and negatively correlated with Amphora sp., Euglena viridis, and Ceratium hirundinella. Chlorophyceae correlated positively with K, Mg, Cl, SO4 and NO3. Cyanophyceae correlated negatively with K, Mg, Na, B, Cl and SO4. Bacillariophycea positively correlated with Ni and NO3. Dinophyceae negatively correlated with Cl and SO4. Phytoplankton species expressed different dominance, diversity indices and statistical correlation with each water quality parameter, which reflected the selectivity and growth manners of algae. From the former mentioned results, it was concluded that the phytoplankton groups are very sensitive and useful indicator of the health status of any water stream. Concerning the bad quality of water in Bahr El Baqar Drain and Hadous Drain, management plan should be implemented for both drains, in particularly Bahr El Baqar Drain, to preserve the environmental status of Lake Manzala.

The total suspended solids (TSS) concentration is a relevant parameter for stream management. A high content of TSS has a negative impact on the ecological habitats and the aquatic environment, and could also be a limitation for the exploitation of surface water. The determination of TSS concentration through water sampling and posterior laboratory analysis is a complex and economically expensive procedure. In this regard, turbidity arises as a useful surrogate measure that allows the indirect estimation of the TSS concentration in a simple and economically convenient way. In the context of a severely deteriorated water supply system, the Naposta Grande stream constitutes a valuable resource for human and industrial consumption in the City of Bahia Blanca. The general objective of the present investigation is to develop statistically based relations between the parameters involved in the suspended solids transport, in order to characterize this phenomenon through the measurement of variables of simple and straightforward field determination. The statistical relationship between the TSS concentration and turbidity and between discharge and solid flow rate was explored. In both regression analyses, the statistical correlation resulted highly significant, and therefore represent valid calibration tools for future solids transport modelling analysis and prediction as well as for sedimentological balances. A comparative analysis of the solids transport between the closure of the medium drainage basin and at the outer limit of the suburban area of Bahia Blanca City, suggests the existence of erosive processes affecting the stream bed and its margins at the section between both sites.

Constructed wetlands are one of the most viable wastewater treatment technologies, with an additional aspect of biomass production that could be utilized in the manufacturing of valuable products. With this objective, four species of divergent commercial plants were grown individually and polyculture in horizontal subsurface flow constructed wetlands (HSFCW). Rural sewage was supplied from a storage tank to each CW through the inlet chamber. The experiment was continued for 12 weeks (July to October). Collectively, the HSFCW having polyculture of plants was more effective in the removal of all pollutants. While monoculture of Ipomoea aquatica exhibited better performance for the reduction of chemical oxygen demand (COD) and nutrients, viz., total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH4+–N), and nitrate-nitrogen (NO3–N) with a removal efficiency of 69, 77, 96, 90 and 80%, respectively. Whereas, Iris pseudacorus and Canna indica showed significantly better results for fecal coliform and total suspended solids reduction. At the last stage of the experiment, all plant species achieved the maximum growth rate; particularly, Ipomoea aquatica and polyculture or mixed planting (MP) had the highest growth rate and larger above-ground biomass. Thus, current findings reflect that MP wetland in wastewater treatment coupled with biomass production renders environmental and economic benefits.

Across the Afrotropical ecosystems human activities are increasingly modifying natural flow regimes, nutrient and organic matter loading and processing in streams and rivers with implications on ecosystem structure and functioning. The Mara River Basin has undergone extensive land-use change, but influences of these changes on water quality and aquatic communities are not well understood. This study investigated changes in water quality and macroinvertebrate assemblages across a disturbance gradient arising from rural human activities in nineteen sites; grouped into three condition categories (reference undisturbed (n = 7), moderately disturbed (n = 6) and disturbed (n = 6)). Temperature, dissolved oxygen, total dissolved solids, pH and electrical conductivity were measured in situ at each sampling site, and samples collected for analysis of nutrients and total suspended solids. Sampled macroinvertebrates were identified mainly to family level for analysis of structural and functional composition. There were significant spatial variations in water quality variables across the disturbance gradient (p

Alcaligenaceae and Chromatiaceae were previously reported as the specific pollution bioindicators in the receiving river water contaminated by palm oil mill effluent (POME) final discharge. Considering the inevitable sensitivity of bacteria under environmental stresses, it is crucial to assess the survivability of both bacteria in the fluctuated environmental factors, proving their credibility as POME pollution bioindicators in the environment. In this study, the survivability of Alcaligenaceae and Chromatiaceae from facultative pond, algae (aerobic) pond and final discharge were evaluated under varying sets of temperature (25-40°C), pH (pH 7-9) and low/high total suspended solid (TSS) contents of POME collected during low/high crop seasons of oil palm, respectively. Following treatment, the viability status and compositions of the bacterial community were assessed using flow cytometry-based assay and high-throughput Illumina MiSeq, respectively, in correlation with the changes of physicochemical properties. The changes in temperature, pH and TSS indeed changed the physicochemical properties of POME. The functionality of bacterial cells was also shifted where the viable cells and high nucleic acid contents reduced at elevated levels of temperature and pH but increased at high TSS content. Interestingly, the Alcaligenaceae and Chromatiaceae continuously detected in the samples which accounted for more than 0.5% of relative abundance, with a positive correlation with biological oxygen demand (BOD5) concentration. Therefore, either Alcaligenaceae or Chromatiaceae or both could be regarded as the reliable and specific bacterial indicators to indicate the pollution in river water due to POME final discharge despite the fluctuations in temperature, pH and TSS.

The rapid warming of the Arctic has led to permafrost degradation, accelerating the transport of terrestrial materials by rivers. The quantitative assessment of riverine nutrients and total suspended solids (TSS) flux is important to clarify the land–ocean connections in the Arctic. However, much is unknown about the estimates of these components from direct measurements in the Arctic rivers and the response of the components to permafrost degradation. Here, we report the results from the Arctic Great Rivers Observatory (Arctic-GRO) for the six major Arctic rivers (Yenisey, Lena, Ob’, Mackenzie, Yukon, and Kolyma) to investigate the riverine exports of TSS, total dissolved nitrogen (TDN), nitrate ( NO 3 − ), bicarbonate ( HCO 3 − ), total dissolved phosphorus (TDP), and phosphate ( PO 4 3 − ). The results showed that from 2004 to 2017, the annual TSS, TDN, and NO 3 − exports to the Arctic Ocean were approximately 106,026 Gg, 692 Gg, and 130 Gg, respectively, and the HCO 3 − , TDP, and PO 4 3 − exports were approximately 79,092 Gg, 32 Gg, and 18 Gg, respectively. There were remarkable variations in component concentrations and fluxes between seasons. More than 80% of the TDN, TDP, PO 4 3 − , and TSS exports mainly occurred in spring and summer, and a high HCO 3 − flux was recorded in summer, while a high NO 3 − flux in some rivers occurred in winter. The active layer thickness was significantly positively correlated with the annual TDN, NO 3 − , and HCO 3 − exports. In addition, the HCO 3 − flux of the six Arctic rivers increased by 247 Gg per year during 2004–2017. The positive relationship between the active layer thickness and river discharge indicates that permafrost degradation accelerated riverine carbonate, nitrogen, and phosphorus exports. This study demonstrates that riverine exports play an important role both in the Arctic terrestrial and marine ecosystems, and permafrost degradation will likely increase the riverine material exports to the ocean.

This research studies the implementation of artificial neural networks (ANN) in predicting the concentration of total suspended solids (TSS) for the Fei Tsui reservoir in Taiwan. The prediction model developed in this study is designed to be used for monitoring the water quality in the Fei Tsui reservoir. High concentrations of total suspended solids (TSS) have been a crucial problem in the Fei Tsui reservoir for decades. As the Fei Tsui reservoir is a primary water source for Taipei City, this issue impacts the drinking water supply for the city due to etherification problems in the reservoir. 10-year average monthly records and 13-year average annual records have been collected for 26 parameters and correlated with the TSS concentrations to determine the parameters that have a strong relationship with the TSS concentrations. The parameters that were shown to have a strong correlation with the TSS concentration are the trophic state index (TSI), nitrate (NO3) concentration, total phosphorous (TP) concentration, iron concentration (IRON), and turbidity. Linear regression was used to develop the model that estimates the TSS concentration in the Fei Tsui Reservoir. The results show that model 3, a three-layer ANN model that uses three-input parameters namely NO3 concentration, TP concentration, and turbidity, with five neurons, to predict the output parameter which is TSS concentration, produces the highest coefficient of determination (R2) and Willmott Index (WI), which are 0.9589 and 0.9933 respectively, and the lowest root mean square error, which is 0.4753. Based on these performance criteria, model 3 is concluded as the best model to predict TSS concentrations in this study.

In order to understand the hydrogeochemical pattern, ground (n = 23) and surface water (n = 2) samples were collected from three different landscapes (mountain, plain, valley) of Hidalgo State, Central Mexico. Physicochemical characteristics (pH, electrical conductivity, total hardness, alkalinity, total acidity, total solids, total dissolved solids, total suspended solids, CO2; cations (Ca2+, Mg2+, Na+), anions (NO3−, Cl−, PO43−and SO42−) and dissolved geochemical elements (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd and As) were analyzed. Results illustrated they are neutral to slightly alkaline due to the dissolution of carbonates. Average concentrations of anions and cations presented an order of (in mg/l): Na+ (273) > Ca2+ (206) > SO42− (181) > Cl− (163) > Mg2+ (115) > NO3− (11.07) > PO43− (0.12) revealing the local geogenic and anthropogenic influences. High mean concentrations of dissolved trace metals (0.052 mg/l) in the mountains is attributed to their diverse geochemical environment of the terrain and climatic variability. Concentrations of Cr, Cu, Ni and Zn were below the permissible limits set forth by WHO and the Mexican Government. Piper trilinear diagram revealed that they are mainly of Ca-Mg-HCO3 and Ca-Mg-SO4 type. Sodium Absorption Ratio (SAR) indicated that nearly 96% are of excellent quality, while Magnesium Adsorption Ratio (MAR) showed that 68% of them are unsuitable for irrigation purposes.

International audience; The process of ultrafiltration (UF) of natural seawater often encounters the problems of variation in water quality and coastal blooms. To validate the feasibility of UF in shellfish farms, this study compared the hydraulic performance and pollutant removal efficiency of the UF process with those of the commonly used treatments that combine several filtration steps with ultraviolet (UV) disinfection. The comparison was conducted in the cases of natural seawater and a coastal bloom. Given that the UF process encountered the specific type of pollution, this study evaluated the filtration performance of the UF process and the retention of total suspended solids (TSS), bacteria, phytoplankton, and zooplankton. A real coastal bloom was considered in the case study of an experimental shellfish hatchery/nursery in France. The results show that both treatments were able to eliminate approximately 50% of TSS. However, in contrast with UV treatment combined with filtration, the UF process retained total amounts of phytoplankton, zooplankton, and bacteria in the bloom. Although the hydraulic performance of the UF process was impacted by the coastal bloom, the fouling was eliminated through chemical cleaning conducted at a frequency less than once per 12 h. Despite the severe pollution, this study confirmed the pollution resistance and treatment performance of the UF process, indicating that UF has the potential to enhance the biosecurity level. (C) 2021 Hohai University. Production and hosting by Elsevier B.V.

This study presents biomagnetic nanoparticles (BMNPs) as a biostimulant for wastewater treatment and biogas upgrading to natural quality (>90% CH4). Notwithstanding, application of anaerobic digestion (AD) in wastewater settings is still limited with slow kinetics and low methanation yield. Here, four BMNPs (CuO, Fe2O3, TiO2, Cu/Fe-TiO2) were investigated to enhance the high-rate anaerobic system for complete degradation of organic waste to value – added products (water and biogas). Sugar refinery wastewater was used as a substrate and activated sludge as inoculum. This was carried out in 800 mL working volume bioreactors at a mesophilic temperature of 35 °C and hydraulic retention time of 30 days. Results showed the substrate – inoculum degradation in the control system, when induced with the BMNPs increased the methane (CH4) potential from 63% to 100%. Likewise over 75% water index of chemical oxygen demand, total suspended solids, and volatile solids were removed. Stimulatingly, the biogas production and wastewater treatability was significantly improved upon adding the BMNPs to the bioreactors which enriched the methanogenic activities. The post-sludge analysis showed the morphological and elemental distribution of the BMNPs, and their biomagnetic interactions with the micobes which enhanced the adsorptive removal of the contaminants and the biogas production yield. The Gompertz modified kinetic model significantly (P

Universiti Malaysia Sabah (UMS) campus in Kota Kinabalu consists of a large detention pond that stores the stormwater and limits the outflow rate into Likas' estuary. It is no doubt the detention pond has been designed per the Urban Stormwater Management Manual (USMM) requirement in terms of quantity control, however rapid development and changes in surrounding landscapes may affect the water quality. This study investigates the stormwater quality from the UMS detention pond and drainages within the campus. Water sampling was primarily taken during the dry period to justify worst-case scenarios without dilution from the rainfall season. Then the water quality parameters were tested using standard laboratory procedures mainly for Biochemical Oxygen Demand (BOD), Ammoniacal Nitrogen (AN), and Total Suspended Solids (TSS) with a minimum of a triplicate experimental run at the Environmental Laboratory, Faculty of Engineering, UMS. The determined water quality was compared with the National Water Quality Standards (NWQS) from the Department of Environment Malaysia. Overall the stormwater quality obtained for Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), AN and pH is within Class II to III, which is slightly polluted. However, the TSS from ponds near to main road and construction areas exceeds Class IV, indicating polluted conditions. There is a slight increase for BOD and AN parameters when comparing samples between June 2020 (post-MCO) and January 2017, which was suspected briefly due to fertilizing work for the campus landscapes. Although the TSS value is low, the TSS volume would increase over a period, raising the temperature while reducing the DO concentration and endanger the aquatic species and the ecosystem. Hence, it is recommended for a future study to emphasize TSS value as it would contribute significantly in designing sustainable stormwater management, particularly for the stormwater treatment, such as when optimizing for the utilization of alternative filter media, which reduces the maintenance and increasing the lifespan of the system.

Eco machine is deteriorating each day because of Industrial effluents. The effluents are containing poisonous chemical compounds which can be in turn polluting ground drinking water and developing new diseases. Treatment strategies for those Industrial effluents have become extra costly. The Present observation is aimed and concentrated at lowering the toxicity of Industrial waters and the goal is Reduction, Recycle and Reuse (RRR) with the usage of Microbial Fuel Cell. Microbial Fuel Cell experiments have been finished in batch operations for waste waters, the usage of microorganism in an effort to boom oxygen tiers and reduce toxicity. The parameters studied are layout of MFC, NaCl concentration, Agar concentration, glucose dosage, pH, Chemical Oxygen Demand, Biological Oxygen Demand, Dissolved Oxygen, Total Suspended Solids, Total Dissolved Solids, Sulphates, Chlorides. The consequences produced that excessive oxygen tiers and discount in pH tiers is appreciable. COD and BOD have reduced while DO has increased.

The infiltration-percolation process adopted at the M'zar wastewater treatment plant (WWTP) is a widely used treatment process capable of depolluting and decontaminating the effluent. The first objective of this study was to evaluate the purification performance of this treatment process with regard to the elimination of carbonaceous pollution and nitrate ions. The obtained results confirmed that infiltration-percolation is an advanced treatment technique for the treatment of organic pollution parameters such as: chemical oxygen demand (COD), biochemical oxygen demand measured after five days (BOD5) and total suspended solids (TSS). Nevertheless, this process contributes to the increase of nitrate ions by oxidation of nitrogen pollution at the sand filter level; consequently, this pollutant causes serious ecological problems, such as the eutrophication phenomenon. Therefore, it is therefore essential to reasonably control nitrates before they are released into the environment. The second objective of this work was to develop and valorize new low-cost, widely available and environmentally friendly adsorbents of animal origin. Raw shrimp shell (RSS), a biomaterial of animal origin, is abundant, available, renewable and non-toxic. It has physicochemical properties that can induce a significant adsorptive activity. The surface micro-morphology of the biomaterial was investigated using scanning electron microscope; while the qualitative element composition was analyzed using energy dispersive X-ray and infrared spectroscopies. For this reason, our research team proceeded to evaluate the effectiveness of crushed shrimp shell particles in order to remove nitrate ions from municipal wastewater effluents. The founded results of raw wastewater decanted (RWWD) and purified wastewater (PWW) are encouraging and show significant purification yields: 68% (RWWD) and 79% (PWW) for nitrate ions.

Combining solar PV based electrolysis process and textile dyeing industry wastewater for hydrogen production is considered feasible route for resource utilization. An updated experimental method, which integrates resource availability to assess the wastewater based hydrogen production with highlights of wastewater treatment, use of solar energy to reduce the high-grade electricity for electrolysis (voltage, electrode materials) efficiency of the process was employed. Results showed that maximum pollutant removal efficiency in terms of conductivity, total dissolved solids, total suspended solids, biological oxygen demand, chemical oxygen demand, hardness, total nitrogen and total phosphorus were obtained from ≅73% to ≅96% at 12 V with steel electrode for pollutant load. The maximum input voltage was found at 3 V for the best efficiency i.e. 49.6%, 67.8% and 57.1% with carbon, steel and platinum electrodes respectively. It was observed that with high voltage (12 V) of the electrolyte the rate of production of hydrogen was higher with carbon, steel and platinum electrodes. However, the increase in the efficiency of the production of hydrogen was not significant with high voltage, may be due to energy loss through heat during extra-over potential voltage to the electrodes. Hence, this integrated way provides a new insight for wastewater treatment and hydrogen energy production simultaneously.

We evaluated mercury (Hg) behavior in a full-scale sewage sludge torrefaction plant with a capacity of 150 wet tons/day, which operates under a nitrogen atmosphere at a temperature range of 250–350 °C. Thermodynamic calculations and monitoring results show that elemental Hg (Hg0) was the dominant species in both the pyrolysis gas during the torrefaction stage and in the flue gas from downstream air pollution control devices. A wet scrubber (WS) effectively removed oxidized Hg from the flue gas and moved Hg to wastewater, and an electrostatic precipitator (ESP) removed significant particulate-bound Hg but showed a limited capacity for overall Hg removal. Hg bound to total suspended solids had a much higher concentration than that of dissolved Hg in wastewater. Total suspended solid removal from wastewater is therefore recommended to reduce Hg discharge. Existing air pollution control devices, which consist of a cyclone, WS, and ESP, are not sufficient for Hg removal due to the poor Hg0 removal performance of the WS and ESP; a further Hg0 removal unit is necessary. A commercial packed tower with sorbent polymer catalyst composite material was effective in removing Hg (83.3%) during sludge torrefaction.

The present study discuss regarding ground water quality and also estimation of the water quality index (WQI) near the municipal dump site in Guntur which has non engineered and improper land fill. Through this landfill leachate is generated and pollute the ground water quality and the local water bodies near it. This has been determined by collecting the ground water samples at different points around the dump site in the poly-ethylene bottles and subjecting the samples to a comprehensive physico-chemical analysis. For calculating the water quality index certain parameters has been considered: Ph, turbidity, total dissolved solids, electrical conductivity, chlorides, alkalinity, acidity, fluorides, total dissolved oxygen, total suspended solids, total solids. The results are compared with the Indian Standards of the drinking water (BIS -10500-1991). By using the weighted arithmetic method the water quality index is analyzed. This study is a reference to implement the best suitable technique to construct the land fill. The construction of landfill will help the dump site for not allowing the Leachate to percolate into the soil. The research suggests upgrading of municipal dump to landfill for the protection of ground water.

The rapidly transforming technologies and changing of people’s expectations triggered the fourth industrial revolution, commonly referred to as Industry 4.0. Water is the core resource and a vital for life of all species, as it is a limited resource that needs to be utilized efficiently. Monitoring various aspects of the water quality leads to a clear understanding of the aspects that should be considered for a healthy life and to avoid wastage of water. Using Internet of Things (IoT) should allow for the integration of real time monitoring and controlling of water quality. The suggested system utilizes Internet of Things (IoT) through using sensors to measure the water quality factors such as (pH, temperature and turbidity) for home applications. The system should allow for autonomous decision making for controlling the water quality factors such as (acidity, alkalinity, temperature and amount of total suspended solids expressed by cloudiness or haziness) measured by mentioned sensors within the acceptable limits and keeping records of the historical readings on a cloud based platform. The system will lead to real time data acquisition, transmission and processing of water quality data. This will give the ability to automatically react to the changes in the system outputs. Using Internet of Things (IoT) means the system can be accessed from anywhere through Internet, for example through a mobile application remotely. The objective of the system is to allow the water consumer in home to be able to judge the quality of the incoming water and to control it to the required levels. The system also utilizes the different filters used in home to enhance the water quality in an efficient way. As the filters will only be used once needed and not all the time. Utilizing such, a system should lead to improving the public health and the cost of controlling the quality of the consumed water. The system should eliminate the inconvenient and lengthy off line lab analysis of collected water samples. The system should provide a user-friendly interface with infographics and meters to illustrate the quality factors as Lower-Upper limits and the acceptable values. In addition, the system should provide an easy way for the configuration of the controllers and the communication with the sensors.

Four different types of ecological concrete (EC), including an applied concrete (AC), and three kinds of modified concretes (MC1-MC3) were used to study the removal performance of rainfall surface runoff and their impacts on changes in dissolved organic matter (DOM). The results showed that MC3 indicated the best performance of water purification; the removal ratios of total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH4+-N), total organic carbon (TOC), and total suspended solids (TSS) were 58.08%, 95.57%, 92.44%, 91.72%, and 87.62%, respectively. Fluorescence excitation-emission matrix (EEM) spectroscopy combined with parallel factor analysis (PARAFAC) was able to identify five fluorescent components (C1-5), including three humic-like components (C1, C3, and C4) and two protein-like components (C2 and C5). The three MCs could more effectively remove both small-molecular-weight protein-like component C2 and high-molecular-weight humic-like components C1, C3, and C4, compared to the AC. The result of two-dimensional correlation spectroscopy (2D-COS) showed that protein-like components had higher susceptibility than humic-like substances did. Fluorescent components at 330, 305, 410, and 410 nm were found with a preferential change in the AC, MC1, MC2, and MC3 respectively, suggesting that fulvic-like, protein-like, humic-like, and humic-like substances can be removed preferentially in the AC, MC1, MC2, and MC3 respectively. This study is valuable for improving surface runoff purification of rainwater in rural areas and for reducing agricultural non-point source pollution.

Constructed wetlands (CWs) are recognized as a useful method to reduce sediment and nutrient loading from arable land to surface waters. Automatic monitoring systems with continuously measuring sensors were utilized for several years to obtain accurate, up-to-date information of the retention performance of two differently dimensioned and located CWs in agricultural catchments in southern Finland. Here, results derived from the data recorded by the sensors measuring height, turbidity and nitrate-nitrogen (NO3-N) concentration of the water entering and exiting the Hovi (established in 1998) and Rantamo-Seitteli (est. in 2009) CWs are presented. Study periods ended in autumn 2014 and they lasted 7 years at Hovi and 4.5 years at Rantamo-Seitteli. Annual total suspended solids (TSS), total phosphorus (TP) and total nitrogen (TN) per cent retentions were much higher in the older, more generously dimensioned (CW-to-catchment area ratio 5%) Hovi CW (TSS 74%, TP 58% and TN 54% on average during 7 years) than in the newer, more scantly dimensioned (CW-to-catchment area ratio 1.3%) Rantamo-Seitteli CW (TSS 7%, TP 12% and TN 9% on average during 4.5 years). Moreover, the annual retentions of the Rantamo-Seitteli CW appeared to decrease with increasing runoff, while the retentions at Hovi were not affected by runoff fluctuations. In terms of TSS and TP retentions in the Hovi CW, they were in this study at similar levels to those observed shortly after the establishment of the CW. Meanwhile, the retention of dissolved nutrient fractions, i.e. NO3-N and dissolved reactive P (DRP, based on water sampling) at Hovi were clearly higher in this than in the previous study. The results confirm the importance of CW dimensioning and locating near the sources of loading, and refer to improved performance as CWs get older with increasing vegetation and biological activity. Our experiences of CW measurements with sensors have been positive. The information obtained with new technology has provided retention estimates that are more accurate than they would have been if they were derived from sparse grab sampling.

Vertical-flow constructed wetlands remove pollutants from combined sewer overflows (CSOs) and have been in operation for approximately 20 years in Germany. More than 150 sites are currently operated in the state of North-Rhine Westphalia, with most of them constructed according to the same guidelines. This number provides an adequate statistical population to evaluate the treatment efficiency of this design; however, most available data have not been collected in a standardized way. This study presents the results from a survey amongst operators of these plants, who provided long-term data for 24 sites. It also describes a statistical approach to harmonizing the data and evaluating the removal efficiencies of wastewater pollutants while considering errors and uncertainties with a Monte Carlo simulation. This method makes it possible to harmonize data from surveys and to draw generalized conclusions on the treatment efficiency of large-scale facilities. In this study, the evaluation could be adapted for the removal efficiencies of chemical oxygen demand, total suspended solids and total phosphorus.

An experimental simulation device was used to evaluate the water purification performance of soil improved with two different conditioners, which were cornstalk and zeolite (CSZ), turf and quartz sand (CTS) in this study. The results showed that the removal rates for total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) reached 75.58%, 25.71%, 68.37%, and 64.67%, respectively, for CSZ, and 85.09%, 92.75%, 76.71%, and 98.33%, respectively, for CTS, suggesting that soil improvement showed higher water purification performance with the CTS conditioner than with the CSZ conditioner. The structure, composition, and source of dissolved organic matter (DOM) were probed using ultraviolet visible (UV–Vis) spectra and fluorescence spectra. The spectral parameters indicated that the CTS conditioner-improved soil showed a relatively high humification and aromaticity of DOM, and a relatively higher contribution of organic matter derived from microbial substances. In addition, the results of 2D-COS suggested that the binding sites and sequences can be significantly influenced by soil improvement, and vary between the two kinds of conditioners. The CTS-improved soil was more effective in reducing fluorescent DOM than was the CSW-improved soil. This study can provide a scientific foundation for the treatment of agricultural non-point source (NPS) pollution.

The purpose of this study was to apply numerical modeling to assess the water quality in Nam Trieu and Lach Tray coastal estuaries. The wind reanalysis data from the Weather Research and Forecasting (WRF) Model were used to simulate waves and hydrodynamic regimes with a definition of 14 km within the longitude range from 105oE to 120oE and latitude range from 5° to 22° in the study area. The calibration and validation results for the wind–wave, hydrodynamic regimes showed that the performance of the 2D hydrodynamic model is extremely good, with a Nash coefficient ranging from 0.89 to 0.92, a root–mean–square error (RMSE) observation standard deviation ratio (RSR) varying from 0.25 to 3.6, and a percent bias (PBIAS) from −4.2% to 0.2%. The calibrated 2D hydrodynamic model was combined with the Ecolab model to evaluate and simulate the spreading of water quality parameters (biochemical oxygen demand (BOD), NH4+-N, and total suspended solids (TSS)). The water quality parameters BOD (16.5–22.5 mg/l), NH4+-N (0.003–0.009 mg/l), and TSS (29.63–40.8 mg/l) were smaller than the parameters of the national technical regulation on coastal water quality and surface water quality in March and August. The assessment results of water quality an industrial zone can help in management, planning, and decision–making to reduce wastewater discharge.

In the study, the Weibull reliability theory was used to analyze the reliability of a small Sequencing Batch Biofilm Reactor (SBBR) for domestic wastewater purification. Also, the relative frequency and probability of exceedance of effluent discharge limits for the analyzed pollution parameters (BOD5, COD, total suspended solids, total nitrogen and total phosphorus) were determined. Full technical scale tests were carried out at a facility with a mean throughput of 0.6 m3/d, for a period of 34 months from December 2016 to September 2018. An analysis of the test results regarding the reliability of removal of the contaminants to the maximum effluent discharge levels yielded the following figures: BOD5 – 77.5%, COD – 97.8%, TSS – 100%, TN – 12.2% and TP – 21.7%. The relative exceedance frequencies measured in treated wastewater, expressed as proportion of all measurement series for a given parameter were: BOD5 – 17.14%, COD – 3.7%, TSS – 0%, TN – 85.2% and TP – 81.2%. The study showed that the small SBBR system was reliable in removing the basic contaminants (TSS, BOD5, COD) from domestic wastewater, but did not ensure effective removal of biogenic compounds. Large-scale use of this type of treatment plants may contribute to the eutrophication of wastewater receivers.

Green roofs are emerging as practical strategies to retain stormwater runoff and improve water environment quality of urban cities. However, the impacts of green roofs on stormwater runoff quality remains a topic of concern to urban planners and mangers. In this study, we designed the scale based runoff plots of extensive green roofs with different substrate and vegetation types, and investigate whether the studied green roofs act as a sink or source of nutrients and suspended solids in their runoff compared to a conventional roof. The influences of substrate and vegetation on the water quality of green roof outflows were also assessed. The results showed that the average TSS (total suspended solids), TN (total nitrogen), and TP (total phosphorus) concentrations of the green roof runoff were all significantly higher than that of the conventional roof runoff. Except substrate S3 (the composition ratio of rural soil:peat soil:perlite:vermiculite was 2.5:5:2:0.5) and S1 (the composition ratio of rural soil: peat soil was 1:1) in TP, the substrate S2 (the composition ratio of rural soil:peat soil:pine needle:perlite was 1:1:1:1) displayed significantly higher TN and TP concentrations than either of the runoff from the substrate S1 and S3. The TN and TP concentrations of 5 cm substrate depth were significantly lower than that in the 15 cm substrate depth treatments. Significant differences were observed in TN concentrations between vegetation Sedum Spectabile and Radix Ophiopogonis. However, no significant differences were observed between any of the vegetation types with regard to TP concentrations. Therefore, we suggest that green roofs need to be constructed of suitable substrate materials and plants based on their function on runoff water quality in order to mitigate the pollution risk of green roof runoff on urban water environment.

In this study, wet oxidation of sewage sludge and struvite-precipitation processes were integrated to safely manage sludge and to recover organic acids and phosphorus. To understand this process integration, the effects of temperature, treatment time, and sludge concentration during wet oxidation, and pH and magnesium dosage during struvite precipitation on total suspended solids (TSS), volatile suspended solids (VSS), organic acids production, and phosphorus recovery were investigated. The results showed that TSS and VSS destruction, organic acids production, and phosphorus recovery from sludge into the liquid phase are more sensitive to temperature and time than sludge concentration during wet oxidation. These are novel findings of this work. Furthermore, pH during struvite precipitation had a strong effect on phosphorus recovery. Wet-oxidised sludge was mainly converted to acetic acid, and its concentration increased with increasing temperature and time. These results may be used for optimised operation and revenue generation from wastewater treatment processes when integrated with wet oxidation and struvite precipitation.

Recent sedimentation rates are useful for quantifying how changes in a watershed affect soil erosion; however, typical geochronological methods for dating sediments are limited in temporal resolution, particularly for newly deposited sediments. We used sediment traps to measure short-term sediment accumulation rates in a natural oxbow lake whose watershed has a mix of agricultural and forested land. Precipitation data from a local Soil Climate Analysis Network (SCAN) site and water quality measurements from Beasley Lake were used to explain intra-annual patterns in sediment deposition. We found that sediment accumulation in the traps was highest in July and August, while the highest rate of runoff, indicated by increased precipitation and total suspended solids, occurred in late winter and early spring (February-April). Our results indicate that the trapping efficiency of Beasley Lake may be lower than expected due to timing of particle settling predominantly in the summer months. The rate and timing of sediment accumulation in Beasley lake was highly seasonal and occurred when water temperature and pH increased, potentially through interactions with algal blooms. Our findings contribute new understanding of the interactions between suspended sediments, algal biomass, and water chemistry in a natural oxbow lake and provide support for using sediment traps to measure intra-annual variability in sedimentation rates in oxbow lakes.

In situ treated real textile wastewater was subjected to electrocoagulation for reuse in agricultural irrigation The effect of several parameters such as electrode type (Al and Fe), current density (12.5-100 mA/cm(2)), initial pH (5-10), and electrocoagulation time (0-120 min) were investigated to determine the optimum electrocoagulation condition. Monopolar electrodes connected in parallel were used for all experiments. The performance of the experiments was mainly evaluated using the Total Organic Carbon (TOC) removal. The Al electrode, 25 mA/cm(2) of current density and a pH=5 was selected as the optimum conditions. Under these conditions 42.5% TOC, 18.6% chemical oxygen demand (COD), 83.5% turbidity, 64.7% of the total suspended solids, and 90.3-94.9% color removal efficiencies were achieved. The operating cost was calculated by considering the energy and electrode consumption and evaluated as 1.5 $/m(3) of treated wastewater. The electrocoagulation reaction followed the second order reaction kinetics. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

African star apple seed husks, oil seed and whole seed were used for activated carbon production for the treatment and elimination of suspended and dissolved particles from industrial waste water. The activated carbon was produced using chemical activation method with phosphoric acid (H3PO4) and zinc chloride (ZnCl2) as the activating agents at a carbonization temperature of 500 °C. The morphological interpretations and functional groups of the activated carbon were observed using scanning electron microscopy and Fourier transform infrared spectroscopy respectively. Results obtained from the various pollution indicators showed an appreciably improvement on the quality of the water. The pH, temperature, total suspended solids, total dissolved solids and biological oxygen demand were determined with variation of the contact time of the activated carbons with the industrial wastewater. Seed husks of zinc chloride and Oil seed of phosphoric acid produced an activated carbon with the highest adsorptive performance for pH, temperature, Total Dissolved solids (TDS), Total suspended solids (TSS) and Biochemical oxygen demand (BOD) removal at 7.01, 7.14; 25.1 °C, 25.0 °C; 24.20 mg/L, 21.09 mg/L; 17.64 mg/L, 15.4 mg/L and 6.28 mg/L, 4.8 mg/L respectively at 150 min and yield of 75.2% and 54.3%.

New York City (NYC)’s drinking water reservoirs supply over four billion liters each day to over nine million consumers in NYC and upstate communities. In the last 25 years, the City has invested nearly $2 billion in watershed protection programs (WPPs) to maintain high source water quality, allowing NYC to avoid filtration for 90% of the supply. This study involves the use of a model to evaluate the impact of WPPs on phosphorus (P) loading in the Cannonsville Reservoir watershed, one of the unfiltered water supply sources. The model is SWAT-Hillslope (SWAT-HS), a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. We applied the SWAT-HS model to this watershed to test its ability to simulate conditions observed after the implementation of watershed protection and evaluate the impact of point and non-point source WPPs on watershed export of P. When applied to a 12-year period of WPP implementation, SWAT-HS predicted streamflow very well with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the calibrated outlet and values ranging from 0.56 to 0.78 at six other locations within the watershed. Moreover, the monthly predictions of soluble P (total dissolved P), particulate P, and sediment (total suspended solids) were good with NSE of over 0.73. Model simulations indicated that the dominant source of soluble P was pastures while particulate P originated from both from croplands and pastures. A significant quantity of P was derived from near-stream areas, particularly from pastures where cattle spent time grazing and had access to streams. SWAT-HS was also used to estimate what the P export would have been over this 12-year period without WPP implementation. Point and non-point source programs were found to be important for P control, with non-point source controls most effective during high streamflow, and point source controls more beneficial at low flow.

Urbanization has significant effects to ecosystems in watersheds, but the link between surface water quality and the dissolved organic matter (DOM) composition is poorly understood. We investigated the fluorescent intensities (Fmax) of DOM components and examined their correlation with the water quality parameters in peri-urban (Zhangxi River) and urban (Lu River) watersheds in Ningbo, East China. DOM quality was measured by fluorescent excitation-emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC). Terrestrial humic-like components (C1 and C2) and protein-like component (C3) were derived by the PARAFAC model. We found more serious water pollution (significantly higher values for most water quality parameters, i.e. chemical oxygen demand (COD), chlorophyll a (Chl-a), dissolved organic carbon (DOC), ammonia and total suspended solids (TSS)) in urban than peri-urban watersheds. However, there were no significant differences in the levels of total nitrogen (TN) and total phosphorus (TP) between the urban and peri-urban watersheds. The results showed that the urban watershed had higher terrestrial humic-like C1 (39%) and lower protein-like C3 (30%) than the peri-urban watershed, while the peri-urban watershed showed an inverse trend (33% and 37%, respectively). The results also revealed that the DOM fluorescent indices were significantly different between the peri-urban and the urban watersheds. Redundancy analysis (RDA) was applied to evaluate the correlation between DOM fluorescent indices and water quality parameters (i.e., COD, TN, TP, DOC). It revealed that the pollution sources and water quality correlated to the fluorescent indices and the C1-C3 DOM fluorescent components. A significant linear relationship between COD and C2 was found in both watersheds, suggesting that C2 might be a good COD indicator. Our results suggest that the distinctive DOM composition between the watersheds could be attributed to different human activities at both sites. The correlation between DOM fluorescent components and water quality can be assessed by the EEM-PARAFAC method, indicating considerable potential for the use of this technique to monitor surface water quality.

The exponential washoff model was originally developed based on observations of particulate pollutants, however, its applicability when applied to different forms of pollutants is not well understood. Data from a previous study of 6 stormwater pollutants from 126 events at 12 sites in Singapore was used for event based model parameter calibration using a Monte Carlo technique. The accuracy of the calibrated exponential washoff model was clearly best for particulate pollutant total suspended solids (TSS), and worst for dissolved pollutants Ortho-Phosphate (PO 4 ), nitrate (NO 3 ) and ammonium-nitrogen (NH 4 ). Model accuracy for mixed forms of pollutants total Phosphorus (TP) and total Nitrogen (TN) were in between these two extremes. Relationships between model parameters with rainfall and flow characteristics were also investigated. Statistically significant relationships could only be found for TSS, where the total rainfall depth was identified as being the most significant variable to explain model parameter behaviour. Antecedent dry period (ADP) was shown to have little or no importance across all land uses and pollutant forms. The results showed that the model parameter behaviour could be explained only for particulate pollutants and small (≤10 ha) sub-catchments, and that replicating washoff of mixed or dissolved forms of pollutants as a fraction of solids is likely to lead to misleading results.

Alluvial gold mining poses a threat to river water quality, yet methods for assessing its impacts on water quality remain laborious and costly. Water quality modelling offers an alternative, which is cost-effective. In this study, we assess the effect of alluvial gold mining on surface water quality at three sites located along the Mazowe and Mwenje rivers in northern Zimbabwe using a simple exponential decay model. The model predictions were regressed against measured in-situ Total Suspended Solids (TSS) and turbidity. Strong linear relationships were observed between the measured and predicted pollutant concentrations. Specifically, the results indicate that TSS concentrations can be predicted in the catchment, with high accuracy (R2 values of 82%, 88% and 93% and root mean square errors (RMSEs) of 5, 2 and 3 mg/l across the three monitoring sites, respectively). Similarly, comparison between predicted and measured values river turbidity equation showed high prediction accuracies for the three sites. The results showed that water turbidity could be predicted at R2 = 77%, 88% and 93% at sites 1, 2 and 3, with correspondingly low RMSEs of 4.5, 1.4 and 2.7 NTU, respectively. Overall, these results provide an alternative approach to assess the impact of artisanal mining on physical water quality in a tropical environment.

The intermittent nature of stormwater runoff impacts the treatment performance of biofilters, also known as stormwater biofiltration or bioretention systems and raingardens. During extended dry periods, which are common even in temperate climates, plants can perish, creating unattractive and non-functional systems that might leach pollutants during the next rainfall event. The current solution is to irrigate during long dry spells, which is costly and unsustainable as biofilters become more widespread. This paper presents the development of dual-mode biofilters, where stormwater and greywater are treated within the same system. Fifty columns, utilising eight plant species, including understory and climbing ornamentals, and designs with and without a carbon source in the submerged zone, were subjected to alternating greywater and stormwater inflows over five months. Six sampling events investigated treatment performance across these switching inflows and an extended dry period (atypical event). Good removal of total suspended solids (>83%), biochemical oxygen demand (>86%) and some heavy metals (e.g. lead >96%) were reported irrespective of design. Plant species selection was critical for the removal of nitrogen (2 to 79%) and phosphorus (12 to 75%) under dual-mode operation. However, following the extended dry period, plants with the lowest nutrient outflow concentrations also experienced some of the highest sediment and carbon concentrations, suggesting that a mixture of plant species may be beneficial for withstanding abnormal conditions. Differences between the treatment performance of designs with and without a carbon source were negligible, with potential benefits possibly negated due to the increased root mass that comes with age (systems were approximately two years old) and the release of carbon from root exudates. The results demonstrate the potential for dual-mode stormwater-greywater biofilters as an alternative to single-mode systems as they can provide effective treatment, along with greater volumes of treated water, while maintaining system performance throughout the year.

The activated sludge process is widely used to treat both municipal sewage and a variety of industrial wastewaters. We investigate the steady-state behaviour of an activated sludge process. We use the activated sludge model number one, an internationally accepted model, to describe the biochemical, biological, and physical-chemical phenomena that occur inside the bioreactor. The treatment configuration consists of a single aerated reactor attached to a settling unit. Continuation methods are used to determine the steady-states of the model as a function of the hydraulic residence time. From these solutions we construct important operational parameters including the chemical oxygen demand, total suspended solids and total nitrogen. These are determined inside the bioreactor, in the effluent stream and in the wastage stream. We show that there are two critical values of the hydraulic retention time. As the hydraulic retention time is increased through the first critical value heterotrophic biomass become viable. This bifurcation is associated with a substantial decrease in the chemical oxygen demand in the effluent stream and a corresponding increase in both the total suspended solids and total nitrogen in the reactor. Autotrophic biomass become viable as the hydraulic retention time is increased through the second bifurcation point. Associated with this bifurcation there are dramatic changes in the concentration of soluble ammonium nitrogen and soluble nitrate/nitrite inside the reactor; the former being converted to the latter. Of particular practical interest is the value of the hydraulic retention time at which the chemical oxygen demand in the effluent stream is equal to a preset target value. We investigate how this value varies as either the composition of the influent stream or the recycle ratio is varied.

The fate of filter materials and microbial communities during the vermifiltration process were studied for 5 months while treating the concentrated greywater. Four filters were filled with 10 cm gravel of which a layer of medium size gravel (5 cm thickness, aggregate size 20–40 mm) at the bottom and a layer of coarse gravel (5 cm thickness, aggregate size 10–20 mm) at the top, then filled with 20 cm sand (d60 = 0.2 mm, d10 = 0.118 mm). Finally, Vermifilter 1 (VF1), control unit and Vermifilter 2 (VF2), were filled with 40 cm fine sawdust (0.05–5 mm) but Vermifilter 3 (VF3), was filled with 40 cm cow dung (0.05–5 mm). Three filters were inoculated with 200 individuals of Eudrilus eugeniae except for the control unit which was filled with sawdust. Five sampling ports were installed on the wall of the filters at 10 cm intervals with reference to the surface of the top layer. Three of the filters were supplied with concentrated greywater and VF1 was supplied with drinking water at the hydraulic loading rate of 16 L m−2.d−1 on batch basis, i.e., four times a day at 8:00 a.m., 11:00 a.m., 2:00 p.m. and 5:00 p.m. Weekly, samples from influent and effluent, and monthly, samples of filter materials collected via sampling ports, were collected and analyzed.The removal efficiencies of biological oxygen demand (BOD5), total chemical oxygen demand (tCOD), and dissolved chemical oxygen demand (dCOD) of VF2 and VF3 were 5–7% higher than the control unit, but little differences were observed in terms of total suspended solids (TSS). However, the removal efficiencies of nutrients for the control unit was slightly better than VF2 and VF3. The pH and Moisture content (MC) of filter materials increased along the depth, but percentage of volatile solids to total solids (VS/TS) decreased through time due to the high number of microbial communities and earthworms dominating the top layer compared to the bottom. The performance of VF2-sawdust was slightly better than VF3-cow dung to treat concentrated greywater., Highlights • Fate of filter materials and microbial communities during vermifiltration process were studied. • Ratio of volatile solids to total solids decreased during vermifiltration process in filter materials. • The bacteria, actinomycetes and fungi intensified where earthworms dominated. • VF2-Sawdust performed slightly better than the VF3-Cow dung.

Commercial nurseries grow specialty crops for resale using a variety of methods, including containerized production, utilizing soilless substrates, on a semipervious production surface. These “container” nurseries require daily water application and continuous availability of mineral nutrients. These factors can generate significant nutrients [total nitrogen (TN), and total phosphorus (TP)] and sediment [total suspended solids (TSS)] in runoff, potentially contributing to eutrophication of downstream water bodies. Runoff is collected in large ponds known as tailwater recovery basins for treatment and reuse or discharge to receiving streams. We characterized TSS, TN, and TP, electrical conductivity (EC), and pH in runoff from a 5.2 ha production portion of a 200-ha commercial container nursery during storm and irrigation events. Results showed a direct correlation between TN and TP, runoff and TSS, TN and EC, and between flow and pH. The Storm Water Management Model (SWMM) was used to characterize runoff quantity and quality of the site. We found during irrigation events that simulated event mean concentrations (EMCs) of TSS, TN, and TP were 30, 3.1 and 0.35 mg·L−1, respectively. During storm events, TSS, TN and TP EMCs were 880, 3.7, and 0.46 mg·L−1, respectively. EMCs of TN and TP were similar to that of urban runoff; however, the TSS EMC from nursery runoff was 2–4 times greater. The average loading of TSS, TN and TP during storm events was approximately 900, 35 and 50 times higher than those of irrigation events, respectively. Based on a 10-year SWMM simulation (2008–2018) of runoff from the same nursery, annual TSS, TN and TP load per ha during storm events ranged from 9230 to 13,300, 65.8 to 94.0 and 9.00 to 12.9 kg·ha−1·yr−1, respectively. SWMM was able to characterize runoff quality and quantity reasonably well. Thus, it is suitable for characterizing runoff loadings from container nurseries.

The reuse opportunities of separate wastewater streams and end-of-pipe composite wastewater were investigated in an integrated woolen textile mill. The main purpose was to reuse either the treated composite wastewater and/or treated/untreated separate streams depending on the water quality demand of different water use points in the production processes. In this context, three separate wastewater streams (tops-fiber, bobbins thread and fabric dyeing-finishing wastewaters) and composite wastewater were analyzed in terms of quality and quantity. Moreover, raw groundwater, softened process water, cationic ion exchangers’ regeneration wastewater, and reverse osmosis (RO) concentrates were also characterized. Wastewater treatability studies were conducted in pilot-scale employing membrane bioreactor (MBR), nanofiltration (NF) and brackish water reverse osmosis (BWRO) processes at different test conditions. In the wastewater characterization studies, peaks and oscillations were found in the separate wastewater streams depending on the production schedules and applied dyeing recipes. Therefore, due to mixing effects of separate streams, it was decided to employ pilot-scale treatability tests on the composite wastewater. In the MBR process, the average chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and color removals were 70, 74, 86, 28, 43, and 62%, respectively. In MBR + NF and MBR + RO tests, the removals of all analyzed parameters were 40–99 and 52–99%, respectively. The pH, conductivity, turbidity, color, and TN concentrations in MBR + RO effluent were 7.6–7.8, 57–65 μS/cm, 0.6–1.2 NTU, 25–44 Pt Co, and 14–16 mg/L, respectively. In addition, the COD, BOD5 and total hardness values were found under 1 mg/L. The treated water was finally disinfected with ultraviolet (UV) light to ensure microbial safety before reuse in dyeing process. Treated water samples were tested in different dyeing recipes in lab-scale to determine their impacts on woolen textile product quality. Dry-wet rubbing, water fastness, dry-cleaning and alkali-acid perspiration fastness tests were performed on the fabrics dyed with MBR + UV, MBR + NF + UV and MBR + RO + UV effluents and the results were compared with those dyed with process water (softened groundwater). It was found that especially MBR + NF + UV and MBR + RO + UV effluents did not negatively affect product quality. Surprisingly, the color depth was increased in some shades with MBR + UV effluent, possibly due to the presence of already existing salts. Overall, the product quality tests with reclaimed wastewaters exhibited very promising results. Therefore, capital and operational costs were estimated for a potential full-scale wastewater treatment and reclamation plant in the textile mill.

Mariculture-impacted areas contain organically-enriched sediments that sea cucumbers could potentially thrive on. The viability of growing sandfish (Holothuria scabra) to marketable size (>300 g) in a milkfish (Chanos chanos) fish farm area was investigated through simultaneous pen grow-out experiments in a fish farm site and a seagrass site. We determined the growth and survival of juveniles in conjunction with environmental parameters during each experiment. Smaller juveniles (6.7 ± 0.7 g) stocked in the fish farm experienced mass mortality within 15 days whereas survival was low in the seagrass (12%). In contrast, survival of larger juveniles (57.4 ± 4.3 g) was high in the fish farm (49%) and not significantly different from the seagrass (63%). Moreover, absolute growth rates (AGR) were much higher in the fish farm (1.2 ± 0.2 g m−2) than those in the seagrass (0.2 ± 0.1 g m−2). The fish farm site supported about 3-fold higher biomass, and sandfish reached marketable sizes (> 300 g) within 7 months primarily due to a higher total organic matter and chloroplastic pigment equivalent in the sediment. AGR was negatively correlated with strong water movement and positively correlated with total suspended solids and salinity. Additionally, temporal variability in AGRs indicates that sandfish is highly sensitive to the decrease in salinity due to heavy precipitation. An intermediate grow-out culture of juveniles to >50 g in a seagrass area was essential prior to release in the fish farm site. Results provide new insights into the coupling of the environmental factors and life stage of the organism in mediating grow-out success.

Pearl River Delta (PRD) is the third largest and one of the most productive Deltas in south China, where long-term monitoring and its assessment of water quality are necessary to understand the distribution patterns to infer the coastal zone management. The studies on long-term monitoring in water quality variable concerning the changing climate and anthropogenic effects can be made possible by continuous coverage of Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. This study attempts to study the long-term trends, quantitative measurements, and assessment of water quality variables including total suspended solids (TSS), diffuse attenuation coefficient for downwelling irradiance at 490 nm (Kd (490)), and sea surface temperature (SST) using 8-day composite and monthly data products of MODIS data for the period between July 2002 and August 2018 in the turbid waters of the PRD. Monthly products are used to quantify the variability of these water quality properties on long-term climatology, seasonal and as well as spatial distributions to interannual timescales. We observed a decreasing trend of TSS and Kd (490) between 2002 and 2018, though not significant, whereas, an increasing trend of SST has recorded for the PRD region during the same time. Seasonal patterns of TSS, Kd (490) and SST showed significant differences between the seasons. The high values of TSS (>15 gm−3) and Kd (490) (>2 m−1) were found in summer, autumn followed by winter, and low values (

With painting operations as a major origin of environmental concerns in automotive industry, novel and effective technologies are required for treatment of automotive paint wastewater. In this experimental study, a continuous-flow electroflotation reactor with effective volume of 38.4 L and stainless-steel electrodes were designed and implemented for treatment of this industrial wastewater. The system performance, namely the total suspended solids removal, was investigated with operational parameters including the hydraulic retention time, current density and influent total solids concentration. The removal rate ranged between 57 ± 1% and 95 ± 7% under initial total solids concentration 3000 mg/L, current density 50 A/m2, retention time 4 min, and initial total solids concentration 500 mg/L, current density 100 A/m2, retention time 8 min conditions, respectively. It was found that the removal rate decreases with the increase of influent total solids concentration. The results revealed that the suspended solids removal rate is directly related to the applied current density and hydraulic retention time. The electroflotation system showed to be energy-efficient compared to the commercial systems. Further, an empirical equation for the total suspended solids removal rate was established with the R2 value of 92.74%. The independent variables were the retention time, influent suspended solids concentration and applied current density.

High concentrations of total suspended solids (TSS) need to be controlled, as they can affect shrimp production due to the excess of particles in the water column. Water renewal and clarification are alternatives used to reduce TSS. In order to determine the better method of TSS control, we carried out a study using water renewals and clarification on a commercial scale with nine ponds (600 m2 each) in an intensive biofloc system. A total of 87 shrimp m−2 were stocked in each unit divided into three treatments: R (water renewal), C1 (one clarifier) and C2 (two clarifiers in series). Each treatment had three replicates, and the experiment lasted 105 days. There were no significant differences (p > 0.05) in the parameters of water quality and zootechnical performance. Significant differences (p

In this study, the performance of an integrated technology, combining biological treatment with advanced oxidation process in sequence, was evaluated for the degradation of sulfolane in aqueous media. In addition, the impact of biological process on AOP was also studied by assessing residual sulfolane, nutrient and total suspended solids (TSS) concentrations. The integration of activated sludge process with UVC/H2O2 resulted in more than 81% of sulfolane degradation in less than 24 h. It was observed that mineralization was much faster in biological system compared to AOP. Mechanistically, the process of degradation is different in the two processes as various by-products were identified during UVC/H2O2 but not during the biological process. The impact of residual sulfolane concentration on UVC/H2O2 was significant beyond a concentration of 30 mg L−1, while below 30 mg L−1 the rate of degradation was independent of sulfolane concentration. Residual nutrients from biological systems did not impact AOP performance. Nevertheless, presence of TSS >44 mg L−1 had a negative impact on the performance of UVC/H2O2 by reducing UV transmittance which led to retardation of sulfolane degradation. The application of UVC/H2O2 after biological treatment was an advantage as UVC/H2O2 could perform dual roles of oxidant and disinfectant.

Large scale inter-basin water diversion projects would have a set of ecological and environmental impacts on aquatic ecosystems. However, knowledge regarding water transfer induced water quality changes in determining fish communities in the impounding ecosystems remain largely unknown. In the current study, we filled this research gap by using a set of machine learning algorithms to ensemble modelling fish community indices with water quality indicators in the impounded lakes along the eastern route of China's South-to-North Water Diversion Project (SNWDP). Overall, our results realed that water quality changes can be good predictors for the variation of fish community structures in these lakes. Although different model techniques highlighted different variable importance of water quality in determining fish communities, there is generally a consensus that the hydrological related water quality indicators like: water clarity (e.g., total suspended solids) and nutrient loading (e.g., phosphate) contributed the most to the changes of fish communities. Our results also indicated that water diversions could bring knock-on effects on fish communities. Thus, more attention should be paid to long-term ecological effects from future water diversions.

In this paper, we investigated the treatment and reusability of laundry wastewater (LW) by novel sequential integrated system including ultrafiltration (UF) of raw wastewater at first step and treatment of filtrate (permeate effluent) by the use of either adsorption processes (AD) (granular activated carbon GAC or polymeric resin PR) or nano-filtration (NF) system, or electro-oxidation (EO) to remove mainly total suspended solids (TSS), turbidity, chemical oxygen demand (COD), and surfactants such as nonylphenol ethoxylates (NPEO3-17) in order to meet the environmental rejection and reusability standards. Concentrate (retentate effluent) of UF and NF were also treated using electrocoagulation (EC) and electro-oxidation (EO) methods, respectively. Optimum conditions in order to obtain best results were determined in each case. The UF separated the raw wastewater into a filtrate with a low organic pollutant content (300–400 mg/L of dissolved COD) and a concentrate with a total COD of 700–1200 mg/L and 140–200 mg TSS/L. Following application of UF, NPEO3-17 were found not only in the concentrate but also in the filtrate and subsequently were treated using mentioned techniques which was effectively removed by NF and AD.

In situ suspended growth aquaculture systems for oligotrophic species suffer from excess total suspended solids, low dissolved oxygen, and other associated problems. To address these disadvantages, this study designed and tested a closed recirculating aquaculture system containing 3 pilot-scale suspended growth bioreactors (SGBRs) for the water treatment of pollutants. These SGBRs were designed to control extra carbon addition at carbon/nitrogen ratios of 12, 8, and 4, respectively. It was determined that the culture tanks removed total ammonia nitrogen (TAN) and nitrite (NO2−-N) by nitrification, and the SGBRs removed nitrate (NO3−-N) by denitrification and also soluble reactive phosphate (SRP). Concentrations of NO3−-N and SRP in the effluent decreased, as the controlled carbon/nitrogen ratio of the SGBR increased. When carbon was controlled at a carbon/nitrogen ratio of 12, the influent concentrations of NO3−-N (35.41 ± 1.22 mg·L−1) and SRP (4.60 ± 0.67 mg·L−1) were reduced to 7.70 ± 3.58 mg·L−1 and 0.30 ± 0.16 mg·L−1, respectively. Thus, this proposed system had the ability to control simultaneously TAN, NO2−-N, NO3−-N and SRP. The survival rate of Anguilla marmorata was 98.00 ± 1.41%, with a final stocking density of 56.46 ± 0.51 kg·m−3. We suggest that various adjustments in the carbon/nitrogen ratios of SGBRs can be practically controlled according to the concentrations of pollutants in the culture tanks.

Estuaries are biogeochemically and physically dynamic environments, resulting in diverse optical water properties that vary in space and time. This natural variability challenges effective monitoring. We develop semi-empirical linear models of the two main water clarity aspects, visual clarity and light penetration, as functions of more routinely monitored and/or modelled water quality measures, to simplify approximations and allow more expansive modelling in space and time. At multiple points along salinity gradients in six northern New Zealand estuaries, we made discrete measurements of horizontal black disk visibility (yBD) and downwelling irradiance attenuation (Kd(PAR)), with surface concentrations of the main light-attenuating constituents (LACs): total suspended solids (TSS), coloured dissolved organic matter (CDOM – ag(340)), and phytoplankton chlorophyll a (Chl.a). Estuaries on the east coast (Tauranga and Tairua Harbours) were relatively clear compared to those on the west coast (Kaipara and Raglan Harbours). Although Kd(PAR) (controlling light penetration and euphotic zone depth) and yBD (inversely proportional to beam attenuation at 550 nm, controlling visual clarity) were strongly corelated over all estuaries (r2 > 0.8), there were small, yet significant, differences between regression lines in different estuaries. This suggests regional differences in light scattering and absorption properties of the LACs. Variability in water clarity was mainly accounted for by TSS alone in west coast Kaipara Harbour sub-estuaries (r2 > 0.7), while in east coast estuaries, TSS was a weak predictor (r2 0.7). West coast Raglan Harbour had intermediary responses. In most cases, the inclusion of CDOM significantly improved estuary models, but Chl.a was a significant term only in a few cases, such as during one survey on the Kaipara River sub-estuary. Co-linearity of LACs was an issue in some cases for semi-empirical models. The application of a literature-derived Lambert-Beer Law (LBL) type model to our data more effectively partition the contributions of the LACs, which confirmed and quantified differences between west coast (TSS dominant), and east coast (TSS + CDOM) estuaries. Although we expect that ‘simple’ semi-empirical models will have wide practical application for estimating visual clarity and light penetration in estuaries in New Zealand and elsewhere, consideration of all LACs in an LBL type model is advised across entire estuaries, and local verification and ‘tuning’ is desirable.

Nutrient or/and organic pollutions have been used as one of the key factors influencing the stream health, so research approaches were frequently focused on chemical analysis rather and biological analysis. Our objective of the present study was to diagnose the chemical and biological stream health using chemical multi-metric model of nutrient pollution index (NPI) and biological multi-metric fish model of the index of biotic integrity (IBI), respectively in an urban stream. Seven years dataset from 2008 to 2014 were used for the health assessments. The nutrients regime (TN, TP), sestonic chlorophyll, total suspended solids (TSS), electrical conductivity, BOD, and COD showed a typical polluted stream with large temporal and spatial fluctuations due to variations of Asian monsoon rain. The analysis of fish trophic guilds and fish tolerance guilds showed that omnivore fish species and tolerant species were dominated the community and the proportions were directly determined by water chemistry (nutrient and organic matters). Chemical model of NPI showed “poor-very poor health condition” by the criteria of the model and showed same results with the biological model of fish IBI. The degradation of the stream health was mainly due to massive effluents from the wastewater treatment plants. Overall, our data suggest that the multi-metric chemical and biological models may be used as a key tool diagnosing the stream health condition in an urban stream.

Forward osmosis (FO) and membrane distillation (MD) are emerging technologies of interest for the treatment of high salinity brines. In this study, we aim to demonstrate the feasibility of an integrated FO-MD system for water recovery from high salinity produced waters obtained from shale gas extraction facilities. In the proposed hybrid system, FO draws water from high salinity feed, while MD regenerates the diluted FO draw solution. We show that this process integration can combine the advantages of both processes; low fouling tendency, possibility of using low-grade waste heat as the main energy source and high quality permeate. We further integrate the FO-MD system with an electrocoagulation (EC) system as pretreatment and show stable performance with minimal fouling. EC removed total organic carbon and total suspended solids by up to 78% and 96%, respectively. We studied the impact of experimental conditions (temperature, flow velocity and draw solution concentration) on performance of the integrated system in short-term experiments. In addition, we conducted long-term experiments using two different produced waters. We show that to achieve continuous high recovery with maximized water flux, a combination of two MD membranes can provide a viable solution.