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The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent. The clay characterization shows that the used clay is a rich-smectite clay. The response surface methodology (RSM) technique based on Box-Behnken design (BBD) was used to optimize the process. At optimum conditions which are initial pH solution of 8.24, effluent flow rate of 0.5 L·min−1, voltage of 70 V, and added suspension of clay flow rate of 100 ml·min−1 the achieved color, chemical oxygen demand (COD) and total suspended solid (TSS) removal efficiencies were respectively 96.87%, 89.77% and 84.46% with 0.75USD·m−3 as total cost. The additional laboratory experiments at optimum conditions agree with the predicted results, which confirm the accuracy and the capability of RSM to predict results in the defined space. Finally the designed process could be a good eco-friendly alternative to treat and reuse wastewater in industrial process with reasonable cost.

With the continuous improvement and economic development of China’s coal mining industry, research on the characteristics of wastewater discharge has gained attraction in recent years. Ballasted flocculation technology, has been widely used in recent years. However, its effect on the settling velocity of the flocs in wastewater has not been quantified. This study aimed to screen optimal reaction condition for ballasted flocculation and to derive the settling velocity of the ballasted flocs under these conditions. The results showed that, the size of the ballasted material had no significant effect on the turbidity and suspended solids removal rate; however, the settling time was effectively shortened, and the turbidity removal rate could reach more than 95% within 15 s. Owing to the optimization of the reaction conditions, 90% of the flocs sizes were distributed in the 80-200μm range. Moreover, the difference between the theoretical and the measured value of the ballasted flocculation was small, indicating that the derived formula could effectively quantify the settling velocity of the ballasted flocs under optimal conditions. These findings may serve as a critical reference for the treatment of high-suspended solids in coal mining water and have significant potential for engineering application.

Cyclone separators are the most cost-effective and economically gas separation devices. They are not very complex to design and offer high collection efficiency; still, their use for the waste management field, i.e., separating solid waste from the liquid, is not explored to its full extends. This paper presents a Computational Fluid Dynamics-based numerical simulation of a hydro-cyclone separator planned to separate suspended particles from the digestate of a biogas plant. The turbulent incompressible flow model is employed during the simulation. The discrete particle method is used to model and track the suspended solid particle trajectory. The fluid properties of the digestate are assigned to the fluid supplied with suspended particle sizes ranging from 10 to 100 µm during the simulation to obtain realistic flow results. The Stairmand high-efficiency hydro-cyclone geometry is redesigned by the numerical experiment method to obtain high collection efficiency for solid particles. Here the effect of inlet flow velocity and suspended solid particle diameter are simulated to understand their effects on the hydro-cyclone collection efficiency. The fluid flow dynamics are observed, and the detailed distribution of particles inside the hydro-cyclone is presented.

Hydrolysis is widely used in sludge treatment as it enables to improve the biodegradability of sludge. However, there was little information about the hydrolysis efficiency with the mixture of primary and secondary sludge. In this study, the hydrolysis and reduction of mixed sludge after thermophilic bacteria (TB) pretreatment was investigated. Volume ratio of 1:3 (primary sludge: secondary sludge) had best release rate of organics, and the soluble chemical oxygen demand (SCOD), carbohydrate and protein in extracellular polymeric substances (EPS) decreased by 7.9, 4.1, 7.2 times, respectively. Meanwhile, the accumulation of SCOD, carbohydrate and protein in dissolved organic matter (DOM) was enhanced with mixed sludge. Excitation-emission matrix (EEM) spectroscopy proved that mixture of sludge was beneficial for the releasing of biodegradable substances. The sludge reduction of mixed sludge was higher than that of single sludge, and mixed sludge (1:3) had the best suspended solid (SS) and volatile suspended solids (VSS) reduction rate of 27.2% and 34.3%.

This paper examines how land use affects water quality and how this impacts the viability of shellfish mariculture (marine aquaculture) in the UK through a synthesis of the current literature, stakeholder workshops and targeted engagement of cross-sector organisations across a case study in South West England. We examine the importance of water quality as a constraint for shellfish mariculture in South West England and explore how current and projected future land uses are likely to influence ongoing viability. Currently, faecal material from agricultural runoff and municipal wastewater discharges is the main water quality issue affecting the viability of shellfish mariculture. Most UK Shellfish Waters, including those in SW England (~90%), do not consistently meet regulatory standards for faecal indicator organisms (FIOs) in shellfish, designed to ensure they are safe for direct human consumption. Other pollutants currently impacting shellfish mariculture include persistent organic pollutants and metals, suspended solids and excess nutrient inputs. Emerging pollutants with the potential to impact on mariculture include a range of consumer- industrial- and agri- chemicals, including biocides, pesticides, veterinary and human medicines. We evaluated possible changes in water quality conditions through deriving and exploring a range of future scenarios, considering policies and trends in land use including regenerative and intensive agriculture, renewable energy generation, afforestation, urban development and climate change. Our findings highlight possible trade-offs and synergies between land and water-based food production systems, applicable in SW England and across other regions of the UK and internationally, for helping to inform environmental policy development and implementation.

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.

The paper concerns the impact of the diverse land use in the Silnica river catchment, within the city of Kielce, on the size and dynamics of concentration and load of transported suspended solids, and the variability of the mineral particles mean grain size, during various flood types. This small river flows through the centre of Kielce, the city of 200,000 population in Poland. In its course, the river flows through areas of various land use. In the upper reaches, the catchment is dominated by forests, in the middle the river flows through a reservoir and the lower – through an urban area. Hydrological measurements and transport of the suspended solids were carried out simultaneously in three hydrometric cross-sections of the Silnica, which close the sub-catchments of the land use as mentioned above. The investigations were carried out during floods of various origins: induced by snowmelt, torrential rainfall and frontal rainfall. The analysis indicates that the two rainfall-induced flood types, characteristic for the summer season, show high runoff dynamics. In contrast, snowmelt-induced floods show high concentration and load of the transported suspended solids. In the section of the watercourse flowing through the city, there is an abrupt increase in runoff and suspended solids concentration. Thus, there may be periodic threats to fish and invertebrates, leading to a reduction in the population of living organisms.

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.

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.

The suspended solids in the acrylonitrile-butadiene-styrene(ABS) wastewater are in the form of viscous latex, which strengthens the blocking phenomenon of the release device, increases the suspended solids in the return water and reduces the removal effect of the air flotation apparatus. Therefore, we designed a new release device. To achieve the goal of controlling the bubbles in the target diameter and enlarge the hole size as much as possible to reduce blockage, we studied the relationship between the geometry structure and performance of the new, which could be describeed by fixed polynomials. The best demulsification effect could be obtained by the hybrid of the polyferric sulfate and FO4440SSH, and the highest removal rate was 92.51 %. After a long-running in the ABS sewage treatment plant of the petrochemical industry, the removal rate of the new could maintain at a high level(>90 %), and the removal effect was stable. Compared with other release devices that reported in the literatures, the new one had advantages significant in both removal efficiency and operation cost.

Urban centers line western Lake Ontario where urban rivers, wastewater treatment plants and stormwater load nutrients, major ions and suspended solids to the nearshore. In 2018, nearshore water quality and associated physical conditions bordering the cities of Toronto and Mississauga were assessed as a benchmark for future effects of urban growth and municipal infrastructure projects to improve water quality. Conductivity and UV-fluorescence were used as water quality surrogates and mapped over blocks of shoreline stratified by distance offshore. Patterns in UV-fluorescence aligned with loading points, and generally higher levels near the shoreline, were correlated with concentrations of nutrients, major ions and suspended solids. Water quality was more land-impacted over the shoreline from the Credit River to Humber Bay contrasting with the more lake-like conditions from Toronto Eastern Beaches to the Rouge River. Within Toronto Harbour, cross-harbour gradients in water quality varied with weather-related changes in river and storm water loading. Mixing areas at wastewater treatment plant outfalls and tributary mouths, frequently shaped by alongshore lake circulation, resulted in a mosaic of water quality over the shoreline. Area-wide elevation of chloride and conductivity, and poorer water quality in late spring, was linked to heightened river discharge. Thermal stratification affected how discharges were distributed in the water column, but measurements at the lake surface reflected the strongest overall land-effects on water quality. The patterns of temporal-spatial variability identified within geographically-defined areas of shoreline can be used as past footprints in future monitoring to detect change.

The impact of non-point source pollution on the aquatic environment caused by surface runoff splash and scour on surface sediments is becoming increasingly prominent and poses a serious threat to water resource security in the Three Gorges Reservoir area. The sponge city-building scheme based on low Impact development (LID) can effectively reduce nutrients pollutants entering water. However, research about the non-point source load reduction by the sponge city in the representative mountain City still remain unclear. In this study, a representative sponge city Yuelai New Town, from Chongqing China, was selected as the research area to establish the Sponge City Aided Design (SCAD) model. In this study, combined with the actual demand for Yuelai New Town construction, a complete and effective urban watershed water system pollution model was established based on the surface pollutant accumulation process and scour process calculation model. The simulation results were in good agreement with the measured data. After the sponge city optimization scheme (SCO), the suspended solid (SS) reduction ratio in Yuelai New Town is 53.7%, the chemical oxygen demand (COD) reduction ratio is 93.0%, the total nitrogen (TN) reduction ratio is 95.9%, and the total phosphorus (TP) reduction ratio is 95.3%, compared with the traditional development (TD). The results will be helpful for promoting this approach in the Three Gorges Reservoir Area and mountain cities in the future.

Removal of contaminants, impurities and suspended solid matter are termed as water treatment. The possible water treatment methods are coagulation, filtration, ion exchange, aerobic and non aerobic methods. But all this involves high cost. Earlier filtration using granular sand was termed as the efficient way of water treatment. But due to the non-availability of sand this method is no more adopted. The most effective and easy means of treatment of water and waste water is adsorption method because it is an easy and convenient method. Though there are many adsorbents like activated carbon, clay minerals, zeolite, plant based and industrial based by products, the commonly used material is activated carbon which is again a costly investment. The next effective material is the zeolite. It has proved to perform well than the granular media and conventional activated carbon in removing heavy metals and ammonia. The advantage of using zeolite is that it adsorbs these contaminants in its pores and forms a strong bond which prevents leaching of these contaminants back to the ground water. The other advantages are the high specific surface area which facilities efficient adsorption, reduces the number of back-wash cycles, non-toxic and environmental friendly. Zeolites are hydrated aluminosilicates classified as natural and synthetic zeolites. The natural one is gluconites or green sand and the synthetic one is permutit which contains sodium in it. Inspite of many advantages in using zeolite the greatest disadvantage is that the treated water has Na+ ions which replaces the Ca2+ and Mg2+ ions. So when such waters are used sodium bicarbonate hydrolysis to sodium hydroxide which causes corrosion of boilers and also water having high turbidity cannot be effectively treated by this method. This research work will be focused on synthesizing alkali activated aerated concrete with graphene oxide which is porous and which can act as an efficient adsorbent in removing the contaminants from water and waste water respectively.

Waste water treatment is major issue in urban and rural area. For this it requires various catalyst which are costly. We have developed simple method for the synthesis of zinc oxide nanoparticles using waste Pineapple peels. Waste pericarp contain various phytochemicals which serve as reducing agent as well as the capping agent. The synthesized plant nanoparticles are characterized by the various analytical methods such as X-ray diffraction, FTIR, UV–Visible transmission electron microscopy, X-ray spectroscopy. The synthesized nanoparticles show good purity, good size. Synthesized nanoparticles are used for the treatment of the textile effluent by assessing the turbidity and conductivity, Chemical oxygen demand (COD), total dissolved solid (TDS), dissolved oxygen (DO), total suspended solid, this analysis indicate that this plant assisted nanoparticles play important role in the purification of water.

In the present investigation, a microbial consortium consisting of four bacterial strains was selected for the treatment of pharmaceutical industry wastewater. The consortium was immobilized on a natural support matrix - Luffa and used for the treatment of real-time pharmaceutical wastewater in batch and continuous processes. The batch process was carried out to optimize the culture conditions and monitor the enzymatic activity. An array of enzymes such as alcohol dehydrogenase, aldehyde dehydrogenase, monooxygenase, catechol 2,3-dioxygenase and hydroquinol 1,2-dioxygenase were produced by the consortium. The kinetics of the degradation in the batch process was analyzed and it was noted to be a first-order reaction. For the continuous study, an aerobic fixed-film bioreactor (AFFBR) was utilized for a period of 61 days with variable hydraulic retention time (HRT) and organic loading rate (OLR). The immobilized microbes treated the wastewater by reducing the COD, phenolic contaminants and suspended solids. The OLR ranged between (0.56 ± 0.05) kg COD·m−3 d−1 to 3.35 kg COD·m−3·d−1 and the system achieved an average reduction of 96.8% of COD, 92.6% of phenolic compounds and 95.2% of suspended solids. Kinetics of the continuous process was interpreted by three different models, where the modified Stover Kincannon model and the Grau second-order model proved to be best fit for the degradation reaction with the constant for saturation value, KL being 95.12 g·L−1·d−1, the constant for maximum utilization of the substrate Umax being 90.01 g·L−1 d−1 and substrate removal constant KY was 1.074 d−1 for both the models. GC–MS analysis confirmed that most of the organic contaminants were degraded into innocuous metabolites.

Today, some of the major disadvantages of conventional palm oil mill effluent (POME) treatment are that the process is time consuming, as well as space consuming. Besides, most of the recent photocatalyst still have a limitation that able to demonstrate their good performances only under sources of light. The visible-light-driven energy storage photocatalyst, which is tungsten trioxide (WO3), has been developed to overcome the limitations mentioned. Therefore, the present study aims to investigate the comparative calcination temperature and the degradation of POME using WO3 as a photocatalyst in adsorption and photocatalytic processes under visible light irradiation. An eco-friendly WO3 photocatalyst was synthesized by coprecipitation method. Subsequently, the resulting WO3 was characterized by Fourier-transform infrared spectroscopy (FTIR) to evaluate the significance of calcination temperature towards WO3. Furthermore, the adsorption activity of WO3 towards POME was investigated at different sources of ponds (cooling, anaerobic and aeration) throughout 300 min. This study reports on the efficiency of adsorption activity of WO3-400 °C towards pond aeration pollution, which showed that it was better than that in anaerobic and cooling ponds based on the chosen study criteria of color and suspended solid removal for the investigation of photocatalytic activity. Moreover, WO3 was proven to be able to conserve energy, where it was demonstrated that POME can still degrade consistently in darkness, with the highest color removal of approximately 48% was obtained. An extraordinary photocatalytic treatment with WO3 functioning simultaneously as the light harvesting and energy storage material is deemed as an efficient photocatalyst for POME in terms of decolorization and removal of suspended solid.

Fresh and clean water is basic need for human health. However unclean and impure water creates access to illness and many diseases which influence the economic growth of the country. A very traditional method i.e. SSF has been used for removing fine suspended particles, microbes, minerals and flocs present in water. The aim of this research article is to invent and install an economic and non-conventional slow sand filter for treating water to resolve the issues related with impure water. Deigned SSF has been operated under the hydraulic loading of 4.6296 L/sec/m2 and an operational period of one hour. Cross sectional area of bed has been taken as 0.0576 m2. This technique is a small-scale scheme and easily employed for intermittent use that made it suitable for household purpose. Four processes namely Mechanical trappings, Predation, Adsorption and Natural death that has been taken place during the filtration process has been widely discussed in this paper. Various chemical and physical characteristics of water has been tested. Major parameters like pH, TDS, turbidity, Salinity, conductivity and salinity of filtered water have been tested for raw water and test results has been compared with Indian standard parameters. Various results from SSF revealed the successful removal of suspended solids, natural and organic materials from raw water. Test results shows that designed SSF is highly efficient for improving the household water quality parameters. Designed SSF removes large number of impurities as compared to other filters and it is socially acceptable.

The importance of water resources forecasting is growing due to changes in precipitation caused by climate change and with hydrologic models are being used mainly for water resource management. Calibration and validation through adjustment of parameters are important processes for increasing the reliability of the application of hydrologic models. This is different from flow rates that can be estimated in real time through level-flow rating curve. The reliability of data depends on observation; therefore, using data with a short can increase the reliability of the results. In this study, daily loads of suspended solids (SS), total nitrogen (TN), and total phosphorous (TP) were generated using three statistical methods: general method, perfect prognosis method, and model output statistics (MOS). Fitness of calibration and validation of hydrologic models were then evaluated using correlation, R2, and anomaly analysis. When these three methods were applied to the Geumho and Hwang rivers, perfect prognosis method and the MOS method showed better results than the general method. For the Geumho River, correlation and R2 improved by up to 0.08% for SS, 0.04% for TN, and 0.12% for TP. For Hwang River, results improved by up to 27% for SS, 12% for TN, and 15% for TP. When the anomaly analysis results were represented by correlation and R2, they showed significant improvements of up to 0.86 in SS, 0.62 in TN, and 0.57 in TP for the Geumho River and up to 0.58 in SS, 0.49 in TN, and 0.49 in TP for the Hwang River. The statistical method suggested in this study can be applied when observation for the water quality data is long or data are insufficient.

In India, there are around 400 dairy plants in operation. Dairy wastewater is characterized by high organic load and suspended solids. The various treatment schemes (e.g. microbial fuel cell, hydrothermal liquefaction & membrane distillation, algal bioreactor, chemical coagulation & membrane bioreactor (MBR), ultrafiltration and MBR) achieve 75–80% organic load removal. The present study aims to improve the water recovery with the complete removal of organic loads and total solids from dairy wastewater (DWW), so that the treated water could be reused in the industry. The study involved an integrated treatment system of MBR and membrane filtration processes. The MBR was inoculated with specific bacterial colony acclimatized with dairy wastewater. Two different types of treatment system (i) submerged flat sheet polyvinylidene fluoride (PVDF) membrane of 0.2–0.3 μm pore size, and (ii) ceramic membrane was used. The MBR-PVDF membrane resulted in the removal of 99.8% COD, 98% BOD, 40% total dissolved solids, 80% NH4-N, and 98.7% PO4. The MBR-ceramic membrane resulted in the removal of 88.8% COD, 90% BOD, 30% total dissolved solids, 75% NH4-N, and 98.7% PO4. Both the MBR’s produced clear treated water with no turbidity. The results mentioned above were obtained after 10 weeks of continuous operations in each MBR. The water produced no foul smell even after storing it in plastic container for more than 3 months at room temperature. The microbial population was identified under microscope as gram-negative rod-shaped bacteria Staphylococcus . FTIR-ATR study shows protein and carbohydrate deposition on the membrane surface. Chemical cleaning produced better flux than physical cleaning of the membrane surface. To reuse the treated water, it was passed through Polyamide Vontron75GPD (ULP 1812-75) commercial membrane in a dead end-filtration unit. The process resulted into 88.5% reduction in conductivity at 20 bar, thereby reducing the conductivity to 1.1 mS/cm. The treated water could be reused in the dairy industry.

Turbidity curtains, also called as turbidity barriers and silt curtains, were designed to contain plumes of suspended solids in water bodies. The high concentration of suspended solids in the raw water impacts on the costs of its treatment. Water with higher turbidity requires more coagulants in water treatment and needs a sludge management. In order to reduce turbidity in the water intake, the present study used a central composite rotational design (CCRD) for a set of 2 in-line turbidity curtains in a laboratory hydraulic flume. Three factors were analyzed: the grammage of the first barrier, the grammage of the second barrier and the solids application rate. The experimental design was made of 18 experiments. Furthermore one blank test was performed. The analyses of variance revealed which factors were significant for each answer. The first curtain efficiency was related positively with the first grammage and negatively with the second curtain grammage. The second curtain efficiency was related positively with the second grammage and application load, and negatively related with the first grammage. The system retention mass was influenced positively by the application load.

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 accumulation of micropollutants (MPs) and their increasing concentration in the aquatic environment are an emerging issue for water quality in the world. The complex web of exposure pathways, as well as the variety in the chemical structure and potency of MPs, represents enormous challenges for researchers and policy initiatives. In order to manage MPs, it has to be decided which of them have to be reduced and to what extent, where in the water cycle this would be the most efficient and which technical means that should be applied to be sustainable. All of these aspects require a knowledge of MPs abundance, properties, fate and impact in the environment, which is essentially determined by two related features: the sources and the physico-chemical characteristics of MPs. Micropollutants including pharmaceuticals, antibiotics and hormones can enter the aquatic environment through both diffuse and point sources, but in urbanised regions wastewater treatment plants (WWTPs) play a crucial role in their dissemination. Conventional WWTPs are effective in removal of macropollutants (e.g. nutrients, suspended solids and some trace elements), while MPs may go through the treatment unchanged or be removed at different rates. Most of the EU countries are convinced that the presence of MPs in the environment poses a serious problem, particularly in highly populated regions where surface water resources serve as a source of potable water. Presently, various technical solutions are available and have been proven possible to integrate with existing treatment processes in an expedient manner. The solutions that have been evaluated are mainly based on ozonation and/or activated carbon treatment technologies which may definitely be considered the most effective compared to the costs incurred.

The design of Pre-sedimentation basins is based on design criteria including surface overflow rate and detention time. The previous studies differ in specifying the criteria values and, subsequently, it is difficult to choose the suitable ones according to raw water source characteristics. The aim of this study is to specify the design criteria values for pre-sedimentation basin treats the water of Shatt Al-Arab River. To satisfy this aim, experimental work was conducted including 51 plain sedimentation experiments and 37 particles size distribution analyses. The work results were used to determine the values of surface overflow rate and detention time in terms of actual and theoretical efficiencies of pre-sedimentation basin. The study results indicated that to use a pre-sedimentation basin in treating the water of Shatt Al-Arab River and the other rivers which have suspended solids with d50 values vary over the range (7.4-20.9) µm at efficiency exceeds 50%, the surface overflow rate must be less than 0.5 m/day and the detention time must be greater than 12.3 hr.

Understanding riverine phosphorus (P) dynamics, its transport, and transformation mechanisms from sources in the watersheds to receiving water bodies are essential for the development of effective strategies to decrease excess P loading and reduce eutrophication. Karst watersheds are thought to be especially vulnerable to P pollution due to their geomorphological features. In this study, we investigated the dynamics of particulate P (PP) chemical phases in two karst watersheds from a Great Lakes Area of Concern in southern Ontario (Bay of Quinte, Canada). Suspended solids were collected during different hydrological regimes representing storm events with low and high discharge, and particulate P binding forms were measured using extraction techniques. Our results show that in these karst watersheds, particulate P is dominated by chemical species that are likely to be highly bioavailable and contribute 62–75% to total PP. Concentrations of these bioavailable P binding forms in suspended solids increase two- to three-fold on dry mass basis during periods of high river flow. Electron microprobe and energy dispersive X-ray spectroscopy suggest that the primary carriers of particulate P are aggregates of Fe oxyhydroxides and Al-silicates. Our results underscore the influence of particulate P sources on the ongoing eutrophication in the Bay of Quinte Area of Concern.

Recently, more and more attention has been paid to the strong oxidation ability of newly prepared potassium ferrate (NAPF) in sludge reduction process, but less attention has been paid to the change of phosphorus in this process. The feasibility of phosphorus migration and transformation during excess sludge reduction pretreatment using NAPF pre-oxidation combined with anaerobic digestion was investigated. After 70 mg/g suspended solids NAPF pretreatment and 16 days anaerobic digestion, the solid-phase volatile suspended solids decreased by 44.2%, and much organic matter had been released into the liquid-phase and then degraded during digestion by indigenous microorganisms. As the sludge pre-oxidation process was performed, solid-phase organic phosphorus and chemically combined phosphorus also released into the liquid-phase as PO43−, peaking at 100 mg/L. During anaerobic digestion, the Fe3+ in the liquid-phase was gradually reduced to Fe2+, and then formed Fe2+-PO43− compound crystals and re-migrated to the solid-phase. The concentration of PO43− decreased to 17.08±1.1 mg/L in the liquid-phase after anaerobic digestion. Finally, the phosphorus in the Fe2+-PO43− compound accounts for 80% of the total phosphorus in the solid-phase. A large number of vivianite crystals in sludge were observed. Therefore, this technology not only effectively reduces sludge, but also increases the proportion of PO43− in the sludge in the form of Vivianite.

Two bench-scale Self-Forming Dynamic Membrane BioReactors (SFD MBR), equipped with 50 μm nylon meshes were set up and operated under aerobic conditions in order to treat canning and winery wastewaters. The results showed different behaviors of the two systems, confirming the strong dependence of SFD MBR performance on the type of biomass and, in turn, on the type of stream being treated. Both plants achieved good results in terms of effluent quality, demonstrating the suitability of the proposed technology. Median values of effluent turbidity were 2.7 and 15.4 NTU (Nephelometric Turbidity Units) in the reactors fed with canning wastewater and winery wastewater, respectively. The removal of organic matter (as COD, Chemical Oxygen Demand) was consistently above 90 %, although the retention of suspended solids was variable and somewhat dependent on operating conditions and feed composition. The activated sludge characteristics were observed to affect filtration performance and in particular the capillary suction time (CST) was a possible indicator of efficiency, with a threshold value of 11 s above which filtration performance decreased. This parameter is proposed as an early warning tool for changes in the filtration performance of an SFD MBR, both for effluent quality and cleaning requirements.

In this study, we investigated the effect of sample pretreatments (ultrasonication and alkaline extraction) on total organic carbon (TOC) measurements for water samples containing suspended solids (SS) of four different origins (algae, soil, sewage sludge, and leaf litter) to more clearly assess the impact of particulate organic carbon (POC) in water. The effects each of ultrasonication (power, pulse, etc.) and alkaline extraction condition (concentration, time, etc.) on the TOC recovery and precision were investigated, and the results were compared with those of a new sample pretreatment method combining both methods. Alkaline treatment (0.01 mol/L NaOH) showed higher precision than ultrasonication (100/5 on/off pulse), and notably, the differences among the measured TOC values in samples of different origins were also further reduced in the alkaline treatment. This suggests that the ultrasonic pretreatment results can be mainly attributed to the increase in POC recovery through particle size reduction, whereas the alkaline treatment results are achieved through the enhancement of POC solubilization. It is also particularly noteworthy that a higher TOC recovery of 87.6% ± 7.4% with a higher precision of 8.4% could be obtained using the combined method, compared to each treatment (ultrasonic: TOC recovery 34.7%, relative standard deviation 63.1%; alkaline: 49.6% and 23.0%, respectively). Thus, simultaneous pretreatment with ultrasonication and alkaline extraction is expected to increase the oxidation rate of organic matter and the homogeneity of the samples, minimizing the loss of POC measurement values, and thereby improving the reliability of the TOC measurements of water samples containing SS.

This article presents a perspective on the current reclaimed water quality standards for clogging control during aquifer storage and recovery (ASR) in China. Water reuse and ASR in China are reviewed, and we examine how clogging contributes to the failures of ASR. We identify loopholes in current standards for clogging control. The threshold values of suspended solids and turbidity in these standards are effective for the prevention of clogging triggered by inorganic mineral suspended particles in regular recharge water sources (e.g., rainfall and floodwater). However, these threshold values are not low enough to prevent clogging when secondary effluent from wastewater treatment plants containing organic flocs of active sludge is introduced. Therefore, revision of current standards for clogging control is urgently needed.

Nowadays many emerging countries have seen a substantial increase in supply for fresh water. In present scenario water comes into a drought. This paper represents converting of sea water into Drinking water processing machine. To reach the demands of the basic needs filtration and purification of water has been investigated. This paper presents on the effects of purifying water in behavior of activation carbon in comparison to conventional method. Activated carbon is used to investigate the efficiency in the water filtration mechanism Activated Carbon frequently used to extract water contaminants from tap water and salt water in water treatment. In domestic water filters, activated carbon is used because of its excellent ability of adsorption. In this research, the grades A of Activated Coal are used to analyze their efficiency in the filters. Ultraviolet radiation is used for the purification of water without abandoning hazardous chemicals. Prototype is produced through the use of a water treatment with activated carbon and ultraviolet radiation. Two activated carbons perform surface region and porosity observation. The magnified image of Granulized Activated Carbon is used for the contrast between ground structures by Scanning Electron Microscopy (SEM). Before and after water treatment, two forms of water tests investigated, the ground water and the bore-well water are evaluated. The pH test, total suspended solid particle test, biochemical oxygen requirement check, and Chemical Oxygen Demand (COD) experiment were used to evaluate the water samples. The assessment conducted is an initial effort to deal with such an issue. The maximum intensity of the radiation is 256 nm which is the most effective wavelength in inactivating bacteria. The UV-C portion is totally blocked out with prevalent bottles. A fraction of UV-C radiation exits. However, the purified water layer that implemented in larger containers. Thus, paper examines an effectiveness of technology and economics in future studies.

Garbage enzyme is a dark brown, strong sweet sour fermented smell, complex solution, obtained by the fermentation of fruit/vegetable peels, molasses and water, which has got many functions to degrade, modify and speeding up the reactions. This solution is expected to provide a best alternative method to reduce the higher proportions of suspended solids from dairy waste waters. The main aim of this paper is to find out its efficiency as a replacement of conventional biological methods to reduce TSS in dairy waste waters. It was prepared in the laboratory by mixing 1 Kg of jaggery, 3 kg of fruit peels with 10 kg of water, i.e. in the ratio 1:3:10, respectively. The garbage enzyme characteristics were determined, and 10% enzyme was mixed with the synthetic dairy wastewater at different pHs 4.0, 6.5. The values of percentage reduction of TSS were taken until 5 days. After 5 days the reduction % in case of pH 4.0 was found to be 22% and 26% in pH 6.5. Thus the results show that garbage enzyme is effective in reducing TSS. Also further examinations are to be done to find out the optimum dosage of enzyme and also to check its efficiency in reducing BOD, COD, SCOD, TVS.

Direct discharge of bathroom greywater (BGW) with high content of chemical derivatives from soap and detergent products may alter the receiving environment. Therefore, this research was undertaken to study the quality and effects of BGW and treat the BGW by solar water distillation (SWD). Three samples of BGW were taken at the study area and designated as House A, House B, and House C. Testing of the soil was conducted prior to the irrigation using greywater to specify the soil characteristics. Towards the end of this study, chemical properties of the soil (pH), electrical conductivity (EC), cation exchange capacity (CEC), exchangeable sodium percentage (ESP) and sodium adsorption ratio (SAR) of the soil were determined. SWD treatment was tested for pH, biochemical Oxygen demand (BOD), chemical Oxygen demand (COD) and total Suspended Solid (TSS) of the BGW. The pH of the soil before irrigation was 3.22 ± 0.02 and increased to 4.06 ± 0.12, 4.32 ± 0.09, and 4.67 ± 0.05 after irrigation with BGW from House A, B, and C respectively. The highest EC (756 ± 5.68 µs/cm) was found in the BGW from House A, indicating the presence of high range of salt content. For saturated hydraulic conductivity; tap water recorded the highest value of 51.88 cm/h, followed by 24.24 cm/h, 31.12 cm/h, and 45.01 cm/h for irrigation with BGW from House A, B, and C respectively. For CEC, ESP, and SAR, it was found that the BGW from House A recorded the highest values compared to others, with values of 0.835 meq/100gm, 36.41%, and 10.73 respectively. Treatment of BGW with SWD shows the highest removal percentage BOD is 60%, COD is 72.2%, TSS is 64.7%. Hence, the use of SWD has a good potential to enhance the quality of the BGW before directly discharged to the water bodies.

Anaerobic treatment of domestic wastewater can only partially treat the effluent and still contains concentration of organic matter, suspended solids, nutrients and pathogens beyond the recommended safe limit. This study aims to observe the effect of sand filter as a low cost post treatment solution. A 250 L pilot scale upflow anaerobic sludge blanket (UASB) reactor was fed septic tank effluent and operated at an average ambient temperature of 19 °C. The reactor was fed intermittently at 6 h hydraulic retention time and the performance was monitored. The UASB effluent was filtered in a 1 m3 sand filter unit. The removal efficiencies of Total Suspended Solid, Chemical Oxygen Demand and Faecal Coliform for combined system were 93%, 87% and 93%, respectively. However, the top layer of the sand in the filter needs to be replaced in every two to three months to maintain acceptable filtration capacity performance. The tested combined anaerobic and filtration system was sufficient to treat effluents from a typical Nepalese family and the result could be useful to design and develop a suitable compact, low cost onsite sanitation system in developing countries like Nepal. The result should encourage investigating on the establishment of a safe route of sand replacement and handling as well as alternative low cost filtration media in order to avoid frequent replacement of the sand.

The purpose of the present work is to establish a state of the production of waste from olive oil mills in the province of Al-Hoceima and to evaluate the physico-chemical quality of three different types of mills (traditional mills, semi-modern, and modern units) used in the region. The results of the physico-chemical analysis of OMW for these three mill types showed an acidic pH with an average value of 4.7. They are also rich in organic matter with an average COD of 159.57 g of O2/L, including a remarkable value for the traditional mill on the order of 213.44 g of O2/L, and an average BOD5 on the order of 70.33 g of O2/L. Electrical conductivity, suspended solids, oil grass, polyphenols and chloride content were exhibited average values of 17.34 ms/cm, 6.14 g/L, 0.93 g/L, 4.3 g/L, and 6.1 g cl−/L, respectively. We also assessed the degree of metal pollution of the OMW; the results obtained showed a total absence of Cadmium and Zinc with a few traces of Nickel in all units, and Lead found only in the semi-modern units.

Improper tertiary treatment of industrial effluent discharged causes an excessive phosphorus input which leads to eutrophication. Excessive growth of algae will degrade the natural ecosystem of surface waters. Conventional treatment such as activated carbon filter used as a polishing unit in the tertiary treatment is unable to eliminate the phosphorus completely. Approximately, 0.3–15 mg/l of phosphorus still presents in the final discharge of industrial effluent. Therefore, this study is conducted to provide alternative solutions using natural treatment with cost saving materials to further remove phosphorus from the textile industrial effluent. Aerated and unaerated lab-scale steel slag filters systems were run for 12 weeks at water treatment plant. The sample collected was analyzed twice a week for the parameters of pH, alkalinity, temperature, dissolved oxygen, total phosphorus, chemical oxygen demand, and total suspended solid. The results of this study showed that the unaerated steel slag filter (USSF) has a high percentage of phosphorus removal compared to aerated steel slag filter (ASSF) which is 55% to 86% while ASSF have removal efficiency of 52% to 71%. However, the removal efficiency of activated carbon filter (ACF) used in treatment plant is slightly better than ASSF which is 52% to 81%. The mechanism of removal involved is likely to be through adsorption.

Nearly one-half of foodborne illnesses in the United States can be attributed to fresh produce consumption. The preharvest stage of production presents a critical opportunity to prevent produce contamination in the field from contaminating postharvest operations and exposing consumers to foodborne pathogens. One produce-contamination route that is not often explored is the transfer of pathogens in the soil to edible portions of crops via splash water. We report here on the results from multiple field and microcosm experiments examining the potential for Salmonella contamination of produce crops via splash water, and the effect of soil moisture content on Salmonella survival in soil and concentration in splash water. In field and microcosm experiments, we detected Salmonella for up to 8 to 10 days after inoculation in soil and on produce. Salmonella and suspended solids were detected in splash water at heights of up to 80 cm from the soil surface. Soil-moisture conditions before the splash event influenced the detection of Salmonella on crops after the splash events-Salmonella concentrations on produce after rainfall were significantly higher in wet plots than in dry plots (geometric mean difference = 0.43 CFU/g; P = 0.03). Similarly, concentrations of Salmonella in splash water in wet plots trended higher than concentrations from dry plots (geometric mean difference = 0.67 CFU/100 mL; P = 0.04). These results indicate that splash transfer of Salmonella from soil onto crops can occur and that antecedent soil-moisture content may mediate the efficiency of microbial transfer. Splash transfer of Salmonella may, therefore, pose a hazard to produce safety. The potential for the risk of splash should be further explored in agricultural regions in which Salmonella and other pathogens are present in soil. These results will help inform the assessment of produce safety risk and the development of management practices for the mitigation of produce contamination.

Mountain rivers not only play an important role in flood control, but also perform other functions such as conserving water sources, regulating microclimate, and maintaining water ecology and biodiversity. Because the conventional approach to managing mountain rivers overlooks the intrinsic requirements of river water, alters the natural landscape of river channels, and destroys habitats, it leads to water quality deterioration and ecological imbalance. The Yang River is characteristic of northern mountain rivers, and so the ecological management project for this river – at the site of the forthcoming Beijing 2022 Olympic Winter Games – was selected as an example of comprehensive ecological management. This comprises an ecological, permeable dam–pond–wetland system. Results showed that: (Zhu et al., 2006): river water quality improved substantially; improvements in the water quality indices exhibited the trend suspended solids (SS) > ammonium-nitrogen (NH3-N) > chemical oxygen demand (COD) (Mikus et al., 2019). The Shannon–Wiener diversity index, Margalef species richness index, and Pielou evenness index all indicated increased phytoplankton by an average of 52.1%, 2.4%, and 98.9%, respectively. These three diversity indices showed increased zooplankton, by an average of 1.2%, 0.5%, and 3.3%, respectively. Water quality in the Yang River was found to have changed from moderate to light pollution (Kuemmerlen et al., 2019). Each subsystem increased removal of pollutants from the Yang River. Removal efficiencies of COD, total phosphorous (TP), total nitrogen (TN), NH3-N, and SS by the dam system were 28.57%, 28.3%, 20.5%, 24.0%, and 95%, respectively. Corresponding pollutant removal efficiencies by the pond system were 16.7%, 29.58%, 21.63%, 20.0%, and 99.8%, respectively. The wetland system achieved pollutant removal efficiencies of 44.0%, 17.1%, 6.7%, 13.9%, and 80.0%, respectively. This approach can mitigate flood control pressure, restore river ecology, and improve water quality in northern mountain rivers, and allow such rivers to achieve “retention–storage–restoration” effects. The ecological treatment approach provides an important theoretical foundation and technical reference for global mountain river management, and is especially applicable to mountain rivers in cold and arid regions in the northern hemisphere.

In this study, two dual-anode assembled microbial desalination cells (DA-MDCs) composed of two anodes, one cathode and two membrane stacks were constructed, with a hollow fiber membrane (HFM) module coupling into the cathode to filtrate suspended solids and microbes. Enriched domestic wastewater treatment performance of the DA-MDC system under different hydraulic retention time (HRT) was investigated in detail. When HRT sequentially decreased from 10 h, 8 h, 6 h to 4 h, the conductivity in diluent effluent kept stable at first, but increased 519% at 4 h compared with 6 h. Nevertheless, the chemical oxygen demand, total nitrogen and total phosphorus in the effluent met the wastewater discharge standards in China at all HRTs. Additionally, transmembrane pressure of the HFM modules increased sharply when HRT changed from 6 h to 4 h. Therefore, HRT 6 h was selected as the optimal condition. Under such short HRT, the system realized wastewater treatment capacity of 10 L/d, surpassing all bio-cathode microbial desalination cell systems aiming to realize efficient treatment of domestic wastewater. Additionally, the salt removal rate of 0.215 g/h was more than two times compared with most similar systems. Finally, stratified microbial community structures in the cathodes of the system were found. This gave evidence on the efficient catholyte recirculation which might facilitate nitrogen removal from wastewater.

The study is to treat spent caustic wastewater by using bioelectrochemical cell (BeCC) integrated with Granular Activated Carbon (GAC) as the bacterial attachment medium. BeCC is a bioelectrochemical reactor which employed microorganisms for substrate degradation, while also capable in producing energy. The study investigated the optimum GAC dosage in BeCC whereby it was tested at 0 g (blank) to 25 g of GAC and its performance in terms of Chemical Oxygen Demand (COD) and sulfide removal and open circuit voltage (OCV) were assessed throughout 30 days of operation. From the study, GAC dosage of 10 g was the optimum GAC dosage with the highest COD and sulfide removal of 97.56% and 96.25%, respectively and highest voltage of 583 mV. Comparing the optimum BeCC performance with the blank, the result demonstrated 16% and 25% higher in COD and sulfide removal, respectively with increment of OCV from 115.7 mV to 583 mV. The biomass characteristics at different GAC dosage were indicated by the mixed liquor suspended solid (MLSS), mixed liquor volatile suspended solid (MLVSS), biomass extracellular polymeric substance (EPS) and sludge volume index (SVI). It is found that the dominant bacteria attached on the GAC was Klebsiella oxytoca identified by biochemical identification method.

Objective This study aims to determine the effectiveness of the Drum of Wastewater treatment (DOWT) in reducing levels of Total Suspended Solid (TSS) in domestic wastewater. Method This study was an experiment to determine the effectiveness of Drum of Wastewater Treatment (DOWT) in reducing TSS levels of domestic wastewater. It was conducted from September to October with Pretest–Postest Design. Pretest data obtained from examination of wastewater parameters before processing, while posttest data was after processing. Result The pH level of wastewater during the measurement process is in the range between 6.12 and 6.85 where in this circumstance the bacterial microorganisms are very dominant from others. The temperature ranged from 24 to 32. The measurement results of TSS obtained an average 34 mg/L before processing and 2.85 mg/L after processing with an efficiency of 91.6%. Conclusion DOWT wastewater treatment has been able to reduce TSS levels according to the specified quality standards.

The design of wastewater treatment plants (WWTP) includes facilities for the removal of suspended solids, organic matter, nitrogen and phosphorous, as required in current legislation, while removal of microorganisms is not literally emphasized. Although the different unit processes have some effect on microbial populations, disinfection is not achieved in many cases unless a specific step is included to regenerate wastewater. This study assesses the effect of the unit processes of six WWTPs that treat municipal wastewater on five microbiological parameters (total coliforms, E. coli, Enterococcus sp., Staphylococcus aureus and Pseudomonas aeruginosa), as well as their contribution to receiving waters. Bacterial concentration in the inlet of WWTPs varies from the lowest concentration of Staphylococcus aureus (104 CFU/100 mL), to the highest for total coliforms (108 CFU/100 mL), independently of the industrial activity discharging to the WWTP. Considering log bacterial removal of each step of treatment processes, trickling filters reduced 2.6 and 1.5-log Enterococcus sp. and Pseudomonas sp. respectively, secondary decanters achieved 2.5-log average removals and ponds reduced bacteria in a range from 1 to 2.2-log, being the processes with the highest bacteria removal, although in the case of secondary decanters this depends on design parameters such as hydraulic residence time, loads of solids, or types of previous biological treatments. The average of the bacteria concentration in the outlet of the six WWTPs was between 103–106 CFU/100 mL. The effect of discharging these bacteria on the quality of receiving waters was assessed by analyzing microbial concentration upstream and downstream of the discharge point. In almost all cases, the bacterial concentration upstream of the discharge point was similar to downstream concentration because the effluent is rapidly diluted in the receiving river, not representing a risk to ecosystems.

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.

Green roof is an important measure in "Sponge Cities" to reduce the runoff and improve the runoff quality. The runoff quantity and quality control capacity of five types of extensive green roofs (EGRs) were analyzed in Beijing for 51 nature rainfall events and 6 simulated events from July 2017 to October 2018. Different module scales (sizes) and substrate depths were examined to study their correlation to runoff retention, peak flow reduction, pollutant event mean concentration (EMC) and load reduction performance of EGRs. In general, both the single-field rainfall events and the long-term monitoring showed that as the module scale and substrate thickness increased, the retention capacity of the EGRs increased. As the module scale increased, the peak flow reduction rate (Pfrr) of the EGR modules increased, while the thickness of the substrate appeared to have less of an effect on Pfrr. When water quality effect was considered, compared with module scale, the substrate thickness had a more obvious effect on the average EMC of different pollutants. As the substrate thickness increased, the EMC of pollutants decreased. Under six simulated design rainfalls, EMC reduction rate of suspended solid (SS) of all types of EGRs ranged from 64.3%-73.1% while no reduction was found in the EMC of chemical oxygen demand (COD). The EMC trends of ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3--N), total nitrogen (TN) and total phosphorus (TP) were almost the same, and their EMCs decreased with increasing total rainfall depth. When the pollutant load was considered, the EGRs in this study were a sink of NH4+-N, NO3--N, TN, and TP but a source of COD.

The emerging eco-industrial parks are established in an attempt to use shared infrastructure efficiently in industrial communities, while the concentrated discharge of wastewater in eco-industrial parks causes great pressure on the water ecosystem. The modern environmental challenges require updated systematic approaches to assess the water risk in eco-industrial parks. This research established a comprehensive index evaluation system with Analytic Hierarchy Process (AHP) and fuzzy theory to evaluate the risk of the water ecosystem in eco-industrial parks. Geographic Information System is combined with pollutant diffusion model to analyze the risk status of water ecosystem and provide early warning of water pollution. The model is applied to a case of Shenzhen Eco-industrial Park. The result showed that the concentrations of TN, suspended solids and coliforms in Longgang River at the entrance to the eco-park were 11.71 mg/L, 29.01 mg/L and 8.65×104 CFU/L, respectively, which exceeded the 5th class of environmental quality standard for surface water. The concentration of coliforms at the exit of Chunzi River reached 15.5×104 CFU/L, reaching the inferior 5th class standard. The early warning result shows that the ecological hazards caused by the same amount of pollutants in the dry season present much higher risks than those in the wet season. Stringent pollutants discharge regulations in dry season are suggested to effectively manage water risks in eco-industrial parks.

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.

Hydrodynamic fluctuations can trigger sediment suspension concomitantly with internal phosphorus release, while the interactive effect of turbulence mixing and sediment suspension on the regulation of phosphorus dynamics is in need of deep understanding. This study addressed the changes in total phosphorus (TP), phosphate (PO43--P) and suspended sediment (SS) in the overlying water, and measured the profile of dissolved oxygen (DO), Fe(II) and soluble reactive phosphorus (SRP) across the sediment-water interface in the simulated environmental turbulence scenario, For a turbulence intensity (e) of 3.6 × 10−3 m2/s3, the SRP flux increased hence PO43--P showed a 36.36% increase relative to its initial level. Although e of 1.3 × 10−2 m2/s3 benefited the delivery of oxygen from the bulk aqueous phase to the upper sediment which can trigger the formation of Fe oxides and hydroxides, the turbulence-induced phosphorus diffusion from the sediment exceeded its inactivation and resulted in a large SRP flux. However, a protion of the released PO43--P can be immobilized through SS adsorption and biotic (likely cyanobacteria) assimilation. Higher turbulence intensities (e of 3.3 × 10−2 and 7.4 × 10−2 m2/s3) led to an approximately 40-fold increase in TP concentration and a significant increase in sediment suspension, which contributed to the immobilization of a majority of the phosphate through adsorption; thus, the PO43--P concentrations in the overlying water displayed 47.75% and 41.67% decline, respectively. This study also confirmed the sequential phosphorus buffer mechanisms associated with increasing turbulence intensities. With an e of 3.6 × 10−3 m2/s3, bounding to Fe ion had a significant impact on phosphorus inactivation but with an e of 7.4 × 10−2 m2/s3, the main immobilization mechanism is switched to phosphorus adsorption from the large quantity of suspended sediment.

[EN] Permeable pavements are part of stormwater management practices known as sustainable urban drainage systems (SUDS). This study describes the influence of several environmental variables, such as the rainfall regime or the pollution build-up level, on the hydraulic and water quality performance of permeable pavements. Four infiltrometers with different configurations of pavement layers were used to study the influence of two rainfall regimes (Atlantic and Mediterranean) and two rainfall intensities (0.5 and 2.2 nn/min). The influence of the progressive pollution build-up level was studied by dry sprinkling of road deposited sediments collected with a mechanical street sweeper with a dose of 5 g/m(2)/d. The results show that permeable pavements retained a significant rainwater volume and improved the infiltrated water quality in terms of suspended solids, organic matter and nutrients when compared to the corresponding surface runoff potentially generated from an impervious pavement. The volume of rainwater retained inside them varied between 16 and 66% depending on the variables studied. The water infiltrated from permeable pavements subjected to a Mediterranean rainfall regime contained, in general, higher concentrations of organic matter (22 to 89 mg Chemical Oxygen Demand/l) and nutrients (0.6 to 2.1 mg Total Nitrogen/l and 0.05 to 045 mg Total Phosphorus/l) than those under Atlantic regime. However, the latter infiltrated higher loadings in terms of mass. Nitrogen was the substance that infiltrated the most, reaching a 25% of the total mass of nitrogen deposited on the pavements surface. The concentration and mass loading in infiltrated water increased as the pollution build-up level did. The leachability of nutrients and organic matter was greater for high rainfall intensities. The results suggest that it is essential to carry out an adequate cleaning in dry conditions, especially when high intensity rainfall events are foreseen, because of its greater capacity to mobilize pollutants., This research was funded through the SUPRIS-SUPeI (Ref. BIA201565240-C2-2-R MINECO/ERDF, UE), financed by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF). Miriam Fernandez-Gonzalvo has a pre-doctoral contract funded by Generalitat Valenciana within the framework of the Program for the promotion of scientific research, technological development and innovation in the Valencian Community (ACIF/2018/111-FSECV 2014-2020). Authors would like to thank the manufacturer QUADRO for yielding paving stones and information on their composition for the research.

Extensive studies have been conducted on bioretention filter media applied in best management practices for stormwater runoff treatment. To date, more reported studies are focused on pollutants elimination such as suspended solids and nutrients. There has been limited research on pathogen removal from stormwater runoff. More focused studies on pathogen removal are therefore required if the intended stormwater is harvested for indirect potable use. In this study, water treatment residuals (WTR), a recycled biofilter media was surface-modified with metals to assess its potential for E. coli removal from stormwater runoff. To achieve this goal, four types of modified WTRs, prepared using iron, copper, platinum, and silver as antibacterial agents, were tested in parallel batch tests. After the cost-effectiveness evaluation among the four modified WTRs for bacterial removal, Fe2O3- and CuO-WTRs were shortlisted for further mechanism and stability studies. Stable antibacterial performances (E. coli log removal of 0.58 ± 0.04 and 0.90 ± 0.04, respectively) were achieved using the Fe2O3- and CuO-WTRs under intermittent synthetic and natural stormwater runoff conditions. No significant metal leaching was observed over prolonged continuous treatment. The experimental results showed the bio-adsorption onto the surface modified Fe2O3- and CuO-WTR was a key mechanism for E. coli removal followed by E. coli inactivation at solid-liquid interface caused by the antibacterial effect of metal coatings (where CuO was reported to have higher biotoxicity than Fe2O3). These findings clearly suggested the potential of CuO-modified WTR for pathogen removal in stormwater treatment practices.

Solubilization of activated sludge is a crucial process before its use as an appropriate renewable feedstock for biofuel generation which could be a legitimate alternative arrangement for contemporary concerns on fuel crisis, climate change and food security. The present study investigates the thermo-sonic assisted enzymatic pre-digestion of municipal waste activated sludge (MWAS) to cultivate oleaginous yeast Naganishia liquefaciens NITTS2 to produce lipids for biodiesel production. The maximum suspended solids reduction and sCOD observed were 36.42 ± 0.7 and 41.35 ± 0.5%, respectively at optimum conditions. The pre-digested sludge was used as a nutritional medium for yeast cultivation and the obtained maximum biomass and lipid content were 17.85 ± 0.64 g/L and 65.43 ± 1.60%, respectively. The consumption of nutrients present in the medium was analyzed before and after the batch cultivation. Lipid extraction was optimized using ultrasonication at different temperature and its characteristic profile was analyzed by GC-MS. Fatty Acid Methyl Esters (FAMEs) was produced (88.45 ± 1.2%) through enzymatic transesterification and further confirmed by 1H NMR spectroscopy. Thus, the combined pre-digestion would help to improve the solids reduction in the MWAS and the solubilized sludge could be used as a renewable substrate for biodiesel production.

Water quality data in the sewer system are indispensable for modelling, but rarely available, as measurements in sewers are challenging to conduct. Optimal experimental design (OED) is a powerful tool to identify and maximize the information content of measurement data. This paper adopts a model-based OED methodology to efficiently plan a measurement campaign for final model calibration and validation of a new sewer water quality model. To do so, a preliminary calibrated model of the case study is used to evaluate the information content of different potential measurement locations and scenarios for suspended solids as measured variable. The case study first demonstrates how OED can identify the best measurement location within a complex sewer network. It secondly demonstrates that measuring the beginning of a big rain event results in the most information-rich data among all scenarios evaluated. Thirdly, it analyses in detail the information content of dry weather flow (DWF) data. In comparison to previous studies the methodology is improved by considering the actual measurement error characteristics when calculating the information content of measurement data.

In this study a microbial consortium, dominated by members of the genera Marinobacter and Alcanivorax (Gammaproteobacteria) isolated from marine sediments of Southern Gulf of Mexico, was assessed to grow in a bubble column bioreactor using 13 g L−1 of diesel (aliphatic and aromatic hydrocarbons mix including nonane and hexadecane) as the sole carbon source. The consortium was able to produce 3.3 g L−1 of biomass, measured as suspended solids. Microbial growth was detectable, even substrate depletion, after 8 days of cultivation. The emulsifier activity and its influence on the droplet size were also evaluated: it was observed that droplet diameter decreases as emulsifier activity increases. The bubble column bioreactor system proposed in this research could be used as a biotechnological process for the remediation of a contaminated body in important petrochemical regions, for example, Veracruz, Mexico, where some points of sea and fresh-water bodies were analysed to find nonane and hexadecane in all sample water. It is important due to a lack of information, regarding hydrocarbon pollution in this port area, is filled.