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A huge quantity of textile effluent sludge is generated from 21 076 textile units of India and dumped in large areas, leading to contamination of soil, surface water and groundwater. Hence, effective management of this sludge is important for its reuse and safe disposal. Considering the utilization of this waste in construction activities, the current paper explores the potential of textile sludge produced from textile industry effluent treatment plants. Many researchers have attempted to reuse this sludge for the development of sustainable construction materials and suggested its optimum usage as a partial substitution for fine aggregate, cement and clay with or without additives for the manufacturing of non-structural building components. This paper provides a critical review of the production of non-structural elements – namely, sustainable building blocks, clay bricks, mortar and paver blocks – using textile effluent treatment plant sludge and recommends optimum ranges of 5–30, 5–40, 5–50 and 20–40%, respectively. The prominent gaps are suggested as the outcome of studies such as techno-economic feasibility of the product, thermal and energy building simulation along with the life-cycle assessment and fatigue life assessment of the developed paver blocks.

Palm oil mill effluent (POME), a wastewater from the most significant agricultural industry in Southeast Asia is produced in tremendous amounts that requires proper management to mitigate its negative environmental effects. The feasibility of treating POME in a closed dark fermentation (DF) system to replace the existing inefficient open ponding treatment has been thoroughly investigated. Theoretically, the maximum H2 yield obtained by DF process is 4 molH2/molglucose, however, it is not achievable due to the nature of POME. In this study, several enhancement methods for increasing H2 yield and DF process stability were discussed. An apprehension into the different pre-treatment methods on POME including physicochemical, chemical and biological and their effects on the characteristics of POME including pH, temperature, sugar content, solid content, viscosity, nutrients and by-product toxicity on the biohydrogen production and effluent quality were reviewed. Various bioreactor designs were used for biohydrogen from POME, the modifications applied on the system design to increase the stability and productivity of POME treatment have been examined. Moreover, higher biohydrogen productivity could be obtained with the addition of nanoparticle nutrients and introducing genetically modified H2-producing bacteria. Finally, further investigation in the future shall focus on the development of a more inclusive and efficient POME treatment via DF process that favours biohydrogen production, environmental benign and economically viable.

The quality of the groundwater in the study area was evaluated through various water quality indexes for drinking and irrigation purposes. To evaluate the water quality index, 186 groundwater samples were sampled during 2 different seasons, likely pre-monsoon (PRM) and post-monsoon (POM). The collected samples were measured for physical-chemical parameters like pH, EC, TDS, Na, K, Ca, Mg, Cl, HCO3, PO4, SO4, NO3 and H4SiO4. The research findings indicated that groundwater of the study area is approaching an alarming stage of its suitability for drinking purpose because a major percentage (i. e. 56%: PRM, 46%: POM) of samples are within poor category. Thus, the proper management strategy for water resources must be developed and a preventive management practice to address this issue must be implemented. Various water quality parameters such as electrical conductivity (EC), pH, salinity hazard, sodium hazard and permeability indexes (PI) were considered for irrigation water quality evaluation and it is inferred that the groundwater of the study area is suitable for irrigation. The PRM and POM samples with higher Na + and Cl concentrations were identified. The primary source of groundwater contamination is anthropogenic factors like domestic, agriculture effluents and mining activities. However, the groundwater of these regions is also greatly influenced by geogenic factors like weathering, rock-water interaction and precipitation which results in groundwater water level fluctuation. The research findings suggest the groundwater quality of this region is approaching an alarming stage for drinking purposes. Thus, developing a management strategy for drinking water sources and implementing preventive management practices to address this issue becomes imperative.

The performance of a membrane aerated biofilm reactor (MABR) treating raw municipal wastewater primary effluent was optimized. The MABR performance was challenged by the gradual increase of the organics and ammonia surface loading rates with hydraulic retention times (HRT) of 10.7, 6.24, 4.0, 2.0 and 3.0 h. With organics and ammonia surface loading rates of 20 g total chemical oxygen demand m−2 d−1 and 3.32 gNH4 +-N m−2 d−1, respectively, the reactor achieved simultaneous organics, nitrogen and total nitrogen reductions of 98, 96 and 67%, respectively. Microbial analysis indicated the coexistence of nitrite oxidizing bacteria, ammonia oxidizing bacteria, aerobic denitrifying bacteria and other bacteria within the MABR biofilm, correlating to simultaneous nitrification, denitrification and organics within the reactor. Acceptable effluent water quality was obtained when the MABR was operated at an HRT as low as 3 h.

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.

Geotextile tube dewatering is a pre-treatment method utilized in the remediation of high-water content materials (i.e. sediments and slurries). However, given the association some contaminants (e.g. dioxins and furans, (i.e. PCDD/F)) have with particulate matter in these contaminated sediments, understanding the fate and transport of this particle matter in the dewatered effluent is essential. In this paper, pressure filtration tests (PFTs) were conducted to investigate the effect of pressure and filter cake formation on both geotextile filtration efficiency and effluent quality. Transport tests were then performed to evaluate the particle transport through the developed filter cake, as well as the hydraulic characteristics of the medium during dewatering. HYDRUS, a one-dimensional model contaminant transport model was then employed to simulate the experimental particle transport test results. Three different mechanisms of particle transport (i.e. attachment only, detachment only, both attachment and detachment) through saturated porous media were examined to identify the possible mechanisms of observed effluent particle concentration. HYDRUS modeling outputs suggest that both attachment and detachment mechanisms are involved in a given particle's fate and transport during geotextile dewatering. In addition, parameters such as confining pressure and filter cake properties affect the particle concentration in the effluent.

The new methodologies to derive discharge limits considering operational flexibility according to international safety standards were developed to help reduce the environmental releases of radioactive effluents from nuclear power plants (NPPs). To overcome the limitations of the two existing methods to set up discharge limits assuming a specific statistical distribution of the effluent discharge, two modified equations were newly proposed to directly derive a particular discharge limits corresponding to the target ‘compliance probability’ based on the actual annual discharge data for a specific NPP and radionuclide groups. By applying these to the actual yearly discharge data of 14 Korean NPPs for 7 radionuclide groups for the past 20 years, the applicability of two new methodologies to actual cases was demonstrated. The ‘characteristic value’ with approximately a 90% compliance probability for each Korean NPP and radionuclide group was proposed based on the results. The new approaches for setting up the discharge limits and the characteristic values developed in this study are expected to be effectively utilized to foster operator's efforts to progressively reduce the environmental releases of radioactive effluents of NPPs relative to the previous discharge data considering operational flexibilities.

The Welland Canal is the only source of raw water to the largest drinking water treatment plant in the Niagara Region in southern Ontario. The water of the Welland Canal has historically been contaminated from different sources, and identifying these potential pollutants to drinking water relies on direct chemical analysis that is time-consuming and costly to identifying the critical contaminants of concern. Therefore, the aim of this research is to access and prioritize the chemicals of concern and the possible sources of contamination impacting the Welland Canal water. Metals and organic contaminants originating from industrial effluent, agricultural runoff, Port Colborne STP effluent, Lake Erie sediments and antifouling paints on ship vessels are identified as major contributors of pollutant loads into the Welland Canal. Specifically, atrazine, glyphosate, metolachlor, TBT, mercury, lead and zinc are identified as major contaminants that could pose a health risk to over 300,000 residents in the Niagara Region.

Aims: Microalgae are ubiquitous in aquatic environments, including aquaculture farms, but few studies have delved into their phytoplankton diversity and bioremediation potential. In this study, the cultivable phytoplankton of a rainbow trout freshwater aquaculture farm was isolated, phylogenetically analysed and used to assemble a consortium to polish an aquaculture derived effluent, with low concentrations of ammonium, nitrite and nitrate. Methods and Results: Through standard plating in different selective media, a total of 15 microalgae strains were isolated from sludge from a rotary drum filtering system which removes suspended solids from the water exiting the facility. Based on 18S rRNA gene sequences, isolates were assigned to nine different genera of the Chlorophyta phylum: Asterarcys, Chlorella, Chloroccocum, Chlorosarcinopsis, Coelastrella, Desmodesmus, Micractinium, Parachlorella and Scenedesmus. Species from most of these genera are known to inhabit freshwater systems in Galicia and continental Spain, but the Coelastrella, Asterarcys or Parachlorella genera are not usually present in freshwater streams. In an onsite integrative approach, the capacity of a consortium of native microalgae isolates to grow on aquaculture derived effluents and its nutrient removal capacity were assessed using a raceway pond. After 7 days, removal efficiencies of approximately 99%, 92% and 49% for ammonium, nitrite and nitrate, respectively, were achieved concomitantly with a microalgae biomass increase of ca. 17%. Conclusions: Sludge from the aquaculture filtering system presents a high diversity of microalgae species from the Chlorophyta phylum, whose application in a consortial approach revealed to be efficient to polish aquaculture derived effluents with low nutrient content. Significance and Impact of the Study: The use of native microalgae consortia from aquaculture systems can contribute to the development of efficient treatment systems for low nutrient wastewater, avoiding nutrients release to the environment and promoting water recirculation. This may further strengthen the use of phycoremediation at the industrial scale, as an environment friendly strategy.

One of the greatest environmental issues related to the development of the mining activity is the generation of Acid Mine Drainage (AMD). This effluent generated by active and abandoned mines in Peru produces multiple discussions about the role of the industry for a sustainable development. Many methods have been developed for AMD treatment, being wetlands a good option for heavy metal removal. In this sense, removal of heavy metal by using laboratory constructed wetlands with phragmites australis (cav.) trin. ex steud. was studied. During a 9-day period the variation of different physicochemical parameters and heavy metals concentrations was recorded. The pH decreased to a constant value of 8.24 after the sixth day. The electrical conductivity presented a slight variation from 1 to 1.33 μS cm−1 on the ninth day. Moreover, fluctuating values of Dissolved Oxygen and Turbidity were observed. A reduction between 69% and 93% of ammonia nitrogen (NH3-N) was registered. Cu concentration was reduced in 68% and 87%; Zn concentrations dropped in 53% and 95%; and Pb was reduced in 20% and 55%. It was concluded that phragmites australis (cav.) trin. ex steud. can be an alternative in the treatment of the contaminants produced by AMD.

To evaluate direct greenhouse gas emissions from Membrane Biological Reactor (MBR), measurements of nitrous oxide (N2O) and methane (CH4) were made at a pilot-scale MBR treating municipal wastewater Measurements were conducted during two campaigns with some changes in processes, i.e. introducing a pre-aeration tank in the second measurement, different distributions of aeration in the treatment line, not the same wastewater inflow rate, two types of ultrafiltration membrane. It was found that about 0.004% and 0.07% of the total ammonium loads were emitted as N2O, CH4 emissions were 0.026% and 0.12% of incoming TOC (0.008% and 0.04% of incoming COD) in 2014 and 2018. The obtained N2O emission values were relatively low. The study suggested that a high aeration at the beginning of the treatment line may result in significantly high emissions of both N2O and CH4. A significant change in aeration in the membrane ultrafiltration tank did not have the same impact. The MBR process is known for high quality effluent but have been questioned due to its higher carbon footprint due to energy consumption. This study gave a reference case about direct GHG emissions from MBR process and provide information for the further evaluation of MBR processes.

Tangxi River receives effluents from several wastewater treatment plants (WWTPs), which need additional treatment to meet the more stringent standards for discharge into this river. A field-scale s...

The wastewater of the aquaculture industry contains harmful pollutants that have harmful effects on aquatic life and population. The main concern is the high values of biological oxygen demand (BOD), chemical oxygen demand (COD), and ammoniacal nitrogen in wastewater, which do not comply with the Environmental Quality (Industrial Effluents) Regulations 2009 under the Environmental Quality Act (1974), the Department of Environment (DOE), Malaysia. This study aims to evaluate the efficiency of natural and commercial wastewater treatment of aquaculture wastewater. Two natural reagents (activated carbon (AC) and MNRg-Treat powder) and a biological coagulant (MNRg-Treat liquid) were used to treat aquaculture wastewater samples. Nine beakers were used in this treatment, and 1.5 L of wastewater samples from the shrimp, tilapia, and patin ponds were poured into three beakers. After that, 7.5% by weight of each reagent was added to 1.5 L of wastewater for each sample and left for three days without mechanical assistance. Then, five parameters were analyzed for the samples in each beaker: pH, BOD, COD, dissolved oxygen (DO), and ammoniacal nitrogen. The results showed that AC is the best material to reduce ammoniacal nitrogen. The ammoniacal nitrogen level of the tilapia pond reduced by 58.82% and the patin pond reduced by 30.77% using AC, followed by 17.64% reduction using MNRg-Treat liquid for the tilapia pond. Meanwhile, MNRg-Treat powder recorded 5.88% reduction for the tilapia pond. The obtained results showed that the treatment agents demonstrated their best performance at 7.5 wt. %.

This research work was focused to evaluate the concentration of heavy metals (i.e., Cr, Pb, Mn, Cu and Fe) in sediment samples collected from the Dhaleshwari River near the area of a newly established tannery industrial estate, Savar, Bangladesh. The heavy metals in sediment samples were ascertained by the atomic absorption spectrophotometer (AAS). This study revealed that the metal concentration for chromium (Cr), lead (Pb), manganese (Mn), copper (Cu) and iron (Fe) were found to be 14.8–748 (186 ± 241) mg/kg, 2.38–21.1 (8.78 ± 6.15) mg/kg, 1.59–6.29 (3.12 ± 1.38) mg/kg, 0.36–4.75 (1.76 ± 1.47) mg/kg and 3.87–154 (42.7 ± 49.1) mg/kg (dry wt) respectively. The concentration of heavy metals in sediment samples descends with the following order: Cr > Fe > Pb > Mn > Cu. Sediment contamination was assessed on the basis of geo-accumulation index (Igeo), contamination factor (CF) and pollution load index (PLI). The average Igeo values for Cr, Pb, Mn, Cu and Fe were found to be (−0.44 ± 1.87), (−2.18 ± 1.20), (−8.80 ± 0.63), (−5.80 ± 1.36) and (1.59 ± 1.87) respectively. The Igeo values values of Cr and Fe for some sampling stations were found to be higher. The PLI value for all the sample stations (S1-S8) were 0.58, 0.66, 0.71, 0.69, 0.88, 0.86, 0.83 and 0.83 correspondingly. The CF values for Cr and Fe in some stations was observed at moderate, considerate and high contamination level. The spatial distribution of heavy metals in the study area was presented by interpolation technique. The results of spatial distribution pattern showed that the high concentrated zones of Cr was found at the dumping zone (~S5) of the leather industrial city. On the other hand, the spatial distribution pattern for the studied metals (Pb, Mn, Cu and Fe) showed that the maximum metals concentrations were found in the southeastern part, which was nearby effluent dumping zone. The ecological risk assessment in sediment samples revealed that there is no significant risk observed by the metal(oid)s at this moment. Considering Cr concentration, the modified hazard quotient (mHQ) showed that about 75% of the samples were low to severely polluted by Cr, while 25% of the samples were extremely polluted by Cr as well as mHQ ≤ 3.5. Based on PMF analysis, two potential sources of heavy metals were identified in the study region: first, biochemical and leather tanning industries (Cr); second, the mixed effect of geogenic sources and atmospheric deposition and traffic emission (Fe and Pb).

The environmental effect of petroleum, refinery, and oily wastewater pollution is considerable owing to the large quantity of water produced throughout the process. Petroleum has mainly negative environmental effects due to its toxicity in nearly all lifestyles. Pollution of the air and water with oil may be harmful and hazardous to people's health. Petroleum industry effluent is often strong and may include hazardous contaminants. Inorganic and organic materials in various quantities, as well as heavy metals, surfactants, and other salts, are often found in wastewater generated by the petroleum industry. Discharging untreated or partly processed petroleum refinery effluents into the environment causes aquatic ecosystem pollution, an unsightly environment, expensive wastewater remediation costs, and the loss of cropland and fish. In the remediation of petroleum effluent, many traditional and common techniques such as biological, physicochemical, and chemical approaches are employed. Physical (mechanical) pre-remediation is often used to remove free oil, grease fractions, and suspended particles from petroleum effluent. The second step is a more advanced remediation that uses a mix of biological and physicochemical techniques to bring the contaminant level down to permissible discharge limits.

High commercial electricity consumption is one of the disadvantages in the operation of lengthy electrocoagulation processes. To cater to this problem, this study develops an integrated photovoltaic-electrocoagulation system in treating oil palm mill effluent (POME). This system has successfully reduced 23,837 mg/L of chemical oxygen demand (COD) and 15,153 mg/L of biological oxygen demand (BOD) in 8 h. It was found that the higher solar radiation harvested by photovoltaics produces a higher current intensity, which in turn generates more in-situ coagulants into the wastewater. This relates to COD and BOD removal's significance from 150 to 390 min, where the current intensities are in the maximum range (between 153 – 181 mA). The first-order kinetic models of COD and BOD are in good correlation coefficient, which is 0.9873 and 0.9837, respectively. Overall, this study findings recommend the possibility of sustainable operation in the actual wastewater pond.

Domestic biogas technology is a promising source of renewable energy for cooking in developing countries. It is popular in Nepal's rural and peri-urban areas and can be scaled-up to replace solid fuel cookstoves. This study focused on the technical assessment of installed biogas plants such as structural components, pipelines and valves, stove and burner, biogas production and utilization, and effluent disposal system in 303 homes in Kavre district, Nepal. Furthermore, it evaluated the feedstock material's physical and chemical parameters to ascertain their implications on biogas production. The plants' problems were mainly due to faulty components and lack of proper operation and maintenance. About 18% of plants were nonfunctional, out of which 9% of the plants were damaged due to the 2015 mega-earthquake. The highest number of damages was found in the mixture of the inlet structure. About 55% of mixtures were nonfunctional. Almost 77% of users used cow dung and toilet waste either individually or in combination with animal urine as feedstock materials in the digester. The Carbon: Nitrogen (C: N) ratio of feedstock materials ranged from 5:1–24:1, with only 4% of samples measuring C: N greater than 20:1. Similarly, pH (7.7) levels were on the higher side.

Dynamic changes in the abundance, composition, and size spectra of dissolved organic matter (DOM) in different size-fractions between influent and effluent from Milwaukee metropolitan wastewater tr...

The extraction of palm oil fruit (E. guineensis) is achieved by a combination of methods such as pressing, sterilizing, digesting, peeling, grading, purifying, and vacuum drying the extracted oil. This process requires excessive use of water and produces a large amount of wastewater with a high concentration of pollutants, called palm oil mill efluent (POME). This waste water is a high-viscosity liquid with a brown color and a temperature of 80-90 °C. It has a very low pH value, between 4.2-4.5, has a high chemical and biochemical oxygen demand, and is extremely toxic. POME treatment has adopted a variety of methods and technologies, including coagulation-flocculation, anaerobic-aerobic treatment and membrane technology. Biological treatment is mainly used to treat POME, and the POME treated through biological treatment is called palm oil mill secondary effluent (POMSE). Unfortunately, the treated wastewater still contains high concentrations of organic matter. The color of the effluent is still dark brown. The remaining pollutants from this biological process are generally difficult to degrade biologically, thus requiring suitable processing methods for its removal, so that it can be discharged to the environment safely or even reused orrecycled. One of the challenging processing methods is photocatalytic process. This method is able to utilize abundant resources in the form of sunlight, and is also effective to degrade a wide variety of recalcitrant organic pollutants in the wastewater. This paper presents the current research and development of photocatalytic degradation process for processing of palm oil mill secndary effluent. The review and analysis are focused on synthesis of photocatalyst and the photoreactor design. Based on the results of the literature review and analysis, some recommendations are formulated for future research for their application in advanced POMSE management so that it can be reused for various purposes.

The disease of soil is a premise of peril to the strength of individuals at diverse stages as well as towns and urban areas. Overwhelming metals unconstrained as poisonous effluents from smelters are dumped into close by biological system and are connected with wellbeing danger. Modern industrialization is main root to release different overwhelming metals which spreads to the dirt as aerosoils, particulate issue, residue, effluents and strong waste. Those substantial metals will portion from soil to plants lastly imperil for human wellbeing. The principle point of this investigation is to solve the problem of heavy metal concentration in the industrial land soils of Gorakhpur (Gida) zone (industrial). Industrial outrush which directly dumped to the atmosphere and its finally disposed into the soil causes pollution at great extent. To study about that 10 distinct samples were collected from distinct sites. Soil tests from these particular destinations got dried and processed through nitric corrosive. By using Atomic Absorptive Spectrophotometry (AAS) these digested samples were examined. The degrees of cadmium, arsenic, lead, chromium, iron, copper, zinc, and manganese in mg/kg went from 35.32–44.9053, ND, ND, 23.603–39.80203,4.2–7.5,0.114–1.8,0.52-4 and 1.04–10. Statistical analysis of data is also presented. After evaluating these samples, we will find out constant of relationship amongst overwhelming metals and other soil belongings which are natural issue (organic matter) and ph. Atomic absorption spectrometry (AAS) is a strategy which is useful for estimating the amounts of follow components present in soil samples.

Water reuse in fish farming is a practice that has been spreading significantly, therefore requiring more efficient and vigorous treatment systems. The objective of this study was to evaluate the potential reuse of aquaculture wastewater after being treated in horizontal subsurface flow constructed wetlands (HSSF-CW). Three HSSF-CWs with dimensions of 1.0 m in width, 3.0 m in length, and 0.30 m in depth were evaluated. One HSSF-CW had stargrass (Cynodon nlemfuensis) cultivated; the other had cattail (Typha latifolia), and the third was used as a control, where there was no cultivation. The wastewater was provided from three Nile tilapia breeding tanks, which recirculated the entire system after going through the HSSF-CW. The following variables were determined every five days at the HSSF-CW influent and effluent: temperature, pH, turbidity, electrical conductivity, redox potential, dissolved oxygen, ammonium, and nitrate. The treatment in the HSSF-CW allowed the reuse of aquaculture wastewater as it provides water quality levels according to the recommendation for Nile tilapia breeding. Furthermore, the water quality parameters monitored in HSSF-CW effluent remained within limits established by CONAMA Resolution No. 357/2005 for aquaculture and fishing activity. Water reuse in fish farming is a practice that has been spreading significantly, therefore requiring more efficient and vigorous treatment systems. The objective of this study was to evaluate the potential reuse of aquaculture wastewater after being treated in horizontal subsurface flow constructed wetlands (HSSF-CW). Three HSSF-CWs with dimensions of 1.0 m in width, 3.0 m in length, and 0.30 m in depth were evaluated. One HSSF-CW had stargrass (Cynodon nlemfuensis) cultivated; the other had cattail (Typha latifolia), and the third was used as a control, where there was no cultivation. The wastewater was provided from three Nile tilapia breeding tanks, which recirculated the entire system after going through the HSSF-CW. The following variables were determined every five days at the HSSF-CW influent and effluent: temperature, pH, turbidity, electrical conductivity, redox potential, dissolved oxygen, ammonium, and nitrate. The treatment in the HSSF-CW allowed the reuse of aquaculture wastewater as it provides water quality levels according to the recommendation for Nile tilapia breeding. Furthermore, the water quality parameters monitored in HSSF-CW effluent remained within limits established by CONAMA Resolution No. 357/2005 for aquaculture and fishing activity.

Olive Mill wastewater is considered as a hazardous olive by-product due to its high organic load and its toxic activity. The drying of this effluent under a greenhouse dryer can be an interesting low-cost treatment to obtain a high added value product. In order to provide an efficient design of the dryer that can consistently meet the needs of the customers, a numerical model was developed, as a first step before project implementation, to simulate the drying process inside a modified even span solar greenhouse dryer. The governing conservation equations were thus solved using COMSOL Multiphysics. To understand and then control the coupled heat and mass transfer as well as the flow, simulations have been first performed for five typical days of July for the proposed dryer as well as under the open sun. Higher air and OMWW temperatures and better air circulation inside the solar dryer reduced more effectively the drying time needed to evaporate 28.7 kg m−1 from 120 hinder open sun to 90 h inside the tested dryer. The overall efficiency of the studied greenhouse dryer and under the traditional open sun drying reached 68.1 and 50.1%, respectively, after the drying period. The study of the effect of some geometrical and Tunisian climatic conditions on the evaporated quantity showed that separated shallow basins in a greenhouse dryer during July make more effective the drying process and provide significant improvement. The obtained results allowed not only a better understanding of the drying kinetics for both studied drying processes but also an optimization of the dryer design.

The aim of this study is to provide a bibliometric analysis and mapping of existing scientific papers, focusing on microalgae cultivation coupled with biomass production and bioremediation of wastewater from cassava, dairy, and coffee industries. Using the Web of Science (WoS) database for the period 1996–2019, a search was performed using a keyword strategy, aiming at segregating the papers in groups. The keywords used in this search were “wastewater treatment,” “microalgae,” “cassava,” “dairy,” and “coffee” for the first step, resulting in 114 papers; for the second step, we used the keywords “wastewater treatment,” “biomass productivity,” “microalgae,” “economic viability,” and “environmental impacts,” which resulted in 29 scientific papers. In these papers, keywords such as “carbon dioxide biofixation” and “removal of nutrients by the production of biomass by microalgae” followed by “environmental and economic impacts” were highlighted. Some of these papers also presented an analysis of the economic feasibility of the process, including costs of production systems, which reveal the state-of-the-art setup required to make the cultivation of microalgae economically viable. Research in eco-industrial parks is needed to improve the integration of microalgae production systems using wastewater as a source of nutrients, aiming to achieve the global goal of bioremediation and clean alternatives for renewable energy generation.

Multiple rivers flowing into the same bay can be correlated in water quality management and together determine the environmental status of the bay. Nonpoint source pollution management for multi-watershed aiming to alleviate environmental contamination as well as yield considerable economic and environmental benefits can be under additional challenges. In this study, a Bayesian simulation-based multi-watershed effluent trading designing model (BS-METM) is established for multi-watershed nonpoint source pollution management through incorporating techniques of water quality simulation, uncertainty analysis with Bayesian inference, optimal design for effluent trading, as well as mechanism analysis. BS-METM is capable of reflecting parameter uncertainties in nutrient simulation, disclosing the detailed optimal trading schemes under the impact of uncertainties and vital factors, and identifying optimal effluent trading mechanisms through revealing interaction among trading processes of multiple watersheds. BS-METM is applied to a real case of adjacent coastal watersheds (i.e. Daguhe and Moshuihe watersheds), which are identified as major sources of total phosphorus and ammonia nitrogen loadings to Jiaozhou Bay, China. Effluent trading optimization under multiple mechanisms, including intra-watershed trading, cross-watershed trading and non-trading, are conducted. The optimized industry scales and trading processes are obtained. The effects of vital factors on the trading process (i.e. environmental allowance-violation risk level and water availability level) are investigated. The interactions between water availability level and trading mechanism are also analyzed. It is proved that non-trading mechanism would be recommended under low water availability level and cross-watershed trading mechanism would be recommended under medium and high water availability level. The results provide a solid scientific basis for nonpoint source pollution management as well as effective sustainable development for multi-watershed region.

Disposal of food waste is generally carried out by incineration, composting, or digestion. Anaerobic digestion of food waste is one of the alternatives for the disposal of food waste. The objective of this work was to investigate the effects of mixing speed and agitator type on biogas production from food waste in pilot plant digesters. Biogas production from food waste was carried out at mixing speeds 20, 5 rpm, and intermittent mixing conditions with turbine and propeller agitators. The highest biogas production obtained with intermittent mixing was 125 L and 123 L from turbine and propeller agitator respectively which is 30% higher than biogas obtained in the stratified digester. Lowest biogas production was obtained at a speed of 20 rpm. Kinetic study of anaerobic digestion was carried out by modified Gompertz model which fits well for experimental data with the coefficient of determination (R2) 0.99. Turbine agitator showed the best results with the highest biogas production rate of 9.2 L/day in a minimum hydraulic retention time (HRT) of 17 days. A significant reduction in HRT of 26% was achieved with intermittent mixing of turbine agitator as compared to the stratified digester. The results showed a 99% reduction in COD and a 97% reduction in BOD of effluent from digester with intermittent mixing facility as compared with inlet substrate values.

Land application of organic wastes such as sewage effluent, biosolids, and animal wastes can introduce pharmaceuticals and personal care products (PPCPs) into soils. Food plants grown in soils receiving organic wastes may take up PPCP contaminants and accumulate them in the edible tissues. The purpose of this review is to summarize the latest findings on root uptake of PPCPs and their transfer in soil–plant systems, aiming to identify potential risks associated with organic waste application in crop production systems. The processes and mechanisms of root uptake of PPCPs and their subsequent transfer in plants are intensively discussed in the present review. Soil properties, PPCP physicochemical properties, and plant species are demonstrated as the most important factors influencing the uptake and transfer of PPCPs in soil–plant systems. The metabolism processes and mechanisms of PPCPs in plant tissues are further elucidated with exemplification of commonly used PPCPs. The estimated daily intake is employed to assess the potential risks of consuming PPCP-containing foods based on their accumulation in edible plant tissues. Two innovative treatment techniques are proposed as cost-effective practices to reduce PPCP transfer into plants from organic wastes. Accumulation of PPCPs in edible plant tissues is governed by the combined processes of their root uptake, translocation, and metabolism in plants. This paper reviews the latest research advances in understanding the transfer of PPCPs in soil–plant systems, proposes mitigation practices to minimize PPCP entry into food chains, and identifies research challenges.

Rapid industrialization and unscientific disposal of industrial wastewaters have resulted in the pollution of water bodies and deterioration of water quality all over the globe. Valorization of industrial wastewaters will help in reducing the negative impact on the environment and will add value to the waste. The present study targets utilization of sugar processing industrial effluent for bio-based production of Volatile fatty acids (VFA) through anaerobic acidogenesis. Batch studies conducted to determine the VFA production potential of sugar processing industry effluent resulted in the VFA yield of 0.70 g/g COD utilized. Further continuous VFA production system was developed and optimization of Organic loading rate (OLR) (2-22 g COD/L·day) was carried out with constant Hydraulic retention time (HRT) of 1 day. The continuous reactors studies resulted in a maximum VFA yield of 0.72 g/g COD utilized and productivity of 11.04 g COD/L·day at OLR of 14 g COD/L·day and 22 g COD/L·day, respectively. The developed process will provide an environmentally safe and efficient method for the conversion of complex industrial wastes to valuable products such as VFA.

Despite the nutritional benefits, bivalves like mussels are also an excellent aquatic heavy metal biomonitoring agent due to their high tolerance to varying levels of temperature, salinity and oxygen, as well as pollutants. Although the accumulated toxic heavy metals may not exert direct negative impacts on the mussels, such toxicants in mussel tissues can give harmful effects on human body when consumed in toxic quantities and/or over prolonged period. The booming of urban and industrial activities, and consequently the increment of runoffs, as well as wastewater effluents and leaching, further exacerbated the magnitude of this issue. Hence, continuous monitoring of heavy metal contents in mussels is vital to ensure its compliance with food safety regulations, protecting consumers at large. This review paper discusses the occurrence of heavy metals in mussels especially that of Perna viridis in Malaysia and other parts of the world since year 2000 until 2021. Heavy metal concentration data and patterns from various coastal and/or estuaries were compared. Where applicable, statistical data that indicate variations between sampling sites, sampling months or years and chemical treatments for heavy metal removal were critically reviewed. Health risk assessment findings were also discussed. More importantly, related chemical-based interventions to minimize and/or eliminate toxic heavy metals from mussels are also reviewed.

Surgical cotton production has drastically been increased in the past few years due to excessive use by medical health professionals especially in countries like India, which is among the top three exporters of cotton worldwide. The effluent generated from surgical cotton industries differ from textile effluents by the conspicuous absence of dyeing chemicals. This wastewater has a high concentration of suspended particles, COD, dissolved ions, organic carbon, and alkaline pH. Several studies have been published on the treatment of textile effluents and the degradation of dyeing chemicals, while the treatment studies on surgical cotton wastewater have been rarely reported in spite of their potential to cause pollution in receiving land/water bodies. Activated sludge microbes have been extensively studied and well documented in the treatment of several industrial effluent but does not match to the production of valuable biomass from algae. The global energy demand has prompted the scientific community to investigate and explore the possibility of using algae for energy production with simultaneous wastewater treatment. To the best of the authors' knowledge, no research articles have been published which compare the effectiveness of activated sludge microorganisms, microalgae, and macroalgae in removing contaminants from real wastewater. To date, there is a knowledge gap in understanding and selecting the right choice of biological system for effective and economical effluent treatment. In an attempt to minimize this gap, carbon removal by microalgae, macroalgae, and activated sludge microbes were investigated on real effluent from surgical cotton industries. It was observed that the strain of Chlorella vulgaris could dissipate 83% of COD from real wastewater, while consortia of macroalgae (consisting predominantly of Ulvaceae and Chaetomorpha) and activated sludge microbes could remove 81% and 69% of the carbon, respectively. The microalgal growth (in terms of wet weight) increased from 0.15 to 0.3 g, whereas the macroalgal wet weight increased from 1.5 to 3 g in over 7 days of batch experiments conducted in triplicates. This indicated the superlative performance of microalgae over activated sludge microbes in carbon dissipation.

Improper discharge of industrial effluents would lead to direct contamination of our water, air, and soil systems. Without proper treatment, both these inorganic and organic-matter-containing waste would pose harmful effects towards aquatic organisms, overall water quality, reduction in soil health, and increase in greenhouse gasses from anaerobic microbial degradation activities. Current treatment technologies involve the use of combined chemical, biological, and physical approaches, which has been proven very effective. Another useful alternative is to utilize the high organic content present in the waste as substrate for the metabolism of microbes as catalyst in industrial processes including water treatment as well as production of useful microbial secondary metabolites such as pigments. This review highlights some example for the microbial biotransformation and biomineralization of organic-rich industrial discharges. This is important based on its potential to be applied as useful alternative techniques to dispose huge volumes of industrial waste as well as reducing high cost of sustaining biological-based industrial processes that would require substantial investment notably for the microbial growth medium. Nevertheless, clear insight into the engineering aspects of such processes and sufficient knowledge on its feasibility to function properly at pilot-scale level are of paramount importance prior to any commercialization attempts.

One of the major environmental problems today is hydrocarbons contamination resulting from activities related to the petrochemical industry. Accidental releases of petroleum products are of particular concern in to the environment hydrocarbons compounds have been known to belong to the family of carcinogenic and neurotoxin organic pollutants. The use of plants to clean up this contaminated site is a promising technology and the ability of the plants to germinate and grow in petroleum-contaminated soil differs due to plants species as well as petroleum hydrocarbons types. In this study, total petroleum hydrocarbons (TPH) were determined in Kyllinga pumila and Spirogyra longata growing at Nigerian national petroleum corporation (NNPC) Jos Depot. The chemical analysis was carried out with the aid of Gas Chromatography and Mass Spectrometry (GC-MS) detector, the result showed that Spirongyra longata could germinate and grow in petroleum products contaminated site with TPH level of 6881.98595 ppm and Kyllinga pumila did not survived in the same site with TPH level of 9536. 88801 ppm.

One of the most widespread problems afflicting people throughout the world is adequate access to clean water. Problems with water are expected to grow worse in the coming decades, with water scarcity occurring globally, even in regions currently considered water-rich. Research on the effects of temperature, transmembrane pressure (TMP), and aeration rate on the quality of effluent is of great significance in the case of membrane bioreactor. By means of the box-Behnken design (BBD) response surface methodology experiments; for the experimental investigation, the three factors are selected for optimization like the temperature is optimized in the range of 27.6–37.4 °C, transmembrane pressure is 35–63 mm Hg, and aeration rate is optimized in the range of 75–90 L/min and regression models are established. The optimal control parameters of temperature, TMP, and aeration rate are found utilizing the BBD optimizer. The removal mechanism of pollutants is discussed, and GC–MS analysis of effluent of the MBR system is also reported. The results show that the aeration flow rate affected effluent quality more significantly compared to temperature and TMP. When the aeration flow rate is 90 L/min, the temperature is 37.4 °C, and TMP is 35 mm Hg, the obtained COD, BOD, TKN, and TP values achieve the standard quality governed by the Central Pollution Control Board (CPCB) of India.

Rainwater harvesting and treatment systems (RHTS) are used in many places around the world as a part of sustainable water management. They decrease the risk of overloading the sewage network and environmental pollution. The efficiency and reasonableness of using such solutions in specific erosive conditions are not sufficiently understood. The aim of the study was to evaluate the operation of RHTS, receiving effluents from the wholesale market and fuel station (twenty years of observations). The studied system is located in an area endangered by water erosion. In the study period, due to the accumulation of erosive phenomena, it was necessary to optimise the system (including the installation of new devices and increasing the capacity of reservoirs). The analyses referred to the stability and work safety of the most important equipment and water treatment efficiency. The quality of water in the reservoirs was measured before and after the modernisation of the system. Selected physical, oxygen, biogenic and salinity indicators were determined in the water. During the study, RHTS had a positive effect on the quality of rainwater runoff – the values of many contaminants were reduced (RHTS 1: suspended solids, nitrogen, iron, potassium; RHTS 2: conductivity, suspended solids, nitrogen). Design and operational errors were noticed that in the long run may contribute to deteriorating the operational efficiency and even lead to a building collapse (intense erosive phenomena). This study clearly demonstrates that building a rainwater management system is a highly site-specific issue.

The leather industry has been looking for alternatives to minimize its environmental impacts, including studies to reduce the pollution load of liquid effluents from the leather process. Although studies reducing the supply of chemicals have already indicated optimized offers of fatliquoring and retanning agents, the effect of the scale-up of these optimized conditions on effluents and the quality of the leather remains unknown. This study aims to reduce the pollution load of post-tanning effluents by reducing leather chemicals supply. Tests were performed on pilot and industrial scales, reducing the offer of retanners and fatliquors in two levels: 19% and 26%. The effluents were tested for pH, conductivity, dissolved solids, sulfate, biochemical oxygen demand, and chemical oxygen demand. The leather was tested for organoleptic properties and physical-mechanical tests. The reduction of chemicals allowed the depletion of the raw wastewater pollution load. The leather obtained showed a quality within the established standards. Besides, post-tanning formulation costs were reduced by 24%.

Effluents stemming from the textile industry are concerning from the environmental viewpoint, given that large volumes are generated and they present a high concentration of organic matter and toxicity. Dyes stand out among the substances present in such effluents because part of them does not fix on the fiber during the dyeing process, leaving the effluent with a strongly colored aspect and difficult to be treated. Due to the limitations and low efficiency of conventional processes, alternative forms for the treatment of textile effluents have been evaluated. Among them, the Fenton oxidation processes stand out, which are based on the use of iron as a catalyst in the conversion of H2O2 into highly reactive free radicals. The catalyst may be solubilized or used in the insoluble form (heterogeneous catalysis). Fenton reaction can be enhanced by combining UV, visible (photo-Fenton, solar photo-Fenton), or ultrasound radiation (sono-Fenton), and electrical current (Electro-Fenton). In this review, a brief mention of textile effluent characteristics is presented, and the fundamentals, advantages, limitations, and recent progress of the Fenton processes are addressed as alternatives to the treatment of textile effluents. A survey on the efficiency of such processes regarding the reduction of important characterization parameters (organic matter concentration, color, turbidity) for real textile effluents also is presented. From the real effluent data, it was noted that these processes are efficient in the reduction of organic pollutants and color. Among the Fenton processes, photo-Fenton showed better efficiencies and less variability for the different effluents treated (reducing on average 82% of COD and 95% of color). It has also been observed that such processes can be also efficient when combined with other processes (e.g. coagulation-flocculation or biological processes). Treated effluents present less toxicity and have been reused in the dyeing stage, although such an approach is still poorly evaluated. The costs for the treatment of real effluents calculated by different authors ranged from 1.1 to 28.9 USD per Kg of COD removed, where the processes that presented the lowest costs were classical Fenton and technologies that use solar energy, such Photo-Fenton and Photo-electro-Fenton.

In recent years, research activities on water reuse applications have rapidly increased to manage natural water sources efficiently. Although these applications in centralized treatment systems can be effective, there are some drawbacks, including the economic factors for small settlements. In this study, a textile filtration unit with the integration of a sequencing batch reactor (SBR) was developed and different textile materials were used to enhance the treated effluent quality for reuse purposes. While the textile filtration unit alone could not effectively remove the pollutants, the removal efficiencies could not exceed 36% for COD and 50% for BOD5. However, SBR integration in to the filtration system improved the treated wastewater quality and COD and BOD5 reductions were obtained higher than 93%. Activated carbon coated cotton textile materials and activated carbon cloth, which was used for the first time for wastewater treatment, increased the treatment performance. In the filtration system, although the suspended solids were high in the SBR effluent, no clogging problem was observed even with higher operation times. This paper presents the research results on this textile filtration system, and experimental findings are discussed on the applicability of the system for small communities. HIGHLIGHTS Different textile cloths as low-cost materials were evaluated for wastewater treatment.; Activated carbon impregnated cotton textiles exhibited better treatment efficiencies.; Activated carbon cloth as an outer filtration material on the metal braided cotton textile showed remarkable reductions in all pollutants.; SBR integration enhanced the filtration unit performance.

The present study investigated the phycoremediation efficacy of two freshwater green microalgae Chlorella ellipsoidea and Desmodesmus opoliensis for treatment of water of Ellenga beel, a wetland lo...

The anodising industry releases toxic effluents which have been treated using various technologies over the years. In this paper, we review separation, oxidative degradation and biological degradation wastewater treatment technologies for the anodising industry effluent. We also examined the suitability of these processes based on the effluent nature and composition. The objective was to synthesise the literature to ensure a proper understanding of the research progress and to highlight grey areas that require more investigative insight. It was observed in the review that the wastewater has a very low pH and is rich in heavy metals like aluminium, magnesium and phosphates and other anions. Techniques like nanofiltration, reverse osmosis and adsorption were shown to be able to effectively handle the variety of pollutant species in the wastewater (achieving pollutant removal percentage of > 90%). Oxidative and biological degradation were unsuitable for treating anodising industry wastewater albeit with a serious dearth in published literature. The major limitations of oxidative degradation processes are the non-biodegradability of heavy metals and the •OH radical scavenging of anions like phosphates, sulphates and nitrates. For biological degradation, the very low pH and high concentration of heavy metals make it unsuitable for the survival of most microorganisms. It is recommended that the improvisation of operating conditions of existing technologies and the consideration of alternative tertiary strategies of wastewater treatment to achieve zero liquid discharge and actualisation of the relevant sustainable development goals should be considered.

Microalgal biomass composition can be modulated by changing the type of bioreactor and cultivation conditions. Besides, these microorganisms can produce valuable biomass components from unconventional culture media, including effluents and wastes. Our objective was to evaluate the production and composition of biomass in an airlift bioreactor operated in a semi-continuous mode to cultivate the microalgae Chlorella minutissima in a landfill leachate-based medium. Chlorella minutissima was cultivated in an airlift bioreactor operated in semi-continuous mode, applying a Taguchi L9 orthogonal arrangement and analyzing the effects of factors landfill leachate concentration (LC), percentage flux of CO2 added to the gas stream (GP), aeration flow in the reactor (AF), and feed flow (FR), on the cellular composition of biomass. The microalgae produced high protein levels, reaching a maximum content of 69.60% (LC: 10%, GP: null, AF: 0.30 vvm and FR: 0.9 µmax). The highest contents of lipid and carbohydrate were 17.4% (LC: 15%, GP: null, AF: 0.45 vvm and FR: 0.7 µmax vvm) and 11.6% (LC: 10%, GP: 15%, AF: 0.15 vvm and FR: 0.7 µmax). Statistical analysis showed LC was the most influential factor. GP did not show significance for any response, while the variables AF and FR showed significance in the productivity of proteins. The use of unconventional cultivation media in airlift bioreactor operated in semi-continuous mode was shown as a system with potential to be used to valorize leachate by producing valuable biomass, allowing to obtain different cell composition by varying the process conditions.

The aim of this a pioneering research is to investigate linear alkylbenzenes (LABs) as biomarkers of sewage pollution in sediments collected from four rivers and estuaries of the south and east of Peninsular Malaysia. The sediment samples went through soxhlet extraction, two-step column chromatography purification, fractionation and gas chromatography-mass spectrometry (GC-MS) analysis. Principal component analysis (PCA) with multivariate linear regression (MLR) was used as well for source apportionment of LABs. The results of this study showed that total LAB concentration was 36-1196 ng g-1dw. The internal to external isomer ratios (I/E ratio) of LABs were from 0.56 to 3.12 indicated release of raw sewage and primary and secondary effluents into the environment of south and east of Peninsular Malaysia. Our research supported that continuous monitoring of sewage pollution to limit the environmental pollution in riverine and estuarine ecosystem.

Nigeria, one of the major crude oil producing countries in the world, transports petroleum products through pipelines to several oil depots located across the country from where it is trucked to end users. Activities within these depots are known to have impact on their immediate environment due to the nature of operations and the externalities generated. This paper therefore examined the socio-environmental effects of the Nigerian National Petroleum Depot, Apata, Ibadan on its immediate neighbourhood. A case study approach utilising primary and secondary data collection was adopted in which 205 residential buildings and respondents were proportionally selected for sampling from four neighbourhoods within 500 metres radius of the facility. An environmental audit including ground water samples were randomly collected for testing and analysis from Adebisi stream and residential hand-dug wells. Findings revealed local access road incapacitation emanating from indiscriminate parking of fuel tankers and spiralling into constant traffic congestion on major roads. Desludging of fuel storage tanks (79.5%) resulting into regular effluent discharge into the Adebisi stream and fume emission (62.6%), were attested to by residents. Water quality analysis revealed a high concentration of lead (pb.0.06mg/l) above the maximum permissible limit of (0.01mg/l) for potable water. Other detected metals, Cadmium (0.003mg/l), Copper (0.006mg/l) and Zinc (3.0 mg/l) were all within the appropriate recommended limits. The study recommended a periodic environmental audit and regular dialogue with stakeholders of the host communities for socio-environmental sustainability.

© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Urea can degrade water quality and stimulate toxic phytoplankton in P-rich lakes, yet little is known of its sources, abundance, or transportation in lotic systems, particularly within the Northern Great Plains. We measured physico-chemical parameters biweekly during May–September 2010–2012 at 16 stations along a 250 km lotic continuum to quantify spatial and temporal variation in urea concentrations and discharge, and to identify potential regulatory processes. Urea concentrations were similar to those in regional prairie lakes (range 5.2–792.1, median 78.6 μg N L−1) with variable seasonal mean (± SD) concentrations (96.6 ± 96.1 μg N L−1) and fluxes (4.22 × 105 ± 257.6 μg N s−1). Landscape analysis with generalized additive models explained 68.3% of deviance in urea concentrations, with high temporal variability predicted mainly by positive relationships with nutrient content and chlorophyte abundance, but not temperature, dissolved organic matter, bacterial abundance, or urban effluent. Seasonal analysis revealed that during spring, urea content was correlated negatively with leguminous forage cover (% area) and positively with stream discharge, oilseed and cereal crops, and shrubs or deciduous plants, while during summer, urea concentrations were correlated negatively with discharge and leguminous crop cover, as well as nutrient levels. Mean porewater urea concentrations (528.5 ± 229.8 μg N L−1) were over five-fold greater than stream concentrations, suggesting that hyporheic production may offset declining influx from terrestrial sources during summer. We conclude that urea may be ubiquitous in eutrophic prairie streams and that management of its export from land may reduce detrimental effects on downstream lakes. This work was supported by an NSERC Alexander Graham Bell Canada graduate scholarship, NSERC Canada Discovery Grants program, Canada Research Chairs, Canada Foundation for Innovation, the Province of Saskatchewan, and the University of Regina. Faculty yes

Pig farming moves a large part of the Brazilian economy. However, due to the high polluting potential, alternatives to treat and take advantage of the effluents must be developed, being the use of digesters a possible solution. This study aimed to evaluate the performance of two parallel covered lagoon digesters (CLD) in the treatment of swine wastewater. Monitoring was performed on a farm installed in Teixeiras, Minas Gerais, Brazil, in terms of COD in the period from August 2018 to July 2019. The study demonstrated that COD removal efficiency in the CLD was 40.2 and 39.5%, which did not indicate a statistical difference at a 5% significance level. The two digesters in parallel were compatible with each other in terms of COD reduction. Furthermore, individually they did not present significant changes in their performance in the summer and winter periods. Pig farming moves a large part of the Brazilian economy. However, due to the high polluting potential, alternatives to treat and take advantage of the effluents must be developed, being the use of digesters a possible solution. This study aimed to evaluate the performance of two parallel covered lagoon digesters (CLD) in the treatment of swine wastewater. Monitoring was performed on a farm installed in Teixeiras, Minas Gerais, Brazil, in terms of COD in the period from August 2018 to July 2019. The study demonstrated that COD removal efficiency in the CLD was 40.2 and 39.5%, which did not indicate a statistical difference at a 5% significance level. The two digesters in parallel were compatible with each other in terms of COD reduction. Furthermore, individually they did not present significant changes in their performance in the summer and winter periods.

Zwitterionic, cationic, and anionic per- and polyfluoroalkyl substances (PFAS) are increasingly reported in terrestrial and aquatic environments, but their inputs to agricultural lands are not fully understood. Here, we characterized PFAS in 47 organic waste products (OWP) applied in agricultural fields of France, including historical and recent materials. Overall, 160 PFAS from 42 classes were detected from target screening and homologue-based nontarget screening. Target PFAS were low in agriculture-derived wastes such as pig slurry, poultry manure, or dairy cattle manure (median ∑46PFAS: 0.66 μg/kg dry matter). Higher PFAS levels were reported in urban and industrial wastes, paper mill sludge, sewage sludge, or residual household waste composts (median ∑46PFAS: 220 μg/kg). Historical municipal biosolids and composts (1976–1998) were dominated by perfluorooctanesulfonate (PFOS), N-ethyl perfluorooctanesulfonamido acetic acid (EtFOSAA), and cationic and zwitterionic electrochemical fluorination precursors to PFOS. Contemporaneous urban OWP (2009–2017) were rather dominated by zwitterionic fluorotelomers, which represented on average 55% of ∑160PFAS (max: 97%). The fluorotelomer sulfonamidopropyl betaines (X:2 FTSA-PrB, median: 110 μg/kg, max: 1300 μg/kg) were the emerging class with the highest occurrence and prevalence in contemporary urban OWP. They were also detected as early as 1985. The study informs for the first time that urban sludges and composts can be a significant repository of zwitterionic and cationic PFAS.

PT. X is one of the ice companies in which its largest company is located in Bali, more precisely in the Pidada area, North Denpasar. Based on field observations the area is an area that has a calcareous soil structure. The water source of PT. X was extracted from the groundwater. From the field observation, it was found that the pipeline network, that connected the inlet water to water treatment system and ice production units, was severely covered by faint white scale. In order to discover the origin of this scale, water quality testing need to be carried out. From the results, it was found that the total hardness in the inlet water, taken from the groundwater tap, was 162.85 mg/l with calcium concentration of 2.15 mg/l and iron 3.83 mg/l. Water quality testing was also carried out in the water treatment unit consisting of resin softener where the total hardness surprisingly increased into 279.81 mg/l, calcium concentration was 2.96 mg/l, iron concentration was 0.55 mg/l. Even after being treated in softener resin, the total hardness increased sharply to 483 mg/l, which categorized as extreme hardness. The increase in total hardness indicates that there was a failure in the operation of the water treatment system, even it also contributed to the higher hardness and calcium concentration. This over-year’s treatment failure has been causing accumulation of hardness and calcium concentration in the compartment of both water treatment system and ice production unit that inflicts a higher hardness level in the effluent.

Wastewater reclamation facilities are known sources of emerging contaminants associated with human health and sanitation. This study evaluated the contribution of trace organic contaminants to a previously unmonitored river by water resource reclamation facilities. Six sampling events were conducted on the Reedy River in South Carolina. Sampling locations included sites upstream and downstream of two WRRFs located on the river to examine potential contributions under drought conditions where WRRF effluents comprise a large proportion of total stream flow. Five target analytes were monitored including atrazine, carbamazepine, 17β-estradiol, perfluorooctanoic acid, and sulfamethoxazole. On a mass basis, the WRRFs contributed additional loadings of carbamazepine ranging from 5.4 g/d to 7.2 g/d (mean: 6.3 ± 0.4 g/d), PFOA ranging from 8.6 to 31.9 g/d (mean: 20.0 ± 4.9), and sulfamethoxazole ranging from 49.4 g/d to 75.1 g/d (mean: 62.1 ± 4.8). 17β-estradiol was detected once and atrazine was not detected.

Hydraulic transients occur as a direct result of rapid variations of flow field in pressurized systems. The change in velocity from valve closures or pump operations causes pressure surges that are propagated away from the source throughout the pipeline. The associated pressure changes during a transient period are quite large and occur quickly (within a few seconds). It should also be noted that when the maximum pressures exceed the bar ratings (mechanical strength) of the piping material, failure can occur. Similarly, if the minimum pressure drops below the vapour pressure of the fluid, cavitation can occur. The purpose of the present study is to model and simulate the hydraulic transients in a pipeline network system of the treated effluent rising main of Mpophomeni sanitation scheme using SAP 2R. A total of five scenarios were simulated using different combinations. The simulation results show that the transient pressures in the pipeline exceeded the bar rating of the pipe where the bursts or cavitation may occur for the simulated scenario, but transient pressures were reduced to a safe limit after providing water hammer protection devices.