Showing papers on "Effluent published in 2020"
TL;DR: The sludge of the WWTP sampled in this work, would disseminate 8 × 1011 plastic particles per year if improperly managed and the agricultural use of sludge as soil amendment in the area of Madrid could spread up to 1013 microplastic particles in agricultural soils per year.
290 citations
23 Sep 2020
TL;DR: In this paper, the possibility of achieving better treatment performance in improved designs of macrophyte-based wastewater treatment systems is discussed, and the applicability of the different macro-phyte based wastewater treatment system depends on climatic conditions, effluent quality required, wastewater characteristics, availability and price of land, conservation regulations, etc.
Abstract: Both natural and constructed wetlands have been used as wastewater treatment systems; it is generally found that both systems may act as efficient water purification systems and nutrient sinks. The possibility of achieving better treatment performance in improved designs of macrophyte-based systems is discussed. Emergent macrophyte-based wastewater treatment systems can be constructed with different designs. The concept of treating wastewater in constructed wetlands with subsurface flow was developed in Germany in the 1970s. A design consisting of several beds laid out in parallel with percolation flow and intermittent loading will increase soil oxygenation several-fold compared to horizontal subsurface flow systems. The applicability of the different macrophyte-based wastewater treatment systems depends, among other things, on climatic conditions, effluent quality required, wastewater characteristics, availability and price of land, conservation regulations, etc. Water hyacinth-based systems can, for instance, only be used in warm climates, as the plant does not tolerate frost.
273 citations
TL;DR: Overall, both the coagulation combined with sedimentation and the granular activated carbon (GAC) filtration performed well in removing microplastics and it was worthy of attention that a larger amount of polyacrylamide was detected in the effluent of the sedimentation compared to raw water.
256 citations
TL;DR: A detailed description of a variety of chemical, physical, and biological approaches for pesticide removal from water, such as advanced oxidation processes, adsorption, activated sludge, membrane bioreactors, and membrane technologies is provided in this article.
Abstract: The levels of pesticides in water have increased due to their excessive use in the modern agricultural domain Choosing a suitable water treatment method for pesticide removal depends on the type of pesticide and the efficacy of the treatment process This review critically discusses and provides a detailed description of a variety of chemical, physical, and biological approaches for pesticide removal from water, such as advanced oxidation processes, adsorption, activated sludge, membrane bioreactors, and membrane technologies Both single-treatment and hybrid methods are thoroughly described and critically discussed The use of hybrid removal techniques offers potential opportunities to develop innovative pesticide removal techniques A thorough analysis of influent composition and recognition of the best removal technique is very important to design a water treatment plant that targets the maximum possible removal rate for different types of pesticides Furthermore, the decentralization of water treatment was also discussed in which it is an important approach that would lead to better effluent water quality for lower prices Many affordable techniques such as activated sludge and adsorption by agricultural adsorbents showed high efficacy in treating high levels of different pesticides
244 citations
TL;DR: The recent advances in microalgal biotechnology to establish a biorefinery approach to treat wastewater are highlighted and the possible merits, and demerits of phycoremediation are discussed.
238 citations
TL;DR: This review summarizes the current state of knowledge regarding the use ofsilver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.
Abstract: The current scenario of water resources shows the dominance of pollution caused by the draining of industrial effluents. The polluted waters have resulted in severe health and environmental hazards urging for a suitable alternative to resolve the implications. Various physical and chemical treatment steps currently in use for dye effluent treatment are more time consuming, cost-intensive, and less effective. Alternatively, nanoparticles due to their excellent surface properties and chemical reactivity have emerged as a better solution for dye removal and degradation. In this regard, the potential of silver nanoparticles in dye effluent treatment was greatly explored. Efforts were taken to unravel the kinetics and statistical optimization of the treatment conditions for the efficient removal of dyes. In addition, the role of silver nanocomposites has also experimented with colossal success. On the contrary, studies have also recognized the mechanisms of silver nanoparticle-mediated toxicity even at deficient concentrations and their deleterious biological effects when present in treated water. Hence, the fate of the silver nanoparticles released into the treated water and sludge, contaminating the soil, aquatic environment, and underground water is of significant concern. This review summarizes the current state of knowledge regarding the use of silver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.
209 citations
TL;DR: Influent wastewater with high concentrations of suspended solids proved to have a low MP burden with a larger MP size, possibly due to a hetero-aggregation with particulate matter.
188 citations
TL;DR: In this paper, the authors evaluate the treatment process both in the presence and absence of heavy metals using ASM3 (activated sludge model no.3) so as to improve the model by means of incorporating other novel inhibitory kinetic and settler models.
Abstract: The combination of industrial and domestic wastewater in municipal WWTPs (waste water treatment plants) may be economically profitable, but it increases the difficulty of treatment, and also has some detrimental effects on the biomass and causes a low-quality final effluent. The present study evaluates the treatment process both in the presence and absence of heavy metals using ASM3 (activated sludge model no.3) so as to improve the model by means of incorporating other novel inhibitory kinetic and settler models. The results reveal that the presence of heavy metal, a case study for copper and cadmium at a concentration of 0.7 mgL −1 in a biological treatment system has a negative effect on heterotrophic bacteria concentration by 25.00 %, and 8.76 % respectively. Meanwhile, there are no important changes in COD (chemical oxygen demand), SS (total suspended solids) and TN (total nitrogen) in the final effluent in the conventional system. However, all these parameters are acceptable and consistent with EU Commission Directives. The results indicate that ASM3 can predict and provide an opportunity of the operation for an activated sludge wastewater treatment plant that receives the effluent from an industrial plant.
153 citations
TL;DR: Hierarchical clustering identified the two main pathways of antibiotic transfer in various environmental compartments, which are from animal wastewater/WWTP effluent to surface water/sediment and from animal manure/ WWTP sludge to soil/groundwater.
147 citations
TL;DR: In this article, the authors evaluated the efficacy of advanced wastewater treatment methods with regard to removal of these three-aspects from hospital effluents before discharge into a sewage treatment plant (STP).
136 citations
TL;DR: In this article, the authors evaluated the quality of Kor River water located in southern Iran, and presented techniques for identifying the main sources of contaminations discharged to the river by neighboring factories.
TL;DR: This review paper provides a thorough discussion on the challenges and opportunities regarding the further utilization and application of biocoagulants/bioflocculants in water and wastewater treatment, including the importance of the selection of raw materials, the simplification of extraction processes, the application to different water and Wastewater characteristics, and the scaling up of this technology to a real industrial scale.
Abstract: The utilization of metal-based conventional coagulants/flocculants to remove suspended solids from drinking water and wastewater is currently leading to new concerns. Alarming issues related to the prolonged effects on human health and further pollution to aquatic environments from the generated nonbiodegradable sludge are becoming trending topics. The utilization of biocoagulants/bioflocculants does not produce chemical residue in the effluent and creates nonharmful, biodegradable sludge. The conventional coagulation-flocculation processes in drinking water and wastewater treatment, including the health and environmental issues related to the utilization of metal-based coagulants/flocculants during the processes, are discussed in this paper. As a counterpoint, the development of biocoagulants/bioflocculants for drinking water and wastewater treatment is intensively reviewed. The characterization, origin, potential sources, and application of this green technology are critically reviewed. This review paper also provides a thorough discussion on the challenges and opportunities regarding the further utilization and application of biocoagulants/bioflocculants in water and wastewater treatment, including the importance of the selection of raw materials, the simplification of extraction processes, the application to different water and wastewater characteristics, the scaling up of this technology to a real industrial scale, and also the potential for sludge recovery by utilizing biocoagulants/bioflocculants in water/wastewater treatment.
TL;DR: It is suggested that chemical coagulation plays a key role in the removal of MPs, and the process can be optimized by selecting the right coagulant and pH.
TL;DR: In this article, the authors used sugarcane bagasse based agricultural biomass waste in the form of activated granular carbon as an adsorbent to study its sustainability for chromium removal from effluent water in a batch process.
TL;DR: Investigation of the levels of selected antibiotics in four wastewater treatment plants and the receiving water bodies found a medium to high risk of antibiotic resistance developing within the study areas, indicating risk mitigation and prevention strategies are a matter of priority in the affected areas.
TL;DR: In this article, a case study of chromium removal from tannery effluent by a low-cost absorbent is presented, which represents the review of various available techniques as well as represents a case case study for the removal of heavy metal chromium.
Abstract: Industrial activities that consume water generate wastewater as a by-product of processing which introduces various contaminants such as heavy metals into the neighbouring water bodies that creates adverse effects on the surrounding environment. Tannery industry releases more toxic effluent than most industries, which directly and indirectly exerts stress on various ecosystems. The heavy metal chromium (Cr), one of the pollutants found in tannery effluent, is very much detrimental to human health, animals, and plants. Conventional physico-chemical and biological processes can remove this heavy metal in considerable amounts. Recently, various applications of advanced technologies such as membrane technology, electrocoagulation, ion exchange, and electrodialysis for tannery wastewater have been growing due to their relative advantages over other technologies in terms of sustainability. This paper represents the review of various available techniques as well as represents a case study of chromium removal from tannery effluent by a low-cost absorbent.
TL;DR: In this paper, aerated electrocoagulation combined with phytoremediation treatment was conducted in dairy industry wastewater and the results showed that both treated and untreated wastewater favored bacterial growth.
TL;DR: Although the WWTP was effective in maintaining most of the wastewater parameters within South African Green drop Standards, the higher Cu, Zn, Pb and COD in its final effluent is a concern in terms of Vaal river health and biological diversity.
Abstract: Industrial effluents with high concentrations of toxic heavy metals are of great concern because of their persistence and non-degradability. However, poor operation and maintenance of wastewater treatment infrastructure is a great concern in South Africa. In this study, physico-chemical parameters and heavy metals (HMs) concentration of wastewater from five different industries, Leeuwkuil wastewater treatment plant (WWTP) inflow and effluent, and Vaal River water samples were monitored between January and September 2017, to investigate the correlation between heavy metal pollution and the location of industries and ascertain the effectiveness of the municipal WWTP. Physico-chemical variables such as pH, biological oxygen demand (BOD), dissolved oxygen (DO), chemical oxygen demand (COD), total dissolved solids (TDS) and electrical conductivity (EC) exhibited both temporal and spatial variations with the values significantly higher in the industrial samples. Inductively coupled plasma optical emission spectrometry (ICP-OES) results also showed that aluminium (Al), copper (Cu), lead (Pb) and zinc (Zn) were significantly higher in industrial effluents (p < 0.05), with only Zn and Al exhibiting significant seasonal variability. Statistical correlation analysis revealed a poor correlation between physicochemical parameters and the HMs compositional quality of wastewater. However, toxic HMs (Zn, Cu and Pb) concentrations in treated wastewater from WWTP were above the permissible limits. Although the WWTP was effective in maintaining most of the wastewater parameters within South African Green drop Standards, the higher Cu, Zn, Pb and COD in its final effluent is a concern in terms of Vaal river health and biological diversity. Therefore, we recommend continuous monitoring and maintenance of the WWTPs infrastructure in the study area.
TL;DR: In this paper, the authors used electrocoagulation (EC) process to treat wastewater from industries for meeting the effluent discharge standards is a challenging task, and Electrochemical methods, especially electroco-agulation process received great attent...
Abstract: Treatment of wastewater from industries for meeting the effluent discharge standards is a challenging task. Electrochemical methods, especially electrocoagulation (EC) process received great attent...
TL;DR: In this paper, a pilot-scale wastewater treatment was inspected on a pilot scale wastewater treatment plant by electrochemical techniques, electrocoagulation (EC), electroflotation (EF), and electrophoretic deposition (EPD).
Abstract: In this research, wastewater treatment was inspected on a pilot-scale wastewater treatment plant by electrochemical techniques, electrocoagulation (EC), electroflotation (EF) and electrophoretic deposition (EPD). The wastewater samples have been characterised by applying different parameters to determine optimum working conditions of the electrocoagulation reactor. Two electrodes have been tested separately with an outflow coming from primary and secondary sedimentation tank. The outflows from these tanks are introduced in EC reactor then EC reactor efficacy is determined for the removal of chemical oxygen demand (COD), suspended solids, micropollutants and amount of coagulants in agglomerates at different current densities. The amounts of suspended solids (SS) in influent and effluent streams were determined by the membrane filtration technique. The operational applied current values range from 1–4 A in the case of COD removal by Fe and Al. While for SS aggregation the applied current ranges from 0.5–3 A and inflow rate was tested from 250 to 500 L/h. The pH of outflows increased by increasing applied current and both of these parameters were found a positive increase in the amount of SS aggregations after EC treatment. Furthermore, the COD removal efficiency was found to be 56–57 % and 12–18 % in case Fe and Al electrode respectively after EC treatment. The results showed that applied current is the most effective parameter, whereas the aluminium electrodes have produced more amounts of flocs and bubbles in comparison to iron electrodes at similar amount of current density.
TL;DR: It is recommended that a range of optimum conditions be established to increase the efficiency of Bacillus in modulating water quality and the development of new genetic tools is recommended since the ability of microorganisms to modulate water quality is related to their genetic make-up.
TL;DR: In this paper, the authors investigated three protocols of chemical digestion, prior to analysis of microplastics, one directed to the effluents, using peroxidation, and two for activated sludge (peroxidation and Fenton).
TL;DR: In this paper, the performance of the electro-Fenton and ultrasonic process was evaluated separately and in combination under optimal conditions, and the results showed that the biological toxicity of the outlet effluent from the sono-electro-fenton process, compared to the inlet solution, was significantly reduced.
TL;DR: The sludge thickener is identified as a suitable spot for detecting SARS-CoV-2 particles thanks to its higher solids concentration and longer residence time (less sensitive to dilution caused by precipitation) and the role of WWTPs in COVID-19 mitigation.
Abstract: SARS-CoV-2 genetic material is detectable in the faeces of a considerable part of COVID-19 cases and hence, in the urban wastewater. This fact was confirmed early during the spread of the COVID-19 pandemic and prompted several studies that proposed monitoring its incidence by wastewater. This paper studies the fate of SARS-CoV-2 genetic material in wastewater treatment plants using RT-qPCR with a two-fold goal: i) to check the safety of the water effluent and also of the sludge produced and ii) based on the understanding of the virus particles fate, to identify the most suitable spots for detecting the incidence of COVID-19 and monitor its evolution. On the grounds of the affinity of enveloped virus towards biosolids, we hypothesized that the sludge line acts as a concentrator of SARS-CoV-2 genetic material. Sampling several spots in primary, secondary and sludge treatment at the Ourense (Spain) WWTP showed that, in effect, most of SARS-CoV-2 particles cannot be detected in the water effluent as they are retained by the sludge line. We identified the sludge thickener as a suitable spot for detecting SARS-CoV-2 particles thanks to its higher solids concentration (more virus particles) and longer residence time (less sensitive to dilution caused by precipitation). Although more studies will be needed for confirmation, these results contribute to clarify the role of WWTPs in COVID-19 mitigation.
TL;DR: In this article, the authors reviewed the anaerobic digestion of food waste, the composition of its digestate and trends in the treatment of ADFE with emphasis on treatment using microalgae.
Abstract: Food waste constitutes a significant portion of waste in the world. Indeed, it is estimated that about one-third of edible human food is wasted globally. Anaerobic digestion has been identified as a promising technology for the treatment of food waste as it generates a significant amount of energy and can remove a substantial portion of the organics. However, this process has not been adequately applied due to technical and economic challenges. Most importantly, anaerobic digestion of food waste produces waste in the form of Anaerobic digestate food effluent (ADFE), with high amounts of nutrient such as ammonium (up to 3000 mg L−1 NH3-N). It has been established that this effluent can be used as a substrate for the cultivation of microalgae allowing both a means of its treatment and its possible valorization. This paper reviews the anaerobic digestion of food waste, the composition of its digestate and trends in the treatment of ADFE with emphasis on treatment using microalgae. Potential microalgal cultivation methods applicable to the treatment of anaerobic digestate, especially ADFE, and possible optimization of the cultivation methods are also reviewed critically. Further, understanding of the cultivation of microalgae in ADFE is required to aid in better design of its treatment process and valorization to improve its economics.
TL;DR: This study evaluated a UASB reactor followed by a HRAP in terms of sewage treatment efficiency and biogas production, during one year at demonstration-scale, and showed an overall removal of 65% COD and 61% N-NH4 in the system.
TL;DR: Investigation of pharmaceuticals belonging to several therapeutic groups in Mahdia, Tunisia revealed that sulfadiazine, sulfamethoxazole, and fluoxetine could pose medium/high risk to the tested aquatic organisms for maximum measured concentrations in wastewater (including hospital and WWTP samples).
Abstract: In the present study, the occurrence of 40 pharmaceuticals belonging to several therapeutic groups was investigated for the first time in hospital effluent, wastewater treatment plant influent and effluent, and seawater in Mahdia, Tunisia. Forty-six samples were collected within a 6-month sampling period. Pharmaceuticals were analyzed using solid-phase extraction followed by ultra-performance liquid chromatography-triple quadrupole mass spectrometry. Thirty-three out of the forty target compounds were detected over a wide concentration of ranges, from nanograms per liter to micrograms per liter, depending on the type of sample. Maximum values were detected for caffeine at 902 μgL-1 in hospital wastewater. This compound, as well as salicylic acid, sulfadiazine, and sulfamethizole, were detected in all samples. The average concentration of total pharmaceuticals in hospital wastewater (340 μgL-1) was higher than those detected in influent and effluent wastewater and seawater (275.11 and 0.2 μgL-1, respectively). Risk quotients (RQs) were also estimated to provide a preliminary environmental risk assessment and results revealed that sulfadiazine, sulfamethoxazole, and fluoxetine could pose medium/high risk to the tested aquatic organisms for maximum measured concentrations in wastewater (including hospital and WWTP samples). Although the measured environmental concentrations (MECs) detected in seawater samples might not pose a toxic effect to the aquatic organisms (except for salicylic acid, sulfamethoxazole and fluoxetine), further researches are needed due to the continuous release of wastewater in the environment and the limited efficiency of wastewater treatment processes.
TL;DR: The adsorbent capacity was around 975.4 mg g-1, showing the potential of the hybrid material to remove fluoride from a real matrix, and the high adsorption capacity was attributed to the chitosan functional groups and thehigh interaction area promoted by sponge form and the carbon nanotube.
TL;DR: It is demonstrated that co-fermentation can increase VFA yield and shift products from acetic acid to caproic acid in long-term operation and the VFAs can be used within wastewater treatment plants to close the loop.
TL;DR: Results obtained from this study indicate porous NiLa-LDOs/Fe3O4 can be a promising multifunctional material for the treatment of secondary effluent and the presence of Ni and La species greatly enhanced the antibacterial performance of the Ni La-LD Os/Fe 3O4 toward E. coli.