Synthetic Effluent Research Articles

Towards passive bioremediation of dye-bearing effluents using hydrous ferric oxide wastes: Mechanisms, products and microbiology

A novel, circular economy-inspired approach for the “passive” (non-powered and reagent-free) treatment of dye-bearing effluent is presented. The treatment utilises the biogeochemical interaction of dye-bearing wastewater with hydrous ferric oxide (HFO) bearing sludges. The work presented demonstrates for the first time the reuse of HFO-rich waste sludges from potable water and mine water treatment. The waste was used directly without modification or reagent addition, as media/substrate in simple flow-through reactors for the decolourisation and biodegradation of methyl orange (MO) and mixed dyes textile effluent. Three phases of exploratory proof of concept work were undertaken. Columns containing HFO sludges were challenged with solution of MO, and MO amended with glycerol (Phase I), MO in a synthetic textile effluent recipe (Phase II), and real mixed textile effluent containing a mixture of dyes (Phase III). After an initial lag period extensive decolourisation of dye was observed in all cases at rates comparable with pure strains and engineered bioreactor processes, with evidence of biodegradation beyond simple cleavage of the mono azo chromophore and mineralisation. The microbiology of the initial sludge samples in both cases exhibited a diverse range of iron oxidising and reducing bacteria. However, post experiment the microbiology of sludge evolved from being dominated by Proteobacteria to being dominated by Firmicutes. Distinct changes in the microbial community structure were observed in post-treatment MWTS and WTWS where genera capable of iron and sulphate reduction and/or aromatic amine degradation were identified. Average nitrogen removal rates for the columns ranged from 27.8 to 194 g/m3/day which is higher than engineered sequential anaerobic-aerobic bioreactor. Postulated mechanisms for the fast anaerobic decolourisation, biodegradation, and mineralisation of the dyes (as well nitrogen transformations) include various direct and indirect enzymatic and metabolic reactions, as well as reductive attack by continuously regenerated reductants such as Fe(II), HFO bound Fe(II), FeS, and HS−. The ability of iron reducers to degrade aromatic rings is also considered important in the further biodegradation and complete mineralisation of organic carbon. The study reveals that abundant and ubiquitous HFO-rich waste sludges, can be used without amendment, as a substrate in simple flow-through bioremediation system for the decolourisation and partial biodegradation of dyes in textile effluent.

Assessment of Metal Accumulation by Arthrospira platensis and Its Adaptation to Iterative Action of Nickel Mono- and Polymetallic Synthetic Effluents.

Cyanobacteria-mediated wastewater remediation is an economical, efficient, and eco-friendly technology. The present work deals with the bioaccumulation performance of Arthrospira platensis (Spirulina) grown for four cycles in a medium containing nickel mono- and polymetallic synthetic effluents. The metal uptake by spirulina biomass was evaluated using neutron activation analysis. The effects of effluents on biomass production, protein, and phycobiliprotein content were assessed. Metal accumulation in the biomass depended on the effluent composition and metal ion concentrations. Nickel accumulation in the biomass was directly proportional to its concentration in effluents, and maximum uptake (1310 mg/kg) was attained in the Ni/Cr/Fe system. In the same system, biomass accumulated 110 times more chromium and 4.7 times more iron than control. The highest accumulation of copper (2870 mg/kg) was achieved in the Ni/Cu/Zn/Mo system and zinc (1860 mg/kg)—in the Ni/Cu/Zn/Sr system. In biomass grown in the media loaded with nickel and also chromium, iron, copper, strontium, zinc, and molybdenum, a decrease in productivity (on average by 10%) during the first cycle of cultivation and moderate reduction of protein content (by 15–27%) was observed. The presence of metals in the cultivation media inhibited phycobiliprotein synthesis, especially of phycocyanin, and promoted the synthesis of allophycocyanin. The maximum reduction of phycocyanin content was 77%, and the increase of allophycocyanin content—by 45%. Arthrospira platensis may be deemed as bioremediation of nickel-polluted wastewaters of complex composition.

Multifunctional in-situ ferrate treatment and its removal mechanisms of membrane bioreactor residual pollutants

Membrane bioreactors (MBRs) integrate the technique of membrane separation with biologically activated sludge and produce high-quality effluent that can be used for water reclamation. However, removal of residual pollutants, including phosphorus, non-biodegradable organic matter, and microorganisms, is necessary for water reuse in areas with high human exposure to water, necessitating further water treatment. In this study, ferrate(VI) was used to remove various residual pollutants that can be contained in the MBR effluents, and the removal mechanisms were studied by comparing with ferric chloride (FeCl3). Optimal ferrate production using the in situ wet oxidation method in the synthetic MBR effluent occurred at pH 7.0 and Fe3+:OCl− = 5, with a ferrate yield of 1.8 mg L−1. Based on the results of the jar test, the optimised ferrate dosage was 7.5 mg L−1, which removed 90% of total phosphorus, 20% of dissolved organic matter, and 90% of microorganisms in the real MBR effluent. Ferrate was more effective than FeCl3 even at a lower dosage (∼25%). The simultaneous oxidising, coagulating, and disinfecting properties of ferrate are expected to reduce the number of post-treatment steps for water reclamation, thus reducing the capital and operational expenses.

Investigation of micellar‐enhanced ultrafiltration (MEUF) using rhamnolipid for heavy metal removal from desalter effluent

AbstractThe removal of heavy metals from desalter effluent is an important issue due to the toxicity of these pollutants. In this study, micellar‐enhanced ultrafiltration (MEUF) is applied for the removal of heavy metals from synthetic desalter effluent. MEUF is a process in which surfactants above their critical micellar concentration (CMC) form micelles. Micelles bind compounds with low molecular weight; then, these are rejected by a semi‐permeable membrane. Rhamnolipid is an anionic biosurfactant that has advantages such as biodegradability and low CMC. Rhamnolipid complexation with synthetic desalter effluent demonstrates high efficiency for heavy metal removal. The highest overall removal efficiency was reached at a rhamnolipid concentration of 300 mg/L with 94.07%, 81.93%, 99.81%, 76.00%, and 41.91% for Zn+2, Mg+2, Cu+2, Mn+2, and Na+, respectively. Additionally, loading capacity on rhamnolipid micelles was evaluated to have better selectivity for Mn+2 > Cu+2 > Zn+2 > Mg+2 > Na+. Also, the results showed that phenol has a significant effect on heavy metal removal, decreasing CMC, which increases micelles. Finally, the permeate flux decreases after increasing the rhamnolipid concentration due to the formation of the gel layer, creating an additional resistance to the permeate flux that goes through the membrane. This work shows that MEUF with rhamnolipid is a reliable method for heavy metal removal from desalter effluent.

Synthetic Dye Application in Textiles: A Review on the Efficacies and Toxicities Involved

The application of dyes in textile colouration has existed for centuries. Dyes are obtained from both natural and synthetic sources. Synthetic dyes are manufactured from chemical compounds and have been placed on a high pedestal in the textile industry due to their improved colour fastness, varied range of pigments and easy application as compared to natural dyes. However, they have been identified to be harmful to the environment and human health by researchers. When effluent containing harmful chemicals like sodium sulphide is discharged into the environment improperly, they cause a lot of diseases and hinder smooth air flow. With current submissions made by researchers on synthetic dyes application as a backbone, this review throws more light on the dangers and benefits involved in the use of synthetic dyes in the textile industry. It also touches on waste management as far as textile dyes are concerned. The application of synthetic dyes, precisely vat, reactive and sulphur dyes are highlighted in the study. With the purpose of addressing appropriate means of curbing undesired hazards caused by textile wastes water, several technological approaches to effluent treatment such as Physical, Chemical and Biological are brought to light in the study. The study recommends the adaptation of waste management principles such as the 5R hierarchy to curb environmental harm caused by synthetic dye effluents.

Decolorization of Textile Dyes in a Fixed‐Bed Biofilm Reactor

AbstractA fixed‐bed biofilm reactor (FBBR) was developed and its performance in decolorizing synthetic dye mixtures and textile industry effluents was evaluated in both batch and continuous modes. It was observed that yeast extract was important as the carbon source in the FBBR feed for color removal. However, the requirement for yeast extract in FBBR is very small compared to that in suspended cell cultures. Structural changes in dyes due to biological treatment were assessed from ultraviolet‐visible spectral and high‐performance liquid chromatography (HPLC) analyses. Gas chromatography‐mass spectrophotometry (GC‐MS) investigations confirmed that the metabolites formed were nontoxic and benign.

Kinetic of nitrogen consumption by Anammox process in membrane biofilm reactors operated in sequential batch

Biological nitrogen removal via Anammox is an advantageous technology in the nitrogen treatment effluents with a low Carbon/Nitrogen ratio, a process that makes this route interesting for the most different types of industries, agribusinesses, and urban effluent treatment plants. Achieving robust Anammox biomass for use in full-scale plants is still a challenge that motivates studies of biomass enrichment and the search for kinetic parameters of substrate consumption rate that help optimize the conduction of reactors. According to the previously mentioned, this work aimed to carry out the kinetic study of nitrogen consumption by the Anammox process in a membrane aerated biofilm reactors operated in sequential batches (MABR-BS). 6 MABR-BS reactors were used, each one of them inoculated with a specific Anammox sludge, obtained from the enrichment of anaerobic and aerobic sludges coming from 3 different sludge sources, namely, a municipal wastewater treatment plant, a landfill leachate treatment plant, and a swine slaughterhouse effluent treatment plant. For the kinetic study, 6 reactors were used, made in glass flasks with a total volume of 1L, with a useful volume of 500 mL, with the 300:200mL ratio between synthetic effluent (with 100mgN-NH4+.L-1) and sludge from the sources: R1 - anaerobic sludge from a UASB reactor for urban sewage treatment; R2 - mixed sludge from a UASB reactor, consisting of waste sludge and supernatant scum; R3 - anaerobic sludge from landfill leachate treatment; R4 - mixed sludge consisting of aerobic and anaerobic sludge from landfill leachate treatment plant; R5 - anaerobic sludge from the swine slaughter effluent treatment plant and R6 - aerobic and anaerobic sludge from the swine slaughter effluent treatment plant. The experimental apparatus had 3 aerators coupled to 3 flowmeters with an air flow regulated at 1.0 L.min-1; 30 cm of silicone membrane in a curved shape with one of the inlets connected to the aerator and flowmeter, the other outlet was immersed in a 75 cm water column, exerting negative pressure on the air inside the tubular silicone membrane, forcing the air to exit through the microporosity of the membrane. Aeration was intermittent, with an interval of 0.16 h between each minute of aeration, the reactors were shaken in a water bath at 30 rpm and temperature of 32°C. The kinetic test had a duration of 24 hours with sampling every 2.5 hours. The nitrogen removal efficiencies (%) determined in the kinetic test were 61.36 (R1); 61.01(R2); 59.03 (R3); 56.70 (R4); 62.77 (R5) and 64.40 (R6). Regarding pH, all reactors had an initial pH above 8.0 and a final pH close to neutral. The specific nitrogen removal rates (in mgN.gVSS-1h-1), were on average 29.43 (R1); 33.50 (R2); 33.62 (R3); 33.42 (R4); 28.90 (R5) and 30.34 (R6). The best performance in the kinetic assay was obtained in the R1 reactor, obtaining a specific activity of maximum nitrogen removal of 57.61 mgN.gVSS-1h-1 and molar generation of residual nitrate with a stoichiometric coefficient of 0.018 mol.

Use of Bacillus spp in the bioremediation of fats, oils and greases (FOG's), and other waste substrates in food processing effluents

Food production industries generate large amounts of untreated water-borne food wastes that accumulate and block drains and pipes, increasing life cycle operating costs. Food wastes contain high concentrations of protein, carbohydrates (sugars), and fats, causing a high nutrient load in the receiving water. Due to stringent waste disposal regulations and threats to water sustainability, these industries need viable waste treatment solutions. This study focused on augmenting food waste effluents using indigenous Bacillus organisms selected from a proprietary CSIR database. These microorganisms were screened for their constitutive enzyme production and other bioremediation markers. The biodegradation ability of selected isolates was tested individually and as mixed cultures using both synthetic and industrial food processing effluents. This study revealed that a consortium containing three microbial isolates, all identified as Bacillus cereus variants, demonstrated good bioremediation potential when used for the degradation of fats, oils, greases, and the reduction of odours.

Enhanced UV Direct Photolysis and UV/H2O2 for Oxidation of Triclosan and Ibuprofen in Synthetic Effluent: an Experimental Study.

This study aimed to evaluate the implementation of an advanced oxidation system based on UV radiation and UV/H2O2 for degradation of TCS and IBU in synthetic effluent. The assays occurred in a 2-L reactor, protected from external light and equipped with a UV lamp (λ = 254 nm). The effect of contaminant concentration, fractions of chemical species present, and mineralization were evaluated. In the UV/ H2O2 system, different concentrations of H2O2 were studied for oxidation of the contaminants. The kinetic experiments took place between 75 and 270 min of UV irradiation. The results showed > 99% oxidation of TCS in the direct photolysis system at pH 9.4 after 12 min. The degradation of IBU in the UV/H2O2 system, when 10 mg L−1 of H2O2 was used, was 97.39% oxidation. We obtained k′ values of 0.189 min−1 for TCS when its highest oxidation occurred and k′ values of 0.0219 min−1 for IBU. The system was not able to completely mineralize the contaminants, presenting high values of TOC and COD after treatment, thus suggesting the occurrence of phototransformation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11270-022-05583-z.

Adsorption of Chromium (VI) from Aqueous Solution Using Phytoremediation

The goal of this study is to assess how well sunflower waste can remove chromium (VI) from an under various process settings, an aqueous system is examined. Sunflower stalks were burned to create adsorbents, which were subsequently used to soak up water in a variety of applications. The use of Sunflower (Helianthus annuus L.) It has been investigated as a Cr (VI) reducing agent for the removal of hexavalent chromium from synthetic waste water. Adsorbent properties were determined via the use of ultraviolet (UV), x-ray diffractograms (XRD), infrared (FTIR), and magnetic hysteresis methods. 20 milligrams per liter of hexavalent chromium experiments a study on chromium recovery in batches found that increasing the pH of the aqueous solution enhanced metal recovery. pH = 7, adsorbent dose of 0.03 gr, and 25°C temperature were shown to be optimal for the removal of Cr (VI). Cr (VI) may be removed from synthetic model effluent by using Sunflower, according to the results of this study. The Sunflower plant has successfully cleaned synthetic waste water by rapidly removing Cr (VI) from aqueous solution.

Investigation of the Degradation Behavior of Cyclophosphamide by Catalytic Ozonation Based on Mg(OH)2

Metal hydroxides, owing to their catalytic active sites for the decomposition of O3 to Reactive Oxygen Species (ROS), have been adapted for catalytic ozonation of micropollutants in wastewater. In this study, commercial Mg (OH)2 was used for the degradation of cyclophosphamide (CYP) by ozone. The crystal phase was confirmed by X-ray powder Diffraction (XRD). Percent degradation of 10 ppm CYP after 30 min by O3 and Mg (OH)2/O3 was 56 and 93, respectively, suggesting enhanced decomposition of O3 to ROS by the catalyst. The presence of ROS was further confirmed using pCBA as a probe, which showed that the concentration of ROS was eight times higher in the presence of Mg (OH)2/O3 than O3 alone. Catalytic ozonation experiments in the presence of scavengers showed that OH· radicals play a significant role in the degradation of CYP. The catalyst was found to be reusable for at least three cycles without significant loss in degradation efficiency. To study the compatibility of Mg (OH)2 for wastewater treatment applications, synthetic effluent was spiked with CYP and subjected to ozonation by Mg(OH)2/O3. The TOC of CYP before and after the treatment showed that Mg (OH)2/O3 not only degrades CYP but also mineralizes to a certain extent unlike O3 alone.

Investigation of lead adsorption from synthetic effluents by modified activated carbon particles using the response surface methodology

Investigation of lead adsorption from synthetic effluents by modified activated carbon particles using the response surface methodology

Evaluation of petroleum as extractor fluid in liquid-liquid extraction to reduce the oil and grease content of oilfield produced water

This work aims to evaluate the use of petroleum as a solvent in the liquid-liquid extraction of oil and grease content from oilfied produced water. Initially, tests were performed with synthetic effluent, using cyclohexanecarboxylic acid as model compound through the study of physical-chemical parameters: pH, temperature, stirring speed and time, petroleum type and concentration, and initial concentration of naphthenic acids. Afterwards, the process was evaluated for the removal of oil and grease content from a real oilfield produced water sample. The pH and petroleum concentration proved to be significantly influential in removing cyclohexanecarboxylic acid from the synthetic produced water (ANOVA). The greater the amount of petroleum present, the greater the efficiency. By acidifying the synthetic effluent, the efficiency of removing these naphthenic acids from the synthetic produced water was increased. Response surface methodology (RSM) evaluated these two factors. On the other hand, the initial concentration of cyclohexanecarboxylic acid and petroleum type did not presented great influence on the obtained results, indicating robustness of the process. The methodology carried out with synthetic effluent proved to be efficient in removing the oil and grease content from real effluent (≈ 60% of removal at pH range 2–5).

Microalgae biomass as a sustainable precursor to produce nitrogen-doped biochar for efficient removal of emerging pollutants from aqueous media

Preparing sustainable and highly efficient biochars as adsorbents remains a challenge for organic pollutant management. Herein, a novel nitrogen-doped carbon material has been synthesized via a facile and sustainable single-step pyrolysis method using a wild mixture of microalgae as novel carbon precursor. Phosphoric acid (H3PO4) was employed as activation agent to generate pores in the carbon material. In addition, the effect of melamine (nitrogen source) was evaluated over the biochar properties by the N-doping process. The results showed that the biochar's specific surface area (SSA) increased from 324 to 433 m2 g−1 with the N-doping process. The N-doping process increased the percentage of micropores in the biochar structure. Chemical characterization of the biochars indicated that the N-doping process helped to increase the graphitization process of the biochar and the contents of oxygen and nitrogen groups on the carbon surface. The biochars were successfully tested to adsorb acetaminophen and treat two synthetic effluents, and the N-doped biochar presented the highest efficiency. The kinetics and equilibrium data were well represented by the General-order model and the Liu isotherm model, respectively. The maximum sorption capacities attained were 101.4 and 120.7 mg g−1 for the non-doped and doped biochars, respectively. The acetaminophen adsorption mechanism suggests that the pore-filling was the dominant mechanism for acetaminophen uptake. The biochars could efficiently remove up to 74% of the contaminants in synthetic effluents.

Towards Use of Persulfate Electrogenerated at Boron Doped Diamond Electrodes as Ex-Situ Oxidation Approach: Storage and Service-Life Solution Parameters

To date, a wide range of synthetic and real effluents have been treated using in situ electrochemically driven BDD-SO4 2−/SO4 ·−/S2O8 2− systems to eliminate persistent organic pollutants and microorganisms. Although reactive sulfate-based species are electrochemically generated in situ with free heterogenous ·OH radicals, SO4 2−/SO4 ·−/S2O8 2− species have a half-life greater than that of the ·OH radicals. However, no information has been published regarding the properties of the oxidant solution after its electrochemical synthesis. Here, an electrochemical BDD-SO4 2−/SO4 ·−/S2O8 2− system was evaluated in terms of solution oxidation power as a function of storage temperature, storage time, and ex situ applicability. Results clearly show that storage temperature has an influence on the storage and service-life of the solutions called fresh-persulfate (25 °C) or cold-persulfate (10 °C). Greater stability in the cold-persulfate solution was observed, as a function of time, and it was effective in degrading organic pollutants as an ex situ oxidation approach, eliminating 80.73%, 79.25%, and 63.25% after 120 min for methyl orange dye, 1,4-benzoquinone (1,4-BQ), and caffeine, respectively. Cold-persulfate solution also proved to be a feasible off-grid technology after 14 days storage. These results contribute to understanding of the fundamentals of sulfate aqueous solutions as precursors of sulfate-based oxidizing solutions and their applications.

Comparative Evaluation of Membrane Filtration on the Tertiary Treatment of Synthetic Secondary Effluent

Wastewater reuse is essential for sustainable water management. However, it requires tertiary treatment within the plant to ensure suitable water quality. This project aims to investigate the comparative performance of conventional tertiary treatment (sand filtration) against membrane filtration technology to demonstrate the viability of membrane treatment for wastewater reuse. Sand filtration along with two membrane filtrations, Nano Filtration (NF) and Reverse Osmosis (RO), were tested for their efficiency in removing the target pollutants: chromium, phosphate, and UV-254 from secondary effluent. Standard medium-sized laboratory setups were used. Synthetic secondary effluent was used for comparison among the different treatment processes. The synthetic effluent was compared to the real wastewater to demonstrate the reliability of using synthetic effluent. Evaluation of the role of time and pressure on the treatment efficiency was also examined. Based on the experimental results, RO had the highest removal efficiency for all pollutants with more than 90% removal. The experimental results also showed that synthetic wastewater was reliable in representing the treatability of real wastewater. Time did not seem to have an impact on the quality of filtration. Moreover, as pressure increased there was a slight increase in the efficiency. This trend was observed in all pollutants except UV-254. ANOVA showed different results of the effect of pressure on the removal efficiency in both RO and NF as well as time in NF.

A comparative study of chemical treatment by MgCl2, ZnSO4, ZnCl2, and KOH on physicochemical properties and acetaminophen adsorption performance of biobased porous materials from tree bark residues

Preparing sustainable and highly efficient biomass-based carbon materials (BBPM) as adsorbents remains a challenge for organic pollutant management. In this work, novel biobased carbon material has been synthesized via facile, sustainable, and different single-step pyrolysis chemical methods (KOH, ZnCl2, ZnSO4, and MgCl2) using a Norway spruce bark as suitable and efficient carbon precursor. The effects of each chemical activator on the physicochemical structure of synthesized were thoroughly investigated as well as its performance on the acetaminophen adsorption. The results showed that the use of different chemical activation provoked remarkable differences in the BBPM physicochemical characteristics. The KOH activation generated material with the highest specific surface area (2209 m2 g−1), followed by ZnCl2 (1019 m2 g−1), ZnSO4 (446 m2 g−1), and MgCl2 (98 m2 g−1). The chemical characterization of the carbon materials indicated that the activation of MgCl2 yielded a material around three times more hydrophobic when compared with the other activation methods. The acetaminophen removal showed to be ultrafast, not only due to the BBPM’s microstructure but also to the abundant active sites provided by the different chemical activation methods. The adsorption equilibrium times were reached at 1 min for BBPM-KOH and BBPM-MgCl2 and 15 min for BBPM-ZnSO4 and BBPM-ZnCl2. The adsorption process suggests that the pore-filling mechanism mainly dominates the acetaminophen removal but also some physical-chemical interactions such as hydrogen bonding between the amide group of acetaminophen and oxygenated or nitrogenated groups of biochar, π-π interactions between the aromatic ring of the pharmaceutical and the aromatics of biochar, n-π interaction, van der Waals interactions. The BBPM regeneration studies showed very good cyclability; in the 3rd cycle, the removal was approximately 70% for all four samples. The samples were also used to treat two synthetic effluents, which attained a removal percentage up to 91.9%.

Concentrating Fish Farm Effluent for its Nutrient Recovery via Nanofiltration

Excessive nutrients in aquaculture effluent have become an alarming environmental issue. However, current treatment methods for recovering nutrients are ineffective since the effluent contains trace amounts of nutrients. Pressure-driven nanofiltration (NF) is a potential solution to the problem of low concentration gradient. In this work, NF was applied to concentrate and recover the nutrients (ammonium (NH4+), phosphate, (PO43-), and nitrate ions (NO3-)) from the synthetic and real fish farm effluents. The experiments were first carried out to study the effect of membrane type, feed concentrations, and operating pressures on membrane performance. It is found that NF 90 membrane was able to retain more nutrient ions but compromise with a lower flux compared to NF 270. This study also revealed that an increase in feed concentration enhanced the concentrating ability for both PO43- and NO3- ions but reduced the concentrating factor of NH4+ ions. Moreover, both NF flux and concentrating factor increased with pressure. NF on actual fish farm effluents were investigated under optimal conditions (NF 90, 5 bar). Surprisingly, prefiltered effluent was found to have lower flux than raw effluent due to the presence of denser cake layer. NF could concentrate more nutrients from prefiltered fish farm effluent with concentrating factor up to 6.17 for PO43- ions and 1.55 for NH4+ions, claiming that NF was a promising approach for concentrating nutrients. These nutrients concentrate has an opportunity to be reapplied as fertilizer as a part of sustainable resource management.

Enhanced removal of nutrients and diclofenac by birnessite sand vertical flow constructed wetlands

The application of constructed wetlands (CWs) in organic micropollutants elimination is receiving increasing attention worldwide. However, acclimatization periods of CWs were long due to uncontrollable biotic factors and external conditions. In this study, manganese oxide was applied to enhance the simultaneous removal of nutrients and diclofenac (DFC) in CWs. To evaluate the treatment performance, two vertical up-flow CWs (VFCWs), with/without (experimental/ control) birnessite-coated sand VFCW, were set up to treat synthetic secondary effluent of the wastewater treatment plant. The removal performance of ammonia was significantly higher in experimental VFCW than that of control during the first 80 d, indicating that experimental VFCW could maintain a stable NH4+-N treatment performance (over 60%) when wastewater contained DFC. After 200 d of operation, the removal efficiency of DFC was achieved 98.5% in experimental VFCWs. The application of birnessite sand increased 12.8% of nitrogen load in the substrate, while phosphorus removal performance was enhanced by 10.0% on account of plant uptake. Though the final nutrients treatment performance was equivalent in experimental and control VFCWs, micro-environments at the middle layer were diverse for microbial communities. This work presents birnessite sand as the potential substrate of VFCWs for treating DFC as well as nitrogen and phosphorus pollutants.

Synthesis of Poly[dimethylaminoethyl Methacrylate–Hydroxyethyl Methacrylate] As an Adsorbent for Removal of RR195 from Synthetic Effluent: Kinetic and Thermodynamic Study

Synthesis of Poly[dimethylaminoethyl Methacrylate–Hydroxyethyl Methacrylate] As an Adsorbent for Removal of RR195 from Synthetic Effluent: Kinetic and Thermodynamic Study