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Landfill leachate is an important source of microplastics (MPs) and antibiotic-resistance genes (ARGs). Here, in the presence of polystyrene MPs (PS-MPs) and polyethylene MPs (PE-MPs), the nitrogen and phosphorus removal effect and sludge structure performance were affected in an anaerobic–anoxic–aerobic system, a typical biological leachate treatment process. The abundance of tetracycline-resistance genes (tet genes) in biofilms on the two types of MP was significantly higher than that in the leachate and sludge, and the load on PE-MPs was higher than that on PS-MPs because of the porous structure of PE-MPs. Aging of the MPs increased their surface roughness and abundance of oxygen-containing functional groups and shaped the profile of ARGs in the MP biofilms. The biofilm biomass and growth rate on the two types of MP increased with the incubation time in the first 30 days, and was affected by environmental factors. Structural equation models and co-occurrence network analysis demonstrated that the MPs indirectly affected the spectrum of ARGs by affecting biofilm formation, and, to a lesser extent, had a direct impact on the selective enrichment of ARGs. We discuss the mechanisms of the relationships between MPs and ARGs in the leachate treatment system, which will have guiding significance for future research. Our data on the colonization of microorganisms and tet genes in MPs biofilms provide new evidence concerning the accumulation and transmission of these ARGs, and are important for understanding the mechanisms of MPs in spreading pollution. [Display omitted] • The tet genes was enriched on the MPs biofilm and it boosted in leachate and sludge. • The aging of MPs shaped the profile of ARGs and ARB on MPs biofilm. • MPs reduced the richness and diversity of microbial community in A/A/O. • MPs integrated regulatory environmental factors to assemble ARGs and ARB. • Enhanced biochemical resistance and pathogens aggravated the MPs pollution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phosphate uptake on La-Fe-CNT film was a spontaneous-exothermic-multimechanism process. • Adsorption conditions were optimized by the response surface methodology. • The adsorption process was controlled by both intraparticle and surface film diffusion. • Adsorption mechanisms included ligand exchange, electrostatic attraction and surface complexation. Decreasing phosphate concentration in wastewater before discharge is crucial for preventing eutrophication. In this study, a novel La-Fe-CNT film was developed and its mechanism study for highly efficient phosphate adsorption was carried out. The morphology, thermal, structure and element analysis suggested that La and Fe hydroxide species were successfully fabricated on the CNT film and phosphate could be successfully adsorbed. The adsorption condition optimization of the La-Fe-CNT film was carried out by response surface methodology (RSM) with a Box–Behnken design (BBD). A low pH and low temperature were beneficial for the adsorption process, while the phosphate concentration showed little impact on phosphate uptake. It was indicated that pH = 4, temperature = 35.6 °C and phosphate concentration = 500 mg/L were the optimum adsorption conditions for La-Fe-CNT, with the optimized adsorption capacity of 137.8 mg/g, which was in good agreement with the actual value (140.3 mg/g). Thermodynamic analysis revealed that the q m of La-Fe-CNT film calculated from Langmuir model decreased from 164.9 mg/g to 121.7 mg/g from 30 to 80 °C, and the adsorption occurred through a spontaneous-exothermic-multimechanism process. This physicochemical process was controlled by both intraparticle and surface film diffusion. Adsorption experiments in presence of different ionic strengths and co-existing anions further confirmed the occurrence of inner-sphere and outer-sphere complexation during phosphate uptake. Overall, the La-Fe-CNT film showed ideal phosphate removal performance with high selectivity, indicating its potential for actual wastewater purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • The selective separation of V from BVS was achieved in the form of Pb 5 (VO 4) 3 OH. • Maximum Vanadium extraction efficiency reached 99.09% together with V 2 O 5 purity of 99.81%. • Removal of P, As and F was enhanced by double-salts precipitation of 2Na 3 AsO 4 ·NaF·19H 2 O, Na 3 PO 4 ·NaF·19H 2 O and NaSO 4 ·NaF. • The internal circulation system of auxiliary materials was established. Traditional approaches of vanadium recovery from Bayer vanadium sludge (BVS) discharged during the Bayer alumina production process affords large quantities of unusable solid waste and wastewater. In this study, a novel and sustainable process based on PbSO 4 precipitant was proposed to separate and recover vanadium from BVS. The results show that 99.09 % of vanadium was selectively extracted in the form of Pb 5 (VO 4) 3 OH with a Pb/V molar ratio of 1.7, NaOH concentration of 60 g/L at 70 °C for 30 min, whereas along with only 0.52 % of arsenate, 0.53 % phosphate, and 0.16 % of fluoride. To facilitate further recovery, the remaining phosphate, arsenate, and fluoride were simultaneously separated from NaOH solutions by evaporation crystallization and enriched into residue in the forms of 2Na 3 AsO 4 ·NaF·19H 2 O, 2Na 3 PO 4 ·NaF·19H 2 O, and NaSO 4 ·NaF. Subsequently, H 2 SO 4 leaching followed by (NH 4) 2 SO 3 leaching realized the maximum vanadium leaching efficiency of 99.15 % from Pb 5 (VO 4) 3 OH precipitate. Finally, the vanadium was deposited as (NH 4) 2 V 6 O 16 from leachate by adding stoichiometric (NH 4) 2 S 2 O 8 and then prepared the V 2 O 5 product with a purity of 99.81 %. Herein, the whole process realized the internal circulation of PbSO 4 , NaOH, water and solved the difficult treatment of solid waste and wastewater, which provides a new strategy for cleaner comprehensive utilization of BVS. [ABSTRACT FROM AUTHOR]

[Display omitted] • The introduced F-SBR had negligible effects on nutrient removal in S-SBR. • SVI 30 /SVI 5 of 86.9 % and SVI 30 of 45.8 mL/g reflected excellent sludge settleability. • The D av and D 90 of DAS particles were respectively less than 43 and 80 µm. • Shift work mode induced F/M rise and filamentous bacteria temporary proliferation. • The formation of DAS was attributed to applying shift work mode in the SNDPR system. Forming granular-like sludge in the Simultaneous Nitrification-Denitrification and Phosphorus Removal (SNDPR) process would promote nutrient removal and improve the sludge settleability. This study introduced the "shift work mode" into an SNDPR system, which featured that 50 % of sludge was temporarily transferred into and "rested" in a side-stream reactor a cyclic time rather than let it keep "working" in the mainstream SNDPR reactor. Results showed that 77.6 % of inorganic nitrogen and 80.6 % of orthophosphate were removed well even after the combination, which attributed to the co-work of Candidatus_Competibacter (10.1 %–29.0 %), nitrifiers, and phosphate accumulating organisms. The 30-min settled sludge volume and sludge volume index were 8 % and 45.8 mL/g, respectively, the sludge density was 1.045 g/mL, and cumulative 90 % of the particle diameter was less than 80 µm; these indicated the densified activated sludge was formed. After analyses, the increase in the food-to-microorganisms ratio and temporary enrichment of filamentous bacteria Thiothrix might be the causes. Such shift work mode promisingly serves as a simple and practical way to improve settleability and promote granulation. [ABSTRACT FROM AUTHOR]

[Display omitted] As a novel adsorbent to removal phosphate from water, Co 3 O 4 magnetic nanoparticles functionalized with zeolite-A-@silica nanocomposites were created. The produced adsorbent was evaluated for phosphate removal efficiency using batch adsorption tests, as well as X-ray diffractometry (XRD), scanning electron microscopy (SEM), EDX, BET, and FT-IR. The synthesized adsorbent with a BET (Brunauer–Emmett–Teller (BET) surface area of 8.367 m2/g, porous zeolite-A, was successfully constructed with Co 3 O 4 and nanosilica, according to characterization results. The newly created adsorbent performed incredibly well at adsorbing phosphate; according to the Langmuir model, it had a maximum adsorption capacity of 344.83 mg/g. The adsorption occurred quickly, and the pseudo-first-order kinetic model provided the greatest fit for the kinetic data. As the pH of the solution increased (2 to 10), the elimination of phosphate reduced. The experimental results indicated negative ΔG, negative ΔH, and positive S, suggesting the exothermic and spontaneous process of PO 4 -3 adsorption on synthesized adsorbents. [ABSTRACT FROM AUTHOR]

Large amounts of nitrogen and phosphorus elements were discharged into the environment. They would lead to severe eutrophication of water bodies. The development of economically efficient, green and ecological adsorbents is the current focus for adsorption technology. In this research, the cost-effective biochar modified by Mg/Ca bimetallic oxide composites (Mg/Ca@PS) for adsorption of NO3- and PO43- ions in aqueous solution was investigated. Additionally, Mg/Ca@PS also was characterized by scanning electron microscopy, transmission electron microscopy, energydispersive X-ray analysis, X-ray diffraction, and Fourier-transform infrared spectroscopy, respectively. The experimental results showed that the adsorption process of NO3- ions in aqueous solution by Mg/Ca@PS could be described by pseudo-second-order kinetic model and Langmuir isotherm model, respectively. However, the adsorption process of PO43- ions in solution by Mg/Ca@PS could be described by pseudo-second-order kinetic model and Freundlich isotherm model, respectively. Additionally, the adsorption capacity of NO3- and PO43- ions in aqueous solution by Mg/Ca@PS were 18.52 and 47.85 mg/g, respectively. The adsorption mechanisms of NO3- ionsand PO43- ions in solution by Mg/Ca@PS mainly contain surface adsorption, intraparticle diffusion, electrostatic attraction, and ion exchange. Moreover, the adsorption mechanism of PO43- ions in solution by Mg/Ca@PS also includes chemical precipitation. In the five recycle times, the removal rate of NO3- and PO43- ions still reached 55.31% and 48.12%, respectively. It indicated that the chemical stability of Mg/Ca@PS was very well, and it was a good environmental friendly material. [ABSTRACT FROM AUTHOR]

Leather tannery wastewater pollutes the environment because it contains BOD, COD, and chromium at levels above safe thresholds. The main objective of this study was to determine the effect of exposure to tannery wastewater on the viability of the soil PSB community and selected PSB isolates, and to examine the ability of selected bacterial isolates to dissolve phosphate in Picovskaya's broth medium supplemented with tannery wastewater. The viability of the bacterial community was determined based on their growth in soil exposed to the waste at concentrations of 30, 60 and 100%, under field capacity moisture conditions, while the ability of the isolates to dissolve phosphate was observed using liquid Pikovskaya's medium which was added to the waste so that the concentration reached 30, 60, and 100%. The bacterial isolates RP-1 and RP-2 were used, which were obtained from the soil surrounding the tannery which was contaminated with leather tanning waste. The parameters that were analyzed were the number of cells and the amount of soluble phosphate. The number of cells was determined through the pourplate method using an agar nutrient medium, and the amount of soluble phoshate was examined using the P chlorostannous reduced molybdophosphoric acid blue method. According to the findings of this study, exposure to effluents reduced PSB viability in the soil. Exposure to waste also negatively affected cell viability and the ability of isolates to solubilize phosphate. [ABSTRACT FROM AUTHOR]

Wastewater consisting of different pharmaceuticals and drug residues is quite challenging to treat and dispose of. This situation poses a significant impact on the health aspect of humans and other biotic organisms in the environment. The main concern of hospital wastewater (HWW) is the resistivity towards treatment using the different conventional methods. For the treatment of HWW, this study was performed using an electro bioreactor using hospital wastewater. The electro reduction overcomes the effect of toxic elements in hospital wastewater, and biodegradation removes organic matter and nutrients from wastewater. This study investigated electro bioreactor performance for treating hospital wastewater connected with tubesettler. The parameters of chemical oxygen demand, nitrate, and phosphate concentration were analyzed to evaluate an influent and effluent from electro bioreactor and tubesettler. Also, Kinetic modelling for chemical oxygen demand, nitrate, and phosphate removal was done. The chemical oxygen demand was reduced by 76% in electro bioreactor, and 31% in tubesettler, 84%. The nitrate and phosphate were reduced within permissible discharge limits with a final effluent concentration of 1.4 mg L−1 and 3 mg L−1. Further studies are required to assess the impact of pharmaceutical compounds in hospital wastewater on the system's performance. [ABSTRACT FROM AUTHOR]

Phycoremediation of swine wastewater is a promising treatment since it efficiently removes nutrients and contaminants and, simultaneously, its biomass can be harvested and used to obtain a wide range of valuable compounds and metabolites. In this context, biomass microalgae were investigated for the phycoremediation of swine wastewater, and biomass extracts for its virucidal effect against enveloped and non-enveloped viruses. Microalgae were cultivated in a pilot scale bioreactor fed with swine wastewater as the growth substrate. Hexane, dichloromethane, and methanol were used to obtain the microalgae extracts. Extracts were tested for virucidal potential against HSV-1 and HAdV-5. Virucidal assays were conducted at temperatures that emulate environmental conditions (21 °C) and body temperature (37 °C). The maximum production of microalgae biomass reached a concentration of 318.5 ± 23.6 mgDW L−1. The results showed that phycoremediation removed 100% of ammonia-N and phosphate-P, with rates (k1) of 0.218 ± 0.013 and 0.501 ± 0.038 (day−1), respectively. All microalgae extract reduced 100% of the infectious capacity of HSV-1. The microalgae extracts with dichloromethane and methanol showed inhibition activities at the lowest concentration (3.125 µg mL−1). Virucidal assays against HAdV-5 using microalgae extract of hexane and methanol inhibited the infectious capacity of the virus by 70% at all concentrations tested at 37 °C. At a concentration of 12.5 µg mL−1, the dichloromethane microalgae extract reduced 50–80% of the infectious capacity of HAdV-5, also at 37 °C. Overall, the results suggest that the microalgae can be an attractive source of feedstock biomass for the exploration of alternative virucidal compounds. [ABSTRACT FROM AUTHOR]

Phosphorus is essential to the growth of living organisms, and, therefore, its presence is considered vital for all forms of life. Research shows that phosphate rock reserves are reducing. Phosphate rock is used as raw material for the production of phosphate- based fertilizers, and its lack of supply could have adverse effects on the global food supply. New resources that can be a potential replacement for phosphate rock in the production of fertilizers and other phosphorus-containing substances are investigated. This paper provides an overview of technology implementations, methods, and processes, as well as the latest achievements in the field of phosphorus recovery from waste streams. Different methods of phosphorus regeneration from sewage sludge and solid waste, and forms of phosphate regeneration are described. In addition, an overview of the following methods is given: nanonucleation, adsorption and ion exchange, solar evaporation, biological assimilation of P, and membrane technologies. [ABSTRACT FROM AUTHOR]

Microalgal cell leakage from immobilized beads due to mass transfer limitation and inert support matrix pose major problem during its application in the wastewater treatment process. To overcome this, Ca2+-alginate immobilization with water (AWIM—Alginate in Water Immobilized Microalgal system) and Blue Green (BG)-11 media (ABIM—Alginate in BG-11 Immobilized Microalgal system) using Chlorella sorokiniana NCIM 5561 was employed to determine their efficacy. Upon comparison of microalgal growth in the beads, ABIM resulted in better kinetic properties such as biomass yield, specific growth rate and productivity as 933.12 mg L−1, 0.42 day−1 and 77.78 mg L−1 day−1, respectively, as compared to AWIM. Flow cytometry and SEM analysis revealed that ABIM could hold up more cell density as compared to AWIM due to the reduced pore size and growth nutrient localization in the bead matrix. A novel strategy of co-cultivation of yeast along with microalgal cells under immobilized condition was attempted for improved phosphate uptake from the simulated wastewater. The results indicated that the co-cultivation resulted in minimum residual phosphate concentration of 0.75 mg L−1 as compared to ABIM and AWIM with corresponding concentration of 1.02 and 1.71 mg L−1, respectively. However, the rate of uptake was found to be superior with ABIM (0.41 h−1) than co-cultivation (0.29 h−1) and AWIM (0.23 h−1) that correlates to overall removal efficiency of 94.54%, 80.64% and 67.07%, respectively. [ABSTRACT FROM AUTHOR]

Tomatoes (Solanum lycopersicum) plant were provided with bio-fertilizers issued from anaerobic digestion of olive mill wastewater without and with 1%, 5% of phosphate residues in mesophilic conditions for 25 days. 1% of raw substrates (OMW raw; OMW + 1%PR raw; olive mill wastewater + 5%phosphate residues raw; and phosphate residues) and digestates (olive mill wastewater digestate, olive mill wastewater + 1%phosphate residues digestate and olive mill wastewater + 5%phosphate residues digestate) was provided fortnightly to the plants. Reclaimed water from a wastewater treatment plant located in the study site was used for automatically controlled irrigation. It contained a low level of chemical fertilizers to compare tomato plant growth, leaf analysis, steam water potential, production yield and fruit quality results to plants fed with bio-fertilizers. Generally, parameters and results were progressively increased during the growing and harvesting stage, which refer to the essential elements that cover the plant's needs. Plants fed with bio-fertilizers showed the most extended plant height (olive mill wastewater + 5% phosphate residues raw), and the best accumulation of essential elements in leaves (olive mill wastewater + 1% phosphate residues digestate and olive mill wastewater + 5%phosphate residues digestate). The maximum average fruit weight per treatment (35.5 g) was obtained when applying the digestates mixture of olive mill wastewater raw and olive mill wastewater + 5% phosphate residues. The maximum yield production per plant was obtained when applying phosphates residues. Bio-fertilizers (digestates) showed good performances, high fruit quality and perfect tomato yield production compared to the control plants. Results obtained during this study are considered promising regarding environmental framework. However, this study was done in a laboratory scale and needs to be applied in a large scale to provide more data on the effectiveness of the digestates application. It is also recommended to apply these bio-fertilizers on different crops and various soils for a better evaluation. [ABSTRACT FROM AUTHOR]

The wastewater originates from different industrial, municipal, and agriculture processes and contains different nitrogen sources, for example, nitrate, ammonium, nitrite, and phosphate such as inorganic and organic sources. The discharge of high nitrate and phosphate to the ecosystem or nearby water bodies can cause eutrophication which disbalances the aquatic ecosystem. Furthermore, ingestion of these pollutants can cause severe toxicity and disease to humans and animals. Thus, from an environmental and social perspective, its treatment is essential with no negative impact on the ecosystem. Microalgae are fundamental, mixotrophic microorganisms that treat different wastewater and utilize nitrate and phosphate in the medium as a source of nutrients. Among them, Picochlorum sp., have the potential to remove nitrogen and phosphate from wastewater. The biomass produced by Picochlorum sp. can be a promising candidate as a sustainable feedstock for biofuel and bioproducts formation. Thus, the present review provides a brief knowledge and understanding about the concentration of nitrogen and phosphate in different wastewater, their negative impacts, and the uptake mechanism of microalgae. Furthermore, the review also provides an insight into Picochlorum sp., and the effects of different physiological and nutritional factors on their growth, wastewater treatment efficacy, and biomass for value‐added products and biorefinery applications. In addition, the review is useful to understand the potential of Picochlorum sp. for a tenable wastewater treatment process. [ABSTRACT FROM AUTHOR]

The novel two-stage treatment system consisting of cascade cum trickling filter (CCTF) and multilayer adsorption (MLA) bioreactor was developed to enhance the contaminants removal such as chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP). The maize cob and date palm fiber were used as biofilm support media in trickling filter. The MLA bioreactor was operated using the composite adsorbent (refused crushed brick + rice husk + steel slags). The maximum adsorption uptake of composite adsorbent was observed as 0.6 mg/g for ammonium and 3.5 mg/g for phosphorus. Kinetic analysis showed that the composite adsorbent had a faster removal rate for phosphate than ammonium. The maximum desorption of ammonium and phosphate was found to be 14.6% and 6.5%, respectively. The performance of both cascade cum trickling filter and multilayer adsorption (CCTF-MLA) systems was also evaluated using the various COD-TN ratios and flow rates. The removal efficiencies of COD, TN and TP were found 93%, 87% and 86%, respectively, and their corresponding mean effluent concentrations were noted 18 mg/L, 5.5 mg/L and 2.3 mg/L. The developed CCTF-MLA system removed the 3log of the total count and total coliform and 2log of Escherichia coli and salmonella. So, the CCTF-MLA system could be efficient for wastewater treatment due to the steady removal rate of COD, TN and TP. [ABSTRACT FROM AUTHOR]

Phosphate containing untreated wastewater, discharged into water bodies, can cause eutrophication, leading to harmful effects on the ecosystem and human health. This study focuses on a simple, low‐cost, and novel approach towards removing excess phosphate ions from aqueous solutions by adsorbing on onto two‐dimensional (2‐D) magnesium oxide nano‐flakes (MONFs). The phosphate removal efficiency was tested with different concentrations of phosphate solutions (2–25 mg L−1), pH levels (3–11), adsorbent dosages (0.025‐0.250 g), and contact times (10‐50 min). The maximum phosphate removal percentage of 100 % was obtained with 50.0 mL of 3 mg L−1 phosphate solution using 0.125 g of the synthesized MONFs with a phosphate absorption capacity of 29.9 mg g−1. Moreover, the adsorption data fit with the Freundlich isotherm, with an R2 value of 0.952. The adsorption kinetic data follow the pseudo‐second‐order model, with an R2 value of 0.995, suggesting that the adsorption process is chemisorption. [ABSTRACT FROM AUTHOR]

To control eutrophication and recover phosphate from wastewater, a calcium carbide slag and red mud composite material (CR-LDH) was prepared using industrial waste as raw material for phosphorus adsorption. The morphology and structure of synthesized CR-LDH were characterized by FT-IR, SEM, EDS, and XRD measurements. Bath adsorption test results showed that the optimal dosages of adsorbent and pH for phosphate were 5 g·L−1 and pH of 7, respectively. The experimental data could be well described by pseudo-second-order kinetic and Langmuir isotherm models, suggesting that the adsorption process of CR-LDH with respect to phosphate was a chemical and monolayer process. The theoretical maximum adsorption capacity obtained by Langmuir isotherm model was 16.06 mg·g−1 at 25 °C. The intra-particle diffusion model fitting results indicated that the adsorption of phosphate by CR-LDH was controlled by both liquid membrane diffusion and intra-particle diffusion. Phosphate was bound to CR-LDH via synergistic effect of physical adsorption, ion exchange, anion intercalation, and chemical precipitation as evidenced from a combination of microscopic analysis and adsorption mechanism study. The actual phosphate-containing wastewater investigation showed that CR-LDH not only exhibited good removal effect on phosphate, but also could greatly reduce turbidity, COD, and ammonia nitrogen, which was suitable for disposal of practical wastewater. The COD, turbidity, and NH4+-N could be reduced by 42.39%, 77.20%, and 20.71%, respectively. These results indicate that CR-LDH can be considered as potential adsorbent for the treatment of phosphate-containing wastewater, which will be helpful to achieve the goal of "treating waste with waste and turning waste into treasure". [ABSTRACT FROM AUTHOR]

Developing easily separable materials for efficient treatment of low-concentration phosphate which causes eutrophication of water bodies are full of challenges. A magnetic CuFe2O4/MIL-101(Fe) composite composed of hollow spheres CuFe2O4 and octahedrons MIL-101(Fe) was first fabricated via a facile solvothermal approach. CuFe2O4/MIL-101(Fe) (1.0 g·L−1) exhibited above 88.4% adsorption efficiency for low-concentration phosphate (5.0 mg·L−1) removal, over a wide pH ranging 2–12 at 293 K. Phosphate adsorption was a spontaneous endothermic process, in good association with Langmuir and pseudo-second-order kinetic model. The XPS and FT-IR analysis elucidated that electrostatic interaction and coordination exchange were main mechanisms. In addition, after four cycles, CuFe2O4/MIL-101(Fe) displayed 75.0% adsorption of phosphate, by treatment with external magnetic field separated and 0.1 mol·L–1 NaOH desorbed. Therefore, CuFe2O4/MIL-101(Fe) exhibited high selectivity and recycling for removing phosphate from wastewater. [ABSTRACT FROM AUTHOR]

Sewage sludge from municipal wastewater treatment plant was a rich phosphorus resource. In this study, HCl, H2SO4, and HNO3 were investigated as leaching acids for extraction of phosphate from the sludge to recover this value nutrient by adsorption using layered double hydroxide (LDH) nanomaterial. Mg-Al LDH was synthesized by coprecipitation at room temperature and at a constant pH of 10 (±0.5) with Mg/Al molar ratio of 2.0. The material was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET), and Fourier transform infrared spectroscopy (FTIR) and then was used to adsorb phosphate leaching from the sewage sludge. Adsorption experiments were carried out as a function of adsorbent dose, phosphate initial concentrations, and pH. The adsorption isotherm data fitted the Langmuir model perfectly. The high adsorption capacity of Mg-Al LDH and slowly released phosphate of the post-adsorption LDH suggested that this material was an excellent adsorbent for phosphate recovery and could be considered as a potential phosphate release fertilizer. [ABSTRACT FROM AUTHOR]

Besides existing methods of urban wastewater treatment processing (WWTP), microalgae culture systems are one of the environmental friendly methods for improving urban wastewater treatment. In this research, the removal efficiency of N-nitrate and orthophosphate from urban wastewater were investigated using free and immobilized Chlorella vulgaris microalgae, Pseudomonas fluorescens bacteria and symbiosis of microalgae with bacteria. Pseudomonas fluorescens bacteria are a group of bacteria that stimulates plant growth. The performance of immobilized microalgae and immobilized bacteria in nitrate removal was better than that in free microalgae and free bacteria. The results showed that the maximum removal efficiency of N-NO3 was 87.06% in immobilized microalgae (MIM). In removing orthophosphate, free microalgae-bacteria (MBFr) and immobilized microalgae—bacteria (MBIm) had higher performance among other treatments with removal efficiency of 89.64% and 86.38%, respectively. According to significant reductions of orthophosphate on the second day of measurements, the residence time could be considered about two days. [ABSTRACT FROM AUTHOR]

High amounts of phosphate discharged in receiving water can lead to eutrophication. Once a water body is enriched with phosphate, it can prompt the growth of plants and cause algal blooms. The water body may also lose its important functions and cause adverse effects on the environment and human health. In this study, removal of phosphate from domestic wastewater treatment plant effluent was elucidated using iron-coated waste mussel shell. The phosphate adsorption by iron-coated waste mussel shell was examined with respect to initial phosphateconcentration (7 mg L–1), solution volume (0.2 L), adsorbent dosage (4–20 g), and contact time (1–5 day). The chemical composition of iron-coated waste mussel shell was analyzed using energy dispersive X-ray fluorescence spectrometer. The measurement of the specific surface area of iron-coated waste mussel shell was performed by multiple-point method according to the Brunauer, Emmett, and Teller theory. Several kinetic models (i.e., pseudo-first order and pseudo-second order) and isotherm models (i.e., Freundlich and Langmuir) were used to describe the adsorption behavior. The optimum removal efficiency of phosphate can reach at 95.7% after 120 h with the amount of iron-coated waste mussel shell used to run the experiment was 20 g and the treated effluent phosphate concentration of 0.3 mg L–1, was verified. Experimental data can be well described by pseudo-second order kinetic model (R2 > 0.99) and Freundlich isotherm model (R2 = 0.93), suggesting that chemisorption and multilayer adsorption occurred. Furthermore, a two-stage batch system was proposed to assess the optimum adsorbent dosage for phosphate removal. The two-stage system has contributed to reduce iron-coated waste mussel shell dosage by 56.94%, as compared to one-stage and thus reduced the operating cost of iron-coated waste mussel shell. [ABSTRACT FROM AUTHOR]

Open sewage contaminated channel wastewater (OSCCW) has high pollutant loads, responsible for eutrophication, when mixed with various channels of urban communities. But, these pollutants can be converted and recovered into useful end products with the help of algal species. In this study, two species of Chlorella (C. vulgaris and C. pyrenoidosa) were selected and investigated for the production of algal biomass and nutrient removal efficiencies with 50% concentration of OSCCW, in a comparative way at lab-scale. Chlorella sp. cultivated in OSCCW have removed nitrate (76.9–78.8%) and phosphate (67.6–79.7%) whereas COD (72.4–76.2%) and BOD (62.3–72.4%) respectively. Correlation analysis was investigated between physico-chemical parameters and biochemical profile of both species to analyze the positive and negative correlation between two variables. The bio-chemical profile and biomass productivity of both species of Chlorella were observed well on the basis of productivity of biomass (60.1, 56.5 mg/l/d), carbohydrate (15.71, 8.82 mg/l/d), protein (11.21, 15.82 mg/l/d), lipid (20.8, 17.5 mg/l/d) and chlorophyll (0.78, 0.67 mg/l/d) in OSCCW. The maximum lipid content (34.6%) was obtained with C. pyrenoidosa as compared to C. vulgaris. Findings also support that OSCCW is well-off with nutrient resources, which can be suitable alternative for algal biomass production and remediated wastewater can be used for animal and fish farming type activities. [Display omitted] • Chlorella sp. are used to treat open sewage contaminated channel wastewater (OSCCW). • Nutrients and pollutants in OSCCW have been investigated for dual benefits. • Maximum resource recovery is observed from OSCCW. • C. pyrenoidosa produced the highest 34.6% lipid in 50% of OSCCW. • Correlation analyzed between biochemical profile of algae and parameter of OSCCW. [ABSTRACT FROM AUTHOR]

Excessive discharge of phosphorus into the water bodies is the key factor to cause eutrophication. The fruit and vegetable wastewater contains large amounts of phosphorus, and it may be directly discharged into water bodies, which has a great burden on the municipal sewage pipe network. Therefore, coagulation was used to remove phosphorus, recovered the phosphorus from the wastewater into the precipitate, and then the precipitate was pyrolyzed as an efficient adsorbent for phosphate removal. By comparing the adsorption effects of adsorbents (XT-300, XT-400, and XT-500) with pyrolysis temperatures of 300 °C, 400 °C, and 500 °C on phosphate in actual phosphorus-containing wastewater and simulated phosphorus-containing wastewater at different adsorbent dosage (4 g/L, 7 g/L, and 10 g/L), it was found that XT-300 had the best performance of adsorption, and the adsorption of phosphate was endothermic and obeyed the Langmuir isotherms and Elovich kinetics. The influence of pH, coexisting anions, and the structure of XT-300 revealed that the removal of phosphate was associated with electrostatic attraction, pore filling, but could not be determined whether it was related to surface precipitation. This study provides a way and method for the recovery and utilization of phosphorus in fruit and vegetable wastewater and proves that the synthetic adsorbent was an efficient phosphorus adsorbent. In the long term, we can try to use the adsorbent after phosphorus adsorption to promote plant growth in agricultural systems. [ABSTRACT FROM AUTHOR]

In order to increase the reuse of wastes and residues, as required by the Waste Framework Directive, the potential use of waste, residue and natural minerals as low-cost permeable reactive barrier (PRB) materials was investigated. The performance of a kitchen waste compost, sepiolite and steel slag was compared with that of volcanic slag, pumice and activated carbon in removing specific contaminants from landfill leachate. The experiments represented that the activated carbon removed 27% of the ammonium (NH4+), 75% of the chemical oxygen demand (COD) and 100% of the phosphate (PO43-), zinc (Zn2+) and nickel (Ni2+) from the landfill leachate. Volcanic slag exhibited removal efficiencies of50% COD and 100% PO43- and pumice exhibited removal efficiencies of 20% NH4+, 27% Zn2+, 65% COD and 100% PO43-. The reactive materials were also checked for their potential in releasing unwanted constituents and represented different levels of the solute (e.g., PO43-, SO42-, NH4+) release. Among the reactives, sepiolite was found to be the reactive material reflecting a minor release (e.g., Zn2+, Cd2+ and Ni2+), but also delivering removal efficiencies of 40, 50, 65, 95, 97, 98, 98 and 100% for Ni2+, COD, Zn2+, SO4²-, Cl-, F-, NH4+ and PO43-, respectively. The results show that the studied materials have the potential as reactives for PRB systems treating high strength contaminant plumes. [ABSTRACT FROM AUTHOR]

The most common method of treating palm oil mill effluent (POME) is by using various types of bacteria communities. However, the utilization of microalgae in consuming the high nutrient content in wastewater offer additional benefit, particularly for CO2 sequestration. In this study, we proposed to evaluate the performance of multicultural bacteria obtained from municipal wastewater and Chlorella sp. for batch treatment of POME at different COD concentrations (ranges between 600 to 1,300 mg/L), microalgae species (C. vulgaris and C. pyrenoidosa) and speed of agitation (0 and 150 rpm). The results showed that between the bacteria and microalgae that are involved in POME treatment, microalgae give high removal of colour (93%) and ammoniacal nitrogen (95%). As for the COD and phosphate removal, both microorganisms show comparable performances. It was observed that C. pyrenoidosa was able to remove more colour compared to C. vulgaris where higher lipid yield production was obtained (47.6%). However, there is no significant impact of agitation on pollutant removal. This study also reveals that co-cultivation of different microalgae species does not affect the efficiency of the system. This study provides an important insight into developing an efficient and environmentally friendly method to treat wastewater by incorporating green technology in the treatment system. [ABSTRACT FROM AUTHOR]

Biofilter technology for wastewater treatment is relatively complex and is gaining more interest. However, it should be emphasised that various aerobic conditions may occur in biological filter beds, which depend primarily on the velocity of wastewater flow through the bed. Therefore, it is often difficult to precisely determine the transformations of carbon and nitrogen compounds that occur during wastewater treatment on these types of filter beds. This study investigated the effectiveness of the filter bed and analysed the extent of the transformation of carbon and nitrogen compounds in the range of filtration velocities from 0.02 to 0.60 m·h-1. The study was conducted under laboratory conditions, and model wastewater was prepared on the basis of sodium acetate, ammonium chloride, potassium nitrate and potassium dihydrogen phosphate. The model wastewater was prepared with parameters corresponding to those of the treated wastewater. The experiment showed that anaerobic and aerobic conditions occurred in the biological filter bed at filtration velocities of up to 0.16 m·h-1. Above this velocity, aerobic conditions prevailed in the biological filter bed. [ABSTRACT FROM AUTHOR]

Conventional process schemes of municipal sewage water treatment, advantages, and disadvantages of the methods applied when removing biogenic elements were considered. It was shown that the existing shortcomings cause additional explicit costs and difficulties when disposing of the resulting waste. Low efficiency of the removal processes themselves causing residual concentrations of biogenic elements in the treated sewage water was also shown. A process scheme for treating municipal sewage water was proposed. It includes the use of a photobioreactor of a proposed design for the removal of biogenic elements due to the metabolism of microalgae. It was experimentally shown that the use of Euglena gracilis strain for removal of phosphates in initial concentrations of 4, 7, and 14 mg/dm³ from sewage water is the most efficient way. It makes it possible to reduce these concentrations to residual 0…0.55 mg/dm³ in four days. A 3.75…5.58 times increment of microalgae biomass during this period was also shown. A mathematical model was constructed for calculating the time of staying the sewage water and microalgae mixture in a photobioreactor to achieve the required degree of removal of biogenic elements. Based on the proposed model and experimental studies, the required time of staying in the rector working area was calculated. It was shown that with the use of Euglena gracilis strain but without removal of biogenic elements at previous purification stages (process schemes including only mechanical purification), the time of mixture staying in the working zone was 37.81 hrs. With partial removal of biogenic elements at the stage of biological treatment (0.55 mg/dm³ total nitrogen, 0.91 mg/dm³ ammonium nitrogen, 0.44 mg/dm³ phosphates), this time was reduced to 26.66 hrs. It was found that the use of Euglena gracilis strain instead of Chlorella vulgaris (FC-16) in the removal of phosphates results in a 2-time increase in the process efficiency and a 50 % decrease in time of mixture staying in the working zone. Recommendations for calculating geometric parameters of photobioreactors of the proposed design were given for use in the process schemes [ABSTRACT FROM AUTHOR]

In Vietnam, the major problem for the sustainability of the shrimp aquaculture industry is the management of shrimp aquaculture wastewater. A promising solution to remediate pollutants in shrimp aquaculture wastewater is to use floating treatment wetlands (FTWs) in combination with pollutantdegrading bacteria. Hence, this study aimed to evaluate the effect of inoculation of endophytic bacteria isolated from Man Trau grass on the remediation of shrimp aquaculture wastewater in FTWs vegetated with grass (Brachiaria mutica). The results showed that FTWs only vegetated with B. mutica removed organic and inorganic pollutants from shrimp aquaculture wastewater and a significant reduction was observed for total dissolved solids (TDS), chemical oxygen demand (COD), ammonium (NH4+-N), nitrate (NO3--N), and phosphate (PO43--P) with efficiency is 60, 71, 80, 65, and 73%, respectively. Interestingly, the efficiency removal was further improved by the inoculation of endophytic bacteria. The combination of plants and bacteria produced the highest removal of COD (73%), NH4+-N (96%), NO3--N (80%), PO4³--P (81%), Cu (95.3), and Fe (93.4%). Moreover, the inoculated bacteria were also validated their presence in water as well as in roots and shoots of the vegetated plant. In addition, the treated water output met the wastewater discharge standards of the World Health Organization. Therefore, the results suggest endophyte-assisted FTWs are a suitable approach for the remediation of shrimp aquaculture wastewater. [ABSTRACT FROM AUTHOR]

Aniline is a toxic organic pollutant and raw material in industries. In this study, the start-up of sequencing batch reactor for treating aniline wastewater was assessed and functional microbial clusters were analyzed after enrichment of denitrifying phosphate-accumulating organisms (DNPAOs). The aniline degradation and subsequent removal of NH4+-N mainly happened in aerobic condition, and denitrification was conducted in both anaerobic and anoxic conditions. Besides aerobic phosphorus uptake, phosphorus accumulation also occurred via DNPAOs in anoxic condition utilizing nitrate as electron acceptor. The removal efficiencies of COD, NH4+-N, TN, and TP was over 91.6, 67.1, 65.0, and 79.9% respectively. Proteobacteria, Bacteroidetes, and Firmicutes were found to be predominant at phylum level treating aniline wastewater. Blastocatella, Ferruginibacter and Clostridium were predominant strains involved in aniline degradation and Pseudomonas was enriched in the presence of aniline. Aeromonas, Acinetobacter, and Comamonas may play key roles in nitrogen removal and phosphorus accumulation with tolerance of aniline. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the adsorbent potential of rice husk and its modified form for phosphate and nitrate removal from synthetic and swine-farm wastewater. The mechanism of adsorption as well as the potential of phosphate-/nitrate- adsorbed rice husk as nutrient rich residue was also investigated. Two-step modification of RH (using base-washing (BW) and chemical modification (CM) was conducted to compare the phosphate and nitrate removal. The effects of several factors (pH, sorbent dosage, contact time, initial concentration, and coexistence of both ions) were investigated to gain insight into the adsorption rate, behavior, and mechanism of the modified RH regarding phosphate and nitrate removal. The results of Fourier-transform infrared spectroscopy showed that the modification was successful by crosslinking with the amine group of the chemical agent. Fitting the adsorption kinetic data of phosphate showed physical adsorption, intraparticle diffusion, and chemisorption, whereas for nitrate, the data indicated mainly chemisorption. Fitting the adsorption isotherm data of phosphate and nitrate together showed adsorption on a monolayer coating of anions on the homogeneous sorbent's surface. The maximum phosphate and nitrate adsorption capacities were 6.94 and 2.46 mg/g, respectively, for a single adsorbate and 11.14 and 1.76 mg/g, respectively, for the binary solution. In real swine wastewater, removal efficiencies of phosphate, nitrite, nitrate, sulfate, and ammonia were 83.8%, 65.0%, >45.0%, 36.6%, and 2.6%, respectively, indicating that the modified RH would be effective for phosphate and nitrate removal from real wastewater. Finally, nutrient analysis of the phosphate- and nitrate-sorbed RH showed increases in nitrogen and phosphorus, which would be beneficial for further use of the RH as nutrient or fertilizer after adsorption. [ABSTRACT FROM AUTHOR]

The aim of this study is to find out a sustainable and cost‐effective solution to manage hazardous shock loads from metal finishing and electro‐coating industry. Results indicated that the main sources of hazardous wastewater are coming from batch chemical cleaning of degreasing basin (CCDB) (pH 13) and contains very hazardous chemicals, batch chemical cleaning of phosphating basin (CCPB) (pH 1.03) and contains high concentrations of iron (2300 mg/L) and zinc (2400 mg/L) and degreasing basin contents (DBC). Different treatment approaches were investigated. Results indicated that mixing CCDB with CCPB at their actual discharge allowed to form a self‐coagulant of metal hydroxide which was utilized to treat the (DBC) followed by sedimentation. Removal efficiency of COD (87%), TSS (94%), and oil and grease (92%) were achieved. To compare the efficiency of this treatment approach, conventional chemical coagulation of DBC was carried out using FeCl3 but the amount was very high. In conclusion, results proved the advantage of using self‐coagulation to treat DBC since it eliminates the use of external chemicals and provides an integrated solution for the three main sources of hazardous pollutants. Practitioner points: The manuscript provide an innovative and sustainable solution to the shock loads of hazardous wastewater generated from metal finishing and E‐coating industry by utilizing iron‐rich wastewater from chemical cleaning of phosphating basin and alkaline wastewater from chemical cleaning of degreasing basin to produce metal hydroxide.The metal hydroxide was cost‐effective and technically effectively than external coagulant in treating highly polluted degreasing basin content at due discharge time.Iron‐rich wastewater could be used to produce self‐coagulant of iron hydroxide.Mixing iron rich wastewater and alkaline wastewater produce iron hydroxide.Iron hydroxide is cost‐effective in treating hazardous wastewater of degreasing basin. [ABSTRACT FROM AUTHOR]

[Display omitted] The release of high amount of nitrogen and phosphorous from agricultural, municipal and industrial sewage into natural water body is the major source of eutrophication in aquatic ecosystems. This leads to the depletion of oxygen, cyanobacteria bloom and proliferation of aquatic weed plants, and destruction of water ecosystem. Therefore, effective treatment of municipal wastewater is crucial prior to discharge into natural water bodies in order to prevent pollution, and to meet the wastewater acceptable limits set by government and Environmental Protection Agencies. The present study evaluates the performance of varying weight of S. molesta plants in phytoremediation of treated domestic wastewater samples for 14 days at 24 h retention time. Physicochemical analysis such as turbidity, phosphate, ammoniacal nitrogen and nitrate tests were conducted on the wastewater samples according to spectrophotometric methods. Also, S. molesta plants were harvested once in a week and the relative growth rate (RGR) was calculated. The outcome of the study indicated that the treated domestic wastewater from the sewage treatment plant contains pollutants that stimulates the growth of S. molesta plants. Similarly, the highest reduction efficiency of up to 97.7%, 99.7%, 99% and 90.6% was observed for turbidity, phosphate, ammoniacal nitrogen and nitrate, respectively. In addition, the outcome of the study also demonstrated that S. molesta plants with the highest weight (280 g) were more efficient in removal of the excess nutrient present in the influent samples. Furthermore, the free energy content in the wastewater provided a suitable consortium for the plant cultivation and growth. Therefore, this method can be used for lab-scale production of wastewater-based biomass for the generation of biofuels. [ABSTRACT FROM AUTHOR]

Microalgae are known to grow on wastewater utilizing their available nutrients. The residual algal biomass thus obtained could be used for producing value-added products thereby making it an economically viable and sustainable option for the dairy industry. The present study evaluates the ability of the microalgal consortia composed of Chlorella variabilis and Scenedesmus obliquus to treat and valorize diluted synthetic dairy wastewater under controlled laboratory conditions. The effect of time, inoculum concentration and light intensity on five responses, namely phosphate removal, ammoniacal nitrogen removal, COD removal, biomass productivity and lutein content, are studied by response surface methodology utilizing central composite design. The quadratic models are found to be suitable for phosphate removal, ammoniacal nitrogen removal, COD removal and biomass productivity. At optimized experimental conditions, the microalgal consortia exhibited phosphate removal of 70.19%, ammoniacal nitrogen removal of 86.22%, COD removal of 54.72%, biomass productivity of 29.13 mg/L/day and lutein content of 12.59 mg/g respectively. This study is of high importance as the lutein content exhibited by the microalgal consortia is higher when compared to other microalgal species and could be considered in the future as a commercial source of lutein. [ABSTRACT FROM AUTHOR]

In the present study, Mg–Al and Zn–Al layered double hydroxides (LDH) were synthesized by the co–precipitation method and employed to remove phosphate from synthetic aqueous solutions and industrial wastewaters. LDH were characterized by X–ray diffraction (XRD), N2 adsorption/desorption isotherms (BET method), thermal analyses (TG–DTA) and Fourier transform infrared spectroscopy (FTIR). XRD and TG–DTA analysis showed that Mg–Al and Zn–Al formed the LDH structure. Experimental adsorption data indicated that pseudo–second order model best described phosphate adsorption kinetics. Data of equilibrium experiments fitted well to Sips and Freundlich models for Mg–Al and Zn–Al, respectively. The effect of co–existing anions on the phosphate adsorption capacity was analyzed by utilizing industrial wastewater. The results showed that the phosphate removal decreases in the presence of other anions. Mg–Al adsorbent exhibited 74% removal of phosphate with a dosage of 5 g/L in industrial wastewater. [ABSTRACT FROM AUTHOR]

The present study was to reflect the use of some bacteria in the treatment and removal of pollutants in three selected wastewater sites, including a vegetable oil plant (viz. Al-Etihad Food Industries), the main wastewater treatment station in the city of Hila, and Al-Hila River water from October 2019 to January 2020. The bacterial isolates identified in these three sites were Klebsiella pneumoniae, Escherichia coli, Enterobacteria cloacae, Pseudomonas aeruginosa, Thalasobacillus devorans, Acinetobacter baumannii, and Bacillus subtilis. The molecular study of the bacterial isolates involved the detection of bacterial genera using the polymerase chain reaction (PCR). The results showed that water had a variable nature, depending on the substances in it. It recorded varying chemical and physical property values, ranging between 6.36 and 7.82 for pH and from 2500 to 7100 mg∙dm–3 for total alkalinity. Additional values were 713–2051 µS∙cm–1 for electrical conductivity (EC), 5.90–9.80 mg∙dm–3 for chemical oxygen demand (COD), and 480–960 mg∙dm–3 for total hardness. The given values were also 0.20–0.65 µg∙dm–3, 0.03-0.23 µg∙dm–3, and 0–107 mg∙dm–3 for nitrite (NO2), phosphate (PO4) oils, respectively. [ABSTRACT FROM AUTHOR]

Wastewater treatment coagulation is one of the most important physicochemical operations used in industry. The adsorption capability of marigold leaf powder, tea waste and ferrous sulfate was investigated for domestic and tannery effluents. These adsorbents significantly affected the pH, electrical conductivity (EC) and turbidity of wastewater. Maximum decrease in all the attributes was observed for 10 g of adsorbents application. All the adsorbents significantly affected the physiochemical attributes of both wastewaters. Similarly, maximum adsorption potential was observed in case of tea waste powder. Maximum decrease in all physiochemical attributes such as pH (15%), EC (21%), turbidity (54%), total dissolved solids (TDS; 36%), total suspended solids (TSS; 43%), total hardness (TH; 52%), chloride contents (59%) and phosphate contents (60%) was observed with the application of 10 g of tea waste. Regarding the heavy metals, maximum decrease for cadmium (Cd; 47%), lead (Pb; 81%), arsenic (As; 44%), copper (Cu; 75%), iron (Fe; 49%), chromium (Cr; 68%) and zinc (Zn; 64%) was observed in same treatment. The decreasing order in terms of their adsorption potential for coagulants was tea waste > marigold leaf powder > ferrous sulfate. However, for the wastewater, the maximum effect of adsorbents was observed in case of domestic wastewater as compared to the tannery water. Based on these data, it is suggested that tea waste has maximum adsorption potential for the remediation of wastewater. [ABSTRACT FROM AUTHOR]

An MBBR and CW combo bio-reactor (MBCW) was designed as a novel hybrid process for simultaneous organic, nitrogen and phosphate removal through the long-term operation. The effect of the internal recycling rate (IRR), hydraulic retention time (HRT) and chemical oxygen demand/total nitrogen (C/N) ratio were all discussed, and the recommended values were 5:1, 12 h and >6, respectively. A higher C/N ratio was a key factor for achieving a higher TN removal. The mixed biocarrier system was realized by inoculating porous polymer carriers (PPC) and cylindrical polyethylene carriers (CPC) and achieving a higher organic biodegradation and nitrification rate compared to a single carrier system. Microorganism activities and plants' uptake or utilization both contributed to the nutrient removal in a constructed wetland. High-throughput sequencing results revealed an abundant microbial diversity and a distinct microbial distribution in the whole system where Flavobacterium (14.2%), Acinetobacter (12.87%) and Rhodobacter (10.83%) dominated on PPC, Terrimonas (8.88%), Reyranella (6.61%) and Rubinisphaera (5.63%) dominated on CPC, Comamonas (4.18%), Gemmobacter (4.02%) and Hydrogenophaga (3.97%) dominated on CWs, as well as Citrobacter (53.13%) on suspended floc. [ABSTRACT FROM AUTHOR]

Wastewater arising from manganese phosphate coating contains plenty of biogenic compounds, heavy metals such as nickel, iron, manganese, and therefore also constitutes a serious threat to the environment. The combined method of removing pollutants from wastewater from manganese phosphate coating consisting of coagulation, ozonation and Fenton reaction allowed to reduce biogenic pollutants and remove heavy metals. Coagulation was performed with iron(III) chloride and Flopam AN 934 SHU flocculant. The Fenton reaction was performed in two combinations with and without the addition of iron(III) salt. Ozonation was carried out in a column with an ozone generator, and wastewater was treated in the following sequence: coagulation-ozonation-Fenton reaction. The results of experiments demonstrated that the use of combined methods of coagulation, ozonation and Fenton reaction have brought the expected outturns. As a result of using the Fenton reaction, the content of nitrates(V) was lowered from 13.0 mg/l to 0.012 mg/l. Physico-chemical analyses of wastewater were performed using UV-VIS molecular spectrophotometry. [ABSTRACT FROM AUTHOR]

Microalgae bio-treatment of synthetic fertilizer wastewater is particularly attractive due to their photosynthetic capabilities. Microalgae tend to convert solar energy into useful biomass, incorporating with the nutrients that present in wastewater, such as nitrogen and phosphorus. However, harvesting of microalgae remains a challenge because of the small size (3–30 μm) of microalgae cells and the repulsion between the negatively charged microalgae cells maintains a stable cell suspension. Magnetic-aided-embedding-flocculation strategy, which is one-step method by mixing microalgae, magnetic particles and flocculant together, is proposed for microalgae harvesting in order to meet cost and time effectiveness. In this study, the optimum cell separation efficiency of Chlorella vulgaris microalgae above 96% at 5 mg/L of chitosan dosage is achieved. With the aid of iron oxide particles, either micro- or nano-size, the sedimentation rate of cell flocs up to 250 cm/h is obtained when 10 mg/L of iron oxide is embedded into the cell flocs. The sedimentation rate with the embedding of iron oxide shows about 2 times faster than that of without magnetic particles. This strategy had proven effective for the polishing of the pretreated synthetic fertilizer wastewater by removing up to 53%, 74% and 70% of ortho-phosphate, nitrate and ammoniacal nitrogen, respectively. In addition, the presence of iron oxide particles and chitosan in microalgae harvesting that showed no adverse effect toward the quantity and quality of extracted lipid. This strategy is proven feasible for fertilizer wastewater treatment and biodiesel production. [ABSTRACT FROM AUTHOR]

Phosphorus in wastewater is one of the main causes of water eutrophication. Phosphorus removal from swine wastewater is always a challenge. To achieve on-site recycling of swine farm waste, the low-cost pyro/hydrochars and their Fe-Mn-modified form were prepared from swine manure as an efficient adsorbent for phosphate removal. The results showed that the phosphate removal efficiency of unmodified pyro/hydrochars was less than 7.77%, which was significantly increased to 58.21-83.76% for the Fe-Mn-modified--pyro/hydrochars. The maximum adsorption capacity of pyrochar was found on the Fe-Mn-modified--pyrochar (PC-600M) with a surface area of 102.03 m²/g and a micropore volume of 0.25 cm3/g. The PC-600M exhibited high adsorption capacity (26.07 mg/g) in a low concentration of phosphate (50 mg/dm3), and its removal efficiency reached up to 83.76% within 24 hours. Furthermore, the adsorption of phosphate on biochars without modification (HC-210 and PC-600) was validated using a first-order kinetic model, and the adsorption of phosphate on modified biochars (HC-210M and PC-600M) was well described by the second-order kinetic model and Langmuir isotherm. In addition, there is no significant difference in the adsorption of phosphorus between pyrochars and hydrochars, but the preparation cost of hydrochars is lower than that of pyrochars. It was confirmed that the low--cost Fe-Mn-modified pyro/hydrochar from swine manure had potential for efficient phosphate removal in wastewater treatment and would facilitate value-added utilization of swine manure. [ABSTRACT FROM AUTHOR]

The recovery of phosphorus from wastewater holds promise as a sustainable source of organic phosphorus for agricultural use while aiding in meeting legislative discharge limits for phosphorus to control and mitigate eutrophication. This study introduces a novel approach in which calcium-rich calcined oyster shell (Ca–COS) is immobilized on a starch-based monolithic cryogel, resulting in a green tablet (Cry–Ca–COS) capable of efficiently recovering phosphate from water through chemisorption on the material surface and precipitation in the liquid phase. The formed tablet prevents sorbent loss post-adsorption, facilitating reusability. Under optimal conditions (i.e., three 0.83 cm thick Cry–Ca–COS tablets, an initial phosphate concentration of 12 mg L−1 in 1 L without pH adjustment (pH 6.3), and a contact time of 60 minutes), a phosphate removal efficiency of 83.11% ± 0.68% and a maximum removal capacity of 9.97 mg g−1 were achieved. Both the Langmuir isotherm model and pseudo-second-order kinetic model exhibited good fits to the experimental data, with an estimated activation energy of 81.9 kJ mol−1 and a positive enthalpy of 9.3 kJ mol−1, indicating an endothermic chemisorption process with a monolayer surface coverage of phosphate on Cry–Ca–COS. In real samples, Cry–Ca–COS demonstrated a high removal efficiency ranging from 98.48% ± 1.87%–99.16% ± 0.72%, with the adsorbed material biodegrading within 24 days under soil burial conditions. A preliminary study was conducted to explore the feasibility of utilizing phosphate-adsorbed Cry–Ca–COS as a fertilizer for cultivating water spinach (Ipomoea aquatica Forsk.), and further in-depth investigation is required for a comprehensive report in the future. Thus, Cry–Ca–COS emerges as an environmentally friendly and effective tool for phosphate removal and recovery. [Display omitted] • Oyster shell waste was used to prepare a green calcium-rich adsorbent. • It was crushed, calcined, and composited with starch gel making a calcium-rich tablet. • A calcium-rich tablet (Cry−Ca−COS) can be used for phosphate removal and recovery. • Cry−Ca−COS can remove phosphate from real samples indicating great applicability. • The used material can be biodegraded within 24 days under soil burial conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-capacity, selective, and recyclable magnetic phosphate composites were prepared. • CaFeP-1 can effectively reduce uranium concentration and also neutralize the acidity of the acidic mining wastewater. • Efficient uranium removal by CaFeP-1 is attributed to dissolution-precipitation, surface complexation, and ion exchange. Uranium mining operations produce large volumes of acidic uranium mining wastewater, necessitating the development of environmentally friendly and recyclable materials for efficient uranium removal and recovery. The current study successfully produced hydroxyapatite (HAP-L) and magnetic phosphate composites (CaFeP-1, CaFeP-2, and FePO 4) through a combination of mixing, ultrasonication, hydrothermal precipitation, and calcination methods. The research explores the influence of various parameters such as pH, solid–liquid ratio, contact time, initial uranium concentration, co-existing ions, and recyclability on the uranium removal efficiency of these materials. The findings indicate exceptional uranium adsorption capacities, with CaFeP-1 exhibiting the highest capacity among the materials, especially in acidic environments. Moreover, CaFeP-1 displays strong resistance to interference from other ions and can be recycled multiple times while maintaining high removal rates. Treatment of acidic uranium mining wastewater by CaFeP-1 results in pH adjustment and the reduction of uranium and other ion concentrations, making it a promising solution for comprehensive remediation of acidic uranium mining wastewater. The U(VI) removal mechanism by CaFeP-1 was validated through XRD, FT-IR, and XPS results. The U(VI) removal was attributed to processes such as dissolution-precipitation, surface complexation, and ion exchange. The formation of sodium uranyl phosphate hydrate was identified as a new product following U(VI) abatement by CaFeP-1. In summary, CaFeP-1 shows great potential for the effective treatment of acidic uranium mining wastewater. [ABSTRACT FROM AUTHOR]

It is crucial for the environment, the economy, and society to create low-cost adsorbents from renewable resources to remove phosphate from aqueous effluents. Here, two renewablecarbon and nitrogen sources (Douglas fir and Chitosan) were used to produce engineered N -doped biochars modified with Mg for PO 4 3− adsorption. Mg–N doped biochars were prepared using an impregnation-carbonization process. A central composite experimental design was used to select combinations of independent variables to maximize phosphate adsorption capacity. Phosphate adsorption isotherms were fitted with Langmuir and Freundlich isotherms. The biochar produced at 700 °C, 12 wt % MgCl 2, and Douglas Fir/Chitosan ratio: 1/1, which has the highest PO 4 3− adsorption capacity, was further studied. Proximate analysis, elemental composition, surface area, pore size distribution, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and Scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX) were used to characterize this biochar. This biochar has an adsorption capacity of 112.4 mg PO 4 3−/g char. Its phosphate adsorption rate was adjusted to a pseudo-second-order kinetic model. The phosphate adsorption capacity of the biochar produced was comparable with the most effective biochar reported in the literature. [Display omitted] • Phosphate adsorption was improved when chitosan and Mg added. • Response surface approach was used to assess the thermochemical conditions. • A relationship between N -functionalities and Mg was observed during adsorption. • The utilized biochar from renewable resources can be used as a slow fertilizer. [ABSTRACT FROM AUTHOR]

Efficient removal and recycling of phosphorus from complex water matrices using environmentally friendly and sustainable materials is essential yet challenging. To this end, a novel bio-based adsorbent (DX-FcA-CS) was developed by coupling oxidized dextran-crosslinked chitosan with ferrocene carboxylic acid (FcA). Detailed characterization revealed that the incorporation of FcA reduced the total pore area of DX-FcA-CS to 7.21 m2·g−1, one-third of ferrocene-free DX-CS (21.71 m2·g−1), while enhancing thermal stability and PO 4 3− adsorption performance. Adsorption kinetics and isotherm studies demonstrated that the interaction between DX-FcA-CS and PO 4 3− followed a pseudo-second-order kinetic model and Langmuir model, indicating chemical and monolayered adsorption mechanisms, respectively. Moreover, DX-FcA-CS exhibited excellent anti-interference properties against concentrated co-existing inorganic ions and humic acid, along with high recyclability. The maximum adsorption capacity reached 1285.35 mg·g−1 (∼428.45 mg P g−1), three times that of DX-CS and surpassing many other adsorbents. PO 4 3−-loaded DX-FcA-CS could be further carbonized into electrode material due to its rich content of phosphorus and nitrogen, transforming waste into a valuable resource. These outstanding characteristics position DX-FcA-CS as a promising alternative for phosphate capture and recycling. Overall, this study presents a viable approach to designing environmentally friendly, recyclable, and cost-effective biomaterial for wastewater phosphate removal and value-added applications. • Ferrocene-modified bio-adsorbent (DX-FcA-CS) was developed to boost P removal. • The maximum sorption capacity was ∼1285 mg·g−1 outperforming most adsorbents. • The sorption of PO 4 3− showed high anti-interference against co-existing ions. • Carbonized P-adsorbed DX-FcA-CS showed potential as electrode material. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) based adsorbents derived from waste sludge were utilized to remediate mixed contaminants in wastewater as an integrated waste-to-resource approach promoting a paradigm shift in management of refuse sludge and wastewater. This review specifically focuses on the remediation of constituents of landfill leachate by sludge-based activated carbon (SBAC). The adsorption effectiveness of SBAC for the exclusion of leachate characters including heavy metals, phenols, dyes, phosphates, and phosphorus were explored with regard to modifiers such as pH, temperature, properties of the adsorbent including functional groups, initial doses of absorbent and adsorbate, and duration of exposure to note the impact of each parameter on the efficiency of adsorption of the sludge adsorbent. Through the works of various researchers, it was noted that the properties of the adsorbent, pH and temperature impact the working of SBACs. The pH of the adsorbent by influencing the functional groups. Temperature was expected to have a paramount effect on the adsorption efficiency of the SBACs. The importance of the regeneration and recycling of the adsorbents as well as their leachability is highlighted. Sludge based activated carbon is recommended as a timely, resource-efficient, and sustainable approach for the remediation of wastewater. [Display omitted] • This article emphasizes leachate remediation by Sludge-based Activated Carbon. • The manufacturing of SBAC from waste sludge presents an efficient waste-to-resource technique. • Process parameters impacting the adsorption efficacy of sludge adsorbents have been discussed. • Regeneration and Leachability of sludge adsorbents has been discussed. • This review also enumerates the Economic feasibility and Life Cycle Analysis of sludge biochar. [ABSTRACT FROM AUTHOR]

The effective purification of phosphate-containing wastewater is considered as increasingly important. In this study, a highly effective LC-CNT film was developed for efficient phosphate removal. Kinetic results showed that the adsorbent exhibited an improved mass transfer efficiency and a fast adsorption rate during adsorption (reaching 80% and 100% equilibrium adsorption capacity within 175 and 270 min, respectively). Kinetic model analysis suggested that the adsorption was a combined chemical physical process. Isotherm study revealed that the LC-CNT film showed a superior adsorption capacity (178.6 mg/g, estimated from the Langmuir model) with multiple adsorption mechanisms. pH study suggested that surface complexation and ligand exchange played important roles during adsorption, and the adsorbent worked well within the pH range of 3–7 with little La leakage. The ionic strength and competing anions showed little influence on the adsorbent effectiveness except for the carbonate and sulfate ions. The characterization and mechanism study revealed that the phosphate adsorption of the LC-CNT film was controlled by inner-sphere complexation, outer-sphere complexation and surface precipitation. The LC-CNT film also showed excellent regenerability and stability in cycling runs, further demonstrating its potential in industrial applications. [Display omitted] • A novel LC-CNT film was developed with fast adsorption rate and high adsorption capacity. • External and internal surface adsorption occurred simultaneously during adsorption. • Phosphate uptake consisted of uniform (physical) and non-uniform (chemical) adsorption. • LC-CNT film showed stable performance in aqueous solution under different situation. • Adsorption mechanisms include inner- and outer-sphere complexation and surface precipitation. [ABSTRACT FROM AUTHOR]

Phosphorus is one of the important factors to successfully establish the microalgal-bacterial symbiosis (MABS) system. The migration and transformation of phosphorus can occur in various ways, and the effects of phosphate on the MABS system facing environmental impacts like heavy metal stress are often ignored. This study investigated the roles of phosphate on the response of the MABS system to zinc ion (Zn2+). The results showed that the pollutant removal effect in the MABS system was significantly reduced, and microbial growth and activity were inhibited with the presence of Zn2+. When phosphate and Zn2+ coexisted, the inhibition effects of pollutants removal and microbial growth rate were mitigated compared to that of only with the presence of Zn2+, with the increasing rates of 28.3% for total nitrogen removal, 48.9% for chemical oxygen demand removal, 78.3% for chlorophyll-a concentration, and 13.3% for volatile suspended solids concentration. When phosphate was subsequently supplemented in the MABS system after adding Zn2+, both pollutants removal efficiency and microbial growth and activity were not recovered. Thus, the inhibition effect of Zn2+ on the MABS system was irreversible. Further analysis showed that Zn2+ preferentially combined with phosphate could form chemical precipitate, which reduced the fixation of MABS system for Zn2+ through extracellular adsorption and intracellular uptake. Under Zn2+ stress, the succession of microbial communities occurred, and Parachlorella was more tolerant to Zn2+. This study revealed the comprehensive response mechanism of the co-effects of phosphate and Zn2+ on the MABS system, and provided some insights for the MABS system treating wastewater containing heavy metals, as well as migration and transformation of heavy metals in aquatic ecosystems. [Display omitted] • The role of phosphate on MABS system under Zn2+ stress was investigated. • Phosphate alleviated but did not eliminate Zn2+ inhibition on MABS system. • Co-precipitation of phosphate with Zn2+ and biosorption occurred simultaneously. • Zn2+ inhibition was irreversible and induced the growth of tolerant microorganisms. • Both successions of microalgal and bacterial communities were revealed. [ABSTRACT FROM AUTHOR]

The struvite crystallization method is considered a highly promising approach for phosphate recovery from swine wastewater. However, the utilization of chemicals like magnesium and alkali as sources for struvite crystallization substantially increases the overall cost of this technology. In this study, activated talcum powder (ATP) was used instead of chemical reagents to recover phosphate as struvite from simulated swine wastewater containing 93 mg/L phosphorus and 450 mg/L ammonia nitrogen. The results showed that 93.02 ± 1.56% phosphorus and 14.47 ± 1.89% ammonia nitrogen were removed from simulated wastewater in the continuous flow circulation system. The purity of the struvite collected is as high as 97.24%. Mineralogical analysis showed that mechanical activation destroyed the crystal structure of talcum and increased the reactivity of Mg2+ and OH−, allowing it to be released spontaneously into aqueous solution. The amount of magnesium ions dissolved was affected by factors such as contact time, talcum dose, ammonium concentration and pH. The main components of ATP residue were quartz and magnesite, which will not cause secondary pollution to the environment. The use of ATP to recover phosphate into struvite has the advantages of low chemical cost and no pollution of waste materials, holding broad application prospects. [Display omitted] • Highly active talcum powder was prepared by one-step mechanical activation. • Mg2+ and OH− can be released from ATP into aqueous solution. • The purity of the recovered struvite can be as high as 97.24% in the reactor. • Recycled water can promote the release of magnesium ion. [ABSTRACT FROM AUTHOR]

Although adsorbents are good candidates for removing phosphorus and heavy metals from wastewater, the use of biosorbents for the sequential treatment of phosphorus and copper has not yet been studied. Porous chitosan (CS)-based biosorbents (CGBs) were developed to adsorb phytic acid (PA), a major form of organic phosphate. This first adsorbate (PA) further served as an additional ligand (P-type ligand) for the CGBs (N-type ligand) to form a complex with the second adsorbate (copper). After the adsorption of PA (the first adsorbate), the spent CGBs were recycled and used as a new adsorbent to adsorb Cu(II) ions (the second adsorbate), which was expected to have a dual coordination effect through P, N-ligand complexation with copper. The interactions and complexation between CS, PA and Cu(II) ions on the PA-adsorbed CGBs (PACGBs) were investigated by performing FTIR, XPS, XRD, and SEM-EDS analyses. The PACGBs exhibited fast and enhanced adsorption of Cu(II) ions, owing to the synergistic effect of the amino groups of CS (the original ligand, N-type) and the phosphate groups of PA (an additional ligand, P-type) on the adsorption of Cu(II) ions. This is the first time that sequential removal of phosphorus and heavy metals by biosorbents has been performed using biosorbents. • Sequential adsorption of phosphate and Cu(II) ions by chitosan biosorbents (CGBs) • Recycling of CGBs after adsorbing phytic acid (PA) for removal of Cu(II) ions. • PA acts as a P-type ligand and cooperates with the N-type ligand on CGBs to bind Cu2+ • PA-adsorbed CGBs (PACGBs) adsorb Cu(II) ions faster and more effectively than CGBs [ABSTRACT FROM AUTHOR]

• Three phosphate ester-based MOFs (UiO-66-(OPO 3) X) containing different amounts and spatial positions were prepared. • UiO-66-(OPO 3) X can efficiently remove Pb2+ from aqueous solution. • Even at pH = 2 and pH = 3, UiO-66-(OPO 3) X maintains a high removal efficiency of Pb2+. • UiO-66-(OPO 3) X has excellent selectivity and anti-interference ability for Pb2+. • The adsorption mechanism was investigated in detail by experiment combined with DFT. Metal-organic framework (MOF) materials have emerged as promising candidates for treating heavy metal wastewater because of their controllable pore size, high specific surface area, and abundant active sites. Nevertheless, the currently reported MOFs usually require near-neutral environments (pH = 5–6) to achieve efficient removal of Pb2+ and cannot be applied to acidic environments (pH = 2–3). In this work, the structurally stabilized zirconium-based MOF UiO-66 was chosen as the object of study. Three phosphate ester-based MOFs (UiO-66-(OPO 3) X) containing different amounts and spatial positions were designed and prepared by simple chemical modification and used to remove Pb2+. Adsorption experiments showed that they could reach adsorption equilibrium in 30 min with excellent adsorption rate. Owing to the unique ionization ability of the phosphate ester group, UiO-66-(OPO3) X maintains a high removal efficiency of Pb2+ even at pH = 2 and pH = 3. In addition, selectivity and competition experiments demonstrated that UiO-66-(OPO 3) X possessed excellent selectivity and anticompetitive ability towards Pb2+.The excellent regeneration performance demonstrates their value for practical application. Moreover, the adsorption mechanism was investigated in detail by experiment combined with density functional theory (DFT). [ABSTRACT FROM AUTHOR]

Phosphate holds a critical role as a vital, limited, strategic, and irreplaceable resource. Throughout its production chain, residual phosphate can be found in waste streams. This study aims to enhance production efficiency by exploring methods to limit residual phosphate presence in waste stocks. It investigates the presence of residual phosphate in a phosphate mining site. The presence of residual phosphate throughout the production chain is investigated. Through meticulous analyses of extraction, destoning, and screening processes, the study identifies three primary stages where residual phosphate exists, the study simulates different scenarios of residual phosphate recovery and prevention. The principal data sources are data from mining site, recent literature, and information from a lithological log, the study meticulously analyzes the extraction, crushing, and sieving processes to assess the persistence of residual phosphate. The production chain diagnostic revealed that 76% of resource present is recovered (either integrated into the value chain or stored in the mine for future use), from which 8% goes to the destoning waste rocks (75% of which is residual phosphate) and the screening waste rocks (72% of which is residual phosphate), with an average grade that reaches 25% P 2 O 5. Approximately, 24% of the initial phosphate rock (with an average grade of 22% P 2 O 5) remains as residual phosphate which is retained in the spoil piles. To recover and prevent the presence of residual phosphate, the study proposes four new scenarios for improvement, including an integrated scenario where all the solutions are combined for a comprehensive approach. Both quantity and grade of recovered residual phosphate are assessed in each scenario. To evaluate these enhancements, the study utilizes the AnyLogic software to simulate existing process configuration and the maximal recovery of each scenario. The current flowsheet indicates that extracted phosphate can be directed either to pre-beneficiation and expedition or stored for future use. By prioritizing the extraction of phosphate over the final product, the simulation results suggest that implementing these novel scenarios could potentially save 25% of the total phosphate resource and increase storage by twofold, preserving phosphate that would otherwise be unused. This recovered phosphate can then be destined to various uses, meeting the company's present or future needs. Considering this, the study opts to keep stocks separated based on their grades and avoid mixing new phosphate streams with the final product. The implications of this research extend to sustainable mining practices, with direct ramifications for environmental impact mitigation and the conservation of valuable resources. • About 80% of phosphate rock is extracted from the deposit. • 42% of the current spoil piles, 75% of the current DPWR and 72% of the current SPWR is phosphate rock. • New flowsheets can recover and limit residual phosphate presence in the waste stocks. • Four new flowsheets were proposed and assessed using system dynamic simulation. • Production can be enhanced: the run-of-mine can increase by 32%. [ABSTRACT FROM AUTHOR]