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[Display omitted] • Living biofilters were made from co-immobilized microalgae and bacteria. • Living biofilters had higher nutrient removal than the suspended controls. • Living biofilters were then tested as biofertilizer for three vegetable plantation. • Living biofilters can be used as biofertilizer with no negative impacts on soil. This study investigates nutrient recovery from synthetic municipal wastewater using co-immobilized cultures of Chlorella vulgaris TISTR 8580 (CV) and plant growth-promoting bacteria, Bacillus subtilis TISTR 1415 (BS) as living biofilters for a subsequent biofertilizer activity. The optimal condition for nutrient recovery was at the 1:1 ratio of CV/BS using mixed guar gum/carrageenan (GG/CG) binders. After 7-day wastewater treatment, the living biofilters removed 86.7 ± 0.5% of ammonium and 99.3 ± 0.3% of phosphates and were tested subsequently as biofertilizers for 20 days to grow selected plants. The highest optimal biomass and chlorophyll a content was 2 ± 0.3 g (CV/BS 3:1) and 12.4 ± 0.7 µg/g (CV/BS 1:1) from cucumber respectively, however, the close-to-neutral pH (8.0 ± 0.3) was observed from sunflower using CV/BS 1:1 living biofilters. Conclusively, the designed living biofilters exhibit the potential to recover nutrients from wastewater and be used as biofertilizers for circular agriculture. [ABSTRACT FROM AUTHOR]

Effective removal of phosphorus from water is crucial for controlling eutrophication. Meanwhile, the post-disposal of wetland plants is also an urgent problem that needs to be solved. In this study, seedpods of the common wetland plant lotus were used as a new raw material to prepare biochar, which were further modified by loading nano La(OH) 3 particles (LBC-La). The adsorption performance of the modified biochar for phosphate was evaluated through batch adsorption and column adsorption experiments. Adsorption performance of lotus seedpod biochar was significantly improved by La(OH) 3 modification, with adsorption equilibrium time shortened from 24 to 4 h and a theoretical maximum adsorption capacity increased from 19.43 to 52.23 mg/g. Moreover, LBC-La maintained a removal rate above 99% for phosphate solutions with concentrations below 20 mg/L. The LBC-La exhibited strong anti-interference ability in pH (3–9) and coexisting ion experiments, with the removal ratio remaining above 99%. The characterization analysis indicated that the main mechanism is the formation of monodentate or bidentate lanthanum phosphate complexes through inner sphere complexation. Electrostatic adsorption and ligand exchange are also the mechanisms of LBC-La adsorption of phosphate. In the dynamic adsorption experiment of simulated wastewater treatment plant effluent, the breakthrough point of the adsorption column was 1620 min, reaching exhaustion point at 6480 min, with a theoretical phosphorus saturation adsorption capacity of 6050 mg/kg. The process was well described by the Thomas and Yoon–Nelson models, which indicated that this is a surface adsorption process, without the internal participation of the adsorbent. [Display omitted] • A novel modified biochar was prepared from harvested wetland plant Lotus Seedpod. • LBC-La showed excellent phosphate adsorption performance. • Inner sphere complexation is the main adsorption mechanism. • The dynamic adsorption was well described by the Thomas and Yoon–Nelson models. [ABSTRACT FROM AUTHOR]

Monoammonium phosphate removal from the low-concentration solution resulted from phosphate-based fertilizers production was experimentally studied in a laboratory scale three-chamber electromembrane setup. Through the use of electrodialysis process for treatment of monoammonium phosphate solutions it was possible to obtain more concentrated salt solution and desalted water suitable for industrial application. Influence of the basic operating parameters on the monoammonium phosphate recovery efficiency was evaluated. A mathematical model of electrodialysis for a setup with circulating flows was developed. Comparison between the calculated and experimental data showed that the mathematical model proposed allows reliably predicting the content of monoammonium phosphate in the concentrate. [ABSTRACT FROM AUTHOR]

Chemically enhanced primary treatment (CEPT) with ferrate(VI), a multifunctional treatment agent, was investigated for the treatment of municipal wastewater in a laboratory‐scale study. The treatment performance was evaluated at different ferrate(VI) doses (0.0–9.0 mg/L as Fe) and pH (6.0 and 7.5). The optimal removals of total suspended solids (TSS) (52%), total chemical oxygen demand (COD) (34%), and total phosphorus (47%) were achieved at the highest ferrate(VI) dose (9.0 mg/L as Fe) and the weakly alkaline condition (pH 7.5). The pollutant abatements principally ascribed to the formation of large‐sized aggregate and ensuing sedimentation fell within the reported ranges of CEPT with traditional coagulants. However, different from conventional CEPT, ferrate(VI) appreciably removed recalcitrant dissolved organic phosphorus (49%) and simultaneously inactivated total coliform (3.30 log removal) and Escherichia coli (3.67 log removal) at 9.0 mg/L Fe(VI) and pH 7.5. The CEPT with ferrate(VI) offers an innovative alternative for improving municipal wastewater treatment. Practitioner points: Ferrate(VI) represents a promising agent for chemically enhanced primary treatment (CEPT) of municipal wastewater.CEPT with ferrate(VI) can effectively alleviate TSS, total COD, and total P via the formation of large‐sized aggregates and ensuing sedimentation.Ferrate(VI) can substantially remove recalcitrant dissolved organic phosphorus in municipal wastewater.Different from other CEPT coagulants, ferrate(VI) can appreciably inactivate bacterial indicators during CEPT.Higher ferrate(VI) dose and weakly alkaline pH favor the performance of ferrate(VI) CEPT. [ABSTRACT FROM AUTHOR]

A new bacteria named Pseudomonas fulva K3 (P. fulva) strain was isolated from the surroundings of weathered crust rare earth tailing with efficient NH4+-N removal ability via heterotrophic nitrification and aerobic denitrification. The nitrogen removal properties could be intensified by the synergistic effect between as-prepared magnesium-modified biochar (MgBC) and P. fulva strain. The results show that P. fulva exhibited a rod-shaped morphology and NH4+-N can be completely biodegraded under the optimal conditions of pH=7.0~8.0, temperature 30 oC and initial NH4+-N concentration of 100 ~150 mg/L. The NH4+-N tolerant concentration for P. fulva was determined to be 300 mg/L. The magnesium-modified biochar (MgBC) worked as an adsorbent of NH4+-N. The kinetics and isotherm model for adsorption could be described by the pseudo-secondorder kinetic and Freundlich model, respectively. The XPS results showed that NH4+-N was mainly adsorbed on the surface by chemical adsorption. Furthermore, the P. fulva could be immobilized on MgBC due to its large surface area, adjusting the concentration of NH4+-N to a proper range for the growth of P. fulva by adsorption and desorption equilibrium, and leading to the intensified effect on nitrogen removal. The total nitrogen removal efficiency of the eluted weathered crust rare earth tailing reached 84.7 % in MgBC + P. fulva system. [ABSTRACT FROM AUTHOR]

The physicochemical treatment (PT) of food industry wastewater was investigated. In the first stage, calcium magnesium acetate (CaMgAc4) was synthesized using eggshell (biocalcium), magnesium oxide and acetic acid in a 1:1:1 stoichiometric ratio. In the synthesis process, the thermodynamic parameters (ΔH, ΔS and ΔG) indicated that the reaction was endothermic and spontaneous. The samples were characterized by infrared spectroscopy (IR), scanning electronic microscopy (SEM), X-ray diffraction (XRD) and electron X-ray dispersive spectroscopy (EDS). CaMgAc4 was used to precipitate the phosphate matter. IR analysis revealed that the main functional groups were representative of the acetate compounds and the presence of OH− groups and carbonates. In the physicochemical treatment, a response surface design was used to determine the variables that influence the process (pH, t, and concentration), and the response variable was phosphorus removal. The treatments were carried out in the wastewater industry with an initial concentration of 658 mg/L TP. The optimal conditions of the precipitation treatment were pH 12, time 12 min, and a CaMgAc4 concentration of 13.18 mg/L. These conditions allowed the total elimination (100%) of total phosphorus and phosphates, 81.43% BOD5 and 81.0% COD, 98.9% turbidity, 95.01% color, and 92% nitrogen matter. [ABSTRACT FROM AUTHOR]

Phosphate (PO43−) and nitrate (NO3−) contamination causes the threatening issue of eutrophication. A major waste from seafood industries of various seashells including Anadara inaequivalvis, Saccostrea commercialis, Perna viridis, Tegillarca granosa, Filopaludina martensi, Babylonai areolate and Meretrix lusoria was thermally modified and investigated for PO43− and NO3− removal from synthetic and domestic wastewater. It was found that some raw seashells could remove ≥85% of PO43−, whereas their NO3− removal efficiency was poor. However, after calcination, among others, only M. lusoria pyrolysed at 800 °C (M. lusoria F800) was found as a novel adsorbent for both PO43− and NO3− removal. An increase in temperature and increased Ca(OH)2 content enhance the removal of PO43− and NO3− by precipitating with calcium ions (Ca2+). M. lusoria F800 was the best for PO43− and NO3− removal compared with commercial lime and other calcined seashells. The maximum adsorption capacity (Qmax) of M. lusoria F800 for PO43− and NO3− was 700 mg/g and 170 mg/g, respectively, which was higher than the Qmax of PO43− and NO3− by commercial lime Ca(OH)2 which was about 465 mg/g and 18 mg/g, respectively. The crystals of calcium phosphate-hydroxide and calcium nitrate-hydroxide complexes were mainly found in M. lusoria F800 that adsorbed PO43− and NO3, respectively, as confirmed by X-ray diffractometer (XRD). Also, M. lusoria F800 could completely remove PO43− and NO3− from domestic wastewater. Hence, easily handled and cost-effective M. lusoria F800 would increase the value of this waste material, increase water quality and mitigate eutrophication. [ABSTRACT FROM AUTHOR]

Different individually applied commercial salts at different concentrations are generally used to precipitate contaminants in wastewater. In this study, we developed a treatment complementary to the lagoon system of a wastewater treatment plant by adding a combination of trivalent metal salts to chemically precipitate phosphate contaminants. Laboratory tests were conducted to determine the most efficient treatment for the removal of phosphate in wastewater by analyzing orthophosphate using the ascorbic acid method. Three trivalent metal salts—iron (III) sulfate, aluminum (III) sulfate, and iron (III) chloride—were combined with each other at three different concentrations, obtaining an experimental design involving 27 treatments replicated three times each. Analysis of variance (ANOVA) with Tukey's test revealed the treatment for which the highest percentage of orthophosphate removal (99.04%) was obtained. Finally, the selected treatment was implemented for field evaluation over three weeks, obtaining an average removal of 93.13%. [ABSTRACT FROM AUTHOR]

In this study freely suspended, Ca-alginate immobilized Chlorella vulgaris cells and blank alginate beads were used for removal of Pb(II) from municipal wastewater. Experimental data showed that biosorption capacity of algal cells dependent on the operational condition such as pH, dosages, contact time and temperature. The maximum biosorption of Pb(II) was achieved with Ca-alginate immobilized algal cells at an optimum pH of 5, algal dosage of 3 g/L and contact time of 30 min at room temperature. Results revealed that biosorption rate initially increased rapidly, the optimal removal efficiency was reached within about 30 min. Increasing initial pH resulted in an increase in ions uptake. These results showed that immobilized algal cells in alginate beads could potentially enhance the biosorption of considered metal ions than freely suspended cells. Moreover, the biosorbent has significantly removed lead ions from municipal wastewater at the optimized condition. Immobilized algae in alginate beads were more effective than free cells. Consistently high ions removal was achieved. [ABSTRACT FROM AUTHOR]

Phytoremediation and bioremediation are eco-friendly methods of wastewater treatment that are widely used throughout the world to reduce anthropogenic water contamination. This study was conducted to assess the effectiveness of symbiotic bacteria in phytoremediation using two aquatic plants, Echinodorus cordifolius and Lepironia articulata, that were tested in sterilized and unsterilized groups. The results showed that unsterilized plants removed more phosphate, ammonium, nitrate and nitrite than the sterilized plants. In untreated and unsterilized E. cordifolius groups, the dominant bacterium was Calothrix (46.90 and 49.69%, respectively), which was higher than in the sterilized E. cordifolius group (38.88%). In untreated and unsterilized groups of L. articulata, Clostridium was a dominant bacterium. The proportion of Clostridium was much lower in the sterilized L. articulata group (1.31%) than in the untreated (13.71%) and unsterilized (49.02%) groups. Our results suggested that root-associated bacteria in E. cordifolius and L. articulata were effective in the removal of phosphorus and nitrogen from domestic wastewater. [ABSTRACT FROM AUTHOR]

The aim of this study is to reduce the phosphate concentration in treated wastewater using a small amount of the reactive filter media, Filtralite P. Biologically treated wastewater was passed through a filter with 215 g of Filtralite P. In the laboratory, the phosphate removal efficiency was 51% at a flow speed of 0.87 m/h. Under real conditions, in an experimental stand filled with 0.5 m3 of Filtralite P, the phosphate removal efficiency was 85% and the removal efficiency of total suspended solids was 57% after a 5‐month period. The residual phosphate concentration in the filtrate from the experimental stand was 1 mg/L of PO4‐P after the 5‐month period. The experimental filtration plant was buried in the ground, and it did not freeze and worked well under winter conditions. The results of this study can be useful in the design and development of tertiary wastewater treatment plants in view of their sustainability potential. [ABSTRACT FROM AUTHOR]

Immobilized Pseudomonas aeruginosa beads with alginate and biochar as composite carriers and a nonionic surfactant (TX100) as degradation promoter were prepared by the gel embedding method. The optimal preparation parameters for the biochar addition amount and the concentrations of the bacterial suspension and TX100 were 1%, OD600 = 1 and 200 mg/L, respectively. The addition of TX100 can simultaneously promote biochar sorption of PAHs and PAH degradation by P. aeruginosa. The removal ratio of acenaphthene was 24% higher for the TX100-facilitated immobilized bacterial beads than the beads in the absence of TX100. The surfactant-facilitated immobilized bacterial beads can thoroughly remove PAHs in wastewater under the conditions of 10~50 °C, pH 2.5~10.5, and less than 0.2 mol/L NaCl. The immobilized bacterial beads are suitable for continuous-flow reactors, and 2-mm-diameter beads will achieve better application results than larger beads. The new immobilized material can be widely used in various wastewater treatment reactors and in the in situ remediation of organic polluted water. [ABSTRACT FROM AUTHOR]

Lanthanum molybdate/magnetite (M-La2(MoO4)3) with various LaCl3/Fe3O4 mass ratios was synthesized and optimized for selective phosphate removal from wastewater. M-La2(MoO4)3 (2:1) was selected on the basis of phosphate sorption capacity for further experiments and characterized by a variety of methods. The phosphate sorption kinetics, isotherms, and matrix effect were studied. The maximum sorption capacity at initial pH 7 indicates the possible applicability M-La2(MoO4)3 (2:1) in removing phosphate from the aquatic environment. Phosphate removal by M-La2(MoO4)3 (2:1) with high selectivity was achieved in the presence of other co-existing anions, while calcium and magnesium ions were found to inhibit the sorption process. The sorption isotherm study showed that Freundlich and Sips models fit better the Langmuir model, indicating that heterogeneous multilayer sorption was dominant during the phosphate sorption process. Sorption kinetic results showed that the pseudo-first-order kinetic model can describe well the phosphate sorption process by M-La2(MoO4)3 (2:1). Consecutive sorption–desorption runs showed that M-La2(MoO4)3 (2:1) could be reused for a few cycles. Simultaneous removal of phosphate and organic matter was achieved in real wastewater by using M-La2(MoO4)3 (2:1). The sorption mechanism was inner-sphere complexation. [ABSTRACT FROM AUTHOR]

Background: Highly-concentrated phosphate and nitrate anions from sugarcane wastewater are often discharged into public waters without standardized treatments. This study assessed the effects of electrical coagulation, initial pH and reaction time in the removal of phosphate and nitrate pollutants. Methods: We used aluminum electrodes to remove the pollutants at Hakhim Farabi Agricultural and Industrial complex, Khuzestan Province, Iran. A septic tank was used for collecting water samples followed by measuring the pH, and the concentrations of phosphate and nitrate in the samples. The pH was set at 5, 7, 9 or 11. Six aluminum electrodes were placed perpendicular to the water flow and were connected to power in a single-polar method. They were used to assess the effects of pH changes, electrical power at 10 and 30 volts and the water retention time at 15, 30, 45 or 60 min. on the efficiency of thep ollutants' removal. Results: The results indicated that under equal retention time and varying pH values, as voltage increased from 10 to 30, the phosphate and nitrate removal increased progressively. It was further demonstrated that the maximum phosphate removal efficiency was achieved at pH7, while it declined at higher pH levels. The highest possible nitrate removal efficiency was achieved under alkaline pH levels. The overall results showed that at every pH and voltage, the percentage of phosphate and nitrate removal increased over time. Conclusion: This study demonstrated that electro-coagulation process is an appropriate and efficient method to remove phosphate and nitrate pollutants from sugarcane wastewaters. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of increasing CO2 concentration on the growth and the capability of Tetraselmis chui. in removal of nitrate, ammonium and phosphate from shrimp pond wastewater (SPWW). The factorial experimental design was used with the treatment of SPWW percentage in culture medium, namely: 100% SPWW, 75% SPWW + 25% Sea Water (SW) and 75% SW + 25% SPWW coupled with three CO2 concentration treatments: 390 ppm, 550 ppm and 1000 ppm using CO2 system. Growth of T. chui. for lengh of cultivation period tended to be higher at treatments of 390 ppm CO2 and 100% SPWW, however there was a declining growth over period of cultivation for both treatments. The growth rate of T. chui was higher for all percentage of SPWW treatments in culture medium at 390 ppm CO2 concentration compared to other percentage of SPWW treatments and CO2 concentration treatments. There was a decreasing of growth rate with increasing CO2 concentration at 100% SPWW and 75% SPWW + 25% SW in culture medium. Nitrogen removal efficiency and removal rate by T. chui. were strongly affected by CO2 concentration. However, there was no significant effect of increasing CO2 concentration to removal efficiency and rate of PO4 by T. chui. [ABSTRACT FROM AUTHOR]

Ionic hydrogels with great water absorption capacity generally display poor mechanical strength that limits their use and narrows down their application areas. In this study, the new ionic hydrogel composed of poly (3-methacrylamido propyl trimethyl ammonium chloride) crosslinked with N, N-methylenebisacrylamide and sulphate ions was synthesized to obtain the hydrogel formulation which exhibits both huge swelling capacity and high mechanical stability, simultaneously. The successively synthesized gels with this strategy achieved a swelling capacity of 270 g/g and a modulus increased up to 20.43 kPa, indicating that they have a great potential to use in applications in which the both properties are required. The gels carrying a great number of cationic sites were also found to have a high affinity to phosphate ions, attaining an sorption value of 370 mg/g gel and to exhibit pseudo-second-order kinetic and Langmuir sorption isotherm models. The obtained results revealed that the new pMAPTAC gels have good potential for both phosphate sorption and high water uptake capacity without losing structural integrity owing to their enhanced mechanical strength. [ABSTRACT FROM AUTHOR]

As a summary of this Special Issue, it can be concluded that sustainable, green, low-cost, attractive and efficient adsorption and ion-exchange processes can be used for resource recovery from wastewater. For that reason, this Special Issue is centered on wastewater treatment by adsorption and/or ion-exchange processes for resource recovery. Nowadays, resource recovery is a trending topic following the circular economy schemes proposed by the European Union. [Extracted from the article]

• Spent mushroom waste showed great potential to treat wastewater. • The Mg-Fe@BSMW was characterized by different techniques FT-IR, XRD, XPS and SEM-EDX. • The interaction between the phosphate and Mg-Fe@BSMW were evaluated. • Mg-Fe@BSMW shows a superior adsorption capacity for phosphate and can be easily recycled. Excessive phosphate in water bodies causes eutrophication, which can be harmful to human and animal health. This study aimed to fabricate biochar adsorbent based on Mg-Fe modified spent mushroom waste for removing phosphate from aqueous solutions. Various characterization tools such as scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Brunauer Emmett Teller (BET), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) were applied to determine the surface structure and properties of biochar from spent mushroom waste (BSMW) and biochar from Mg-Fe modified spent mushroom waste (Mg-Fe@BSMW). The result confirmed that Mg and Fe were successfully embedded into the biochar matrix. Mg-Fe@BSMW showed an excellent adsorption capacity for phosphate (247 mg g−1). Kinetic and isotherm analyses revealed that the current study's data fitted well with the pseudo-second-order model and the Langmuir model. A thermodynamic study indicated that phosphate removal was exothermic and spontaneous. Our study indicated that Mg-Fe@BSMW was a potential adsorbent with high efficiency, and excellent reusability for phosphate removal. [ABSTRACT FROM AUTHOR]

The study was conducted to use different microbial species isolated from low-level radioactive wastewaters (up to 2 mSv) for removing non-radioactive (Co(II)) and radioactive cobalt (Cobalt-60) from waste solutions using different immobilization techniques; beads and thin film. Simple and innovate technique was used to prepare calcium alginate thin film. The isolated bacterial species investigated were Bacillus haynesii and Bacillus aerius while fungal species were; Aspergillus foetidus, Aspergillus parasiticus, and Penicillium oxalicum. The bacterial species were immobilized in wet form, while the fungal species were immobilized in wet and dry forms using sodium alginate gel. Screening of bacterial and fungal species in free and immobilized shapes for Co(II) and Cobalt-60 removal percent and capacity was studied. Moreover, the efficient immobilized weight could be used in the different immobilization shapes was investigated. Batch experiments were used to determine the optimum environmental conditions for cobalt removal by the immobilized beads or thin film. Scanning electron microscopy was done to observe the surface changes. However, the energy-dispersive X-ray analysis results indicated the accumulation of cobalt ions on the surface. The immobilized dry P. oxalicum beads showed higher Cobalt-60 removal percent about 79.3% as compared to all other immobilized bacteria and fungi biomasses. The statistical analysis using Statistical Package of Social Science (SPSS) indicated that the studied bacterial species had significant high means with (p-value < 0.05) for the removal efficiency either free or immobilized than studied fungal species. Also, there was a significant high means for immobilization in thin film shape than immobilization in beads for removal of Co(II) in both bacteria and fungi. In contrast, the immobilized beads had a significant high mean for Cobalt-60 removal in both bacteria and fungi. [ABSTRACT FROM AUTHOR]

Over the last few years, new advanced oxidation processes (AOPs) have been developed to the removal of organic pollutants from waters and wastewaters. The effectiveness of these AOPs as powerful way for the removal of POPs is related to the in situ production of strong oxidative species such as the hydroxyl radicals (·OH). Among the techniques involving AOPs, photo-electrocatalysis (PEC) has come out as a powerful AOP consisting of the combination of both photocatalytic and electrocatalytic processes for the objective to retard and/or avoid the fast recombination of the formed electron/hole pairs during the PEC. This can be achieved by the extraction of the photogenerated electrons directed to the cathode when an external bias potential is applied to the photoanode. This general and critical review deals with the application of PEC to the remediation of organic pollutants from wastewaters (i.e. dyeing effluents) using phosphate-based photoanodes namely BiPO4, Ag3PO4, Cu2(OH)PO4 and others. A detailed description of the PEC power of different photoanode has been discussed. The fundamentals and main applications of photo-electrochemical oxidation are reported. Finally, some critiques are proposed in order to improve and develop new effective photoanodes with perspectives to industrial applications. [ABSTRACT FROM AUTHOR]

Rubber latex wastewater contains high level of inorganic anions such as nitrate and phosphate which are more prevalent as groundwater contaminant. The applicability of biofilm forming bacterial isolates to treat rubber latex wastewater was investigated. Microscopic analyses (CLSM and SEM) evaluated that the major component of biofilm other than bacterial cell is EPS matrix. EPS was found to contain higher proportion of lipids and polysaccharide which are required for attachment and absorption of nutrients. ATR‐FTIR and 1H NMR revealed the functional groups present in EPS. Rhodococcus rhodochrous CTI‐14 showed robust biofilm followed by Cellulosimicrobium sp. CTB‐10. Out of six bacterial consortia tested, consortium‐D efficiently removed 95% NO3-–N and 75% PO43-. Taguchi method revealed the optimum parameters to remove the nutrients. The consortium‐D optimally reduced nitrate and phosphate at pH 7 at 37°C. Consortium‐D composed of Cellulosimicrobium sp. CTB‐10, Aeromonas veronii OS‐01, Lysinibacillus sphaericus RTA‐01 and Rhodococcus rhodochrous CTI‐14 was found to be the most efficient bacterial consortium to treat rubber latex wastewater. [ABSTRACT FROM AUTHOR]

The unrestricted discharge of domestic and industrial wastewaters along with agricultural runoff water into the environment as mixed-wastewater pose serious threat to freshwater resources in many countries. Mixed-wastewater pollution is a common phenomenon in the developing countries as the technologies to treat the individual waste streams at source are lacking due to high operational and maintenance costs. Therefore, the need to explore the potential of the suspended growth process which is a well-established process technology for biological wastewater treatment is the focus of this paper. Different wastewater constituents: representing domestic, pharmaceutical, textile, petroleum, and agricultural runoff were synthesized as a representative of mixed-wastewater and treated in two semi-continuous bioreactors (R1 & R2) operated at constant operating conditions, namely MLSS (mg/L): 4640-R1, 4440-R2, SRT: 21-d, HRT: 48–72 h, and uncontrolled pH. The system attained stable condition in day 97, with average COD, BOD and TSS reduction as 84.5%, 86.2%, and 72.2% for R1; and 85.1%, 87.9%, and 75.1% for R2, respectively. Phosphate removal on average was by 74.3% in R1 and 76.6% in R2, while average nitrification achieved in systems 1 and 2 were 56.8% and 54.7%, respectively. The biological treatment system has shown potential for improving the quality of mixed-wastewater to the state where reuse may be considered and tertiary treatment can be employed to polish the effluent quality. [ABSTRACT FROM AUTHOR]

Struvite crystallization for low-concentration ammonium wastewater provides a promising yet challenging way to recover nitrogen from bulk municipal wastewater. This research focused on the direct removal of low-concentration NH4+-N by fluidized bed reactor (FBR) with induced crystallization. NH4+-N (30 mg/L) was efficiently removed and Mg2+ and PO43- were employed as the precipitation reagents. The maximum of 82.0% NH4+ was removed when the pH was 10 and the stoichiometric ratio of [NH4+]:[PO43-]:[Mg2+] was 1:1.1:1. The rank of the influences of the three single factors on NH4+-N removal efficiency (%) was pH > P:N > Mg:N. The crystals achieved under optimal conditions were mainly struvite, while the addition of excess phosphate (N:P = 1:1.5) promoted the formation of crystals clusters instead of maintaining the typical orthorhombic structure, until Mg3(PO4)2·22H2O formed with an N:P ratio of 1:1.625. As most previous studies mainly focused on high-strength wastewater, this research demonstrated the potential of induced struvite crystallization by FBR for nitrogen recovery from low-strength ammonium wastewater treatment. [ABSTRACT FROM AUTHOR]

Nanocomposites containing mixed metal oxides show excellent phosphate removal results and are better compared to individual metal oxides. In this research, cerium/manganese oxide nanocomposites, embedded on the surface of modified cellulose pine wood shaving, were synthesized by a simple technique that is both eco-friendly and economically feasible. No toxic or petroleum chemicals were employed during preparation. Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface area analysis, and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy were performed to study the shape and size of nanocomposites as well as composition of elements present on the surface of the nanocomposites. Adsorption isotherm (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich) and kinetic studies (pseudo first and second-order, Elovich and Weber-Morris) were carried out to determine the adsorption mechanism for phosphate removal from contaminated water. The maximum adsorption capacity of nanocomposites was found to be 204.09 mg/g, 174.42 mg/g, and 249.33 mg/g for 100 mg, 300 mg, and 500 mg, respectively. The results indicate that the nanocomposites were able to decrease the phosphorus concentration from 10 to 0.01 ppm, below the threshold limit required by EPA guidelines in the USA. We also demonstrated that the media could be regenerated and reused five times without loss of performance. [ABSTRACT FROM AUTHOR]

The dairy industry is one of the basic industries that are important for the sustainability of life and because this industry uses and consumes a lot of water to produce milk, it discharges a lot of waste water. Because of the acute shortage of water needed to meet domestic, industrial and agricultural needs and increase pollution on the other, and of high fresh water demand in recent years, therefore; treatment of wastewater present very important. The most important pollutants of dairy wastewater discharged are phosphate. The present paper offers an ability of membrane distillation process (MD) for the treatment of dairy wastewater and removal of phosphate in Iraq. Artificial samples of wastewater prepared to implement the proposal. Opinions will be considered to make these wastewater samples within the standard properties of world dairy wastewater classifications. To alleviate membrane disturbances by organic and inorganic substances applied to physical deposition. The results showed the ability of the MD to remove a high concentration of phosphate from wastewater from dairy wastewater, with a clearance rate of 95 per cent. This value affected by temperature and temperature affects the effectiveness of The MD and is directly proportional to the flow. [ABSTRACT FROM AUTHOR]

Application of wastewater for algal biomass production can not only lead to production of thousands of tons of biomass for subsequent biofuel production, but also can provide for significant removal of contaminants in wastewater. The aim of the present study is to evaluate the growth, contaminant removal, and biochemical component (lipid, carbohydrate, and protein) accumulation potential of Chlorella vulgaris, Scenedesmus obliquus, and Oocystis minuta cells in wastewater supplemented with different concentrations of sulfate, nitrate, and phosphate. The results show maximum biomass productivity of 33, 19, and 98 mg dw/L/d for C. vulgaris, S. obliquus, and O. minuta, respectively. Phosphate removal (more than 90%) was highest in the culture with O. minuta; about 93% nitrate was removed by C. vulgaris, and the highest sulfate removal of 36% was observed in the culture with S. obliquus. The biochemical composition of the microalgae cells is in the ranges of 22–65% carbohydrate, 19–38% protein, and 8–17% lipid. This indicates that carbohydrate and protein are preferentially accumulated as compared to lipids under the growth conditions investigated for each of the microalgae strains. [ABSTRACT FROM AUTHOR]

• Novel La-modified platanus ball fiber biochar (La-TC) with 148 mg P/g were obtained. • La-TC had strong anti-interference of competitive ions and wide pH tolerance of 3–9. • Adsorption mechanism was explained by ligand exchange and inner-sphere complexation. • Fixed bed test of actual wastewater showed that La-TC had broad application prospect. In this study, a novel adsorbent of lanthanum-modified platanus ball fiber biochar (La-TC) was developed for efficient adsorption and reuse of phosphate from actual wastewater. La-TC adsorbing phosphate could be used as agricultural fertilizer. The saturated adsorption capacity of phosphate on La-TC was 148.11 mg/g at dosage of 0.4 g/L, initial solution pH of 6.0, contact time of 20 min, and temperature of 35 ℃, which was much higher than most phosphate biochar adsorbents. Simultaneously, La-TC had a wide pH (3–9) adsorption stability, a strong ability to resist interference of anti-competitive anion (SO2− 4 and NO− 3), and an outstanding regeneration ability. Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were used to reveal the adsorption mechanism of La-TC to phosphate, including electrostatic adsorption, ligand exchange, and complexation mechanisms. In the fixed bed column experiment of phosphorus removal from real wastewater, the maximum treated bed volume was 420, 440 and 480 (BV) under the bed flow of 1 mL/min and La-TC of 0.5, 0.75 and 1.0 g, respectively. Outcomes suggested that La-TC had a broad prospect of engineering application for removal and reuse of phosphate from wastewater, also realizing the resource utilization of wasted platanus ball. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate mixotrophic cultivation of microalgae-bacteria consortium in raw wastewater by stepwise addition of fermented effluent containing volatile fatty acids (VFAs). Results: Stepwise increase of VFAs enhanced algal biomass and lipid production, ammonia and phosphate removals. The highest biomass and lipid yield were 1.94 g L−1 and 310 mg L−1 when the addition of fermented effluent containing VFAs increased to 30% (v/v). With the same cultivation conditions, the maximum removals efficiency of ammonia and phosphate were 26.4 and 11.3 mg L−1 d−1. Bacterial diversities increased with the increasing concentration of VFAs and their communities were identified as phyla Actinobacteria, Bacteroidetes, Cyanobacteria and Proteobacteria. Conclusions: Although bacterial quantities increased with algae growth concurrently, the objective of culturing microalgae-bacteria consortium in raw wastewater without sterilization to produce biomass and lipid yield still can be realized. [ABSTRACT FROM AUTHOR]

Wastewaters and agricultural sludges can contain high concentrations of phosphate and ammoniumor nitrate–nitrogen, which run off easily to waterways causing eutrophication in water bodies. However, it is possible to precipitate phosphate and ammonium as struvite and use it as recycled fertilizer. In this research, MgSO4 solution obtained by treating fly ash (FA) or dolomite (DOL) with sulfuric acid was used as a precipitant for simultaneous phosphorus and nitrogen removal from synthetic (NH4)2 HPO4 solution. Precipitation experiments were performed at room temperature (20°C ± 2°C) using different molar ratios Mg:P:N (1.1-2:1-2:1-2) and precipitation times (4–24 h). The pH was adjusted to 9.0 and kept constant. In all cases, there were only minor changes in the removal of both ammonium and phosphate after 4 h of reaction time. Highest ammonium removal percentages after the 4 h test were 79.5% for MgSO4 1.3:1:1, DOL 1.1:1:1, and DOL 1.3:1:1. Highest ammonium removal percentages (75.5%) for FA based MgSO4 solution were achieved using molar ratios Mg:P:N 2:1:1 and 1.1:2:2. Also, the highest phosphate removal percentages were achieved with these samples (97% for MgSO4 1.3:1:1, 93.3% for DOL 1.3:1:1, 89.8% for DOL 1.1:1:1, 84.5% for FA 2:1:1, and 82.5% for FA 1.1:2:2) Struvite was the only formed precipitation product in all cases as was confirmed by X-ray diffraction. Results indicate that fly ash and DOL based MgSO4 solutions performed quite well compared to commercial MgSO4 salt and they have great potential in the ammonium and phosphate precipitation. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the use of Spirogyra sp. green algae for wastewater treatment process in sewer. The effects of light and carbon sources were investigated on growth of the algae Spirogyra sp, removal of nitrate, nitrite, phosphate, chemical oxygen demand (COD) and pH changes. Samples 1 & 4 were grown in autotroph form, while samples 2 & 5 and 3 & 6 were grown in media containing 100 and 200 mg/L of glucose, respectively. Samples 1 up to 3 were grown in cycling light but samples 4 up to 6 were grown in continuous light. Results indicated that algal growth, levels of nitrites and pH and removal of nitrate and phosphate were increased in continuous illumination and carbon sources availability (100 and 200 mg/L of glucose). It can be recommended to apply Spirogyra sp. for wastewater treatment process in sewer collection system. [ABSTRACT FROM AUTHOR]

Effective removal of nitrogen and phosphorus from sewage before its discharge to the receiving water body is now a key task for scientists and technologists around the world. The widespread problem of eutrophication in the watercourses as well as in the seas and oceans obliges to take actions leading to more effective protection of water resources and implementation of sustainable development principles. One of the methods of increased wastewater treatment from nutrients is the use of a third stage of treatment with the use of macrophytes for the uptake of nitrogen and phosphorus. These systems, called hydroponic, under moderate climate conditions show little effectiveness due to the lack of sufficient light intensifying the growth of aquatic plants. The aim of this study was to evaluate the reduction of biogenic compounds concentrations in wastewater where additional lighting of plants was provided by the use of LED (Light Emitting Diodes), in two different conditions of experiment: with aeration and with carbon dioxide supplementation. Analyses show that the effectiveness of purification was higher in the wastewater supplemented with CO2 and artificial lighting had no significant influence on the reduction of nitrogen forms concentrations. In wastewater with aeration, higher effectiveness of nitrogen removal was observed in the tank with artificial lighting. In both cases, aeration or CO2 supplementation as well as artificial lighting or its lack, had no influence on total phosphorus and phosphates removal. [ABSTRACT FROM AUTHOR]

Featured Application: Authors are encouraged to provide a concise description of the specific application or a potential application of the work. This section is not mandatory. The lack of clean water sources, due to the presence of pollutants in water, is a major issue in many countries, including Malaysia. To overcome this problem, various methods have been introduced, including phytoremediation treatment. Therefore, this phytoremediation study examined the ability of five aquatic plants—Centella asiatica, Ipomoea aquatica, Salvinia molesta, Eichhornia crassipes, and Pistia stratiotes—to remove three pollutants—total suspended solids (TSS), ammoniacal nitrogen (NH3-N), and phosphate—from aquaculture wastewater. Using wastewater samples, each containing 50 g of one of the plants, the pollutant levels were measured every two days for 14 days. The results showed a drastic decline in the concentration of pollutants, where C. asiatica was able to remove 98% of NH3-N, 90% of TSS, and 64% of phosphate, while I. aquatica showed the potential to eliminate up to 73% of TSS and NH3-N, and 50% of phosphate. E. crassipes drastically removed 98% of phosphate, 96% of TSS, and 74% of NH3-N, while P. stratiotes was able to eliminate 98% of TSS, 78% of NH3-N, and 89% of phosphate. S. molesta was efficient in removing 89.3% of TSS and 88.6% of phosphate, but only removed 63.9% of NH3-N. [ABSTRACT FROM AUTHOR]

The present study aims at removal of Cr(VI) using immobilized Limnococcus limneticus from synthetic wastewater. Four different methods were followed to immobilize test cyanobacterial strain onto calcium alginate bead and named as Cyanobacteria Immobilized Calcium alginate Bead (CICB). Based on the preparation method, they were termed as CICB1, CICB2, CICB3, and CICB4. Effect of input variables such as pH (5–11) and concentrations of sodium alginate (20–40 g/L), calcium chloride (14.7–44.1 g/L), and amount of algal dosage (0.957–2.871 g/L) on the efficacy of beads in removal of Cr(VI) were examined. Comparative study showed that CICB1 was least efficient and maximum removal was obtained with CICB2, in which maximum cyanobacterial biomass was used. The effect of initial concentration (IC) of Cr(VI) on removal was studied using both CICB3 and CICB4 individually. The removal gradually decreased with increase in IC of Cr(VI) for both the beads. Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Fourier Transform Infrared studies of CICB3 and CICB4 were done. To understand the molecular transport mechanism of Cr(VI) within the solution, mesoscale simulations using computational fluid dynamics were used for predicting the removal of hexavalent chromium. [ABSTRACT FROM AUTHOR]

· Oxalic acid extracted ∼100% P from digested poultry wastewater at pH 2.5. · Bubble column electrolytic reactor achieved a pH boost from 2.5 to 7 in 6 minutes. · Seeding improved phosphate recovery by 11.5 % and energy efficiency by 52.6 %. · Seeding increased the particle size of struvite by 97.86 % with a purity of 94.7 %. · Estimated operating cost of the process was $12/ kg of struvite. Limited mineralization of organic phosphorus to phosphate during the anaerobic digestion process poses a significant challenge in the development of cost-effective nutrient recovery strategies from anaerobically digested poultry wastewater (ADPW). This study investigated the influence of organic acids on phosphorus solubilization from ADPW, followed by its recycling in the form of struvite using a bubble column electrolytic reactor (BCER) without adding chemicals. The impact of seeding on the efficiency of PO 4 3− and NH 3 -N recovery as well as the size distribution of recovered precipitates from the acid pre-treated ADPW was also evaluated. Pre-treatment of the ADPW with oxalic acid achieved complete solubilization of phosphorus, reaching ∼100% extraction efficiency at pH 2.5. The maximum removal efficiency of phosphate and ammonia-nitrogen from the ADPW were 88.9% and 90.1%, respectively, while the addition of 5 and 10 g/L struvite seed to the BCER increased PO 4 3− removal efficiency by 9.6% and 11.5%, respectively. The value of the kinetic rate constant, k , increased from 0.0176 min−1 (unseeded) to 0.0198 min−1, 0.0307 min−1, and 0.0375 min−1 with the seed loading rate of 2, 5, and 10 g/L, respectively. Concurrently, the average particle size rose from 75.3 μm (unseeded) to 82.1 μm, 125.7 μm, and 148.9 μm, respectively. Results from XRD, FTIR, EDS, and dissolved chemical analysis revealed that the solid product obtained from the recovery process was a multi-nutrient fertilizer consisting of 94.7% struvite with negligible levels of heavy metals. [Display omitted] [ABSTRACT FROM AUTHOR]

Rural areas often rely on decentralized wastewater treatment systems, including individual sewage treatment systems (ISTS), for remote houses, farms, and other establishments. For practical and financial reasons, ISTSs are often exempt from routine monitoring of effluent quality. As a result, they cannot guarantee the same level of treatment performance as their large-scale counterparts. A smartphone-based colorimetric monitoring method has been developed and tested to address this issue. This method can be easily adopted by untrained system owners. It uses modified test strips with built-in color reference zones and fiducial markers, which simplifies data acquisition and interpretation, eliminating the need for positioning accessories or controlled lighting. The proposed method ensures reliable results even when using a regular smartphone with default picture quality settings. The method has been tested with test strips measuring five different relevant wastewater quality parameters: pH, phosphates, ammonium, nitrates, and nitrites. For each type of test strip, the software installed on a smartphone provides a correlation for interpolating the measurements. The R 2 -values ranged from 0.881 to 0.993 for different reagents. The accuracy of this method was verified using lab-grade reference sensors and was found to be sufficient for the intended purpose. [Display omitted] • Smartphone-based colorimetry is a low-cost solution for wastewater monitoring. • Test strips with fiducial markers can be consistently recognized even in bad-quality images. • Reference colors on teststrips make color correction possible. • Modified test strips provide reliable results even when used by inexperienced users. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ceramisite-sulfur-siderite-P@1200AC enhanced biofilter was first established. • 93.23 % removal of EE2 and effluent TN < 5 mg/L were achieved. • Robust response of the enhanced biofilter to C/N fluctuations. • Pseudomonas and Chryseobacterium were dominant contributors to TN and EE2 removal. • Synergy of microbial diversity and electron transfer improved biofilter performance. A sulfur-based biofilter enhanced by phosphate modified activated carbon as particle electrodes was constructed to simultaneously remove total nitrogen (TN) and estrogen from low carbon-to-nitrogen ratio (C/N) wastewater containing 1 mg/L 17-alpha-ethinylestradiol (EE2). Results showed that the enhanced biofilter achieved outstanding performance in EE2 removal (93.2 %) and TN reduction (effluent < 5 mg/L), demonstrating robustness against C/N fluctuations. It was noteworthy that it successfully reduced both acute toxicity (59.5 %) and estrogenic activity (88.6 %). Comprehensive characterization investigations and microbial community structure analysis revealed that enhanced electron transfer and increased microbial abundance likely contributed to improved biofilter performance. Core microorganisms, such as Pseudomonas and Chryseobacterium were identified as key contributors to synergistic estrogen degradation and denitrification. This study presented a feasible and promising strategy of combined process with three-dimensional electrodes and sulfur-based biofilter, highlighting substantial potential for advanced purification and safe reuse of wastewater. [ABSTRACT FROM AUTHOR]

High levels of phosphorus released into the environment can cause eutrophication issues in wastewater, therefore discharge concentrations of such element are regulated in many countries. This study addresses the pressing need for effective phosphorus removal methods by developing a novel La 2 (CO 3) 3 and MnFe 2 O 4 loaded biochar composite (LMB). A remarkable adsorption capacity towards the three forms of phosphorus from wastewater, including phosphate, phosphite, and etidronic acid monohydrate (as a representative of organic phosphorus), was exhibited by LMB (88.20, 16.35, and 15.95 mg g−1, respectively). The high saturation magnetization value (50.17 emu g−1) highlighted the easy separability and recyclability of the adsorbent. The adsorption process was well described by the Langmuir isotherm model and the pseudo-second-order kinetic model, which mainly involved chemisorption. Characterization results confirm the effective loading of La 2 (CO 3) 3 with ligand exchange and electrostatic attraction identified as the primary mechanisms. Importantly, the LMB demonstrated exceptional selectivity for phosphorus in wastewater samples containing various substances, exhibiting minimal interference from competing ions (Cl−, NO 3 −, SO 4 2−, and CO 3 2−). These findings enhance the understanding of LMB's application in efficient wastewater phosphorus removal. Holding significant promise in wastewater remediation, the LMB acts as an effective adsorbent, contributing substantially to the prevention and control of various types of phosphorus pollutants, thereby mitigating wastewater eutrophication. [Display omitted] • La 2 (CO 3) 2 decorated magnetic biochar is synthesized by a facile solvothermal method. • La 2 (CO 3) 3 /MnFe 2 O 4 /biochar shows excellent adsorption performance for different phosphorus. • The presence of competing ions has a negligible effect on adsorption. • The adsorption mechanism of the absorbent for different phosphorus has been analyzed. • The strong magnetism of La 2 (CO 3) 3 /MnFe 2 O 4 /biochar shows separability from wastewater. [ABSTRACT FROM AUTHOR]

Herein, a new hybrid magnetic core@shell biocomposite was prepared based on an alginate-bentonite core and a chitosan shell layer (mAB@Cs) where magnetic Fe 3 O 4 NPs (50.7 nm) were in-situ generated on the surface via a simple non-thermal co-precipitation approach. The biocomposite has a high ability to magnetically separate and remove organic (ciprofloxacin (CPX)) and seven toxic inorganic (Cu2+, Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Hg2+) contaminants from simulated wastewater. Experimental results showed a CPX monolayer chemisorption with a Langmuir maximum adsorption capacity of 264.7 mg/g, maintained effectiveness up to the fifth cycle, and high removal rates of heavy metals ranging from 74.89 % to 99.86 % corresponding to adsorption capacities ranging from 12 to 20 mg/g. For a more accurate evaluation, the biocomposite was tested on a real urban wastewater sample (RWW) and it has manifested a noteworthy efficiency in removing a mixture of inorganic pollutants in terms of potassium K+ and orthophosphate phosphorous P-PO 4 3−, and organic matter in terms of biological oxygen demand (BOD) and chemical oxygen demand (COD) with 46 %, 90 %, 84 %, and 64 % removal efficiencies, respectively. On top of this, a high inactivation rate of E. coli of the order of 96 % was recorded, making the prepared magnetic biocomposite adept for the simultaneous removal of emergent wastewater pollutants, from organic, inorganic, to pathogen microorganisms. [ABSTRACT FROM AUTHOR]

Tributyl phosphate (TNBP), a new type of flame retardant, is an emerging pollutant and has been frequently detected in various matrices such as wastewater. Efficient removal of TNBP is critical for wastewater treatment. In this study, molecularly imprinted polymer (MIP) was prepared using precipitation polymerization for selective adsorption of TNBP. The results showed that MIP had a porous structure and formed effective imprinting cavities, which was primarily responsible for its superior adsorption ability. The adsorption of TNBP by MIP was carried out following both the pseudo-secondary kinetic model and the Langmuir isothermal adsorption model. MIP adsorbed TNBP rapidly and reached adsorption equilibrium within 30 min with 923 μmol g−1 at 298 K. The adsorption capacity and adsorption rate of MIP were respectively 2 and 5.49 times those of non-molecularly imprinted polymers. In addition, MIP could effectively counter disturbances from external parameters like temperature and pH, exhibiting strong environmental flexibility. MIP can specifically adsorb organophosphate esters, and can selectively adsorb TNBP under the interference of coexisting contaminants such as1,3-diphenylguanidine and isazofos. In actual bodies of water, MIP's highly selective adsorption of TNBP retains its advantage. The selective adsorption of MIP was mainly due to the common phosphate skeleton, and the specific substituent of organophosphate esters played an important role in the imprinting process. Hydrogen bonding might be involved in the polymerization process of TNBP with acrylamide and the adsorption process of TNBP by MIP.MIP exhibited good reuse efficiency, the total adsorption capacity decreased by no more than 25% after 7 reuse cycles. This study provides a simple and efficient method for selective removal of organophosphate from wastewater. [Display omitted] • MIP was synthesized with different templates, the synthesis system was optimized. • The adsorption equilibrium reached within 30 min, the q m was 923 μmol g−1 at 298 K. • MIP can selectively adsorb TNBP under the interference of DPG and isazofos. • MIP has good environmental adaptability and potential for practical application. • Hydrogen bonding may play a role in the adsorption and imprinting process. [ABSTRACT FROM AUTHOR]

Using biowaste-based adsorbents to remove phosphorus (P) from wastewater offers significant benefits concerning eutrophication mitigation and addressing waste management challenges. In this work, Ca-biocomposites were prepared by pyrolysis (700 °C) of a mixture of banana peel (BP) and eggshell (ES). The mass ratio of BP to ES was varied in 2:1, 1:1, and 1:2 ratios. Among the tested mixtures, the BPES-1:2 sample exhibited excellent P removal performance, reaching a maximum P adsorption capacity (Qma x) of 214 ± 5 mg P/g. The adsorption process fitted well with the Avrami order kinetic model (R 2 > 0.996) and the Liu isotherms model (R 2 > 0.997). The excellent fit of the experimental data to the Avrami model suggests that chemisorption is the dominant interaction mechanism, leading to precipitation through the formation of calcium phosphates. Additionally, the Liu model anticipates that the energetic characteristics of the adsorbent's active sites cannot be identical. This is in agreement with the presence of Ca(OH) 2 and CaCO 3 in the adsorbent material, where the Ca(OH) 2 active sites are preferred by the adsorbate molecules (PO 4 3−) for occupation. Furthermore, thermodynamic analysis revealed that P adsorption is a spontaneous process of exothermic nature (ΔH° < 0). The calculated activation energy for the process (72.81 kJ/mol) suggests the P adsorption mechanism involves strong chemical bonding between the adsorbent and P species. In addition, precipitation of apatite (Ca 5 (PO 4) 3 OH), a vital component in fertilizer production, was observed during the adsorption process. In tertiary treated wastewater applications, the BPES-1:2 biocomposite demonstrated a P removal efficiency of 90%. The solubility of P in a 2% formic acid solution was 100%, while the water-soluble P content was measured at 5.6%. These findings highlight the product's sustainable and environmentally beneficial nature by demonstrating its potential as a slow-release fertilizer, contributing to the application of the 3R slogan: Reduce, Reuse, Recycle. This value-added product is promising in supplying nutrients to plants over an extended period while minimizing the risk of nutrients leaching into the environment. [Display omitted] • Eggshells and banana peels were used for Ca-biocomposites production. • Ca-biocomposite demonstrated an efficiency of 90% P removal from wastewater. • The presence of Ca(OH) 2 and CaO in the Ca-biocomposites improves the P removal. • Apatite is the main product after P removal. • The production cost of 1 kg of Ca-biocomposite is $ 6.4. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel MM–TCMRs were synthesized for concurrent removal of phosphate and ammonium. • MM–TCMRs exhibits excellent phosphate and ammonium adsorption capacity. • Potential phosphate and ammonium removal mechanism with MM–TCMRs was proposed. • >70 % phosphate and ammonium were recovered from swine wastewater after four cycles. • Nutrient–loaded MM–TCMRs is applied as a fertilizer to promote alfalfa growth. Magnetic magnesium (Mg)–loaded Chinese herbal medicine residues (MM–TCMRs) were fabricated to simultaneously remove and recover phosphate and ammonium from wastewater. The MM–TCMRs exhibited larger specific surfaces and rougher structures with massive spherical particles than those of original residues. They could be separated by adjusting the magnetic field. The phosphate and ammonium adsorption by MM–TCMRs were matched with the pseudo–second–order model, while the Langmuir model yielded the maximum adsorption capacities of 635.35 and 615.57 mg g−1, respectively. Struvite precipitation on the MM–TCMRs surface was the primary removal mechanism with electrostatic attraction, ligand exchange, intra–particle diffusion, and ion exchange also involved. The recyclability of MM–TCMRs confirmed their good structural stability. More importantly, the nutrient–loaded MM–TCMRs enhanced alfalfa growth and improved soil fertility in planting experiments. Collectively, the MM–TCMRs are promising candidates for nutrient removal and recovery from wastewater. [ABSTRACT FROM AUTHOR]

Phosphorus (P) removal from urban wastewater is increasingly relevant in the wastewater treatment sector. The present work aims to contribute to the study of the adsorption process as a P removal technology. Biogenic calcium carbonate from industrial eggshell waste prepared by milling and calcination was used as an adsorbent. Batch adsorption experiments were conducted using real wastewater with 40 mg P/L (orthophosphate), original pH 7.33, under stirring conditions (100 rpm). The adsorbent was characterized using SEM-EDS, XRD, and FTIR-ATR before and after adsorption. From an initial screening of calcination times (15, 30, 60, and 120 min) and considering a balance between P removal and energy saving, the adsorbent selected was eggshell calcined at 700 °C for 60 min. The Langmuir isotherms describe the experimental data with a maximum adsorption capacity of 4.57 mg P/g at 25 °C. The adsorption process reached equilibrium within 120 min for different dosages (5, 10, and 20 g/L at 25 °C). Batch experiments showed that SO 4 2−, at a concentration of 2689 mg/L reduced the P adsorption selectivity for dosages ≤10 g/L at 25 °C. Characterization of the loaded adsorbent shows that P adsorption from real wastewater is mostly electrostatic attraction, with the contribution of ligand exchange and microprecipitation. The adsorption capacity and behavior of the selected adsorbent seem promising for P removal from urban wastewater compared with other low-cost adsorbents. • Biogenic calcium carbonate-based adsorbent has potential for P removal. • The adsorbent showed good performance in real wastewater (4. 57 mg P/g). • Sulfate ions may influence the selectivity of the adsorbent for phosphorus. • The main mechanism for P removal in real wastewater is electrostatic attraction. [ABSTRACT FROM AUTHOR]

Egg-washing wastewater contains a high concentration of nutrition and organic matter since eggs are broken during the washing and cleaning processes. Moreover, the wastewater contains small amounts of detergents or sanitizing agents. These contaminants may pose environmental challenges when they are not properly managed or treated. The study scrutinizes the efficiency of electrocoagulation (EO) and electrooxidation (EO) approaches for egg-wash wastewater treatment. The response surface methodology was employed to optimize the operational parameters. The removal efficiencies of soluble chemical oxygen demand (sCOD 90%), ammonia (NH 3 –N 91%), nitrate (NO 3 −-N 97%), nitrite (NO 2 −-N 89.3%), total dissolved nitrogen (TDN 91%), and phosphate (90%) were measured under various treatment conditions. The optimum treatment conditions achieved in the combined EC + EO process were pH 6.0, current density 20 mA cm−2, and electrolysis time of 60 min, respectively. Degradation kinetics of the egg-wash pollutants showed a significant reduction in half-life (t 1/2) with EO (after EC-Aluminum) at 15 min, 12 min, 17 min, and 15 min for sCOD, NO 2 −-N. NO 3 −-N, and TDN, respectively. Whereas the half-life of NH 3 –N (18 min) and phosphate (17 min) reduced significantly with the EO (after EC-iron). Al and Fe electrodes coupled with boron-doped diamond were found efficient for pollutant removal. Environmental implication. Egg-wash wastewater has a high protein content and contains nutrients that are essential for living organisms. While these compounds can be valuable for agricultural use by increasing soil phosphate concentration, they can also become an issue if the excess nutrients are not properly managed. The soil has a threshold limit for holding phosphate, and any excess amount may be transported through surface runoff or contaminate groundwater through leachate, potentially affecting aquatic ecosystems and water quality. This study explores the efficiency of electrocoagulation and electrooxidation methods in treating egg-wash wastewater. These methods aim to remove pollutants and reduce their environmental impact. [Display omitted] • Egg-wash wastewater contains a higher concentration of pollutants • High COD, TDN, and phosphate increases the environmental concern • Operational parameters were optimized to achieve better pollutant removal • Pollutant reduction could be effective for the resource recovery of contaminates [ABSTRACT FROM AUTHOR]

Polysilicate aluminum ferric (FD-PSAF) was prepared from foundry dust under polymerization temperature of 50 °C, polymerization time of 2 h and pH 2, to produce its amorphous Si–Al–Fe polymer. Removal efficiency of chemical oxygen demand (COD), color, turbidity and phosphate from swine wastewater reached 50.4%, 95.7%, 97.1% and 99.7% after addition of 10 mL/L of the prepared FD-PSAF, which were higher than those obtained when using polysilicate aluminum ferric (PSAF), polyaluminum chloride (PAC) and polymerized ferrous sulfate (PFS). The percentage content of Fe b for PFS, PSAF and the prepared FD-PSAF was 7%, 11% and 24%, respectively. The mean particle size in the swine wastewater increased from 39 nm to 84 nm, 1003 nm, 1198 nm and 2138 nm respectively after the addition of PSAF, PAC, PFS and prepared FD-PSAF into the swine wastewater. The prepared FD-PSAF with the higher coagulation performance could be related to its higher percentage content of Fe b and greater particle aggregation ability. The removal efficiency of color, turbidity and phosphate from swine wastewater by FD-PSAF did not obviously change with storage time from 1 d to 32 d, indicating that FD-PSAF had good stability performance. The FD-PSAF is an efficient coagulant that could be used to treat swine wastewater. [Display omitted] • Polysilicate aluminum ferric (FD-PSAF) was prepared from foundry dust by co-polymerization method. • FD-PSAF has good coagulation performance for swine wastewater. • FD-PSAF keep good coagulation stability after storage 32 d. • FD-PSAF with the higher percentage content of Fe b and greater particle aggregation ability. [ABSTRACT FROM AUTHOR]

• Biochar electrodes were modified by La-Fe (LFNB) to improve selective P-removal. • Migration electric–field assisted electrocoagulation (MEAEC) with LFNB has efficient P-removal. • LFNB-MEAEC is a novelty system with excellent performance for advanced treatment. • LFNB-MEAEC only requires 0.012 kWh/m3 for 95.2% P-removal in raw wastewater. The capacitive deionization-assisted electrocoagulation system has promising application potential in advanced phosphate removal of its low electricity consumption and sacrificial anode material. Phosphate removal in wastewater is crucial since excess phosphate might lead to eutrophication. However, the complex ion composition in raw wastewater can influence the effective phosphate removal by competing with the precipitable metal ions during electrocoagulation. In this study, a novel migration electric-field assisted electrocoagulation (MEAEC) with an assisted capacitive electrode made of N-doped and Fe-La co-modified biochar (LFNB) to achieve specific phosphate electro-adsorption for effective advanced phosphate removal. The LFNB-MEAEC achieved ultrahigh phosphate removal with the effluent of 0.1 mg/L in synthetic and raw municipal wastewater and met the first Grade A standard of total phosphate in the discharge standard of pollutants for municipal wastewater treatment plant (DSPMWTP) in China. The commonly observed coexisting ions in wastewater and a pH range of 2–12 did not significantly fluctuate the phosphate removal of LFNB-MEAEC. Cyclic voltammetry and charging-discharging tests confirmed the high phosphate affinity and excellent durability of LFNB in ion-interference circumstances. The MEAEC assisted with selective-adsorption capacitive electrodes and provided an effective and practical method for advanced phosphate removal from low-phosphorus-contaminated wastewater. The MEAEC with a selective-adsorbed capacitive electrode improved phosphate removal by 21 % (from 74 ± 1.7% to 95 ± 1.0%), reduced the energy consumption by 65.7% (0.012 kWh m−3-wastewater), and saved the sacrificial anode material by 67.5% (from 200 to 65 g m−3-wastewater) than those of MEAEC without phosphate-selective electrode in the same period (Sacrificial anode working time 200 s). [ABSTRACT FROM AUTHOR]

In this study, the potential of alum sludge, obtained from a drinking water treatment plant located in Istanbul, Turkey, as an adsorbent for the removal of phosphate from aqueous solution was investigated. The effects of adsorbent amount, pH, initial concentration, and temperature on phosphate removal were studied by batch adsorption experiments. Equilibrium data were analyzed according to the Langmuir and the Freundlich isotherms. The Freundlich isotherm equation provided a better fit than the Langmuir isotherm equation. Thermodynamic parameters (ÄG, ÄH, and ÄS) related to the process were also calculated and reported. The positive value of ÄH and ÄS indicated the endothermic nature of the phosphate adsorption and the affinity of the adsorbent for the phosphate, respectively. [ABSTRACT FROM AUTHOR]

The occurrence, seasonal variation and emission of nine widely used phosphorus flame retardants (PFRs) were investigated in a wastewater treatment plant (WWTP) located in Guangzhou, China, over 1 year. Results showed that PFRs were widely detected in wastewater and sewage sludge. Tris(2-chloroisopropyl) phosphate (TCIPP) was the most dominant PFRs in influent, effluent, and sludge. Significant seasonal variation of total PFRs in the influent was observed (p < 0.05). However, no significant seasonal variation found in chlorinated and alkyl PFRs. The emission of PFRs was comparable with the previously reported values of decabromodiphenyl ether in WWTPs. Risk quotient for PFRs showed low eco-toxicity risk in effluent for aquatic organisms. Since the removal efficiency of total PFRs was less than 30% and the use of PFRs had been increasing, continuous monitoring of the environmental impact on the receiving water is still needed. [ABSTRACT FROM AUTHOR]