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The removal of natural organic matter (NOM) by coagulation and adsorption on modified wheat straw (MWS) was investigated. Two types of inorganic polymer coagulants, polyferric chloride (PFC) and polyaluminum chloride (PAC), were used during experiments. The removal efficiency of NOM in terms of UV(254), DOC and COD(Mn) increased with the dosage of coagulants and adsorbent increasing. Combined coagulation and adsorption showed better UV(254) and turbidity removal efficiency (61.8% and 95.8% respectively for PFC-MWS, and 61.5% and 94.2% respectively for PAC-MWS) than individual treatment. The effects of combination sequences on DOC fractionation and residual chlorine decay were analyzed and the chlorine data were fitted using a chlorine decay model. In general, the higher the molecular weight of NOM was, the better removal efficiency the combined treatment can achieve. MWS can enhance the removal of NOM with higher molecular weight. The disinfection by-products (DBPs) formation potential in the effluents from coagulation and subsequent adsorption was greater than that in the effluents from adsorption and subsequent coagulation., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Highlights • PDMDAAC modified GO/Fe 3 O 4 was prepared for Cr(VI) uptake. • PDMDAAC changed the charged nature of GO/Fe 3 O 4. • PMGO-2 could be separated rapidly and be recycled from effluents. • PMGO-2 could disinfect water and adsorb simultaneously. Abstract A novel adsorbent was prepared in this work by introducing the poly dimethyl diallyl ammonium chloride (PDMDAAC) onto the magnetic graphene oxide (GO/Fe 3 O 4) for removal of Cr(VI) from aqueous solutions. The PDMDAAC modified magnetic graphene oxide (PMGO) exhibited high adsorption capacity towards Cr(VI) via electrostatic attraction by quaternary amine. The equilibrium isotherm was fit well with the Langmuir model and the maximum Cr(VI) capacity of the adsorbent calculated from the Langmuir model was found to be 95.2 mg/g, which was about twice higher than that of magnetic graphene oxide. The characteristics of the adsorbent indicated that some required functional groups (e.g. C N and N H groups) have been grafted on the magnetic graphene oxide. Regeneration tests were conducted by five successive sorption–desorption processes, and the results indicated that the regenerated PMGO still retained high adsorption capacity towards Cr(VI). All these results identified that PMGO could be employed as an efficient adsorbent for Cr(VI) collection from aqueous solution, which is of high practical value. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Highlights • EP-based hydrogel was used for copper recovery and nanoparticles in-situ synthesis. • Hydrogel–NP composites were used as catalysts in two organic contaminants reduction. • EP-based hydrogel is a post-sorption material for the metal recovery and recycling. Abstract A biomass-based hydrogel prepared from polymerization of Enteromorpha with acrylic acid (p(EP-g-AA)), was tested for application as a green and effective soft reactor for three purposes. First, swelling property of the p(EP-g-AA) hydrogel was tested and its use as an adsorbent for Cu(II) removal was studied. Then, these hydrogel networks were used as a template for in-situ copper nanoparticle synthesis. Both TEM and SEM images confirmed the formation of Cu particles sizing smaller than 100 nm. EDS mapping showed a homogeneous dispersion of the nanoparticles within the hydrogel structure. XRD patterns of the nanoparticles correspond to metallic Cu establishing a hexagonal crystallinity. Finally, the hydrogel-metal nanoparticle (p(EP-g-AA)-Cu) were employed as a catalyst for reduction of two organic contaminants, p-nitrophenol (4-NP) and methylene blue (MB). Reusability and stability studies demonstrated that the p(EP-g-AA)-Cu catalyst still maintained 80–90% of catalytic activity after 5 times use and 30 days storage. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

ABSTRACT: The wheat straw cellulose‐based hydrogels were synthesized by graft copolymerization followed by semi‐interpenetrating network technology. The prepared hydrogels were characterized through various methods including Fourier transform infrared spectra, scanning electron microscope, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. Batch adsorption experiments were carried out to investigate the adsorption performances of hydrogels toward Cu(II) ions. The results suggested that the introduction of semi‐interpenetrating network polymers, sodium alginate and poly(vinyl alcohol), could greatly enhance the adsorption property of hydrogels. And the wheat straw cellulose‐g‐poly(potassium acrylate)/sodium alginate hydrogel showed a highest Cu(II) ions adsorption capacity of 130 mg/g. The equilibrium isotherm and adsorption kinetics were also studied. Besides, the mass transfer coefficients and the thermodynamics of Cu(II) ions adsorption were also probed. Finally, the X‐ray photoelectron spectroscopy analysis further demonstrated that the Cu(II) ions adsorption was mainly via complexation reaction of NH2 and O‐containing groups in hydrogels. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46680. [ABSTRACT FROM AUTHOR]

In this work, a novel corn stalk based modified magnetic biopolymer ion exchange resin (CS-MAB) was prepared and used to remove perchlorate from aqueous solution. The physicochemical characteristics of CS-MAB were observed by SEM/EDS, BET, TEM, VSM, and XPS. The saturated magnetization and average pore diameter of CS-MAB were 3.82 emu/g and 4.83 nm. In adsorption batch experiments, the optimal adsorbent dosage and pH value for perchlorate removal are 1.0–1.5 g/L and 3.0–10.0. The adsorption kinetics fitted well with intraparticle-diffusion model in the first 90 min, and pseudo-second-order model in 90–360 min, which suggested that the potential mechanisms of perchlorate removal are physical adsorption and ion exchange reaction between ClO 4 − and Cl-containing groups of CS-MAB. Based on the analysis of Langmuir model, the maximum adsorption capacities of CS-MAB are 119.05 mg/g, 126.58 mg/g and 178.57 mg/g at 20 °C, 30 °C and 40 °C, respectively. The column adsorption of perchlorate could be described well by Thomas model, and the co-existing ions would restrain the perchlorate adsorption by the order of SO 4 2− > Cl − > NO 3 − . Chemical and biological technologies both can be used to effectively regenerate CS-MAB with the efficiency of 70%–90%. [ABSTRACT FROM AUTHOR]

Potassium tartrate (C 4 H 6 K 2 O 7 ) was utilized as a novel activating agent to prepare activated carbon with relatively high specific surface area by using less activating agent and activation time from marine waste–green alga ( Enteromorpha prolifera ) for the first time. The influences of activation temperature, impregnation ratio and activation time on the pore structure were investigated to obtain the optimum conditions (activation temperature: 700 °C, impregnation ratio: 1:1, and activation time: 30 min). Meanwhile, the activation temperature was evaluated to be the essential factor that dominated the form of pore structure in activated carbon. The green alga-based activated carbon that was prepared under optimum conditions has shown the high surface area of 1692 m 2 /g and total pore volume of 1.22 cm 3 /g, which could be used as an effective adsorbent to remove chloramphenicol. The thermodynamic data of chloramphenicol were well fitted by Langmuir isotherm model and the green alga-based activated carbon has showed high adsorption capacity of 709.2 mg/g towards chloramphenicol. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the adsorption characters of resin, microbial reduction of perchlorate and combined process of perchlorate removal in aqueous solution. Study demonstrated the adsorption equilibrium was achieved in 120 min, which based on ion exchange reaction. Dissolved perchlorate (100 mg/L) can be completely removed by acclimated anaerobic sludge in 15 h, and the concentrated perchlorate (∼200 mg/g) on the surface of resin would be effectively microbial reduced after 3 days. Neutral environment (pH = 7.4), higher biomass and additional electron donor can apparently improve the biological reduction efficiency of concentrated perchlorate. Addition of many co-anions showed the competition adsorption towards perchlorate, especially in the presence of NO 3 − . This study provides an effective method for perchlorate reduction by the adsorption-microbial process. [ABSTRACT FROM AUTHOR]

Four activated carbons (ACs) were prepared from four different solid wastes (SWs), includingEnteromorpha prolifera, Kraft lignin, hair, and petroleum coke, using KOH as the activating agent. The fabricated ACs were characterized by N2adsorption, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infrared and X-ray photoelectron spectroscopy to compare their pore structures and surface chemical properties of the ACs. It was found that ACs produced fromE.proliferaand Kraft lignin were rich in mesopores, whereas petroleum coke and hair were inclined to produce ACs with more micropores. Meanwhile, ACs derived fromE.proliferapossessed the largest surface area of 3,471 m2 g−1and pore volume of 2.681 cm3g−1. In addition, ACs prepared from various SWs displayed different chemical nature. Adsorption behavior of hexavalent chromium on the four fabricated ACs was studied as well, and the adsorption data were all well fitted by Freundlich equation, indicating the similar multilayer adsorption behavior of hexavalent chromium on the heterogeneous surface of the ACs. [ABSTRACT FROM PUBLISHER]

In this work, a new kind of magnetic amine/Fe 3 O 4 functionalized biopolymer resin (amine/Fe 3 O 4 -resin) was prepared and applied to remove various anionic dyes from water. Methyl Orange (MO), Reactive Brilliant Red K-2BP (RBR) and Acid Red 18 (AR) were selected as the typical anionic dye for this research. Meanwhile, amine/Fe 3 O 4 -resin was characterized by VSM, XRD, FT-IR, SEM, TEM and XPS. Three anionic dyes removed by amine/Fe 3 O 4 -resin were investigated using batch adsorption technique, and the parameters including adsorbent dosage, pH, contact time and temperature were considered. Due to a large number of amine groups and high surface areas, amine/Fe 3 O 4 -resin exhibited a remarkably high adsorption capacity for all three dyes, reaching 101.0 mg/g, 222.2 mg/g and 99.4 mg/g for RBR, MO and AR at 25 °C, respectively. The pseudo second order model and Langmuir model agreed well with the experimental data, and regeneration experiments indicated its merit of separability and reusability. [ABSTRACT FROM AUTHOR]

A novel adsorbent of magnetic amine-crosslinked biopolymer based corn stalk (MAB-CS) was synthesized and used for nitrate removal from aqueous solution. The characters and adsorption mechanisms of this bio-adsorbent were determined by using VSM, TGA, XRD, SEM, TEM, FT-IR and XPS, respectively. The results revealed that the saturated magnetization of MAB-CS reached 6.25 emu/g. Meanwhile, the studies of various factors indicated that this novel magnetic bio-adsorbent performed well over a considerable wide pH range of 6.0∼9.0, and the presence of PO 4 3− and SO 4 2− would markedly decrease the nitrate removal efficiency. Furthermore, the nitrate adsorption by MAB-CS perfectly fitted the Langmuir isotherm model ( R 2 = 0.997–0.999) and pseudo second order kinetic model ( R 2 = 0.953–0.995). The calculated nitrate adsorption capacity of MAB-CS was 102.04 mg/g at 318 K by Langmuir model, and thermodynamic study showed that nitrate adsorption is an spontaneous endothermic process. The regeneration experiments indicated its merit of regeneration and stability with the recovery efficient of 118∼147%. By integrating the experimental results, it was found that the removal of nitrate was mainly via electrostatic attraction and ion exchange. And this novel bio-adsorbent prepared in this work could achieve effective removal of nitrate and rapid separation from effluents simultaneously. [ABSTRACT FROM AUTHOR]

A novel method for perchlorate reduction by combination of adsorption and biological reduction was investigated in this work. After being adsorbed by biosorbent, the concentrated perchlorate was completely biologically reduced by mixed bacteria, which were dominated by Proteobacterial species. The reducing efficiency of perchlorate concentrated on biopolymer based adsorbent surface achieved optimal (75–85%) after 4 days of reduction time in the neutral environment (pH: 7.0–7.5). The reduction of perchlorate was enhanced by the Cl − and SO 4 2− ions and weakened by the dissolved NO 3 − ions in the reduction system. Moreover, per gram biopolymer based adsorbent could uptake 134.9 and 102.4 mg of perchlorate in the first and second bio-regeneration cycles of column tests, with regeneration efficiency of 77.7% and 59.0%, respectively. In conclusion, results indicated that the reduction of concentrated perchlorate could be achieved simultaneously with the biosorbent bio-regeneration. [ABSTRACT FROM AUTHOR]

A wheat straw cellulose-g-poly (potassium acrylate)/polyvinyl alcohol (WSC-g-PKA/PVA) semi-interpenetrating networks (semi-IPNs) hydrogel was synthesized by graft copolymerization and used for Pb(II) and Ni(II) adsorption from aqueous solution. The effects of solution pH value, contact time, initial concentration, and temperature on adsorption were investigated. The adsorption process was described by the adsorption models of Langmuir, Freundlich, and Dubinin–Radushkevic. The adsorption kinetics was analyzed using pseudo first- and second-order kinetic models, intraparticle diffusion model, and mass transfer model. Comparison analysis of linear least square method and nonlinear method for estimating the kinetics and isotherm parameters were also made. The results showed that nonlinear regression analysis could be a better way to obtain the model parameters. The pseudo second-order kinetic model was more suitable for describing the whole adsorption process, and both intraparticle diffusion with three steps and mass transfer were taking place in the adsorption. The equilibrium adsorption isotherm was closely fitted with both the Langmuir and Dubinin–Radushkevic model. The changes of free energy, enthalpy, and entropy of adsorption were evaluated for the adsorption of Pb(II) and Ni(II) by WSC-g-PKA/PVA, suggesting that the adsorption process was physical, spontaneous and endothermic. [ABSTRACT FROM PUBLISHER]

Easily separable amine-functionalized magnetic corn stalk composites (AF-MCS) were employed for effective adsorption and reduction of toxic hexavalent chromium [Cr(VI)] to nontoxic Cr(III). The saturated magnetization of AF-MCS reached 6.2 emu/g, and as a result, it could be separated from aqueous solution by a magnetic process for its superparamagnetism. The studies of various factors influencing the sorption behavior indicated that the optimum AF-MCS dosage for Cr(VI) adsorption was 1 g/L, and the maximum adsorption capacity was observed at pH 3.0. The chromium adsorption perfectly fitted the Langmuir isotherm model and pseudo second order kinetic model. Furthermore, characterization of AF-MCS was investigated by means of XRD, SEM, TEM, FT-IR, BET, VSM and XPS analysis to discuss the uptake mechanism. Basically, these results demonstrated that AF-MCS prepared in this work has shown its merit in effective removal of Cr(VI) and rapid separation from effluents simultaneously. [ABSTRACT FROM AUTHOR]

Amine-impregnated cotton stalk (AICS) prepared by the reaction of cotton stalk with epichlorohydrin, pyridine and trimethylamine was used as the effective adsorbent for perchlorate removal. Solid-state 13 C NMR spectra, FT-IR, BET principle and element analysis provided evidence that amine groups have been successfully introduced onto the surface of AICS. The adsorption capacity of perchlorate by AICS was about 83.8 mg g −1 at 20 °C. It was decreased to 80.6 mg g −1 as the temperature was increased to 40 °C, which implied an exothermic nature for this adsorption process. Perchlorate adsorption capacity in fixed-bed column was optimum at neutral condition (pH: 6.0, 70.8 mg g −1 ) with bed depth of 2.7 cm and flow rate of 5 ml min −1 . In addition, chemical regeneration by HCl or NaOH (0.1 mol L −1 ) achieved more than 95% of regeneration efficiency. Biological regeneration of the saturated AICS with mixed bacteria has shown its merit with regeneration and biological perchlorate destruction simultaneously although its regeneration efficiency was only 56.8–74.8%. [ABSTRACT FROM AUTHOR]

Highlights: [•] Adsorption of ciprofloxacin was conducted by carbon from aqueous solution. [•] Adsorption of Ni(II) was conducted by carbon from aqueous solution. [•] Cosorption of ciprofloxacin and Ni(II) was investigated. [•] The addition of ciprofloxacin suppressed the adsorption of Ni(II) onto carbon. [•] The presence of Ni(II) increased the adsorption of CIP in certain pH range. [Copyright &y& Elsevier]

A new feather protein-grafted poly(potassium acrylate)/polyvinyl alcohol (FP-g-PKA/PVA) semi-interpenetrating polymer networks (semi-IPNs) hydrogel was produced through graft copolymerization with FP as a basic macromolecular skeletal material, acrylic acid as a monomer and PVA as a semi-IPNs polymer. The adsorption of ammonium and phosphate ions from aqueous solution using the new hydrogel as N and P controlled-release fertilizer with water-retention capacity was studied. The effects of pH value, concentration, contact time and ion strength on NH4+andremoval by FP-g-PKA/PVA semi-IPNs hydrogel were investigated using batch adsorption experiments. The results indicated that the hydrogel had high adsorption capacities and fast adsorption rates for NH4+andin wide pH levels ranging from 4.0 to 9.0. Kinetic analysis presented that both NH4+andremoval were closely fitted with the pseudo-second-order model. Furthermore, the adsorption isotherms of hydrogel were best represented by the Freundlich model. The adsorption–desorption experimental results showed the sustainable stability of FP-g-PKA/PVA semi-IPNs hydrogel for NH4+andremoval. Overall, FP-g-PKAPVA could be considered as an efficient material for the removal and recovery of nitrogen and phosphorus with the agronomic reuse as a fertilizer. [ABSTRACT FROM PUBLISHER]

In this research, activated carbon fiber heated by microwave (WACF) under nitrogen (N2) atmosphere adsorption of tetracycline antibiotics (TCs) was analyzed. WACF was obtained under the microwave radiation temperature of 600°C and the radiation time of 15 min. The properties of WACF were characterized by a scanning electron microscope (SEM), N2adsorption/desorption isotherms, and X-ray diffraction (XRD) compared with activated carbon fibers (ACF) without any treatment. WACF had lower surface area (1008 m2/g) but higher external surface area (429 m2/g) than ACF (surface area: 1153 m2/g; external surface area: 308 m2/g). Meanwhile, the adsorption efficiencies of TCs (including tetracycline hydrochloride (TC) and oxytetracycline hydrochloride (OTC)) on WACF were both increased by about 4 times. These results indicated that mesoporosity amplification of WACF played a crucial role in the adsorption capacity of the two TCs. The kinetics and equilibrium data were agreed well with the pseudo-second-order kinetics model (R2 > 0.99) and Langmuir isotherm model (R2 > 0.98), respectively. It suggested that the adsorption process was dominated by chemisorption. Batch experiments showed the maximum adsorption capacities for both adsorbates were 339 and 331 mg/g respectively at pH 2. [ABSTRACT FROM AUTHOR]

Abstract: A new innocuous disposal for perchlorate was presented in this study. Perchlorate was first concentrated by wheat straw based adsorbent, and then biologically reduced by mixing with heterotrophic bacteria. The physicochemical properties of modified wheat straw (MWS) were evaluated by SEM, BET specific area, TGA, 13C solid state NMR and Raman spectra. The adsorption capacity for perchlorate was determined by the kinetics and isotherm tests. The surface areas of the raw wheat straw and MWS were in range of 4.6–5.9m2 g−1, which illustrated the absence of porous adsorption in potential adsorption mechanism. The uptake of perchlorate by MWS was based on ion exchange, which would benefit the biological reduction on surface of the biosorbent. The maximum adsorption capacity (Q max) of perchlorate by MWS was about 119.0mgg−1 (20°C) and decreased as temperature grew. The mixed perchlorate-reduction bacteria could reduce about 91% of loaded perchlorate (23.94mgg−1) on MWS in the first biological-reduction cycle and 87% in second cycle, indicating an available method of innocuous disposal for concentrated perchlorate wastes. [Copyright &y& Elsevier]

Abstract: We report a kinetic and equilibrium study of perchlorate adsorption onto giant reed modified by quaternary amine (QA) functional groups in batch reactors. The effect of pH, contact time, and initial perchlorate concentration on removal was investigated. The adsorption capacity for perchlorate was 169mg/g on the modified reed (MR) particles ranging in size from 100 to 250μm. The isotherm results were best described by the combined Langmuir–Freundlich equation. Optimum removal occurred in the pH range 3.5–7.0 and was reduced at pH>8.5. The maximum adsorption rate occurred within the first minute of contact and equilibrium was achieved within 7min. A three-stage adsorption occurred. In stage 1, adsorption was rapid and was controlled by boundary layer diffusion. In stage 2, adsorption was gradual and was controlled by both boundary layer and intraparticle diffusion. In stage 3, adsorption reached a plateau. The kinetic results fit well with a pseudo second-order equation. The adsorption mechanism was explored using Zeta potential analysis and Raman spectroscopy. Zeta potential measurements showed that reed modification enhanced perchlorate removal by increasing the surface potential. Electrostatic attraction between perchlorate anion and positively charged quaternary amine groups on the MR was the primary mechanism responsible for perchlorate removal. [Copyright &y& Elsevier]

Abstract: A series of sols consisting of aluminum magnesium mixed hydroxide (AMH) nanoparticles with various Mg/Al molar ratios were prepared by coprecipitation. The use of AMH as adsorbent to remove Cr(VI) from aqueous solution was investigated. Adsorption experiments were carried out as a function of the Mg/Al molar ratio, pH, contact time, concentration of Cr(VI) and temperature. It was found that AMH with Mg/Al molar ratio 3 has the largest adsorption efficiency due to the smallest average particle diameter and the highest zeta potential; AMH was particularly effective for the Cr(VI) removal in a pH range from acid to slightly alkaline, even though the most effective pH range was between 2.5 and 5.0. The adsorption of Cr(VI) on AMH reached equilibrium within 150min. The saturated adsorption capacities of AMH for Cr(VI) were 105.3–112.0mg/g at 20–40°C. The interaction between the surface sites of AMH and the Cr(VI) ions may be a combination of both anion exchange and surface complexation. The pseudo-second-order model best described the adsorption kinetics of Cr(VI) onto AMH. The results showed that AMH can be used as a new adsorbent for Cr(VI) removal which has higher adsorption capacity and faster adsorption rate at pH values close to that at which pollutants are usually found in the environment. [Copyright &y& Elsevier]

Abstract: Calcined hydrotalcite is a potential ion exchanger/adsorbent which can be used to remove toxic anions from contaminated water. The adsorptive removal of thiocyanate from aqueous solutions by calcined hydrotalcite was investigated in a batch mode. The influence of initial thiocyanate concentration, adsorbent concentration and temperature on the kinetics of thiocyanate removal was tested in kinetic runs. Three kinetic models were used to fit the experimental data, and it was found that the pseudo-second-order kinetics model is most appropriate to describe the adsorption kinetics. A Langmuir isotherm was used to fit the equilibrium experiments, and the saturated adsorption capacity was approximately 96.7mg/g, under the experimental conditions. The calculated activation energy for the process was 48.9kJ/mol. [Copyright &y& Elsevier]

Ultra-filtration technology has been increasingly used in drinking water treatment due to improvements in membrane performance and lowering of costs. However, membrane fouling is the main limitation in the application of ultra-filtration technology. In this study, we investigated the impact of four different pre-treatments: Coagulation, adsorption, coagulation followed by adsorption (C-A), and simultaneous coagulation and adsorption (C+A), on membrane fouling and natural organic matter removal efficiency. The results showed that adsorption process required a large amount of adsorbent and formed a dense cake layer on the membrane surface leading to severe membrane fouling. Compared to adsorption alone, the coagulation and C-A processes decreased the transmembrane pressure by 4.9 kPa. It was due to less accumulation of particles on the membrane surface. As for water quality, the C-A ultra-filtration process achieved the highest removal efficiencies of natural organic matter and disinfection by-product precursors. Therefore, the addition of adsorbent after coagulation is a potentially important approach for alleviating ultra-filtration membrane fouling and enhancing treatment performance. [ABSTRACT FROM AUTHOR]

This study aimed to fabricate new and effective material for the efficiency of phosphate adsorption. Two types of adsorbent materials, the zirconium hydroxides embedded in pomegranate peel (Zr/Peel) and zirconium-lanthanum hydroxides embedded in pomegranate peel (Zr–La/Peel) were developed. Scanning electronic microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) were evaluated to give insight into the physicochemical properties of these adsorbents. Zr–La/Peel exceeded the adsorption efficiency of Zr/Peel adsorbents in batch adsorption experiments at the same pH level. The peel as a host can strive to have a strong "shielding effect" to increase the steadiness of the entrenched Zr and La elements. La and Zr are hydroxide metals that emit many hydrogen ions during the hydrolysis reaction, which contribute to protonation and electrostatic attraction. The highest adsorption capacity of La–Zr/Peel for phosphate was calculated to be 40.21 mg/g, and pseudo second-order equation is very well fitted for kinetic adsorption. Phosphate adsorption efficiency was reduced by an increase of pH. With the background of coexisting Cl−, little effect on adsorption efficiency was observed, while adsorption capacities were reduced by almost 20–30% with the coexistence of SO 4 2 − , NO 3 − and humic acid (HA). Image 1 • Designed a new type of biosorbent containing bimetallic hydroxide nanocomposite. • Zr–La/Peel has excellent adsorption capacity under langmuir isotherm model. • Adsorption mechanism, SEM, XRD, and XP Spectroscopy were characterized. • Spent adsorbent material can be desorbed by NaOH treatment. [ABSTRACT FROM AUTHOR]

The pomelo peel was used as a bio-carrier for anchoring the dual-metal hydroxide (Zr La), forming the Zr La/PP composites. Morphology properties of the Zr La/PP composites indicated that a large amount of Zr La dual-metal hydroxides were self-aggregated on the virgin biomaterials, forming the different sizes (10–100 nm) of nano-structured aggregates on the Zr La/PP composites. The Zr distribution corresponded well to the dispersed La in the Zr La/PP composites. Fluoride capture by Zr La/PP composites increased with the increase in temperature. The preferential fluoride adsorption by the Zr La/PP composites can also be achieved in magnitudes of coexisting ions. The Zr La/PP composites exhibited a promising fluoride adsorption capacity with a significantly excellent stability. Several column adsorption-desorption cycles exhibited that there were no significant loss in fluoride capacity; this indicated the high adsorption stability of Zr La/PP composites. Based on all results above, it was suggested that the Zr La/PP composites could be used as a promising adsorbent for fluoride removal in real application. [ABSTRACT FROM AUTHOR]

A magnetic amine-crosslinked reed (MACR) was synthesized by an insitu precipitation method and used for perchlorate uptake. The morphological properties of clean MACR, perchlorate-saturated MACR and bio-regenerated MACR samples were determined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. The adsorption capacities of perchlorate by clean and bio-regenerated MACRs were determined. The density functional theory (DFT) method was employed to evaluate the binding free energies between various anions and ammonium/hydroxy groups. The maximum adsorption (Q max ) of perchlorate by MACR was calculated to be 195.5–232.8 mg/g at 30–50 °C. The theoretical computation of adsorption-free energies indicated that ammonium groups were dominant in the process of perchlorate adsorption; other anions, such as [H 2 PO 4 ] - , [NO 3 ] - and [SO 4 ] 2- , showed relatively higher binding free energies than [ClO 4 ] - , which corresponded to the results of competitive adsorption. The spent MACR was then bio-regenerated in a sealed 250-ml conical flask with perchlorate-reducing bacteria (30 °C, 160 rpm) and reached 81.4% of recovery within 3 days. Some hydrophobic macromolecules of extracellular polymeric substances (EPS) might have attached to the surface of MACR, which was validated by the zeta potential, SEM and excitation emission matrix (EEM) fluorescence spectroscopy results. [ABSTRACT FROM AUTHOR]

Low-cost activated carbons (ACs) were prepared from four kinds of solid wastes: petroleum coke, Enteromorpha prolifera , lignin from papermaking black liquid and hair, by pyrophosphoric acid (H 4 P 2 O 7 ) activation. Thermo-gravimetric analysis of the pyrolysis of H 4 P 2 O 7 -precursor mixtures implied that H 4 P 2 O 7 had different influences on the pyrolysis behavior of the four raw materials. N 2 adsorption/desorption isotherms, scanning electron microscopy, Fourier transform infrared spectroscopy and adsorption capacities for dyes were used to characterize the prepared activated carbons. AC derived from E. prolifera exhibited the highest surface area (1094 m 2 /g) and maximum monolayer adsorption capacity for malachite green (1250 mg/g). Kinetic studies showed that the experimental data were in agreement with the pseudo-second-order model. The adsorption isotherms were well described by the Langmuir isotherm model, indicating the adsorption of dye onto the ACs proceeded by monolayers. [ABSTRACT FROM AUTHOR]

In this work, perchlorate was first adsorbed by the cotton stalk based resin (CS-resin) and then the laden perchlorate was directly reduced by mixed perchlorate reduction bacteria (PRB) on surface of CS-resin. The characteristics of cotton stalk, clean CS-resin, perchlorate-laden CS-resin and bio-regenerated CS-resin were evaluated by XPS, FT-IR, SEM, zeta potential measurements. All characteristics showed clearly that (i) adsorption mechanism of perchlorate onto CS-resin was based on electrostatic attraction; (ii) biological destruction of laden perchlorate was effective for bio-regenerating the saturated CS-resin. The experimental adsorption capacities ( Q exp ) of perchlorate by CS-resin achieved at equilibrium condition was about 138.9 mg/g. Reduction rate of laden perchlorate on surface of CS-resin were about 2.12, 1.67, 0.032 and 0.009 mg/g (CS-resin) /d for initial redox potentials poised at −193, −70, +169, and +363 mV, respectively. This indicated that the rapid reduction of laden perchlorate may occur only when conditions were present to cause a low E h . [ABSTRACT FROM AUTHOR]

Abstract: Preparation of highly developed mesoporous activated carbons from renewable source Arundo donax Linn was performed using H4P2O7 as activator. The influences of chemical impregnation ratio (mass of H4P2O7:A. donax Linn), activation temperature and soaking time on the properties (yield, BET surface area, pore volume and surface functional group) of activated carbon were investigated. The optimal activated carbon (ALAC) was characterized by scanning electron micrograph (SEM), N2 adsorption/desorption isotherms, X-ray photoelectron spectrometry (XPS) and oxytetracycline (OTC) adsorption experiments. Results showed that the pore development was significant at temperatures >400°C, and reached a maximum BET surface area (1463m2/g) at 600°C and maximum total pore volume (1.24cm3/g) at 500°C. At a low impregnation ratio of 0.4, BET surface area and pore volume could reach as high as 1150.69m2/g and 0.59m3/g. Both BET surface area and pore volume initial increase followed by a decrease after reaching a maximum, with the maximal surface area was obtained at an impregnation ratio of 0.75 and maximal pore volume at 1.0. BET surface area and mesopore volume reached maximum after 10h of soaking. Acidic surface groups followed the order of: strong acidic groups>weak acidic groups>intermediate acidic groups. Low activation temperature was favorable to the formation of acidic surface functional groups. With the increase of soaking time, the acidic surface functional initial increase was followed by a gradual decrease and finally tended to level off. [Copyright &y& Elsevier]

Highlights: [•] The lignin-based activated carbon was prepared by physical activation with steam. [•] The influences of various process parameters were investigated. [•] The optimum preparation conditions were determined. [•] The lignin-based carbon prepared by steam activation exhibited a mesoporous structure. [•] The static adsorption experiment and adsorption isotherms were studied. [Copyright &y& Elsevier]

Abstract: Low-cost activated carbon with high surface area was prepared from lignin of papermaking black liquor (BL) by KOH activation with pre-carbonization method. The effects of lignin/KOH ratio, activation temperature and activation time on the BET surface area were investigated. In addition, the adsorption capacity of Ni(II) on BLAC was also studied. Through BET surface area, scanning electron microscopy, Fourier transformed infrared spectroscopy and thermo gravimetric analysis, the BL-activated carbon (BLAC) was discovered to have porous structure with a high surface area up to 2943m2/g. The results showed that the lignin/KOH ratio was the main factor influencing the surface area and the maximum surface area activated carbon was obtained at lignin/KOH ratio of 3:1, the activation temperature of 750°C and the activation time of 1h. The sorption experiments indicated that the pseudo-second-order model was well fitted the kinetic data and the adsorption equilibrium data were better simulated by Langmuir model. The adsorption ability of Ni(II) increased with increasing pH, indicating the electrostatic attraction mechanism. [Copyright &y& Elsevier]

Abstract: A composite sorbent (ACprepared by grafting amine-group onto activated carbon (AC). Both raw AC and ACcharacterized by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). Batch experiments with variable pH, time, and concentrations of Cr(VI) were conducted to evaluate the sorption performance of Cr(VI) by both adsorbents from aqueous solutions. The total chromium in the aqueous solution was also recorded to study the mechanism of adsorption/transformation of Cr(VI). The ratio of the amount of Cr(VI) to Cr(III) on the sorbent was confirmed by the XPS analysis results. Langmuir, Freundlich and Temkin adsorption isotherms were used to fit the experimental equilibrium data and values of the parameters of the isotherms were reported. When compared with the untreated activated carbon, the modified activated carbon provided more faster kinetics and the sorbent exhibits greater adsorption capacity for chromium(VI) by comparing the maximum adsorption capacity calculated by Langmuir model. Overall, ACffectively remove Cr(VI) from aqueous solutions under a wide range of experimental conditions. [Copyright &y& Elsevier]

Abstract: Continuous fixed-bed column studies were carried out by using modified corn stalk (MCS) as an adsorbent for the removal of Cr(VI) from aqueous solution. The effect of various parameters like bed depths (1.4, 2.2 and 2.9cm), flow rate (5, 10 and 15mL/min), influent Cr(VI) concentrations (100, 200 and 300mg/L) and influent solution pH (2.66, 4.91 and 5.66) was investigated. The exhaustion time increased with increase of bed depth, decrease of flow rate and influent concentration. The Adams–Bohart, Thomas and Yoon–Nelson models were applied to the adsorption under varying experimental conditions to predict the breakthrough curves and to evaluate the model parameters of the fixed-bed column that are useful for process design. The Thomas and Yoon–Nelson models were in good agreement with the experimental data. The MCS column study states the value of the excellent adsorption capacity for the removal of Cr(VI) from aqueous solution. [Copyright &y& Elsevier]

Abstract: Two activated carbons employing Cyperus alternifolius as precursor were produced by using two different activating agents, H3PO4 and H4P2O7 (AC-H3PO4 and AC-H4P2O7). Both of activated carbons were allowed by single-step to get carbonized at 450°C in a muffle furnace for 1h. Activated carbons differed with the physical structure and chemical properties which were derived from Scanning Electron Microscope, N2 adsorption/desorption isotherms and Fourier-transform infrared spectroscopy (FTIR). Batched sorption studies were performed to compare the ciprofloxacin (CIP) adsorption properties of two carbons. The results indicated that AC-H3PO4 had 1066.4m2/g of surface area and 1.151cm3/g of total pore volume, while AC-H4P2O7 had 1040.3m2/g of surface area and 1.227cm3/g of total pore volume. Moreover, AC-H4P2O7 exhibited a higher portion of mesopores than AC-H3PO4. Fourier transform infrared spectra indicated two samples had similar functional groups. For both adsorbents, the adsorption kinetics followed the pseudo-second-order model. The adsorption equilibrium data were very well represented by three commonly used isotherm model for AC-H3PO4 (Langmuir, Freundlich and Temkin equations). As for AC-H4P2O7, the adsorption isotherm models fitted the data in the order: Langmuir>Temkin>Freundlich isotherms. The thermodynamic parameters indicated that the adsorption of CIP onto both adsorbents was spontaneous and thermodynamically favorable, with exothermic nature of the adsorption of CIP onto AC-H3PO4 and endothermic nature onto AC-H4P2O7. [Copyright &y& Elsevier]

Abstract: Anion exchangers were prepared from corn stalks (CS) after reaction with epichlorohydrin and triethylamine by using diethylenetriamine (DETA) as modifying agent in the presence of N,N-dimethylformamide (DMF). The synthesis conditions for preparing corn stalks quaternary amino anion exchanger (CS-QE) by the single-factor experiments were optimized, with removal capacity of Cr(VI) and the production yield as indicators. Factors like CS dosage, volumes of organic liquid chemicals and synthesis temperatures were investigated. The optimal synthesis parameters were CS:epichlorohydrin:DMF:DETA:triethylamine=3g:10mL:8mL:6mL:10mL. The optimal experimental temperature in the synthesis process was 100°C. A relatively large removal (99.4%) was attained from a solution as concentrated as 200mg/L at natural pH (about 4.7) with an optimized adsorbent dosage of 2g/L. The performance of CS-QE was characterized by SEM, BET surface area, FTIR and Raman spectroscopic analysis. The FTIR spectrums analysis validated that a large number of amino groups with positive charge were conducted into the structure of CS-QE. The Raman shift of the Cr(VI) peak indicated the electrostatic attraction between the Cr(VI) ions and positively charged amine sites. [Copyright &y& Elsevier]

Abstract: The adsorbent modified from corn stalks was synthesized after the reaction between epichlorohydrin and triethylamine by using diethylenetriamine (DETA) as modifying agent in the presence of N,N-dimethylformamide (DMF). The performance of the modified corn stalks (MCS) was characterized by BET, SEM, zeta potential, FTIR and thermogravimetric analysis. The adsorption of Cr(VI) from aqueous solutions with MCS which contained amine groups was studied at varying adsorbent dose, initial Cr(VI) concentration, pH, contact time and temperature. Results showed that the Cr(VI) adsorption depended insignificantly on pH but significantly on temperature. The batch equilibrium data fitted well to the Langmuir isotherm. Maximum adsorption capacity of MCS for Cr(VI) was 200.00mg/g at 303K which was relatively large compared to some adsorbents as reported. Kinetic data were best fitted with the pseudo-second-order kinetic model. The intra-particle diffusion model was applied to investigate the adsorption mechanisms. The obtained thermodynamic parameters showed that the adsorption of Cr(VI) onto the adsorbent was an spontaneous and endothermic process. These results showed that the anion exchanger could be considered as a potential adsorbent for the removal of Cr(VI) ions from aqueous solutions. [Copyright &y& Elsevier]

Abstract: A new adsorbent modified from wheat residue was synthesized after reaction with epichlorohydrin and triethylamine by using the modifying agents of diethylenetriamine in the presence of organic medium of N,N-dimethylformamide. The performance of the modified wheat straw (MWS) was characterized by Fourier transform infrared spectroscopy and point of zero charge analysis. The adsorption was investigated in a batch adsorption system, including both equilibrium adsorption isotherms and kinetics. Results showed that MWR had great anion-adsorbing capacity, due to the existence of a large number of introduced amino groups, and the value of pHPZC was around 5.0. Equilibrium data were analyzed using the Langmuir, Freundlich, and Temkin isotherm models and were found to be best represented by the Freundlich isotherm model. Evaluation of the adsorption process identified its endothermic nature. The maximum adsorption capacity of MWS for the removal of Cr(VI) was 322.58mg/g at 328K, indicating that MWS has high chromium removal efficiency, compared to other adsorbents reported. The kinetics of adsorption followed the pseudo-second-order kinetic equation. The mechanism of adsorption was investigated using the intraparticle diffusion model. Thermodynamic parameters (free energy change, enthalpy change, and entropy change) revealed that the adsorption of Cr(VI) onto MWS was endothermic and spontaneous; additionally, the adsorption can be characterized as an ion-exchange process. The results suggest that MWS is an inexpensive and efficient adsorbent for removing Cr(VI) ions from aqueous solution. [Copyright &y& Elsevier]

Abstract: The adsorption kinetics of Cu(II) and Zn(II) from aqueous solution onto humic acid (HA) were investigated under different conditions. The results showed that HA was particularly effective for adsorbing heavy metals and that the effective pH range was above 6. The adsorption force was not single and dependent on solution pH. The experimental data were found to comply with the pseudo-second-order kinetic model with adsorption capacity, q ecal more close to the measured results. Increment of initial adsorbate concentration (1–4mg/L) and temperature (283–303K) are both favorable to adsorption process. Based on the desorption experiments, it is further indicated that the main adsorption force was complexation effect between organic ligands of HA surface and metal ions and the percentage of desorption is 50% for Cu and 30% for Zn, respectively. [Copyright &y& Elsevier]

The low phosphate content in the surface water is considered a pollutant that promotes algae reproduction and leads to eutrophication. Bimetallic Fe/La nanoparticles doped on pomegranate fiber (Fe/La Peel) were fabricated by solvothermal synthesis method and applied as biosorbent for phosphate removal in this study. Fe–La/Peel had an irregular and rough surface with a specific surface area of 93.18 m2/g and its surface was uniformly covered with Fe and La, providing potential adsorption sites for phosphate uptake. At the pH 2.91, the highest capacity of Fe/Peel, La/Peel and Fe–La/Peel were 13.91 mg/g, 38.86 mg/g and 44.5 mg/g, respectively. Batch adsorption experiments indicated that Fe–La/Peel biosorbent had excellent adsorption ability. In batch adsorption experiment, highest adsorption capacities of Fe–La/Peel fitted by Langmuir and Sips isotherms were 75.09 mg/g and 78.99 mg/g at 323 K, respectively. The total lowest metal leaching of Fe/La Peel was found 0.054 μg/mL under alkali condition, and the highest metal leaching was determined 8.13 μg/mL under acidic condition. The adsorption performance of Fe/La Peel was better than those La/Peel and Fe/Peel at the same pH levels. Phosphate capture by Fe–La/Peel bio-nanocomposite was a homogeneous adsorption process and increased capacity with the rising temperature. At neutral pH, phosphate uptake by Fe–La/Peel could maintain high efficiency and metal leaching was almost negligible. The preferential phosphate adsorption by Fe–La/Peel can also be achieved in the same magnitudes of coexisting anions (Cl−, NO 3 −, HCO 3 −). And the adsorption capacity was reduced to less than 20% in the presence of electrolytes. These results showed that Fe–La/Peel has the potential to be used for environmental remediation to remove phosphate from the wastewater. Image 1 • A novel biosorbent containing bimetallic hydroxide nanocomposite was prepared. • The preferential phosphate adsorption can be achieved in the presence of coexisting anions. • The rest of the electrolytes were reduced to less than 20% adsorption capacity. • At neutral pH, phosphate could be effective remove by Fe–La/Peel with less metal leaching. [ABSTRACT FROM AUTHOR]

Abstract The use of biochars formed by hydrothermal carbonization for the treatment of contaminated water has been greatly limited, due to their poorly developed porosity and low content of surface functional groups. Also, the most common modification routes inevitably require post-treatment processes, which are time-consuming and energy-wasting. Hence, the objective of this research was to produce a cost-effective biochar with improved performance for the treatment of heavy metal pollution through a facile one-step hydrothermal carbonization process coupled with ammonium phosphate, thiocarbamide, ammonium chloride or urea, without any post-treatment. The effects of various operational parameters, including type of modification reagent, time and temperature of hydrothermal treatment, and ratio of modification reagent to precursor during impregnation, on the copper ion adsorption were examined. The adsorption data fit the Langmuir adsorption isotherm model quite well. The maximum adsorption capacities (mg/g) of the biochars towards copper ions followed the order of 40-8h-1.0-APBC (95.24) > 140-8h-0-BC (12.52) > 140-8h-1.0-TUBC (12.08) > 140-8h-1.0-ACBC (7.440) > 140-8h-1.0-URBC (5.277). The results indicated that biochars modified with ammonium phosphate displayed excellent adsorption performance toward copper ions, which was 7.6-fold higher than that of the pristine biochar. EDX and FT-IR analyses before and after adsorption demonstrated that the main removal mechanism involved complexation between the phosphate groups on the surface of the modified biochars and copper ions. Graphical abstract Scheme 1. Preparation pathway of sustainable prolifera-green-tide-based biochars. Unlabelled Image [ABSTRACT FROM AUTHOR]

In order to achieve remarkable synergy between adsorption and photocatalysis for antibiotics elimination from water, in this study, a graphitized mesoporous carbon (GMC)-TiO 2 nanocomposite was successfully synthesized by an extended resorcinol-formaldehyde (R-F) method. In the composite, the lamellar GMC nanosheets possessed large specific surface area and mesoporous structure, and could adsorb and enrich antibiotics effectively. This could not only reduce the antibiotic concentration in water shortly, but also greatly increase the chances for antibiotics to contact with and be degraded by photocatalysts and active species. Interestingly, GMC could also facilitate the transportation of photogenerated electrons to further improve the photocatalytic efficiency of TiO 2 , and 15 mg/L ciprofloxacin (CIP) could be totally mineralized in 1.5 h. Meanwhile, the biological inhibition of reaction solution on luminescence bacteria decreased obviously with antibiotics degradation until non-toxicity, reinforcing the thorough elimination of antibiotics. Besides, from the viewpoint of organic chemistry, several plausible CIP degradation pathways were established using HPLC-MS technique, and an interesting intermediate with five-membered ring structure was firstly proposed, which is helpful to deeply understand CIP degradation. Strong synergy between adsorption and photocatalysis, along with quick and efficient antibiotics elimination, double confirm the great potential of GMC-TiO 2 nanocomposite for practical antibiotic wastewater purification. [ABSTRACT FROM AUTHOR]

A new quaternary ammonium anion exchanger derived from the cellulose-based biomaterial (sugarcane bagasse) was prepared for phosphate adsorption and then the phosphate saturated bio-sorbent was used as a slow-release phosphate fertilizer in water or soil. Results indicated that the adsorption of phosphate by the quaternary ammonium based sugarcane bagasse (QA-SB) was increased with the increase of temperature, and the adsorption was optimal at pH of 4.33–5.88. The capture of phosphate by the QA-SB in fixed-bed column was calculated to be 18.9–21.4 mg/g in the background of Cl − or NO 3 − (100 mg/L). In particular, the amount of laden phosphate was significantly decreased to 9.1 mg/g in the presence of coexisting SO 4 2− (100 mg/L). As a result, a stronger competitve effect of SO 4 2− on phosphate capture was observed as compared with those of Cl − , and NO 3 − . Results also indicated that the laden phosphate on the QA-SB could be desorbed efficiently and the recovery of phosphate onto the regenerated QA-SB still attained about 94.5% after 4 cycles. The slow-release of laden phosphate in aqueous solution could be continuously conducted for 12 d, with 43.6% of laden phosphate (11.6 mg/g) released. In contrast, phosphate (7.4 mg/g) released in soil reached equilibrium within 4 d, accounting for only 27.8% of laden phosphate released. [ABSTRACT FROM AUTHOR]

Phosphate capture from aqueous was conducted using hydrous zirconium oxide (HZO) embedded in quaternary-ammonium Chinese reed (CR-N + -HZO), and the characteristics of adsorbent was determined. HZO was dispersed as nanoparticles or nano-clusters on the external or inside the networking pores of CR-N + -HZO. The surface of CR-N + -HZO was heterogeneous with multiple adsorption sites, HZO nanocomposite and N + (CH 2 CH 3 ) 3 Cl − , which both contributed to the adsorption process. The phosphate uptake by CR-N + -HZO was optimal at pH 3.0 and phosphate uptake by HZO nanocomposite was greatly inhibited at alkaline pH. Kinetics studies suggested that both the intra-particle mass-transfer and external resistances were likely to be the rate controlling steps. The Q max (maximum adsorption capacity) of phosphate uptake by CR-N + -HZO and CR-N + (30 °C) calculated based on Langmuir model was about 59.2 mg(P)/g(CR-N + -HZO) and 30.4 mg(P)/g(CR-N + ). A high usage efficiency of Zr in CR-N + -HZO was observed with calculated molar ratio of P/Zr to be 3.07. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOFs with a low ratio of H 2 TCPP to monocarboxylate displays the best BPA removal performance. • The contents of O 2 ∙-, 1O 2 and ∙OH are enhanced by high salinity. • Coexisting salt ions increase the density of states near the Fermi level, boosting the transfer of electrons. • Coexisting salt ions prevent the recombination of photogenerated electrons and holes. The treatment of wastewater containing high salinity has been a pressing challenge due to the inhibition of reactive oxygen species by co-existing ions in the actual wastewater. In this work, four Zr 6 O 8 -porphyrinic MOFs (PCN-223, PCN-224, PCN-225, and MOF-525) with different topologies were selected to investigate their performance and mechanisms for the removal of contaminants from hypersaline waters in a visible photocatalytic degradation system. The results showed that the molar ratios of monocarboxylates, ligands, and Zr of the porphyrin-MOFs led to variations in the porosity, pore size distribution, crystal defects, and surface electrical properties of the as-obtained MOFs, resulting in differences in the adsorption and photocatalytic degradation performance of the materials towards bisphenol A. In-situ electron paramagnetic resonance (EPR) and quenching experiments showed that high salt surroundings can significantly increase the levels of O 2 ∙-, 1O 2 and ∙OH in Zr 6 O 8 -porphyrin-MOFs/visible-light systems. DFT calculations explain that the presence of anions not only promotes the adsorption of BPA by MOFs but also facilitates the conduction of photogenerated electrons and prevents the recombination of photogenerated electrons and holes during the photocatalytic process. The super-exchange charge transfer mechanism was shown to play a key role in the Zr 6 O 8 -porphyrin-MOFs/visible-light system, thereby accelerating the degradation of pollutants in high-salinity wastewater. The catalytic system can maintain consistent contaminant degradation efficiency over a wide pH range, with high concentrations of co-existing ions and in real water matrices. In addition, the catalyst also exhibits excellent stability and reusability. This work provides new insights into the application of porphyrin MOFs based visible photocatalytic processes for the treatment of highly saline wastewater. [ABSTRACT FROM AUTHOR]