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In this article, attapulgite (ATP) as a raw material, hexadecyltrimethylammonium bromide (CTAB) as a modifier, and chitosan (CTS) as a composite are used to prepare a natural mineral-based composite adsorbent CTAB-ATP/CTS for the adsorption of norfloxacin in water. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and specific surface area (BET) were used for characterization. When the initial pH is 7, the dosage of adsorbent is 3 g/L, and the initial concentration of norfloxacin is 50 mg/L, the reaction temperature is 25 °C, the shaking time is 4 h, and the maximum removal rate and adsorption capacity of CTAB-ATP/CTS for norfloxacin reached 94.62% and 23.66 mg/g, respectively. The adsorption of norfloxacin by CTAB-ATP/CTS is more consistent with the pseudo-second-order kinetic model (R2 = 0.9999, 0.9998, 0.9999 at initial concentrations of 25 mg/L, 50 mg/L, 75 mg/L), and the Langmuir isotherm adsorption model(R2 = 0.9903, 0.9935, 0.9933 at temperatures of 25 °C, 30 °C, 35 °C), indicating that the adsorption process of the composite material is controlled by chemical adsorption and its adsorption behavior is mainly single-layer adsorption. [ABSTRACT FROM AUTHOR]

As people's material quality of life continues to improve, water resources become subjected to varying degrees of contamination. As one of the most commonly utilised agents in water treatment, a flocculant exhibits a diverse range of forms and a vast scope of applications. However, the application of flocculants gives rise to a series of issues, including the use of large doses, the formation of sludge, the difficulty of recycling flocculants, and other concerns. The development of new flocculation technology has become a crucial step in enhancing the purification of wastewater and reducing environmental pollution. Magnetic flocculation can be classified into two main categories: magnetic seeds flocculation and magnetic flocculation. This paper presents an overview of the factors influencing magnetic flocculation, including the type of magnetic seeds, magnetic seeds particle size, and other pertinent considerations. Furthermore, the classification of magnetic flocculants in the process of magnetic flocculation is discussed. This includes the types of magnetic flocculant, namely, inorganic composite magnetic flocculants, organic composite magnetic flocculants, and biological composite magnetic flocculants. Inorganic composite magnetic flocculants are inexpensive and simple to produce; however, their dosage is considerable, and the resulting floc is not tightly formed, which impairs the efficacy of flocculation. The use of organic composite magnetic flocculants requires a smaller dosage and exhibits a strong flocculating ability; however, it may possess toxic properties and potentially cause harm to the water body. The biological composite magnetic flocculant exhibits high efficiency and no pollution, yet it is subject to stringent environmental conditions, displays poor stability, and is applicable to a relatively limited range of treatment scenarios. Furthermore, the integration of magnetic flocculation technology with other techniques is classified and summarised in diverse contexts, and the prospective research focus and direction of magnetic flocculants are proposed. [ABSTRACT FROM AUTHOR]

In this study, Y-type zeolite (ZMA: zeolite mineral adsorbent) was synthesized using illite and employed for a series of batch adsorption experiments for removal of heavy metal ions (i.e., Pb(II), Cu(II), Cd(II), Zn(II)). Water pH, adsorption time and adsorbent dosage were varied to observe their influence on the adsorption efficiency. The adsorption capacity of ZMA was in the order of Pb(II) > Cu(II) > Cd(II) > Zn(II), which was attributed to the hydrate radius, electronegativity, hydrolysis constant and charges of the adsorbates. The ZMA was then added to the bioretention unit as a soil amendment to remove Pb and Cu from stormwater runoff. It was proved that the bioretention system with ZMA could effectively remove the heavy metals in stormwater runoff; the average effluent concentrations of Pb and Cu were 26.65 μg L−1 and 42.22 μg L−1. The removal efficiencies of the system for Pb and Cu were 44.4% and 44.9%, respectively, all of which were higher than those of the system without ZMA. It was also found that ZMA could increase the retention capacity of the bioretention system for the heavy metals in the upper 10 cm of the soil layer, thus retard the migration of heavy metals in the soil to some degree. In summary, ZMA synthesized in this study could effectively improve the ability of the bioretention system to retain and immobilize heavy metals and prevent their environmental impacts. [ABSTRACT FROM AUTHOR]

Red mud was modified by impregnation with Co element loading. The Co-RM catalyst was characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-ray fluorescence (XRF), and UV full-band scanning. The results showed that the modified Co-RM catalyst successfully loaded the Co element and formed an irregular pore structure on the surface, thereby increasing the number of active sites of the red mud catalyst and effectively improving the degradation efficiency of tetracycline. Under the optimal conditions of a catalyst dosage of 0.3 g/L, a persulfate dosage of 3 g/L, a reaction temperature of 50 °C, and a pH value of 7, a removal rate of 50 mg/L of tetracycline can be achieved: 89.5% after 90 min. The effects of common anions and humic acids in water, as well as radical quenchers (anhydrous ethanol and tert-butanol), on the degradation of tetracycline were investigated. The results showed that Cl−, CO32−, HCO3−, H2PO4−, NO32−, HPO42−, and humic acids showed inhibitory effects on the degradation of tetracycline, while SO42− showed a promoting effect on the degradation of tetracycline. The free radical quenching experiment showed that the most important free radicals that can degrade tetracycline in the system are sulfate radicals. [ABSTRACT FROM AUTHOR]

Odor is one of the most intuitive indicators for assessing drinking water quality in waterworks. Removing odors is of great importance to improve the quality of tap water, ensure people's health, and address public perception. The effective identification of odors in drinking water and the exploration of the source of the odor are the prerequisites for eliminating odors. Therefore, this article first discusses the sources and types of odors that are typical in current drinking water, focuses on reviewing the research progress of odor removal technologies in water treatment plants, including adsorption technology, chemical oxidation technology, biodegradation technology and combined technology, and explains the advantages, disadvantages, principles, research progress, practical application scenarios, considerations and application prospects of each odor-removal technology. It is expected to provide a reference for controlling odor pollution in drinking water. [ABSTRACT FROM AUTHOR]

Natural clay mineral and its modifier called modified clay have been used in many environmental applications for a number of years. However, they are not capable enough to achieve a higher conversion rate and so-called ecological sustainability. This can be due to a lack of understanding of the selectivity of the clay and its modifier or a lack of compatibility between clay and pollutants. Recently, the development and implementation of green principles into practice have become an emerging field that brings together green chemistry and engineering practices to achieve a pollutant-free environment (air, water, and soil). This review summarizes the role of clay/modified clay in pollution control and discusses the role of green chemistry in creating global sustainability. In this context, this review sheds light on the complete classification of the clay family to identify its properties and to critically examine the applicability of clay and modified clay for air, water, and soil pollution control over the past decade. This is the unique point of this review, showing how the properties of clay/modified clay can be useful for removing any type of pollutant without focusing on a single type of pollutant or clay. Furthermore, the importance of green materials in clay research, as well as the future area of application, was discussed. Overall, this review places value on multidisciplinary researchers to determine the role of the green pathway in the application of clay and modified clay in achieving environmental sustainability. [ABSTRACT FROM AUTHOR]

As an abundant potentially dangerous waste, red mud (RM) requires a straightforward method of resource management. In this paper, an RM catalyst loaded with cobalt (Co-RM) was prepared by the coprecipitation method for the efficient activation of persulfate (PS). Its degradation performance and mechanism of ofloxacin (OFL) were investigated. The characterization results of scanning electron microscopy, X-ray diffractometer, and energy dispersive spectrometer showed cobalt was successfully loaded onto the surface of RM, and the catalyst produced could effectively activate PS. Under the conditions of 15 mg/L OFL, 0.4 g/L Co-RM, 4 g/L PDS, 3.0 pH, and 40 °C temperature, the maximum removal rate of OFL by the Co-RM/PDS system was 80.06%. Free radical scavenging experiments confirmed sulfate radicals were the main active substances in the reaction system. The intermediates in OFL degradation were further identified by gas chromatography-mass spectrometry, and a possible degradation pathway was proposed. Finally, the relationship between defluorination rate and time in the Co-RM/PDS degradation OFL system was described by the first-order kinetic equation. This work reports an economical, environmental solution to the use of waste RM and provides a research basis for the further exploration of RM-based catalysts. [ABSTRACT FROM AUTHOR]

Industrial production is the main reason for excessive fluoride content in wastewater, and it is necessary to adopt economical and effective fluoride removal methods. Therefore, be aware of the existing form of fluorine and the formation mechanism of fluoride pollution, and based on the water purification agents, environmental functions, and material innovation, this overview focuses on the defluoridation mechanism, the advantages and disadvantages of precipitation and coagulation, adsorption, electrochemical technology, and membrane separation technology. In the actual process of treating fluoride-containing wastewater, appropriate methods should be adopted according to the different characteristics of the wastewater. This review describes the research progress of fluoride removal methods for fluoride-containing wastewater at home and abroad in recent years, further analyzes the advantages and technical bottlenecks of these methods, and looks ahead at the major development trends in the future to provide a reference for further research on treatment technology of wastewater with a high fluoride content. [ABSTRACT FROM AUTHOR]

A generation of microplastics caused by improper disposal of disposable masks has become a non-negligible environmental concern. In order to investigate the degradation mechanisms of masks and the release of microplastics under different environmental conditions, the masks are placed in 4 common environments. After 30 days of weathering, the total amount and release kinetics of microplastics released from different layers of the mask were studied. The chemical and mechanical properties of the mask were also discussed. The results showed that the mask released 25141±3543 particles/mask into the soil, which is much more than the sea and river water. The release kinetics of microplastics fit the Elovich model better. All samples correspond to the release rate of microplastics from fast to slow. Experiments show that the middle layer of the mask is released more than the other layers, and the amount of release was highest in the soil. And the tensile capacity of the mask is negatively correlated with its ability to release microplastics in the following order, which are soil > seawater > river > air > new masks. In addition, during the weathering process, the C-C/C-H bond of the mask was broken. [ABSTRACT FROM AUTHOR]

A Y-type zeolite was prepared from illite clay, which was activated and synthesized by a solid-phase alkali fusion technique with reduced reaction conditions and crystal methods. The optimal synthesis conditions were investigated using the Box-Behnken design for a NaOH/illite (mass ratio) of 1:2, an activation temperature of 185 °C, and an activation time of 2.7 h. The synthesized Y-type zeolites were characterized by various analytical techniques such as FT-IR, XRD, and SEM, and the results obtained show that small amounts of quartz and P-type zeolites are present in the synthesized products. The mixture was classified as a zeolitic mineral admixture (ZMA). The adsorption performance of ZMA on Pb(II) and Cu(II) in solution was evaluated by batch adsorption experiments. The results showed that ZMA had good adsorption performance for Pb(II) and Cu(II), with maximum adsorption amounts of 372.16 and 53.46 mg/g, respectively. From the investigation, it was concluded that the adsorption process is chemisorption occurring in monomolecular layers and relying on electrostatic adsorption, ion exchange and complexation of hydroxyl groups on the ZMA surface for heavy metal cations. The ZMA reusability result shows that sodium chloride has the ability to regenerate the active site by restoring the ion exchange capacity without significant loss of Pb(II) and Cu(II) adsorption. [ABSTRACT FROM AUTHOR]

Niobium pentachloride functionalised perlite was prepared via a solid state dispersion technique, which was utilized as an efficient heterogeneous catalyst for the synthesis of pyrans. The immobilisation of NbCl5 over perlite was examined by Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Thermogravimetric analysis (TGA), scanning electron microscope (SEM) with energy dispersive spectra (EDS), and Brunauer, Emmett and Teller (BET) surface area measurements. The wt% of NbCl5-loaded perlite was optimized based on the adequacy with respect to the yield of the pyrans in various solvents. The recyclability of the catalyst was validated in synthesizing pyrans and the results marked its efficiency up to five runs. The efficacy of the NbCl5/perlite catalyst was found to be comparable and better with respect to the other heterogeneous catalysts reported. The structures of pyrans were confirmed by FT-IR, 1H and 13C NMR spectral techniques. The proposed recyclable heterogeneous NbCl5/perlite catalyst simplifies the protocol, and has minimal chemical waste, a lower reaction time and a high-yield. [ABSTRACT FROM AUTHOR]

Using plant material as an additional carbon source is an economical and effective way to enhance nitrogen removal in wetlands. In this study, the reed straw was crushed and then added to the middle layer of the vertical down-flow wetland to investigate the effect of reed straw dosing on the removal of various forms of nitrogen from micro polluted waters in wetlands. The results showed that the addition of reed straw increased the content of organic matter in the wetland and significantly improved the removal of NO3−-N and NO2−-N from the wetland. When the dosage of reed straw was 16.7 g/kg, the wetland nitrogen removal effect was best, the removal rates of NH4+-N and NO3−-N reached 85.72% and 87.10%, and there was no accumulation of NO2−-N. The addition of reed straw decreased the NO3−-N content and nitrification rate in the substrate and increased the NH4+-N content and denitrification rate. Adding cheap reed straw can provide organic carbon for wetlands and greatly improve the removal of NO3−-N. [ABSTRACT FROM AUTHOR]

The global panic caused by COVID-19 has continued to increase people's demand for masks. However, due to inadequate management and disposal practice, these masks have, unfortunately, entered the environment and release a large amount of microplastics (MPs), posing a serious threat to the environment and human health. Understanding the occurrence of mask waste in various environments, release of mask-origin MPs, and related environmental risk is essential to mask-waste management in current and future epidemic prevention and control. This paper focuses on the global distribution of mask waste, the potential release of waste-origin MPs, and the impact on the environment. Specifically, the physical and chemical properties of polypropylene (the most common plastic material in a mask), which show a high adsorption capacity for heavy metals and organic pollutants and play a role as a support for microbial growth, were extensively reported. In addition, several important issues that need to be resolved are raised, which offers a direction for future research. This review focuses on the essentiality of handling masks to avoid potential environmental issues. [ABSTRACT FROM AUTHOR]

Constructed wetlands have been applied to micro-polluted rivers and lakes. However, they often show poor nitrogen removal efficiency due to insufficient carbon sources for complete denitrification in the waters. In this study, a vertical-flow wetland system was built, in which reeds as a carbon source were added in the middle layer of the substrate. Thereby, the effect of the reed carbon source on denitrification of micro-polluted rivers and lakes with a low C/N ratio in the wetland and the denitrification mechanism were studied. The results showed that the concentrations of NH4+-N, NO3−-N and NO2−-N in the effluent of the constructed wetland were reduced to 0.17–0.35, 0.20–0.49 and 0.01–0.02 mg/L after adding the reed carbon source, and the removal efficiencies of the system for NH4+-N and NO3−-N reached 93.84% and 84.69%, respectively. The abundances of nirK, nirS, hzo and nrfA genes in the wetland substrate increased by 95.51%, 54.96%, 52.89% and 731.95%, respectively, which was considered to be related to the enhanced denitrification, anammox and dissimilatory nitrate reduction to ammonium of the wetland system. Reed planting promoted the increased abundances of amoA and nxrB genes, which might play a positive role in enhancing nitrification in wetland systems. The result of this study may provide a theoretical basis for the ecological restoration of low C/N micro-polluted water bodies. [ABSTRACT FROM AUTHOR]

Chitosan (CS), hydrated zinc acetate, and rectorite (REC) were used as raw materials to prepare CS-embedded zinc oxide (ZnO) nanoparticle by a chemical precipitation process. Hydrogen-bonded REC-loaded ZnO-CS nanoparticle was to form ZnO-CS/REC nanocomposite photocatalyst, its morphology and structure were analyzed by means of FTIR, XRD, TGA, SEM, and TEM. The effects of the catalyst dosage, methyl orange (MO) initial concentration and solution pH on photocatalytic performance were also discussed. The experimental results show that the ZnO-CS/REC nanocomposite has a particle size of 100 nm with good dispersion and uniformity. Under irradiation of visible light, 0.6 g/L photocatalyst was used to degrade MO in solution for 90 min at pH 6, then the MO solution (10 mg/L) was decolored by more than 99%, indicating that the ZnO-CS/REC nanocomposite exhibited highly photocatalytic degradation activity. Therefore, the photodegradation kinetic mechanism of MO in aqueous solution is presumed. [ABSTRACT FROM AUTHOR]

The water solubility and polymerizability of maleoyl chitosan (MCS) was significantly improved by introducing a maleoyl group into the chitosan chain and MCS is a promising monomer for preparing chitosan-based flocculants with good water solubility. In this study, MCS was grafted with acrylamide and diallyldimethylammonium chloride to prepared a cationic chitosan modified flocculant chitosan- graft-poly (acrylamide diallyldimethylammonium chloride) (PMAD) with excellent solubility by ultraviolet (UV)-induced copolymerization techniques. The effects of monomer concentration, the percentage of maleated chitosan, photoinitiator concentration and illumination time on the intrinsic viscosity, grafting efficiency and dissolution time of PMAD were investigated by single factor experiments. The optimal synthesis conditions were determined with monomer concentration 12.5%, MCS percentage 10%, cationicity 11.25%, photoinitiator concentration 0.3% and illumination time 120 min, proving that UV initiated method was benefited to improve water solubility of PMAD. PMAD prepared at the optimized condition has the optimal viscosity of 4,823.2 mg L-1, the grafting efficiency of 70.7% and the dissolution time of 75 min. At the same time, the synthesized products PMAD were characterized by infrared spectroscopy, scanning electron microscopy, H-nuclear magnetic resonance, thermogravimetric and X-ray diffraction techniques. The flocculation experiments of PMAD on algae-containing water showed that the flocculation performance of PMAD was remarkably higher than that of commercially available polyacrylamide and polyaluminum ferric chloride. The optimal removal rate of Chl a (81.2%), turbidity (94.9%), and algae cell concentration (99.7%) by PMAD was obtained at dosage of 40 mg L-1, pH value 8 and G value 500 s-1. The obtained zeta potential results proved that the main flocculation mechanism of PMAD was the function of adsorption bridging. [ABSTRACT FROM AUTHOR]

In this paper, highly efficient Ti-Ag/γ-Al2O3 particle electrodes were prepared for efficient degradation of chloramphenicol (CAP) by using three-dimensional electrocatalytic technology. The effects of preparation factors, such as mass ratio of Ti/Ag, loading times, and calcination temperature, on the electrocatalytic performance of Ti-Ag/γ-Al2O3 particle electrode were investigated. In addition, Ti-Ag/γ-Al2O3 particle electrodes under different conditions were characterized by SEM, EDS, XRF, and XRD. The optimal removal rate of chloramphenicol was 84.2% with initial concentration of chloramphenicol 100 mg/L, conductivity 6,000 μs cm–1, initial pH 4.0, current intensity I = 0.2 A, and flow rate 1.0 L/min. The elimination of •OH by addition of t-butanol reduced the chloramphenicol removal rate by 56.0% under the same working conditions, indicating that the degradation of chloramphenicol was caused by the combination of •OH indirect oxidation and anodic indirect oxidation. Meanwhile, the degradation process of chloramphenicol was approximately in accordance with the first-order kinetic equation. [ABSTRACT FROM AUTHOR]

In this work, carboxylated chitosan and acrylamide are used to synthesize a graft-modified natural polymer flocculant carboxylated chitosan-graft-acrylamide (CCSPAM) by UV-induced polymerization for copper and chromium removal. The effects of total monomer concentration, monomer mass ratio, pH value, photoinitiator concentration, and illumination time on the synthesis performance of CCSPAM were investigated regarding intrinsic viscosity (IV), grafting rate (GR), and grafting efficiency (GE). Various analytical techniques characterize the physicochemical characteristics of CCSPAM. Single factor experiments are used to investigate the effect of dosage, pH value, and reaction time on the chelation and capture of heavy metal ions by CCSPAM. The results show that the optimal IV, GR, and GE of CCSPAM achieved at total monomer concentration 30%, monomer mass ratio 1:4, pH 7.0, photoinitiator concentration 0.03%, and irradiation time 2 h are 1412.2 mL/g, 394.1%, and 84.1%, respectively. The experimental data of flocculation show that CCSPAM has a good total Cu and total Cr removal efficiency of 74.8% and 70.6% at dosage 2.0 mg/L, pH 6.0, and reaction time 2h, respectively. Fom the investigation, it is concluded that the grafted chitosan (CCSPAM) could be a be an effective and eco-friendly flocculant for removal of total Cu and total Cr ions from aqueous system. [ABSTRACT FROM AUTHOR]

We explored the occurrence and distribution of nonylphenol (NP) in 13 Taiwanese source waters. From all the surveyed waters, NP was detected at a high concentration, which could be attributed to contamination by wastewater discharges. In this study, we applied modified multi-walled carbon nanotubes (MWCNTs) for removing NP from aqueous solution. The impact of a few experimental factors, i.e., pH, contact time, MWCNTs dose, and temperature on the NP removal efficiency of modified MWCNTs was studied. The maximum adsorption capacity of the MWCNTs was observed to be 1040 mg NP/g when the initial NP concentration was 2.5 mg/L, and the solution pH was 4. The adsorption process followed the Elovich kinetics and the Elovich isotherm, indicating it is multilayer adsorption. The thermodynamic analysis demonstrated the NP adsorption by MWCNTs was thermodynamically satisfactory and, for the most part, endothermic as in the case of phenol adsorption. The result of the current study demonstrated the significance of free binding sites and the pore size of MWCNTs in the NP adsorption. This paper will help to better comprehend the adsorption behavior and mechanism of alkyl phenolic compounds onto MWCNTs. [ABSTRACT FROM AUTHOR]

Functional cellulose nanofiber films for the production of solar fuel from CO2 gas were prepared by immobilizing dendrimer and porphyrin derivative and loading an electron donor and enzymes (formate, aldehyde, and alcohol dehydrogenases) on the films. Porphyrin derivative is a photosensitizer, and the dendrimer plays the role of a reservoir of guest gases and carrier of electron/proton in addition to acting as an intermediate for the binding of porphyrin derivative on the nanofiber. However, after laser irradiation, whereas the remaining amount of gas on the film without an electron donor and enzymes was almost half of that without laser irradiation, it on the films loaded with an electron donor and enzymes was almost equal to or slightly higher than that without laser irradiation, whereas it was almost equal to or slightly higher than that on the films loaded with an electron donor and enzymes without laser irradiation. These results suggest the conversion of CO2 gas under laser irradiation. The conversion efficiency from CO2 to formic acid was only half because of the fact that only the adsorbed CO2 in the vicinity of the reaction system reacted; however, the conversion efficiencies from formic acid to formaldehyde and from formaldehyde to methanol were ∼80 and ∼90 wt%, indicating the successful stepwise conversion by the photoinduced enzymatic reaction. [ABSTRACT FROM AUTHOR]

In this work, a silane modifier with benzyl substitutes (OFS-B) and linear substitutes (OFS-L) was used to modify bentonite clay and soil, and the results were characterized by Fourier transform-infrared absorption spectroscopy (FT-IR) and powder-X-ray diffraction (XRD) analysis. A contact angle analysis was performed to determine the wettability of modified clay and soil. The findings revealed that silane-modified OFS-L clay and soil produced wettable surfaces, while OFS-B exhibited hydrophobic properties. These clays and soils were used in a bioretention system for Cd (II) removal. In the study, seven different types of bioretention systems, including natural, OFS-L, and OFS-B modified clay and soil, as well as natural, OFS-L, and OFS-B modified soil, were applied to Cyperus alternifolius plants without an additional layer. The removal capacity of Cd (II) was measured in the following order: modified clay > modified soil > original clay/soil > no layer, i.e., 99.48%, 92.22%, 88.10/78.5%, and 30.0%, respectively. OFS-L removed more Cd (II) than OFS-B during the modification. OFS-L now improves the bioavailability and accumulation of Cd (II) in the plant (18.5 µg/g) and has a higher chlorophyll-b concentration (1.92 mg/g fresh weight) than other systems. The wettable clay exhibited clay leaching into the various levels of the bioretention system. In the bioretention system, benzyl substituted clay prevented the penetration of water and formed a Cd (II) agglomeration. When compared to non-wettable modifiers, these results indicated that wettable clay material could be a capable material for removing Cd (II). [ABSTRACT FROM AUTHOR]

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater. [ABSTRACT FROM AUTHOR]

In this experiment, a variety of inorganic materials were simply compounded with Polysilicate Aluminum Ferric Sulfate (PSAFS) to treat emulsified oil-contaminated water. Manganese sulfate (MnSO4), magnesium sulfate (MgSO4), and zinc sulfate (ZnSO4) were selected as the materials to modify PSAFS in order to obtain a coagulant with good flocculation performance. During the preparation of modified PSAFS, metal manganese, magnesium, and zinc were introduced for modification, and four factors were used to optimize the best proportion of modifiers and PSAFS. The results showed that the order of demulsification and oil-removal ability is as follows: Mn-PSAFS (Mn-modified PSAFS) > Zn-PSAFS (Zn-modified PSAFS) > Mg-PSAFS (Mg-modified PSAFS) > PSAFS. Modified PSAFS was characterized by infrared spectroscopy (IR) and a Scanning Electron Microscope (SEM). In the range of 604 cm−1 to 1200 cm−1, due to the complexation reaction between metal ions and polysilicic acid, the absorption peaks of the modified PSAFS and PSAFS were significantly different. SEM results revealed that the particles of the spatial network structure were fibrous and arranged more closely (0.5 mm × 50.0 mm) than others. This study provided that the modified PSAFS had good potential application in treating emulsified oily wastewater in the future. [ABSTRACT FROM AUTHOR]