Inorganic Polymer Coagulant Research Articles

Low-carbon emitting Fe-cycle recovery of battery-grade FePO4 from biogas slurry for Li-battery application

Under the background of carbon peaking and carbon neutrality in China, anaerobic digestion of sludge to produce methane was an important way to recover biomass energy. But plenty of as-generated biogas slurry (BS) with high P concentration was valuable and difficult to dispose. Here, this work proposed a low-carbon emitting Fe-cycle strategy to recover battery-grade FePO4 from BS. At pH=1.0, the P-leaching rate of Fe-sludge (42.93 ± 1.49 mg g−1) generated by polymerized ferrous sulfate (an inorganic polymer coagulant) addition into BS was 93.46 ± 3.56% and high-purity FePO4 (99.0%) could further be obtained by Fe3+ supplement and pH adjustment (pH=2.0). The contents of all elements in recovered FePO4 product fully complied with the battery grade of national industry standard of China (HG/T 4701-2021). After battery-grade FePO4 precipitate separation, recovery solution (RS) with remaining Fe3+ was reutilized to remove 88.05 ± 1.77% of P when mixed with BS wit RS/BS ratio of 2:1, thus achieving a Fe cycle utilization. Meanwhile, the recovery cost of 5.42 $/kg P and CO2 emissions of 80.83 kg/kg P were lower than those of current FePO4 industrial production (14.60 $/kg P and 110.60 kg/kg P). Finally, the LiFePO4/C cathode material based on recovered FePO4 from BS exhibited stable discharge specific capacity of 84.6–100.2 mAh/g during 100 charge–discharge cycles. In general, this study successfully manifested the feasibility of novel Fe-cycle battery-grade FePO4 recovery strategy from wastewater, paving a viable low-carbon emitting pathway for future Li-battery manufacture industry.

An efficient separation for fluoride-ions from water supplies by ion precipitate flotation: Pilot scale study with generation of coagulative bubbles

Bubble surface modification is a promising technique that enables to increase the efficiency of a treatment that aims to remove a certain particle with lower consumption of chemical inputs. In this study, the so-called coagulative bubbles were generated from a mixed system consisting of amphoteric surfactant (Cocamidopropyl betaine, CAPB) and inorganic polymer coagulants (aluminum sulfate and calcium chloride) for the removal of fluoride ions present in groundwater destined for human supply. The critical micellar concentration (CMC) of CAPB was 0.26 mmol L−1. The coagulant bubbles (CB) were generated from pressurizing the coagulant solution in distilled water and applied continuously in a helical tubular reactor. The CB treatment method provided higher fluoride removal compared to conventional treatment with simple coagulant application. The CBs generated with Al made it possible to remove approximately 98 % of the initial amount of fluoride measured (3.5 mg L−1) with a dosage of 31 mg L−1 of Al; feed flow rate of 20 L min−1; pH 6 ± 0.5; and saturation pressure of 3 atm. This same operation, but without generation of CBs (regular atmospheric pressure), allowed the removal of 67 % of the initial fluoride concentration.

Reactive Oxygen Species-Mediated Mitophagy and Cell Apoptosis are Involved in the Toxicity of Aluminum Chloride Exposure in GC-2spd.

Aluminum chloride is an inorganic polymeric coagulant commonly found in daily life and various materials. Although male reproductive toxicity has been associated with AlCl3 exposure, the underlying mechanism remains unclear. This study aimed to examine the impact of AlCl3 exposure on mitophagy and mitochondrial apoptosis in testicular tissue and mouse spermatocytes. Reactive oxygen species (ROS) and ATP levels were measured in GC-2spd after AlCl3 exposure using a multifunctional enzyme labeler. The changes in mitochondrial membrane potential (MMP) and TUNEL were observed through confocal laser microscopy, and the expression of proteins associated with mitophagy and apoptosis was analyzed using Western blot. Our results demonstrated that AlCl3 exposure disrupted mitophagy and increased apoptosis-related protein expression in testicular tissues. In the in vitro experiments, AlCl3 exposure induced ROS production, suppressed cell viability and ATP production, and caused a decrease in MMP, leading to mitophagy and cell apoptosis in GC-2spd cells. Intervention with N-acetylcysteine (NAC) reduced ROS production and partially restored mitochondrial function, thereby reversing the resulting mitophagy and cell apoptosis. Our findings provide evidence that ROS-mediated mitophagy and cell apoptosis play a crucial role in the toxicity of AlCl3 exposure in GC-2spd. These results contribute to the understanding of male reproductive toxicity caused by AlCl3 exposure and offer a foundation for future research in this area.

Preparation of polyaluminium silicate sulphate by gravity supercritical method and its coagulation in oily sewage

In this work, different synthetic methods of polymeric aluminum silicate sulfate (PASS) and their coagulability to oily sewage were comparatively studied. PASS was synthesized by two methods: gravity supercritical method and basic titration method, denoted as PASS-B and PASS-S, respectively. The results show that the PASS prepared by gravity supercritical method has better Alb and stability. By applying two coagulants to oily sewage, it was found that PASS-B exhibited better turbidity and oil removal. It was found that PASS-B still has good coagulation by testing its coagulation after placing the coagulant for 2 months. In acidic test water, PASS-B exhibited stronger deprotonation ability. Finally, the polymerization mechanism and coagulation mechanism of PASS-B were analyzed in combination with Al morphology distribution and coagulation experiments. Gravity supercritical method as a new polymerization method may replace the traditional preparation method of inorganic polymer coagulants in the future, especially in large-scale applications.

High-efficiency leaching of Al and Fe from fly ash for preparation of polymeric aluminum ferric chloride sulfate coagulant for wastewater treatment

Preparation of inorganic polymer coagulants from circulating fluidized bed (CFB) fly ash is one of the most significant value-added and environment-friendly approaches. Nevertheless, CFB fly ash presents relatively low solubility in acidic systems, which limits its utilization efficiency. In this paper, enhanced metal leaching from CFB fly ash using combined HCl-H2SO4 leaching process for polymeric aluminum ferric chloride sulfate (PAFCS) preparation was proposed. PAFCS with the different molar ratios of Al3+/SO42− and Al3+/Fe3+ were prepared from as-obtained leaching liquors and characterized by SEM, XRD, FTIR, and coagulation experiments. The leaching efficiencies of Al and Fe in CFB fly ash were up to 96.75% and 97.64% by combined HCl-H2SO4 leaching process. The optimal molar ratios of Al3+/SO42− and Al3+/Fe3+ for the turbidity and UV254 removal were 10:1 and 10:1, respectively, due to the three-dimensional chain-net structure and the highest [Al + Fe]b content. When applied to biochemical effluent of coking wastewater treatment, PAFCS exhibited excellent removal performance on both humic acid-like and fulvic acid-like matters. The resultant flocs of PAFCS presented the largest recovery factor (Rf = 0.37) and strength factor (Sf = 0.79) in contrast with PAC and PAFC. This work provides a novel and high-efficient Al and Fe leaching strategy from CFB fly ash to prepare Al-Fe coagulant.

Response Surface Methodology for Treatment of Paper Mill Wastewater by Using Inorganic Polymeric Coagulant

Response Surface Methodology for Treatment of Paper Mill Wastewater by Using Inorganic Polymeric Coagulant

Effect of polyaluminium silicate sulphate with different alkyl chain lengths on oily sewage in oil fields

When the amount of anionic polyacrylamide (APAM) and petroleum sulphonate in polymer-flooding oily sewage increases, a stable emulsification system forms. This makes the treatment of oily sewage increasingly difficult. To better develop high-efficiency coagulants from scratch, this study first determined the structure and carbon number of petroleum sulphonate using 1H NMR and 13C NMR spectroscopy. Then, hydrophobic monomers with different chain lengths were copolymerised with aluminium salts to prepare inorganic polymer coagulants with different hydrophobic association abilities. Three novel coagulants were successfully prepared, as verified by FTIR and hydrodynamic radius detection, and their coagulation mechanism and performance in oily sewage were investigated and compared with (polyaluminium silicate sulphate) PASSi. The particle size and morphology of flocs after the addition of coagulant were detected by laser particle size analysis and scanning electron microscopy. The structure-activity relationship between emulsifiers and coagulants with different chain lengths was studied via the second virial coefficient A2. Polyaluminium silicate sulphate-hexadecyltrimethoxy (PASSi-C16) was determined to have the best coagulation effect by turbidity, oil removal rate and Zeta potential detection. This may have been due to PASSi-C16 containing a similar lipophilic group to the carbon chain structure of petroleum sulphonate, which could easily destroy the emulsion layer. These results provide insights into methods to improve the hydrophobic association capacity and for the targeted use of associative coagulants in large-scale applications.

Preparation of polyaluminum zirconium silicate coagulant and its performance in water treatment

A novel type of inorganic polymer coagulant, polyaluminum zirconium silicate sulfate (PAZS), was synthesized via co-polymerization. In the treatment of kaolin-humic acid synthetic water, it was found to be most effective when Si/(Zr + Al) = 1, OH/(Al + Zr) = 0.1, and Al/Zr = 3. Through CCD design, zeta potential and floc analysis, PAZS showed excellent coagulation and sedimentation performance in an experimental pH range of 3∼8. The prepared composite coagulant PAZS was characterized by FTIR, XRD, and SEM. Results indicate that PAZS is a highly polymerized complex with rough folded surfaces. The adsorption bridging effect and charge characteristics enabled PAZS to function in an acidic environment. The findings from the research conducted indicate that PAZS is a promising coagulant for efficient water treatment.

Potential of ozone micro-bombs in simultaneously fast removing bloom-forming cyanobacteria and in situ degrading microcystins

Aiming at effectively controlling the worldwide proliferation of cyanobacterial blooms, this study proposed a novel microbubble system – ozone micro-bombs for simultaneously fast removing cyanobacterial cells and in situ oxidatively degrading cyanotoxins. For producing the surface- and core-functionalized microbubbles – ozone micro-bombs, the zwitterionic surfactant-based bubble generation solution was modified with inorganic polymeric coagulant, and meanwhile, the bubble generation method was improved by injecting ozone during bubble creation. Featured as high gas holdup (>38%) and large specific surface area (<90 µm in diameter), the ozone micro-bombs efficiently eliminated Microcystis aeruginosa cells (>93.2%) within 3–5 min; and simultaneously, approximately 88.9–98.4% and 66.1–79.1% of intracellular and extracellular microcystin-LR (MC-LR) were removed, respectively. The efficient performance of cell separation by ozone micro-bombs ensured the high total MC-LR removal in spite of the cell lysis and the intracellular MC-LR release. During the treatment process, the surface-coated coagulant reinforced the capacity of microbubbles in capturing cells and dissolved organic matter; the ozone encapsulation in microbubbles enhanced the ozone transfer in water; the explosion of those micro-bombs released the oxidant of ozone and facilitated the degradation of MC-LR. Moreover, the cell re-growth was inhibited and the dissolved organic carbon got apparently decreased after treatment. With high feasibility and sound performance, the ozone micro-bomb technology is of great potential in in situ and thoroughly treating cyanobacterial blooms.

Removal of fluoride from water by using a coagulant (inorganic polymeric coagulant).

Excess fluoride (F) ion of drinking water is a major problem in many areas of India and causes harmful effects such as dental and skeletal fluorosis. The World Health Organization (WHO 2004) recommends an upper limit of 1.5 mg/L fluoride in drinking water, and the concentration of fluoride in groundwater has been found 10-20 times higher in many of the States in India. In this study, the performance of inorganic polymeric coagulant (IPC) named as IPC-23, IPC-13, IPC-17, and alum for fluoride removal from drinking water was investigated. The amount of IPC was decided according to the Al2O3 amount present in the alum dose recommended in the batch Nalgonda defluoridation technique. The effects of coagulant dosage (IPC) at different pH and initial concentrations of fluoride on fluoride removal have been studied. The synthetic sample having a fluoride concentration of 2 to 6 mg/L was treated at the optimized dosage and residual fluoride was reduced to 1.0 to 1.2 ppm with IPC-17. Residual aluminum in treated water was well within WHO norms (< 200 μg/L) for drinking water. Optimum pH for fluoride removal was 6.5, and there was deterioration in the performance of IPC at both lower and higher pH.

Investigation of Plausible Mechanism of the Synthesized Inorganic Polymeric Coagulant and Its Application toward Fluoride Removal from Drinking Water

Fluoride, an anionic pollutant, existing in concentrations exceeding the allowed limit of 1.5 mg/L in drinking water, has been reported to cause detrimental impact on human health. The traditionall...

Analysis of the Influence of Coagulant on Phosphorus in Landscape Water Environment

This study selected three kinds of inorganic polymer coagulant: polyferric sulfate, polyaluminium chloride, polyaluminium ferric chloride, two inorganic low molecular coagulants: aluminum chloride and aluminum sulfate. The coagulation experiment of lake water without “water bloom” was carried out. The results were analyzed by multivariate linear regression and principal component regression analysis. It showed that the effects of the five coagulants on the phosphorus were the same when the landscape water was treated with different dosages of coagulants. The sequence was: total nitrogen (TN) > dosage > ammonia nitrogen > CODcr > turbidity > PH. Among them: the highest effect of total nitrogen on phosphorus was aluminum chloride (71.73%). The most obvious effect of dosage on phosphorus was polyaluminium chloride (34.68%). The most significant effect of ammonia nitrogen on phosphorus was polyaluminum chloride (16.98%).

Effectiveness of synthesized aluminum and iron based inorganic polymer coagulants for pulping wastewater treatment

Three inorganic polymer coagulants, namely, polyaluminum chloride (PAC), polyferric chloride (PFC) and polyaluminum ferric chloride (PAFC) were synthesized and tested for the treatment of simulated pulping wastewater. PAC exhibited the best performance for organics removal from the wastewater among all coagulants. PACs with basicity 2.0–2.7 were synthesized using three basification reagents (Na2CO3, NaOH and CaO) at ambient as well as elevated temperature. The desirable reactive polymeric content (Alb) were found highest in PACs (basicity = 2 and 2.5) using CaO. The synthesized PAC samples were stable for at least a period of 70 days. Among all the coagulants, PAC synthesized with CaO as basification agent (i.e., PAC2o; basicity = 2) showed similar organics removal as that obtained with aluminum salts. Low dissolved Al concentration in wastewater, good settling characteristics (with sufloc), low cake resistance during filtration and significantly improved biodegradability were the major benefits with the synthesized PAC2o.

Enhanced coagulation process by Fe-Mn bimetal nano-oxides in combination with inorganic polymer coagulants for improving As(V) removal from contaminated water

This study investigated the efficient removal of As(V) from contaminated water using enhanced coagulation by Fe-Mn bimetal nano-oxides in combination with poly-ferric chloride (PFC) and poly-aluminum chloride (PAC). The effects of coagulant dose, initial pH, initial As(V) concentration, Fe-Mn nano-oxide dose and flocs properties were investigated. The results showed that the combination of coagulants and nano-oxides significantly increased the As(V) removal efficiency in the optimal coagulants doses (25 mg/L). The As(V) removal efficiencies for PAC and PFC were 82.93% and 88.22% and for PFC + Fe-Mn and PAC + Fe-Mn were increased to 96.83% and 98.26%, respectively. The residual As(V) concentration was decreased to ˂10 μg/L in the presence of Fe-Mn nano-oxides. The best removal efficiencies for PAC + Fe-Mn and PFC + Fe-Mn were in pH 7 and 9, respectively. Based on FESEM - EDX analysis, the combined floc formation by coagulants - nano-oxides and the existence of Fe, Mn and As elements in the precipitated flocs was confirmed, and the PFC + Fe-Mn flocs were more uniform and bigger than PAC + Fe-Mn flocs. Total Fe and Al residual concentrations in optimum dose of PAC + Fe-Mn and PFC + Fe-Mn were 0.15 and 0.25 mg/L and Cl− residue concentrations were 6.87 and 4.72 mg/L, respectively. Therefore, the combination of Fe-Mn bimetal nano-oxides with PFC and PAC coagulants can be a suitable option to improve the removal of As(V) from the contaminated water resources.

Polyaluminum chloride-functionalized colloidal gas aphrons for flotation separation of nanoparticles from water.

The present work used the coagulative colloidal gas aphron (CCGA)-involved flotation as a robust technology to efficiently remove the typical engineered nanoparticles - silica nanoparticles (SNPs) from water. The inorganic polymer coagulant - polyaluminum chloride (PACl) was used to surface-functionalize the zwitterionic surfactant (C15B)-based CGAs. Results denote that the physicochemical conditions of PACl/C15B mixed solution markedly influenced the flotation behaviors by changing the properties of CCGAs. The C15B molecules showed different dissociated states and interaction behaviors with Al species with the variation of pH. The addition of salt into the PACl/C15B mixed solution decreased the foamability of solution, and the bubbles collapsed before they could efficiently capture SNPs in their rising trajectory. The optimum SNP removal (87.2%) was obtained when the pH and the additional ionic strength of PACl/C15B mixed solution were ∼4.7 and ≤ 1.0 g NaCl/L, individually, and the pH of SNP suspension was ∼9.4. Importantly, modifying PACl on microbubbles took greater advantages than directly using it as coagulant in terms of SNP removal and PACl utlization. The CCGAs were robust since their colloidal attraction and collision efficiency with SNPs were simultaneously enhanced. The PACl was more efficiently utilized during flotation whilst the regular chemical-dosing unit was omitted.

Chemical Coagulation Efficiency in Removal of Water Turbidity

Health promotion and protection of environment constantly depends on providing clean water. Water turbidity caused by suspended particles and colloids in it. So the aim of this study was to review the efficiency of chemical coagulation in removal of water turbidity.In this study all the present articles were searched in internal databases including Iran medex, Irandoc and SID and external databases such as Google Scholar, Scopus, Science Direct, scientific database of World Health Organization (Medicos / WHO / EMR), free journal access guide (Open Access Journal Directory of), PubMed using the Key words of coagulants, chemical coagulation, total water turbidity, the articles were searched and 268 articles were extracted and 25 articles that were completely relevance with the topic was reviewed. Including inorganic polymer coagulants advantages of high efficiency compared to conventional coagulants extensively in a range of pH, and better performance at various temperatures, especially at low temperatures is the Among the advantages of polymeric inorganic coagulants efficiently compared to conventional coagulants is appropriate efficient in an extensively range of pH, and better performance at various temperatures especially at low temperatures.Based on the studies, it was concluded that the use of chemical coagulation is an effective way to reduce water turbidity and the use of poly aluminum chloride due to low sludge production, reduction of PH to a limited extent, creation of large fluke, less residual and high rate of sedimentation in water is greater than other coagulants. © 2018, Advanced Scientific Research. All rights reserved.

Evaluation of oilfield‐produced water treated with a prepared magnetic inorganic polymer: Poly(silicate aluminum)/magnetite

ABSTRACTIn this study, novel coagulant poly(silicate aluminum)/Fe3O4 nanoparticles (PFeNPs) were prepared via magnetic iron oxide nanoparticles (FeNPs) modified by poly(silicate aluminum) (PSA). The physiochemical properties of the PFeNPs were investigated with Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, and ζ‐potential metric analysis. The effect of the aging time on the Al distribution of the PFeNPs was analyzed by the Al‐Ferron timed complex colorimetric method. Oilfield‐produced water was used for the assessment of the coagulation performances. The fractal dimensions, formation, breakage, and regrowth of the flocs were studied in turn. The experimental results show that the PFeNPs exhibited a porous layer of a net structure, and the PSA grafted onto the PFeNPs via SiOFe enhanced the positive charge of the FeNPs. Meanwhile, the coagulation performance of the PFeNPs on total organic carbon, the turbidity, and the calcium removal were beyond 98%. In addition, the moisture content of the flocs derived from the PFeNPs was 68.7% (it is normally &gt; 98%). We found that the compactness of the flocs derived from the PFeNPs was far greater than those of PSA. This will provide new sight into the preparation of magnetic single‐phase inorganic polymer coagulants. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45735.

Preparation of an Aluminum and Iron‐Based Coagulant From Fly Ash for Industrial Wastewater Treatment

Fly ash was investigated to produce a composite coagulant containing aluminum (Al) and iron (Fe) salts through the calcination and leaching processes. The extraction of Al and Fe oxides from fly ash demonstrated similar results for HCl and H2SO4 leaching. Besides, the calcination pretreatment of fly ash (without any additive) was found to be less effective in extraction. However, the conversion efficiencies of Al and Fe were affected greatly by calcination pretreatment with addition of Na2CO3, and leaching conditions of ratio of solution to fly ash (L/S) and H+ concentration. The maximum concentrations of Al and Fe solubilized from fly ash were 0.21 and 0.04 mol/L, respectively, which were attained by calcination pretreatment using an optimal mass ratio (ca. 1:16.7) of Na2CO3 to fly ash at 805°C. These concentrations correspond to conversion efficiencies of 31.2% for Fe and 18.3% for Al in the fly ash. The slurry was filtrated to obtain a solution containing Al‐ and Fe‐sulfates and silicates. The Al/Fe/Si mole ratio indicated the feasibility of further production of inorganic polymer coagulant. The produced coagulant was determined to be effective for treating soybean wastewater and dairy wastewater in terms of COD and SS removal.

Coagulative colloidal gas aphrons generated from polyaluminum chloride (PACl)/dodecyl dimethyl betaine (BS-12) solution: Interfacial characteristics and flotation potential

Bubble surface functionalization is promising in flotation in terms of stronger bubble-particle interaction, less chemical consumption, more flexible and pollutant-oriented. In this study, the coagulant-modified microbubbles were generated via colloidal gas aphrons (CGAs) technique; the specific bubble characteristics and flotation efficiency in removing nanosilica were investigated. The coagulative CGAs were generated from a mixed system consisting of zwitterionic surfactant (dodecyl dimethyl betaine, BS-12) and inorganic polymer coagulants (polyaluminium chloride, PACl). Results denoted that the bubble generation capability of the mixed solution was well maintained; meanwhile, the observed large aggregates indicated the possible interaction between PACl and BS-12. The generated PACl-modified CGAs exhibited a typical CGA morphology with the averaged diameter of 46–100μm. It should be noted that the stability of these positively surface-charged bubbles was strongly influenced by the PACl concentration. The half-life reached ∼100s at the optimum PACl concentration range of 0.92–1.17mmolAl/L. The interaction mechanisms between PACl and BS-12 as well as CGAs were speculated: one the one hand, the monomer Al species might interact with the BS-12 molecules and coat on the CGA surface; on the other hand, the polymerized Al species probably acted as bridge/net in which the BS-12 micelles and CGAs were embedded. Particularly, the coagulative CGA-involved flotation could remove approximately 81% of nanosilica, and a reinforced flotation process was thus achieved.

Preparation of an inorganic coagulant-polysilicate–magnesium for dyeing wastewater treatment: Effect of acid medium on the characterization and coagulation performance

Polysilicate–magnesium (PSM) was prepared with Mg/Si molar ratios of 1.5 by co-polymerization. It is an inorganic polymer coagulant for dyeing wastewater treatment. Acid medium played an important role in the preparation of PSM. In this study, PSMs were prepared using different acids (H2SO4, HCl, HNO3 and H3PO4) as medium, which were denoted as PSM(S), PSM(Cl), PSM(N) and PSM(P) respectively. FTIR, XRD and SEM were used to analyze the structure and morphology of four types of PSM coagulants. The results show that PSM(S) and PSM(N) both have the compact gel network structure, while PSM(Cl) and PSM(P) present layer shape structure and scattered small blocky structure respectively. In the coagulation–flocculation process of dyeing wastewater treatment, PSM(S), PSM(Cl) and PSM(N) exhibit better coagulation performance compared with PSM(P). With an optimal pH of 12 and a settling time of 20 min, the color removal efficiency of the coagulant of PSM(S) can reach above 94% at a relatively lower coagulant dosage of 4 mg/L, whereas PSM(Cl) and PSM(N) brings to about 94% at a higher coagulant dosage of 8 mg/L. However, PSM(P) shows that the highest color removal efficiency reaches only about 63% at a coagulant dosage of 8 mg/L. Therefore, PSM(S) is considered as the best acid modified PSM.