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Journal of Magnesium and Alloys 2023年第9期11卷 3231-3240页

作者： Saeed Ahmed State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing 100029China Department of Chemistry The University of LahoreLahore 54590Pakistan Department of Chemistry University of ChakwalPakistan

In this work, a series of hierarchical flower-like magnesium oxide(MgO) adsorbents were successfully fabricated in a cetyltrimethylammonium bromide(CTAB) assisted solvothermal route using hexamethylenetetramine(HMTA) as a precipitating agent. Effects of CTAB feeding amount on the structure, morphology, pore structure, and corresponding adsorption behavior were investigated. The hierarchical gardenias flower-like MgO demonstrated a surface area of 336.54 m^(2)·g^(-1) at a minimum ratio of the CTAB/Mg^(2+)was 0.02 in the reaction system. The hierarchical MgO phosphate removal capacity was 348.32 mg·g^(-1), which followed the pseudo-second-order and Freundlich isotherm model obtained from the large surface area and appropriate pore size. The value of n also suggests the feasible nature of phosphate adsorption under the examined conditions. Indeed, this CTAB assisted solvothermal method can provide a new understanding to tune the desired properties of a material by merely adjusting the reaction parameters of MgO.

关键词： Adsorption CTAB-assisted Magnesium oxide phosphate removal Solvothermal

In-situ construction of abundant active centers on hierarchically porous carbon electrode toward high-performance phosphate electrosorption: Synergistic effect of electric field and capture sites

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Green Energy & Environment 2024年第1期9卷 126-137页

作者： Peng Zhang Fukuan Li Mingming He Silu Huo Xueli Zhang Benqiang Cen Dezhi Fang Kexun Li Hao Wang College of Environmental Science and Engineering Nankai UniversityTianjin300350China MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlTianjin Key Laboratory of Environmental Technology for Complex Trans-Media PollutionNankai UniversityTianjin300350China State Key Laboratory of Simulation and Regulation of Water Cycles in River Basins China Institute of Water Resources and Hydropower ResearchBeijing100038China

phosphate removal is crucial for eutrophication control and water quality improvement.Electro-assisted adsorption,an eco-friendly elec-trosorption process,exhibited a promising potential for wastewater treatment.However,there are few works focused on phosphate electro-sorption,and reported electrodes cannot attach satisfactory removal capacities and rates.Herein,electro-assisted adsorption of phosphate via in-situ construction of La active centers on hierarchically porous carbon(LaPC)has been originally demonstrated.The resulted LaPC composite not only possessed a hierarchically porous structure with uniformly dispersed La active sites,but also provided good conductivity for interfacial electron transfer.The LaPC electrode achieved an ultrahigh phosphate electrosorption capability of 462.01 mg g^(-1) at 1 V,outperforming most existing electrodes.The superior phosphate removal performance originates from abundant active centers formed by the coupling of electricﬁeld and capture sites.Besides,the stability and selectivity toward phosphate capture were maintained well even under comprehensive conditions.Moreover,a series of kinetics and isotherms models were employed to validate the electrosorption process.This work demonstrates a deep understanding and promotes a new level of phosphate electrosorption.

关键词： Electro-assisted adsorption Electrosorption phosphate removal Active centers MOF-derived carbon

Investigation on mechanism of phosphate removal on carbonized sludge adsorbent

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Journal of Environmental Sciences 2018年第2期30卷 335-344页

作者： Lei Zhang Junxin Liu Xuesong Guo Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

For the removal of phosphate（PO43-） from water, an adsorbent was prepared via carbonization of sewage sludge from a wastewater treatment plant： carbonized sludge adsorbent（CSA）. The mechanism of phosphate removal was determined after studying the structure and chemical properties of the CSA and its influence on phosphate removal. The results demonstrate that phosphate adsorption by the CSA can be fitted with the pseudo second-order kinetics and Langmuir isotherm models, indicating that the adsorption is single molecular layer adsorption dominated by chemical reaction. The active sites binding phosphate on the surface are composed of mineral particles containing Si/Ca/Al/Fe. The mineral containing Ca, calcite, is the main factor responsible for phosphate removal. The phosphate removal mechanism is a complex process including crystallization via the interaction between Ca2＋ and PO43-; formation of precipitates of Ca2＋, Al3＋, and PO43-; and adsorption of PO43-on some recalcitrant oxides composed of Si/Al/Fe.

关键词： Sewage sludge Carbonization phosphate removal Mechanism

removal of phosphate from wastewater using alkaline residue

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Journal of Environmental Sciences 2014年第5期26卷 970-980页

作者： Yubo Yan Xiuyun Sun Fangbian Ma Jiansheng Li Jinyou Shen Weiqing Han Xiaodong Liu Lianjun Wang Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological Engineering Nanjing University of Science and Technology

Alkaline residue （AR） was found to be an efficient adsorbent for phosphate removal from wastewater. The kinetic and equilibrium of phosphate removal were investigated to evaluate the performance of modified alkaline residue. After treatment by NaOH （AR-NaOH）, removal performance was significantly improved, while removal performance was almost completely lost after treatment by HCI （AR-HC1）. The kinetics of the removal process by all adsorbents was well characterized by the pseudo second-order model. The Langmuir model exhibited the best correlation for AR-HC1, while AR was effectively described by Freundlich model. Both models were well fitted to AR-NaOH. The maximum adsorption capacities calculated from Langmuir equation were in following manner： AR-NaOH 〉 AR 〉 AR-HC1. phosphate removal by alkaline residue was pH dependent process. Mechanisms for phosphate removal mainly involved adsorption and precipitation, varied with equilibrium pH of solution. For AR-HCI, the acid equilibrium pH （〈 6.0） was unfavorable for the formation of Ca-P precipitate, with adsorption as the key mechanism for phosphate removal. In contrast, for AR and AR- NaOH, precipitation was the dominant mechanism for phosphate removal, due to the incrase on pH （〉 8.0） after phosphate removal. The results of both XRD and SEM analysis confirmed CaHPOa.2H20 formation after phosphate removal by AR and AR-NaOH.

关键词： alkaline residue chemical modification phosphate removal adsorption precipitation

Adsorption removal of phosphate from aqueous solution by active red mud

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Journal of Environmental Sciences 2007年第10期19卷 1166-1170页

作者： LIU Chang-jun LI Yan-zhong LUAN Zhao-kun CHEN Zhao-yang ZHANG Zhong-guo JIA Zhi-ping State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Shandong Aluminium lndustry Co. Ltd Shandong 255061 China

Red mud is the waste of alumina industry and has high TiO2 and Fe2O3 content which are active components for the adsorption of anion pollutants. In this study, the uptake of phosphate by red mud activated by heat treatment and acid-heat treatment was investigated. The factors influencing the adsorption were also investigated. The result showed that the red mud sample treated using acid-heat method at 80℃ with 0.25 mol/L HCl for 2 h achieved the highest phosphate removal. For the heat-activated red mud, the sample heated at 700℃ for 2 h preformed better than the other heat treatment. phosphate removal by the activated red mud was significantly pH dependent, and pH 7 was the optimal pH for phosphate removal. The adsorption fits Langmuir isotherm model well and the maximum adsorption capacities of the acid-heat activated red mud and the heat activated samples were 202.9 mgP/g and 155.2 mgP/g, respectively.

关键词： phosphate removal red mud activation adsorption

Scrap Iron Filings assisted nitrate and phosphate removal in low C/N waters using mixed microbial culture

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Frontiers of Environmental Science & Engineering 2021年第4期15卷 215-228页

作者： Sanjena Narayanasamydamodaran Jian’e Zuo Haiteng Ren Nawnit Kumar State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China State Key Laboratory of Hydroscience and Hydraulic Engineering Tsinghua UniversityBeijing100084China

This study focuses on identifying the factors under which mixed microbial seeds assist bio-chemical denitrification when Scrap Iron Filings(SIF)are used as electron donors and adsorbents in low C/N ratio waters.Batch studies were conducted in abiotic and biotic reactors containing fresh and aged SIF under different dissolved oxygen concentrations with NO_(3)^(-)−N and/or PO_(4)^(3−)influent(s)and their nitrate/phosphate removal and by-product formations were studied.Batch reactors were seeded with a homogenized mixed microbial inoculum procured from natural sludges which were enriched over 6 months under denitrifying conditions in the presence of SIF.Results indicated that when influent containing 40 mg/L of NO_(3)^(-)−N was treated with 5 g SIF,79.9%nitrate reduction was observed in 8 days abiotically and 100%removal was accomplished in 20 days when the reactor was seeded.Both abiotic and seeded reactors removed more than 92%PO_(4)^(3−)under high DO conditions in 12 days.Abiotic and biochemical removal of NO_(3)^(-)−N and abiotic removal of PO_(4)^(3−)were higher under independent NO_(3)^(-)−N/PO_(4)^(3−)loading,while 99%PO_(4)^(3−)was removed biochemically under combined NO_(3)^(-)−N and PO_(4)^(3−)loading.This study furthers the understandings of nitrate and phosphate removal in Zero Valent Iron(ZVI)assisted mixed microbial systems to encourage the application of SIF-supported bio-chemical processes in the simultaneous removals of these pollutants.

关键词： Scrap iron filing Nitrate removal phosphate removal Mixed culture denitrification Zero valent iron

Renewable molybdate complexes encapsulated in anion exchange resin for selective and durable removal of phosphate

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Chinese Chemical Letters 2021年第11期32卷 3382-3386页

作者： Wei Zhu Xiaohua Huang Yi Zhang Zhonglong Yin Zhen Yang Weiben Yang School of Chemistry and Materials Science Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution ControlNanjing Normal UniversityNanjing 210046China

The existence of many anions in wastewater reduces the removal efficiency of phosphate by adsorbents under realistic conditions.Facing this challenge,the study reports on an insistent and stable composite adsorbent of molybdate complexes Fe-(MoO_(x))embedded in a macroporous anion exchange resin(D-201).[Fe(MoO_(x))]-D-201 shows 93.7%adsorption capacity(28.3 mg/g)for phosphate even when the molar concentration of coexisting ions is 5 times higher than phosphate.The capacity of adsorbent is maintained more than 84.2%after five regeneration cycles to remove phosphate in the wastewater containing coexisting ions.The ability of highly selective removal of phosphate is maintained during the regeneration cycles explained by the change of the binding of molybdate clusters with phosphate,which is due to the different structures of molybdate clusters depending on various pH.In general,this work puts forward a new idea for the development of phosphorus removal adsorbents for the treatment of wastewater containing coexisting ions.

关键词： Molybdate composite adsorbent Resin phosphate removal Selective and durable adsorption Structural transformation of complexes

Efficient recovery of phosphate by La-MOFs: An excellent adsorption performance and mechanism

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Progress in Natural Science:Materials International 2023年第6期33卷 854-863页

作者： Yongyi Yu Jiangyan Song Ziyi Zhang Weisen Yang Wenbin Pan Shaoju Jian Jiapeng Hu Qing Luo College of Environment and Safety Engineering Fuzhou University Key Laboratory of Green Chemical Technology of Fujian Province University Fujian Provincial Key Laboratory of Eco-Industrial Green Technology Wuyi University College of Materials Xiamen University

Lanthanum-type metal-organic frameworks(La-MOFs) can be used to mitigate phosphate pollution in wastewater.Herein, La-MOFs was gained via the solvothermal method and its phosphate removal property was examined under various conditions, like variable initial phosphate concentration, solution p H, and co-existing ions. The material morphology, element composition, and crystal morphology of the La-MOFs was characterized using XRD,SEM, FTIR, and XPS. The phosphate removal mechanism was investigated by combining thermodynamic and kinetic analyses. The La-MOFs exhibited superior adsorption capability for surplus phosphate in water, and also had a high selectivity for phosphate in the complexed environment with some co-existing ions. Maximum adsorption was obtained at pH 4. The sorption procedure of La-MOFs aligned more with the Langmuir and pseudo-second order kinetic models, demonstrating monomolecular-layer-controlled chemisorption. And the maximum sorption capacity was 73.69 mg g-1. Electrostatic interactions and ligand exchange, which enabled the development of an La–O–P inner-sphere complexation, were identified as the primary mechanisms of phosphate removal. This research provides insights into the optimal conditions and mechanism of phosphate adsorption by La-MOFs.

关键词： La-MOFs phosphate removal Adsorption Mechanism

Adsorption and recovery of phosphate from water by amine fiber,effects of co-existing ions and column filtration

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Journal of Environmental Sciences 2020年第1期32卷 123-132页

作者： Jinshan Wei Xiaoguang Meng Xianghua Wen Yonghui Song School of Environment Tsinghua UniversityBeijing 100084China Center for Environmental Systems Stevens Institute of TechnologyHobokenNJ 07030USA State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

A weak-base adsorption fiber,acrylic amine fiber(AAF),was prepared for removal and recovery of phosphate from water.The adsorption properties of the AAF for phosphate and effects of co-existing ions were investigated using batch and column filtration experiments,scanning electron microscope,and Fourier transform infrared techniques.Experimental results showed that AAF had a high phosphate adsorption capacity of 119 mg/g at pH 7.0.The effects of calcium,sulfate,carbonate,nitrate,and fluoride showed that sulfate and calcium inhibited phosphate adsorption.However,AAF showed higher binding affinity toward phosphate than sulfate.Column filtration results showed that AAF could filter 1420 bed volumes of tap water containing 1.0 mg-P/L of phosphate.The saturated AAF could be regenerated using 0.5 mol/L hydrochloric acid solution and reused.After desorption,phosphate was recovered through precipitation of hydroxyapatite(Ca5(PO4)3OH).The easy of regeneration,good adsorption performance,and the fiber morphology of AAF make it an attractive alternative for phosphate recovery from multiple water sources.

关键词： Wastewater treatment phosphate removal Adsorption Acrylic amine fiber Phosphorus recovery

Treatment of phosphate-containing oily wastewater by coagulation and microfiltration

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Journal of Environmental Sciences 2006年第4期18卷 629-633页

作者： ZHANG Jin SUN Yu-xin HUANG Zhi-feng LIU Xing-qin MENG Guang-yao Department of Materials of Science and Engineering University of Science and Technology of China Hefei 230026China School of Chemistry and Chemical Engineering Anhui University Hefei 230039 China National Key Laboratory of Transient Physics Nanjing 210094 China Great Wall New Century Membrane Technology Corporation Hefei 230601 China

The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membrane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling decreased and the permeate flux and quality increased with coagulation as pretreatment. At the coagulant Ca （OH）2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca（OH）2 was not used. The permeate obtained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are transmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparison results show that 0.2 μm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substantial gain in flux and removal efficiency of phosphate.

关键词： ceramic membrane crossflow microfiltration coagulation phosphate removal fouling mitigation phosphate-containing oily wastewater