JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 142
·期 2
·e56336
·
IF 2.7
Xiaoxu Zhao,Rui Zhang,Shuchen Cao,Na Chang,Hao Zhang
In this paper, a starch-based flocculant (ADSt) with medium and low temperature solubility and enhanced flocculation effect was synthesized using corn starch, acrylamide, and dimethyldiallyl ammonium chloride as main materials by the ethanol-alkali method and grafting method. The main mechanism of ADSt's flocculation was electrical neutralization and bridging. The flocculation performance of ADSt was verified by using it along with polymeric aluminum chloride (PAC) as coagulant/flocculant, dispersible dye (dispersible yellow RGFL), and reactive dye (active trimeric blue KN-G) to simulate dye wastewater. For the dispersed yellow water sample and active emerald blue water sample, the dosage of PAC was 40 and 35 mg/L respectively. When the dosage of ADSt was 10 mg/L with a dye content of 100 mg/L, the decolorization rates for both dyes reached up to 96.2% and 94.4% respectively. The properties of the flocs such as size and two-dimensional fractal structure were described. The prepared ADSt maintained a good flocculation effect in the pH range of 5–9 due to its excellent water solubility achieved through the ethanol-alkali preparation process, where its solubility reached 86.7% at 30°C. Overall, the preparation process for ADSt is simple, cost-effective, while providing an effective solution for treating printing and dyeing wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jia Zhu,Wei Wei,Chaosheng Zhang,Hongwei Rong,Yongfeng Cao
ABSTRACT Although synthetic polymeric organic compounds have been widely used in sludge-recycling enhanced flocculation (SEF) process as the coagulant aid, effects of their molecular weight (MW) on strengthening ability and floc characteristics variation of SEF, that is, floc recovery ability, floc morphology structure and distribution, remained unclear. In this study, those effects under two colloidal destabilization mechanisms, namely electrostatic patch (EP) and near charge neutrality (NCN), in kaolin colloidal system and humic acid–kaolin colloidal system were investigated using response of SEF and traditional flocculation (TF) to polyacrylamide (PAM) with various MW. Results showed that when PAM with MW of 6 and 12 million Da was chosen, compared with TF, residual turbidity of SEF decreased by 21.45% and 27.72%, respectively, in system I, EP; –7.50% and 13.20%, respectively, in system I, NCN; 12.86% and 9.38%, respectively, in system II, EP and –98.46% and 2.10%, respectively, in system II, NCN. In most cases, the fractal dimension of SEF floc was higher than that of TF floc. And SEF could not reduce frequency of small floc, which is not beneficial to the strengthening ability exertion of SEF. However, when using PAM with MW of 18 and 20 million Da, SEF could significantly reduce the frequency of small floc, and the fractal dimension of SEF floc was lower than that of TF floc. SEF residual turbidity of PAM with 18 and 20 million Da MW decreased by 22.21% and 22.89%, respectively, in system I, EP; 21.61% and 32.19%, respectively, in system I, NCN; 33.99% and 35.29%, respectively, in system II, EP and 18.28% and 28.15%, respectively, in system II, NCN. These findings suggest that PAM with high MW and EP status was more beneficial for SEF to exhibit the strengthening ability to TF than PAM with low MW and NCN status. In addition, the recovery factor of TF floc was larger than 1, while sludge-recycling exerted a flocculation enhancement role. This suggested that the recovery ability of broken flocs had definite indication effect on exertion of SEF strengthening ability.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
STARCH-STARKE
·
2022
·
IF 2.688
Kexu Wang,Hongfei Liu,Yating Wang,Dishun Zhao,Jianhua Zhai
Dissolved organic matter is one of the difficult problems in the treatment of textile dyeing wastewater, among which humic substances are the most harmful to the environment and human health. Herein, cationic starch-based flocculants are prepared by free radical polymerization of corn starch (St) and methacryloyloxyethyl trimethyl ammonium chloride (DMC) in a redox-initiated system of ammonium persulfate and sodium bisulfite. Corn starch-graft-poly(methacryloyloxyethyl trimethyl ammonium chloride) is denoted as St-g-PDMC. The St-g-PDMC is comprehensively characterized in terms of structural (element analysis, Fourier transform infrared, X-ray diffraction, proton nuclear magnetic resonance spectroscopy), morphological (scanning electron microscopy), and thermal (differential scanning calorimetry) properties. Humic acid (HA) solution is selected to simulate negatively charged dissolved organic matter. The flocculation performance and mechanism of St-g-PDMC, cationic polyacrylamide (CPAM), and polymerized aluminum chloride (PAC) are systematically investigated. The experimental results show that St-g-PDMC functions mainly through the electric neutralization and bridging effect as the flocculation mechanism, CPAM using its own structure and the colloid formed by PAC through hydrolysis is more in line with the bonded bridging and net roll sweep trapping. The combined formulation of St-g-PDMC and PAC shows advantages over a single flocculant in the treatment of textile dyeing wastewater, and its cost is evaluated.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Lei Zhao,Lizhi Zhao,Hongli Li,Ping Sun,Jing Wu,Ke Li,Siqi Hu,Xiayan Wang,Qiaosheng Pu
Exploration of simple and universal methods to quantitatively measure nanoparticle (NP)–protein interaction is of great importance. In this work, pulsed streaming potential (SP) measurement has been used to evaluate the interaction between NPs and proteins within microchannels. Graphene oxide (GO) and SiO2 NPs were selected to represent two kinds of NPs. Lysozyme and common blood proteins, including albumin V, γ-globulins, and fibrinogen, were used as model proteins. The linear relationship between the initial adsorption rate (S = dEr/dt) and the concentration of proteins was observed. Combined with the Hill equation, the microscopic dissociation constant (KD) and the Hill coefficient (n) between NPs and proteins were calculated based on the relationship between S and the concentration of each protein. The concentration of free proteins which have not interacted with the NPs in the NPs–protein mixture could also be measured. The influence of pH, conductivity, and ionic strengths of the incubation buffer on the interaction between GO and lysozyme was evaluated based on the constant KD. The interaction intensity between NPs and proteins was defined as charge neutralization efficiency QC, which could be calculated from the value of S. It takes only 150 s to get the whole set of data under the optimized experiment parameters. The measurement solely depends on the surface charge, no intrinsic fluorescence is required for either the NPs or the proteins, and no labeling or immobilization process is involved as well.
研究领域:
生物物理学
·
分析化学
·
纳米科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 7
·18285-18295
·
IF 5.19
Xu Xia,Guo Jun,Yang Ruoying,Gao Yu,Xue Yingang,Wang Liping,Zhang Ling,Zhang Qiuya,Peng Mingguo,Liu Xuefeng
Titanium xerogel coagulant (TXC) is a new type of coagulant that has attracted much attention in recent years. However, the tetracycline removal performance of TXC was not satisfactory because low isoelectric point (pH iep ) inhibited the electrical neutralization efficiency of TXC in an alkaline environment. To overcome this shortcoming, a composite xerogel coagulant (titanium-aluminum xerogel composite coagulant) was prepared. The removal of tetracycline and turbidity was used as evaluation indexes. It was proved that the combination of aluminum (III) and titanium (IV) enhanced the resistance of TXC to pH. The synthesized titanium-aluminum xerogel composite coagulant (TXAC) has an excellent removal ability of tetracycline in a wide pH range (pH = 5–10). At pH 8.8, the dosage required to remove 80% tetracycline from water decreased from 93 (TXC) to 35 mg/L (TXAC). The reason for this improvement could be attributed to (i) aluminum (III) enhanced the electric neutralization of TXC to negatively charged pollutants in an alkaline environment; (ii) the complexing ability of organic matter and aluminum (III) was enhanced. This work provides a feasible scheme for the pretreatment of tetracycline in water to meet the pretreatment requirements of special water.
研究领域:
环境科学
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2024
·
IF 2.2
Tianju Zhu,Jiao Song,Xiaoling Zhou,Yuqin Liu
Composite flocculant PAFS-PDM was prepared from Polymeric aluminium ferric sulphate (PAFS) and Poly (diallyl dimethyl ammonium chloride) (PDM) in this study. A bacterium was selected from the soil near the shale gas exploitation platform as a bioflocculant-producing bacterium, and polysaccharide was extracted and combined with PAFS-PDM to obtain composite bioflocculant (CBF) to treat shale gas fracturing flowback fluid. The prepared CBF was characterized and the results showed that the prepared PAFS-PDM contained aluminium-iron hydroxyl polymer, which was a cationic flocculant. By measuring the turbidity removal rate and chemical oxygen demand (COD) removal efficiency, the function mechanism of CBF on the shale gas fracturing flowback fluid was discussed. The results showed that CBF had a stable treatment effect on fracturing flowback fluid when the pH value was about 7.0. With the increase of dosage, the coagulation efficiency increased first and then decreased. When the dosage of the CBF was 2500 mg·L−1, the treatment effect of shale gas fracturing flowback fluid was the best, and COD removal rate reached 89.43%. Through Zeta potential analysis, it was concluded that one of the coagulation mechanisms was electrical neutralization. According to the characterization results, it could be concluded that both adsorption bridging and charge neutralization mechanisms played important roles in the treatment of shale gas fracturing flowback fluids.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Congzhong Shi,Qiming Wang,Daiqi Li,Beini Zeng,Qingtao Liu,Yongming Cui,Jinfeng Wang,Xungai Wang
Wool is perceived to be a clean and green natural fibre . However, raw wool contains substantial amounts of contaminants that must be removed in a wool scouring process before the wool can be used as a textile fibre . Coagulation is the first step for scouring wastewater treatment . But the role of inorganic coagulants in increasing sludge density for scouring wastewater treatment remains unclear. This work systematically prepared a series of inorganic composite coagulants (polyaluminium ferric silicate (PAFS)) and investigated their efficiency for treating wool scouring wastewater. Compared with conventional coagulants, polyaluminium chloride (PAC) and polyferric sulfate (PFS), PAFS showed improved coagulation performance over a wider pH range (3–7), achieving higher removal rates of 97 % and 99 % for chemical oxygen demand (COD) and turbidity, respectively. In addition, PAFS showed its advantages for practical wastewater treatment, including fast floc settling rate, increased sludge density (with a reduced sludge volume) and low floc moisture content. This optimized PAFS was successfully obtained in a scaled-up process. Zeta potential tests revealed that PAFS coagulated colloidal particles by the synergistic action of electro-neutralization and adsorption bridging. This work has practical implications for increasing the efficiency of wastewater treatment and reducing the environmental impact of wool scouring.
研究领域:
环境科学
·
纺织工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Liqing Li,Zhenzhen Song,Weijun Zhang,Hanjun Wu,Wanwan Liu,Junxia Yu,Dongsheng Wang
In this work, blast furnace slag was successfully used to prepare five kinds of polymeric titanium aluminium flocculant (PTAC) with different polymerization degrees by two-step acid leaching method, which were applied as the effective dredged sludge conditioners. The results indicated that PTAC can obviously improve the sludge dewaterability. Compared with other four types of PTAC, PTAC 0.6 showed the best sludge conditioning efficiency under the optimum dosage of 4 mg Al + Ti/g TSS. It can reduce the capillary suction time of the sediment by 81.4%, the specific resistance to filtration by 65.1%, and the moisture content of the mud cake from 81.9% to 45.81%. PTAC can significantly increase the zeta potential of the dredged sludge, while it has no obvious effect on the floc size D 0.5 . The electric neutralization substantially contributed to the conditioning of PTAC on dredged sludge dewatering . The concentration of dissolved organic carbon , total phosphorus in the residual water was significantly reduced after PTAC conditioning. PTAC can also remove large molecular weight components in dissolved organic matter by flocculation , or hydrolyze large molecular components into small and medium molecular weight components, furthermore reduce the concentration of these organic components. 3D-EEM analysis results showed that PTAC can effectively remove fulvic acid-like substances and some protein-like substances by flocculation, especially the removal effect of fulvic acid-like substances was more prominent.
研究领域:
环境工程
·
污水处理
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Ting Xiao,Wenjie Zou,Congzhong Tian,Wentao Hu,Zhijun Zhang,Chengyan Xu,Fang Zhou
This study employed a combination of settling tests and molecular dynamics (MD) simulations to investigate the effect of ionic strength and pH on the flocculation of chitosan-grafted cationic polyacrylamide (CPD) in kaolinite suspensions, and its adsorption on kaolinite (001) surfaces. At a CPD dosage of 75 g/t, the settling rate of kaolinite dropped from 12.95 m/h to 7.89 m/h with an increase in KCl concentration from 0 mM to 200 mM. MD simulations revealed that the radius-of-gyration (Rg) of CPD decreased from 17.04 Å to 15.43 Å and the self-diffusion coefficient (D) reduced from 0.0296 Å 2 /ps to 0.0104 Å 2 /ps. The interaction energy rose from 984 kcal/mol to 1416 kcal/mol and the distribution density of CPD became more concentrated. Such results indicated that the increased ionic strength improved the adsorption and electro-neutralization efficiency of CPD, reducing the turbidity of supernatant. However, this increase led to a reduction in the molecular size and mobility of CPD, weakened its bridging capacity and slowed kaolinite settling. For increasing pH, the settling rate of kaolinite initially increased and then decreased, reaching a maximum value of 15.14 m/h at pH 5. This trend was consistent with results of D. The bridging capacity of CPD was enhanced under acidic conditions but weakened at excessively low pH. This can be attributed to the excessively strong electrostatic interaction between CPD and kaolinite, hindered its migration. Our work would enhance the understanding of impacts of solution chemistry on the settling of suspended solids and facilitate the development of effective flocculants.
研究领域:
环境科学
·
化学工程
·
胶体与界面科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2025
·Vol. 236
·期 10
·1-15
·
IF 3
Sun Yongjun,Hu Zhihao,Wang Zihan,Zhang Can,Sun Wenquan
In this work, polymeric aluminum zirconium chloride (PAZC), a defluoridating flocculant, was prepared using calcium aluminate and zirconium tetrachloride as the main materials, and its defluoridation performance was evaluated. At pH 7 and PAZC dosage (Zr) of 50 mg•L −1 , the flocculation and defluorination rates of PAZC in simulated fluorinated wastewater with initial fluoride ion concentrations of 10, 8, and 5 mg•L −1 were 90.90%, 89.38%, and 92.2%, respectively, and the residual fluoride ion concentration in the solution was reduced to 0.91, 0.85, and 0.39 mg•L −1 , respectively. The degree of the effects of the same concentration of anions on the flocculation and fluoride removal performance of PAZC was in the order of SiO 3 2− >PO 4 3− >CO 3 2− >NO 3 − >Cl − >SO 4 2− . Characterization results indicated that PAZC was a polymer containing hydroxyl bonds of zirconium–aluminum metal ions, and the surface of PAZC had a tight, dense, porous nature. Under optimum flocculation conditions, the average particle size of the flocs obtained after fluoride removal by PAZC flocculation was 2.54 μm, and the flocculation mechanism was dominated by adsorption, electro-neutralization, and ion exchange when the dosage of the PAZC was 40–50 mg•L −1 and the pH was 5–7. It is proved that the composite flocculant PAZC has good application prospects and can provide guidance for the treatment of actual fluorine-containing wastewater.
研究领域:
环境科学
·
水处理技术
·
化学工程
·
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Xulin Yu,Junlei Wang,Fan Ye
Currently, most of the industrial demulsifiers are based on petrochemical-derived raw materials, which have the disadvantages of dangerous and complicated synthesizing process, low demulsification efficiency (DE) and significant environmental harm. To tackle these challenges, this study focused on synthesizing a green cationized amphiphilic cyclodextrin demulsifier (CDPA) decorated with quaternary ammonium salt and hydrophobic chain, which exhibits effectively treats oily wastewater at ambient temperature and low concentration. The bottle tests revealed that the light transmittance and the corresponding oil removal efficiency of CDPA was 93.1 % and 99.4 %, respectively. In addition, CDPA consistently maintained an excellent DE in wide pH range (3–11) and high salinity conditions. The possible demulsification mechanism of CDPA was explored in detail and the results showed that CDPA could quickly adsorb and replace natural surfactants, leading to form an unstable composite film and initiating the demulsification process. Furthermore, the positive charge of CDPA also facilitated electrostatic neutralization with the oil droplets, thereby attenuating the strength of the interfacial film.
研究领域:
环境科学
·
化学工程
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2025
·Vol. 17
·期 17
·2386
·
IF 4.9
Bingyu Wang,Wei Guo,Ying Deng,Wenbin Jiao,Linzhu Du,Junhui Yue,Bo Zhang
The effective and rapid separation of oil–water emulsions at room temperature, particularly under harsh environmental conditions like acid–base fluctuations, high salinity, and the coexistence of surfactants, remains a significant challenge in oily wastewater treatment. To address this, a novel amphiphilic demulsifier, MOF-74@SiO 2 -GPTMS grafted ANP (MSG-ANP), was synthesized by first modifying MOF-74@SiO 2 (MS) with γ-glycidoxypropyltrimethoxysilane (GPTMS) to create epoxy-functionalized MSG particles, followed by grafting the non-ionic polyether C 12 –C 14 aliphatic polyethylene oxide polyoxypropylene (ANP) onto MSG. Bottle tests demonstrated that MSG-ANP achieved a high demulsification efficiency of 93% within 15 min for oil-in-water emulsions at room temperature. It exhibited excellent environmental tolerance, maintaining efficiencies of 89% at pH 3.0, 82% at pH 11.0, and 95% under high salinity (50,000 mg/L, pH 6.8). Furthermore, MSG-ANP effectively treated surfactant-stabilized emulsions, exceeding 96% efficiency against both cetyltrimethylammonium bromide and sodium dodecyl sulfate after 30 min, outperforming commercial demulsifiers SP-169 and AR-331 by factors of 1.2 and 1.6, respectively. This superior performance stems from synergistic hydrogen bonding (via hydroxyl, ether, ester, Fe-O, and Si-O groups) destabilizing the interfacial film and electrostatic neutralization of coalescing charged droplets. Consequently, MSG-ANP presents a promising solution for rapid, room-temperature demulsification across a wide pH range and under high-salinity conditions.
研究领域:
环境科学
·
化学工程
·
材料科学
·
纳米技术
·
油水分离
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）