SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Pan Hu,Kexin Su,Yibei Sun,Pengwei Li,Jun Cai,Hu Yang
Microplastic (MP) pollution has increasingly become an enormous global challenge due to the ubiquity and uncertain environmental performance, especially for nano- and micro- sized MPs. In this work, the performance and mechanisms in coagulation of 100 nm–5.0 μm sized polystyrene particles using an etherified starch-based coagulant (St-CTA) assisted by polysilicic acid (PSA) were systematically studied on the basis of the changes in MPs removal rates under various pH levels and in the presence of different coexisting inorganic and organic substances, zeta potentials of supernatants, and floc properties. St-CTA in conjunction with PSA had a high performance in coagulation of nano- and micro- sized MPs from water with a lower optimal dose and larger and compacter flocs. Besides, the MPs removal rate can be improved in acidic and coexisting salt conditions. The efficient performance in removal of MPs by this enhanced coagulation was owing to the synergic effect, that is, the effective aggregation of MPs through the charge neutralization of St-CTA followed by the efficient netting-bridging effect of PSA. The effectiveness of this enhanced coagulation was further confirmed by removal of two other typical nano-sized MPs, such as poly(methyl methacrylate) and poly(vinyl chloride), from different water sources including tap water , river water, and sludge supernatant from a sewage treatment plant. This work provided a novel enhanced coagulation technique that can effectively remove nano- and micro- sized MPs from water.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Binglu Deng,Hanjin Luo,Zhongqing Jiang,Zhong-Jie Jiang,Meilin Liu
A simple co-polymerization method has been employed to prepare polysilicic-zirconium (PSZr), consisting of chemical species of ZrSi 24 O 50 , ZrSiO 4 , and Zr 5 Si 3 . The obtained PSZr is found to be highly active as the coagulant for the purification of the raw water and humic acid wastewater. The performance of PSZr on the wastewater purification is greatly dependent upon the synthetic temperature of PSZr, and the mole ratio of Si:Zr, and the basicity of the PSZr. It shows that PSZr synthesized at the temperature of 20–25 °C with the mass fraction of polysilicic acid of 1.5%, the mole ratio of Si:Zr of 1:1, and a basicity of 0.25, is relatively more efficient for water purification and could achieve the UV 254 (Ultraviolet wavelength less than 254 nm) and total organic carbon removals of 81.23% and 66.85% and residual turbidity of 0.86 NUT in the raw water, and the UV 254 and TOC removals of 99.20% and 74.21% in simulated humic acid wastewater, respectively. These results clearly demonstrate that PSZr could be used as the coagulant for the wastewater treatments.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Yunong Tang,Xinyu Hu,Jun Cai,Zhonghua Xi,Hu Yang
In this work, a simple and environmentally-friendly enhanced coagulation, by using a cationic starch-based coagulant (starch-3-chloro-2-hydroxypropyl trimethyl ammonium chloride , St-CTA) coupled with an optimized polysilicic acid (PSA), has been tried to coagulate the kaolin suspensions and humic acid (HA) aqueous solutions, which are used as the simulated sources of inorganic colloidal particles and organic pollutant , respectively, in micro-polluted turbid surface water. Dosing of St-CTA and PSA at the same time is more efficient and more convenient than other two separated feeding methods in this enhanced coagulation process. The synergic coagulation process and mechanism were studied and discussed in detail based on the apparent coagulation performance, floc properties, and zeta potentials of supernatants. St-CTA caused an efficient charge neutralization, i.e. compression of electric double layer of kaolin particles and electrostatic adsorption of HA, followed by an effective netting-bridging effect of PSA, resulting in an improved purification performance. St-CTA with a higher charge density showed better purification performance due to enhanced charge neutralization effect. In addition to simulated water, the validation of this enhanced coagulation process was further confirmed by comparison with a conventional coagulant, polyaluminium chloride, in treating a real surface water. This work thus provides a simple and environmentally-friendly strategy to efficiently purify micro-polluted turbid surface water and further improve the water safety.
研究领域:
环境科学
·
水处理技术
✓ 已验证
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2021
·
IF 6.158
Yimin Liu,Jie Ma,Lili Lian,Xiyue Wang,Hao Zhang,Wenxiu Gao,Dawei Lou
An inorganic-biopolymers hybrid flocculant (PSAC-SA) was prepared by modifying sodium alginate onto polysilicate aluminum calcium (PSAC) through coordination between SA and Ca 2+ . The preparation conditions of PSAC-SA and the flocculation parameters that influence of the turbidity and color removal efficiency were investigated and optimized. The flocculation experiments results showed that the maximum turbidity and color removal could get 97.2% and 98.4% for kaolin-humic acid suspensions, respectively. The application of PSAC-SA for Songhua River treatment indicated that it had an excellent flocculation capacity in real water samples, and its flocculation efficiency was much better than that of individual flocculants (PSAC and SA). Moreover, the flocculation mechanisms were discussed in detailed, which indicated that the bridging effect and physical entrapment of solid particles played an important role in the flocculation process.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2020
·Vol. 231
·期 7
·1-7
·
IF 1.9
Li Yuying,Zhang Hao,Wang Xiyue,Ma Jie,Lian Lili,Lou Dawei
A composite flocculant (PSAS-CS) consisted of cationic starch (CS) and polyaluminum silicate (PSAS) was prepared and used for the flocculation of simulated water samples. The morphology and structure of PSAS-CS were characterized by X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The effect of flocculation conditions such as the flocculant dosage and the simulated water pH were investigated. The turbidity and color removal rates could reach 97.79% and 98.07% at PSAS-CS dosage of 1.5 mL/L and the simulated water pH of 5–9. Furthermore, the flocculation efficiency of PSAS-CS was compared with PSAS, CS and the starch modified polyaluminum silicate at different dosage. The results indicated that PSAS-CS showed the highest flocculation efficiency due to its plentiful of positive charges and extended molecular chain. Moreover, the removal rate of PSAS-CS could remain 85% at a low dosage of 0.2 mL/L.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Yunpeng Hu,Kai Wang,Chunli Han,Tao Wang,Guangsheng Luo
A novel liquid–liquid microdispersion method for the synthesis of TS-1 has been developed by continuous preparation of the precursor. In the novel process, the solution of TBOT in n-hexane could be very uniformly dispersed into the oligomeric silicate prehydrolysis mixture to form microdroplets by a microsieve pore reactor. Due to the fast mixing and very high mass transfer performance of the microdispersion process, the Ti species could be uniformly distributed into the mixture and were more likely to condense into the oligomeric silicate precursor species rather than appear with self-condensation. The prepared samples had a minimum molar ratio of Si/Ti at 51 without extra-framework Ti species. Furthermore, the solvent of n-hexane can be recycled by simple phase separation rather than evaporation under the conditions of using isopropanol, which reduced energy consumption. This continuous microdispersion technology could be controllable and a reliable scaling-up for the preparation of TS-1.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 41
·34399-34405
·
IF 4.6
Qingwu Yao,Yuying Yang,Xuejun Cheng,Huai Lin,Xueyang Liu,Hongyu Chen
Doping dyes in silica has a wide range of applications, but there is currently no general method of synthesis. Here, we show that 98 cationic dyes of 11 series could be directly doped in silica nanoparticles of uniform size. In this co-precipitation method, the negatively charged silica precursor, poly(silicic acid), basically wraps the dyes as counter ions and preserves them.
研究领域:
纳米医学
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生物材料
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分子影像
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药物递送
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生物分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Shaopu Li,Yong Kang
Polyferric silicate sulfate (PFSiS) was prepared by copolymerization of polysilicic acid (PSi) and Fe 2 (SO 4 ) 3 , and the impacts of the key preparation factors, the ratio of Si/Fe (R Si/Fe ) and the pre-aging time of PSi (T), on the polymerization and flocculation performances of PFSiS were explored in this work. PFSiS with different R Si/Fe and different T were prepared, and the physicochemical properties and flocculation performance of PFSiS on hydrophobic dye (Disperse yellow), anionic hydrophilic dye (reactive turquoise blue) and cationic hydrophilic dye (methylene blue) were compared. The crystal structure and chemical bond of PFSiS were characterized by XRD and FTIR, respectively. The molecular dynamics simulation was used to compare the molecular structures of PFS and PFSiS formed by PSi with different polymerization degree. The results show that the R Si/Fe and T can impact the polymerization degree of PSi. When the R Si/Fe and T is small, there are a lot of (OH) 3 SiO - neutralize with positively charged Fe-polymer during copolymerization, which reduces the neutralization ability of PFSiS, resulting in a worse flocculation performance on RTB. This situation does not affect the improvement of the flocculation performance on DY due to the strengthening of adsorption bridging capacity. With the increase of the R Si/Fe and T, the improvement of the PSi polymerization degree produces long chains of Si-polymer bonded with positively charged Fe-polymer in PFSiS, which has both electric neutralization and excellent adsorption bridging capacity and makes its flocculation performance on three kinds of dye wastewaters better. High R Si/Fe and T influence the neutralization ability and the viscosity of PFSiS and reduce the flocculation performance on DY and RTB. At the same dose, the decolorization rate of PFSiS on DY is 54% higher than that of PFS, but there is little difference on RTB. PFSiS also maintains the part flocculation ability of PSi on MB, but it is affected by positively charged Fe-polymer.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2019
·
IF 0
Jie Ma,Runnan Wang,Xiyue Wang,Hao Zhang,Bo Zhu,Lili Lian,Dawei Lou
In the current work, polysilicate aluminum magnesium (PSAM) and cationic polyacrylamide (cPAM) were stepwise used for drinking water treatment . The flocculant was characterized by fourier transform infrared spectroscopy , scanning electron microscopy, and energy dispersive spectroscopy. PSAM-cPAM was then applied to flocculate the simulated water sample. The simulated water sample was prepared by kaolin and sodium humate. The efficiency of flocculation treatment was highly dependent on the flocculation conditions. Important parameters, such as the pH value of simulated water sample, temperature, settling time, the total dosage of flocculant, and flocculant types, were optimized to ensure an effective flocculation performance. Under optimized conditions, the removal efficiency (more than 98%) was outstanding in terms of turbidity and color removal. In addition, charge neutralization, bridging effect, and co–precipitation interaction could play crucial roles in the flocculation process. Composite flocculants consisting of PSAM and cPAM were found to be environmentally friendly, highly efficient, and fast settling in drinking water treatment.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Jiangfeng Dai,Jiangwei Lou,Zhiyuan Jin,Tianhao Yu,Hui Xu,Dongsheng Wang
The secondary sedimentation tank in wastewater treatment facilities is critical for separating suspended solids and biomass from treated water, producing effluent suitable for discharge or further treatment. This study fabricated poly-aluminum silicate chloride (PASiC) through silicic acid modification of polyaluminum chloride (PACl) as the precursor matrix. The coagulation efficacy of PASiC in treating secondary sedimentation tank effluent was systematically investigated, with particular focus on the impact of ageing processes on floc structural stability.Experimental findings indicated that PASiC effectively reduced organic matter in effluent; however, the silicon component can form fine suspended particles that were challenging to settle, which slightly reduced turbidity removal efficiency. Specifically, the addition of silicon increased supernatant turbidity by 0.2 to 0.5 NTU compared to the control. During floc aging, PASiC proved effective in reducing and stabilizing residual aluminum in the supernatant, with silicon-modified PASiC achieving a residual aluminum reduction exceeding 0.1 mg/L. Notably, PASiC with a basicity of 1.0 and a Si/Al ratio of 1:10 (PACl 1.0 -1:10) yielded flocs with improved resistance to aging, as indicated by slower changes in the humification index and fluorescent active substances in the supernatant. It can be reasonably deduced that the incorporation of silicon facilitates the formation of a more resilient network configuration through its complexation with aluminum, and reinforces the hydrogen bonds. These findings provide a theoretical basis for mitigating floc aging challenges, such as sludge return in wastewater treatment processes.
研究领域:
环境工程
·
水处理
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2024
·Vol. 235
·期 2
·1-17
·
IF 3.8
Song Lei,Zhang Hao,Wang Runnan,Wang Xiyue,Zhu Bo,Sun Dazhi,Lou Dawei
In this study, a magnetic composite flocculant containing Fe 3 O 4 magnetic nanoparticles was prepared using sodium silicate, aluminium sulfate, titanium sulfate, and sodium alginate as raw materials. Then, the effects of preparation conditions and flocculation parameters on the adsorption of Congo red were investigated. Specifically, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermogravimetric analysis, scanning electron microscopy–energy-dispersive X-ray spectroscopy, transmission electron microscopy, and vibrating sample magnetometry were used to confirm the successful synthesis of the composite flocculant. One-way experiments revealed that a flocculant dosage of 40 mg/L yielded the highest Congo red removal rate of 95.43%. Compared with traditional flocculants, the flocs formed by the magnetic composite flocculant could settle faster; further, they could be magnetically separated for reuse, thereby reducing secondary pollution caused by the flocs and improving the utilisation rate. When the magnetic flocculant and flocs were mixed with dye wastewater in an appropriate ratio, recycling experiments showed that removal rates are still good, with no significant change in the adsorption capacity. The flocculation mechanism was dominated by chelation, adsorption bridging, net trapping, and sweeping effects, while charge neutralisation played a minor role in the process. The maximum adsorption of Congo red dye from aqueous solution by a magnetic iron tetraoxide–poly(aluminium–titanium silicate)–sodium alginate (SA) composite flocculant was calculated to be 1710.6 mg/g according to the Langmuir isotherm model. The negative value of ∆G° and positive values of ∆H° indicated spontaneity and heat absorption of the flocculation process.
研究领域:
环境科学
·
材料工程
·
化学工程
·
纳米技术
·
水处理
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Huihui Zhang,Qiang Li,Futang Hu,Changkun Cheng,Nan Su,Zhiyong Zhang,Zhongzhi Zhang,Yijing Luo,Heming Wang
Drilling operations generate large volumes of wastewater; inadequate treatment poses a direct threat of groundwater and soil pollution. Biological treatment is environmentally friendly, yet it is constrained by prolonged treatment times. Coagulation offers the distinct advantages of rapid processing. Nevertheless, conventional organic polyacrylamide (PAM) flocculants increase the total nitrogen concentrations in wastewater, and traditional aluminum–iron salt coagulants exhibit limited efficiency and induce pipeline corrosion owing to their low degree of polymerization and the introduction of chloride ions. Therefore, developing a green and highly efficient coagulant has become a promising solution. In this study, an efficient polysilicate aluminum ferric (PSAF) was synthesized via copolymerization and applied to treat real drilling wastewater. In comparison to commonly used polyaluminum chloride (PAC), PSAF demonstrated a 14.3–21.4 % lower effective dose, a chloride ion release 1/17 that of PAC, and a reduced SV 30 value, indicating enhanced coagulation efficiency and sludge settling performance. In addition, the microscale coagulation mechanism was explored. It was found -OH and -COOH groups contributed to the coagulation process. Organics bearing these functional groups were effectively removed, while S 1 O x surfactants exhibited resistance to removal. This selective removal led to a substantial reduction in the organic molecular formula complexity of drilling wastewater. Notably, PSAF achieved a 2.8-fold greater reduction compared to PAC. Further analysis indicated that the formation of Si-O-Al/Fe-OOC or Si-O-Al/Fe-OH bonds enhanced adsorption and net trapping bridging capacities of PSAF, thereby improving overall coagulation performance. This study provides a technical reference for on-site treatment of drilling wastewater.
研究领域:
环境工程
·
水处理技术
·
高分子化学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）