POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 33
·期 1
·235-245
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IF 3.665
Zhihui Pan,Yingru Huang,Haoyong Guo,Tingjian Huang,Gang Wen,Huarong Yu,Junguo He
An advanced dual pH- and temperature-sensitive hydrogel (NASH2.5) was optimally synthesized through modification of N-isopropylacrylamide (NIPAM) hydrogel with introducing 5 mol% acrylic acid (AA) and 2.5 wt% sewage sludge ash (SSA). The swelling kinetic results showed that NASH2.5 exhibited both high equilibrium swelling ratio and swelling rate, which was attributed to the higher porous structure as shown in scanning electron microscope, and the more hydrogen bonding formed inside of the hydrogel as investigated in Fourier transform infrared spectrometer. In addition, its curve was better fitted to the pseudo-second-order model, indicating that the water absorption process was dominated by chemisorption through forming the hydrogen bonding among the water molecules and carboxyl/silanol groups of the hydrogel. Compared with the pure NIPAM hydrogel, the water transport mechanism switched from Case I diffusion to Case II diffusion by introduction of AA and further SSA. Furthermore, through the results of the deswelling kinetics in pH value change (from 9 to 4 and 2, respectively), temperature value change (from 25 to 40, 50, and 60°C, respectively), and dual pH and temperature values changes, NASH2.5 not only presented a high pH sensitivity, but also showed high sensitive to temperature by achieving high water recovery ratio in rapid dehydrated rate. Therefore, the dual stimuli-sensitive hydrogel with the simultaneously high performance of swelling and deswelling would provide a suitable alternative for specific applications such as pollutant adsorption.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
RESOURCES CONSERVATION AND RECYCLING
·
2022
·
IF 13.716
Yuxiang Zhong,Guanting Liu,Xiao Yang
Natural phosphorus resources are depleting. Phosphorus recovery from waste has become a strategic issue to address the potential threat of phosphorus shortage. Technologies to recycle phosphorus as fertilizers remain in limited applications due to cost and quality reasons. Here, we demonstrate sewage sludge ash as an appropriate resource to prepare elemental phosphorus. By leaching in molten CaCl 2 , PO 4 3- in the ash can be set free and electrochemically split into elemental phosphorus and O 2− . We identify two technical advantages of using sewage sludge ash. Metal cations released from the ash boost the leaching rate of PO 4 3− , while SiO 2 in the ash prevents the accumulation of O 2- in the melt. Electrochemical isolation can keep most impurities in phosphorus within 1.00 ppm, far better than the industrialgrade commercial product. The estimated cost is less than 2 USD (kg-P) −1 . This facile technology may contribute to closing the phosphorus loop for sustainable utilization.
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
WASTE MANAGEMENT
·
2019
·
IF 5.431
Xiangdong Meng,Xiaoji Liu,Qunxing Huang,Huaping Gao,Kangrou Tay,Jianhua Yan
As a phosphorus-rich material, low-temperature combustion sewage sludge ash (LTCA) contains over 9 wt% content of phosphorus (P) and a large proportion of impurities, especially the content of Fe arrives at 14.59 wt%. To fully utilize LTCA as a fertilizer, this study investigated a procedure for P recovery from LTCA via struvite crystallization with fewer impurities. The adsorption characteristics of P and Fe by cation exchange resin (CER) were explored by simulating using the macroscopic parametric equation Thomas model. Optimum purification conditions for P-rich leachate by cation exchange column method were determined. Results showed that approximately 97.21 wt% of P was extracted from LTCA at HCl concentration of 0.8 M and liquid/solid ratio of 20.0 ml/g. More than 90 wt% of impurities could be detached by making P-rich leachate flow through cation exchange bed filled by CER at 300 ml/h. The macroscopic parametric equation Thomas model could clearly describe the adsorption characteristics of Fe in P-rich leachate by CER. Theoretical basis for purification of high concentration Fe in P-rich leachate by CER was provided. Approximately 84.04 wt% of total P in LTCA was recovered as struvite crystal which had low concentrations of heavy metals (5.96 mg/kg for Cr, 45.21 mg/kg for Cu, 29.67 mg/kg for Ni, 2.24 mg/kg for Pb, and 290.6 mg/kg for Zn) and could be eco-friendly for agricultural application. X-ray diffraction and SEM-EDS analysis validated the formation of struvite.
研究领域:
环境科学
·
农业科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Zhihui Pan,Xiongrui Yang,Yilun Liang,Mengze Lyu,Yingru Huang,Hong Zhou,Gang Wen,Huarong Yu,Junguo He
A temperature-sensitive hydrogel modified with sewage sludge ash (SSA) was used as an advanced draw agent for forward osmosis (FO) application in treating chromium-containing wastewater. The performance of the modified hydrogel (SSA-TSH) was measured in terms of the swelling and deswelling properties, as well as adsorption and desorption effects on Cr(VI), chemical oxygen demand (COD), total phosphorous (TP) and ammonium (NH 4 + -N) in chromium-containing wastewater. Furthermore, the efficiencies of wastewater treatment , water flux , and the reusability of the SSA-TSH as draw agent in the FO process (FO-SSA-TSH) using a commercially available thin-film composite membrane (Sterlitech) were also investigated. The results indicated that FO-SSA-TSH achieved high removal rates of pollutants (Cr(VI): 96.9 %–97.4 %, COD: 97.1 %–97.4 %, TP: 97.7 %–99.6 %, and NH 4 + -N: 76.8 %–77.9 %) in various Cr(VI) concentrations (0– 40 mg/L) due to the high rejection rate of FO membrane and notable adsorption capacity of the hydrogel. Moreover, the average water flux of FO-SSA-TSH (1.95– 2.02 LMH) was nearly twice as much as that of the FO with pure temperature-sensitive hydrogel as draw agent (FO-TSH, 1.33– 1.42 LMH) in 24 h chromium-containing wastewater treatment . In addition, SSA-TSH with excellent deswelling property exhibited high water recovery performance and good reusability in low cost and energy consumption after the FO permeation process for wastewater treatment.
研究领域:
环境工程
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废水处理
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
MOLECULES
·
2026
·Vol. 31
·期 16
·2753
·
IF 5.1
Weiwei Zhu,Yi Ren,Yaxin Xiao,Shaoyu Du,Xiaoli Xie,Kao Chen
Due to the fact that municipal sludge incineration generates a large amount of toxic sewage sludge ash (SSA), cement solidification is becoming an efficient harmless treatment method. However, the large amount of phosphorus in sludge ash can delay the setting time of cement pastes and lead to a decrease in its later strength. Moreover, as an important non-renewable resource, the recycling and utilization of phosphorus is also a current research hotspot. To this end, this paper proposes to remove phosphorus from incinerated sewage sludge ash (ISSA) by the acid washing process, and, in response to the problem of reduced volcanic ash activity in acid-washed sewage sludge ash (ASSA), calcium chloride (CaCl2) is added as an activator to explore the optimal process and hydration mechanism for enhancing ASSA activity. This study removed phosphorus from calcined SSA (800 °C, 2 h) via acid washing (0.3 mol/L H2SO4, L/S = 10:1, 2 h) to obtain ASSA, and used CaCl2as an activator to improve its pozzolanic activity. Different CaCl2dosages (1–3%) were tested for paste setting time, 3/7/28 d compressive strength, and characterized by hydration heat, XRD, SEM, etc. Experimental results indicated that the synergistic addition of 2 wt.% CaCl2and 20 wt.% ASSA shortened the initial and final setting times by 38% and 23% to 142 min and 289 min, respectively. Meanwhile, the compressive strength at 28 days was improved by 24%, with a final strength value of 42 MPa. Microanalysis revealed abundant Friedel’s salt formation and a denser structure (fine mesopores 60%, coarse mesopores 26%), confirming CaCl2effectively activates ASSA for cement admixture use.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Zhihui Pan,Haoyong Guo,Tingjian Huang,Gang Wen,Fangshu Qu,Junguo He,Huarong Yu
In this study, a novel and environmentally friendly technology for sludge incineration ash disposal was developed. We proposed to enhance the performance of thermo-sensitive hydrogel as draw agent for forward osmosis (FO) application by loading sewage sludge ash (SSA). The effect of SSA contents on the swelling and deswelling properties and FO performance of the hydrogels was evaluated. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and diffusion model were applied to characterize a series of hydrogels with various SSA contents (0–4.5 wt%). The results showed that as the SSA increased, the swelling ratio of hydrogel and the water flux of SSA-hydrogel-based FO increased initially and then declined. This was due to the combined effects of hydrogen bonding and high-density crosslinking within the hydrogels. In addition, the water diffusion mechanism of all hydrogels was super Case II diffusion type. Furthermore, the SSA-loaded hydrogels not only had excellent swelling property but also exhibited good deswelling performance (water recovery ratios of them were almost 90% at 60 °C water bath for 5 min). Moreover, all hydrogels in this study showed promising reusability with almost no flux drop in four consecutive FO permeation-regeneration cycles.
研究领域:
环境科学
·
材料科学
·
水处理技术
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL ENGINEERING SCIENCE
·
2022
·Vol. 39
·期 11
·896-905
·
IF 2.172
Zhihui Pan,Yingru Huang,Xiongrui Yang,Yilun Liang,Junguo He,Huarong Yu
In this study, an advanced temperature-sensitive hydrogel with sewage sludge ash (SSA) was synthesized and employed as draw agent for forward osmosis (FO) desalination. The effects of the incineration temperature (700–1,000°C) of SSA obtention, particle size (20–300 meshes), and dosage (0–4.5 wt%) of SSA were investigated for optimally synthesizing the temperature-sensitive hydrogel to meet the requirement of FO. The resulting hydrogels were characterized in terms of crystal structure, surface morphology, surface functional groups, and lower critical solution temperature (LCST). It was shown that the dosage of SSA significantly influenced the swelling capacity (in different concentrations of NaCl solution) and deswelling property of hydrogels, whereas the other two factors only affected the swelling of hydrogel, but had no effect on the deswelling. In addition, as a result of higher reticulated pore structure, and the hydrogen-bonding interaction between the chemical surface of SSA and monomers of hydrogels, the best production D2.5H as a draw agent generated high average water flux of 2.22 LMH in FO desalination with 2,000 ppm NaCl as feed solution. Furthermore, despite a little higher LCST with the comparison of D0H (blank sample without SSA), the D2.5H as a draw agent can still maintain the prominent temperature-sensitive performance in that, most of the water can be recovered in 10 min of 60°C water bath, and the average water fluxes of FO with even three times regenerated hydrogels were similar to that with the initial.
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
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2021
·
IF 6.789
Jing Nie,Qiming Wang,Shengya Gao,Chi Sun Poon,Yaoyu Zhou,Jiang-shan Li
With rapid economic growth and urbanisation, the reuse and recycling of solid wastes has become a high priority for the sustainable development of modern cities. In this study, two typical solid wastes, incinerated sewage sludge ash (ISSA) and waste bentonite , were co-valorised to produce granular adsorbents through a simple and energy-saving pelletisation/sintering process. A mixture of ISSA and bentonite at a weight ratio of 3:1 was pelletised and sintered at 700 °C. The resultant ceramsite, with good mechanical strength, could effectively remove Pb(Ⅱ) from aqueous solutions. The adsorption kinetics can be described by the pseudo-first-order (PFO) model. The results indicated that the Pb(Ⅱ) adsorption process was dominated by electrostatic attraction , precipitation, and complexation. The isothermal data exhibited a good correlation with the Freundlich model, indicating that the adsorption process was non-ideal and spontaneous. The maximum adsorption capacity was approximately 21.6 ± 0.35 mg/g at 318 K. After 5 cycles of regeneration, the adsorbent maintained good adsorption performance. Moreover, the removal rate was not greatly affected by ionic strength . These findings demonstrate that the granular adsorbent prepared with ISSA and waste bentonite can be recognised as a promising adsorbent for Pb-containing wastewater treatment .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2021
·
IF 9.501
Zhihui Pan,Haoyong Guo,Huarong Yu,Gang Wen,Fangshu Qu,Tingjian Huang,Junguo He
This work made use of the sewage sludge ash (SSA) to enhance thermo-responsive hydrogel for driving forward-osmosis (FO) process. Results showed that owing to the porous structure and intermolecular interactions between the ionized groups of monomers and the chemical surface of silica , the SSA-based thermo-responsive hydrogel (SSA2.5H) had increased swelling capacity and osmotic pressure , resulting in an average water flux (2.33 LMH) twice as high as the hydrogel without adding SSA (1.18 LMH) during 24 h FO with DI water or different concentrations (2000–8000 ppm) of NaCl as feed solution. More importantly, SSA2.5H can maintain good thermo-responsive dehydration performance in spite of an enhancement to its swelling ability. 93.8% of the adsorbed water can be retrieved from SSA2.5H in water bath of moderate temperature (60 °C) for 10 min and water flux can be recovered to 94.4% of the initial value after 4 times of hydrogel regeneration during FO as draw agent. Therefore, this work showed that SSA was an excellent modifier to enhance the thermo-responsive hydrogel for improving permeation performance in FO and lowering down the actual energy requirement for water recovery and draw agent regeneration.
研究领域:
环境科学
·
材料科学
·
水处理
✓ 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）