ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Lixun Zhang,Shengyin Tang,Yuntao Guan
The discovery of materials as soil conditioners for the improvement of soil nitrogen-use efficiency provides a promising strategy for simultaneously addressing production and pollution problems in agriculture. Herein, adsorption–desorption performance and mechanisms of ammonium (NH4+–N) by a poly(acrylic acid)-grafted chitosan and biochar composite (PAA/CTS/BC) were studied to evaluate its potential in soil amendment. Furthermore, mathematical models were further applied to explore the effects of PAA/CTS/BC on controlling soil NH4+–N loss. Results suggest that PAA/CTS/BC showed a high capacity of NH4+–N adsorption, with a maximum value of 149.25 mg·g–1 at 25 °C, considerably higher than most of the reported BC-based adsorbents. Fast adsorption of NH4+–N was completed with an efficiency of >90% within 20 min, primarily attributed to the dominant electrostatic interactions with carboxyl groups. Adsorbed NH4+–N was capable of being easily re-released with the variation of the liquid-phase concentration because of the weak binding of NH4+–N with the material. These results demonstrate that the PAA/CTS/BC can be considered as a nitrogen slow-release medium to dynamically maintain a plant-available NH4+–N concentration in the soil. Finally, the mathematical simulation of NH4+–N flow in the PAA/CTS/BC-amended soil revealed that soil NH4+–N loss was effectively reduced by 24.18–31.77% at a 1.57–2.02% material dosage during a 10-week rice cultivation.
研究领域:
农业科学
·
环境科学
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DOI
高影响因子
Vietnam Journal of Chemistry
·
2024
·
IF 1.3
Nguyen Binh Duong,Quan Thi Thu Trang,Phan Thi Ngoc Bich,Pham Van Lam
In this article, new interpenetrating polymer network (IPN) hydrogel as an efficient adsorbent for ammonium was prepared by a two-step process. First, semi-IPN hydrogel of chitosan-g-poly(acrylic acid)/bentonite (CAB) and chitosan (CTS) was synthesized by grafting polymerization in the presence of exfoliated bentonite as both cross-linking agent and nanoscale inorganic filler. Second, cross-linking polymer network of chitosan-glutaraldehyde (CGA) was formed by reaction of CTS with glutaraldehyde (GA). The obtained IPN hydrogel (CAB/CGA) was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy and its swelling degree and PZC value were also measured. These results demonstrate that copolymerized graft reaction was occurred between CTS, AA and bentonite forming CAB, and CGA presented as a cross-linker in CAB/CGA polymer network. CAB/CGA has a moderate swelling degree of 7.8. CAB/CGA exhibits high adsorption capacity and fast adsorption rate for ammonium. Adsorption process reaches equilibrium in 30 min and fits well to Langmuir adsorption model with a fairly high maximum adsorption capacity of 41.06 mg g −1 . The material has a good regeneration ability. After five times of adsorption–desorption, there was almost no decrease in ammonium adsorption capacity. Moreover, the low swelling degree leads to an improvement in material strength and a reduction of equipment cost.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Wenyan He,Ruiqing Lu,Kuo Fang,Erfu San,Hui Gong,Kaijun Wang
To achieve ammonium recovery and organic matter enrichment simultaneously, a novel zeolite NaX-doped electrospun porous fiber membrane (Z-EPFM) was fabricated by using the electrospinning technique with the addition of polyvinylidene fluoride (PVDF), zeolite NaX and polyvinylpyrrolidone (PVP) as porogen. The strategy of using PVP as a pore-forming agent to obtain porous Z-EPMFs is more efficient to achieve ammonium adsorption than improving the hydrophilicity of the zeolite NaX-doped electrospun fiber membrane (Z-EFM) by simply adding PVP. As the molecular weight and content of PVP increase, the ammonium adsorption efficiency, hydrophilicity and membrane pore size of Z-EPFMs increase, while their mechanical strength decreases, which is due to the formation of pore structures . The most efficient Z-EPFM (zeolite NaX load density of 0.78 mg/cm 2 ) achieved 96.91% ± 0.50% ammonium adsorption efficiency and 95.48% ± 4.52% organic carbon enrichment efficiency, which were maintained steadily over five regeneration cycles. Therefore, the Z-EPFM offered a novel approach for simultaneous ammonium recovery and organic matter enrichment, which could be proposed as an efficient method to regulate energy flow and control nitrogen nutrient in municipal wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2018
·Vol. 26
·期 12
·4311-4320
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IF 1.971
Wu Chengyi,Zhang Xu,Li Cong,Cheng Chao,Zheng Yin
A novel sodium alginate-grafted poly(acrylic acid)/graphene oxide (NaAlg-g-PAA/GO) composite hydrogel was prepared via ultraviolet irradiation, and characterized by infrared spectroscopy spectrometer. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. It was employed to adsorb NH 4 + from aqueous solution and used as slow-release nitrogen fertilizers (SNFs). Result indicated that the adsorption process for NH 4 + reached equilibrium within 50 min, with the adsorption capacity of 6.6 mmol g −1 even if 30 wt% GO was incorporated. The results of adsorption kinetic and isotherm were well described by the pseudo-second-order and Freundlich model. The thermodynamics analysis showed the adsorption process was spontaneous. The study indicated excellent water-holding ratio of soil with 2 wt% SNFs was 81.2%, and nitrogen release was up to 55.1% within 40 days in soil. Overall, NaAlg-g-PAA/GO could be considered as an efficient adsorbent for the recovery of nitrogen with the agronomic reuse as a fertilizer.
研究领域:
环境科学
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农业科学
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材料科学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2021
·
IF 7.963
Tongtong Wang,Gaoliang Li,Kaiqi Yang,Xiaoyuan Zhang,Ke Wang,Jinjun Cai,Jiyong Zheng
The adsorption treatment of ammonium-containing wastewater has attracted significant global attention. Most enhanced adsorption methods employ chemical modification, and there are few reports on physical activation. We present a physical activation to explore whether physical ultrasound may enhance the adsorption performance and comprehensive utilisation of a new forestry waste, Caragana korshinskii was used as a feedstock to prepare activated biochar (ACB) by controlling the pyrolysis temperatures and ultrasound parameters. The optimal parameters were determined via batch adsorption of NH 4 + , and the adsorption characteristics were assessed by 8 kinds of models and influence experiments. Moreover, the physicochemical properties of ACB during the pyrolysis process were investigated, and the ultrasonic activation and adsorption mechanisms were discussed using multiple characterisation techniques. Additionally, the cost analysis, the safety of the ultrasonic process and disposal method also were evaluated. The results showed that the ultrasonic activation significantly enhanced the NH 4 + adsorption efficiency of biochar by approximately 5 times. ACB exhibited the best performance at 500 °C with an ultrasonic activation time of 480 min, frequency of 45 kHz, and power of 700 W. The ultrasonic activation reduced the biochar ash and induced pore formation, which increased the specific surface area through cavitation corrosion and micro-acoustic flow mechanism. The NH 4 + adsorption mechanisms comprised physicochemical processes , of which physical adsorption was dominant. The preparation cost of 1 kg ACB was about 0.42 US dollar, and no secondary pollution occurred in the activation process. The findings prove that ultrasonic technology is efficient and convenient for enhancing biochar adsorption performance, and thus is suitable for industrial applications and promotion.
研究领域:
环境科学
·
废水处理
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DOI
PubMed
高影响因子
RSC Advances
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2024
·Vol. 14
·期 25
·17843-17854
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IF 3.9
Heng-Deng Zhou,Chu-Ya Wang,Qi Wang,Bo-Xing Xu,Guangcan Zhu
Adsorption is an effective approach for remediating ammonium pollution, and zeolite has exceptional efficacy for the adsorption of ammonium. The investigation of ammonium adsorption using coal-fly-ash-based zeolite has gained remarkable attention in contemporary research. In this work, a sodium-acetate-modified synthetic zeolite (MSZ) was used to absorb ammonium in simulated wastewater. The MSZ had an adsorption capacity for ammonium of 27.46 mg g−1, and the adsorption process followed the Langmuir isotherm model and pseudo-second-order kinetics model. The adsorption and desorption of ammonium were controlled by ion exchange, pore diffusion, and electrostatic attraction processes. Ion exchange was responsible for 77.90% of the adsorption process and 80.16% of the desorption process. The MSZ was capable of continuously removing large amounts of ammonium from wastewater through fixed bed adsorption. After 5 regeneration cycles, MSZ still maintained 75% adsorption characteristics for ammonium. Using MSZ adsorbed with ammonium as a soil amendment increased the germination rate of mung beans by 10%. Furthermore, it also increased the stem length, root length, and fresh weight by 20–30%. These findings suggest that MSZ provides a promising application prospect to mitigate ammonium pollution and recycle ammonium resources.
研究领域:
环境科学
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土壤学
·
水资源管理
✓ 已验证
DOI
PubMed
高影响因子
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