SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Lin-Jiang Zhong,Shu-Jie Hu,Di Wu,Meng-Yue Zhang,Hong Liu,Yuan Liu
Both the sustainable development and environmental protection urge a demand of new paradigm to recover high-quality nutrients from source-separated urine, but the simultaneous recovery of phosphorus and nitrogen is difficult due to the complex composition. Herein, a coupled system consisting of a flow-electrode capacitive desalination and magnesium-air fuel cell (FCDI-MAFC) was proposed to accomplish electrochemical selective separation plus induced precipitation. The results showed that ionic species in urine were effectively separated from the non-ionic components to generate a urea solution with purity up to 99.7%. Ionic species were converted into artificial phosphate ores (APOs) with a phosphate content of 98.2%. The mass proportion of struvite in the APOs exceeded 90%. The energy consumption also decreased by 13% over five batches of operation. The overall results provide a novel method for the electrochemical selective separation and recovery of high-quality nutrients from complex wastewater.
研究领域:
环境科学
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资源回收
·
电化学工程
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DOI
高影响因子
Journal of Water Process Engineering
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2025
·
IF 6.7
Qin-Hua Xu,Yaofeng Cai,Jiajie Li,Minglin Zhou,Yanbin Xu
Anaerobic digestion technology effectively recovers energy from livestock manure but discharges digestate with high ammonia nitrogen (NH 4 + -N). NH 4 + -N in digestate can be effectively recovered by electrodialysis (ED) technology. However, the implementation of ED technology is limited by membrane and energy costs. Here, we present a capacitor-circuit-switching electrodialysis (CCSE) strategy to enhance ED efficiency by integrating an electric double-layer capacitor (EDLC). We reveal that the energy storage mechanism of EDLC improves the power density while the intermittent operation mitigates the concentration polarization effect. In the practice of the real digestate, CCSE elevated the pH to 9.4, and 98.8 % of the NH 4 + ions migrated to the cathode compartment after 3.5 h. The specific energy consumption and the current efficiency are 15 kWh/kg NH 4 + -N (N) and 64.1 %, respectively. High pH contributes to carbon reduction in the stripping process, and subsequent alkaline contamination can be controlled by neutralization of the anode effluent. Moreover, the CCSE-stripping system achieved 95 % NH 4 + -N removal and 93 % stripping recovery efficiency. This work provides valuable insights and solutions for the design and optimization of ED systems.
研究领域:
环境科学
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能源技术
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废水处理
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产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Wang Saier,Sun Kechun,Xiang Huiming,Zhao Zhiqiang,Shi Ying,Su Lianghu,Tan Chaoqun,Zhang Longjiang
Refuse transfer station (RTS) leachate treatment call for efficient methods to increase nutrient recovery (NH4+−N and PO43−−P) and chemical oxygen demand (COD) removal. In this study, the effects of various operational factors (seeding dose, pH, initial NH4+-N concentration, and reaction time) on biochar-seeded struvite precipitation were investigated at laboratory and pilot scales. Mealworm frass biochar (MFB) and corn stover biochar (CSB) were used as seeding materials to compare with traditional seed struvite. The maximum NH4+−N and PO43−−P recover efficiency of the MFB-seeded process reached 85.4 and 97.5%, higher than non-seeded (78.5 and 88.0%) and CSB-seeded (80.5 and 92.0%) processes and close to the struvite-seeded (84.5 and 95.1%) process. The MFB-seeded process also exhibited higher COD removal capacity (46.4%) compared to CSB-seeded (35.9%) and struvite-seeded (31.2%) processes and increased the average particle size of the struvite product from 33.7 to 70.2 μm for better sustained release. XRD, FT-IR, and SEM confirmed the orthorhombic crystal structure with organic matter attached to the struvite product. A pilot-scale test was further carried out in a custom-designed stirred tank reactor (20 L). In the pilot-scale test, the MFB-seeded process still spectacularly recovered 77.9% of NH4+−N and 96.1% of PO43−−P with 42.1% COD removal, which was slightly lower than the laboratory test due to insufficient and uniform agitation. On the whole, MFB-seeded struvite precipitation is considered to be a promising pretreatment method for rural RTS leachate.
研究领域:
环境科学
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废水处理
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Xinyi Tao,Kun Zou,Mengze Yuan,Yixuan Wen,Benben Liu,Taiping Qing,Bo Feng,Peng Zhang
Microbial synthesis is an effective method for carbon and nitrogen recovery in the biological nitrogen removal process. The recycling of alginate-like exopolymers has attracted the attention of many researchers; however, the composition of the polymers and alginate differs. In this study, the capacity and mechanism of a mucoid Pseudomonas aeruginosa to remove nitrate and synthesize alginate were investigated. The results showed that the P. aeruginosa achieved higher nitrate removal efficiency (95.3 %) and alginate yield (298 mg/L) after 36 hours of microaerobic cultivation compare to aerobic condition. The optimal conditions for nitrogen removal and alginate recovery are 35 °C, pH 7 and C/N 15. The transcriptional activities of denitrifying genes in P. aeruginosa were upregulated at the low dissolved oxygen level. Although O 2 may upregulate the expression of alginate synthesis key genes ( algD , alg8 and alg44 ) by activating AlgZ-AlgR two-component signal transduction system, microaerobic condition facilitates P. aeruginosa proliferation and results in a higher alginate yield. Moreover, the P. aeruginosa strain was further coupled with an anoxic/aerobic reactor for deeper nitrogen removal, and the nitrate removal efficiency and alginate yield were maintained above 91 % and 100 mg/L, respectively. The conversion efficiency of sodium acetate to alginate reached 15 %. This work provides an economically and environmentally sustainable strategy for wastewater treatment and the recovery of high-value bioresource.
研究领域:
环境生物学
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微生物学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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IF 9.7
Changjin Guo,Yinghao Xu,Congcong Ni,Xiaofan Pan,Leonard D. Tijing,Ho Kyong Shon,Ning Deng,Xin Huang
Nitrogen and phosphorus recovery from wastewater to produce struvite fertilizer can simultaneously alleviate water eutrophication and phosphorus scarcity. Coupled magnesium mineral dissolution and reprecipitation has been emphasized for struvite formation by avoiding excessive Mg salts addition and pH adjustment. However, the recovery efficiency is limited by the low solubility of magnesium mineral. Herein, we capitalized on the concept of “pore-size controlled solubility (PCS)” to enhance the dissolution of MgAl-layered double oxide (MgAl-LDO), where dissolution rate is inversely related to pore size. By reducing the pore size of LDO X from 9.2 to 5.5 nm, the magnesium release from LDO X dissolution increased from 64.0 to 99.0 mg/L, accompanied by OH − release to maintain an alkaline condition. This resulted in effective recovery of NH 4 -N (80.54%) and PO 4 -P (80.57%) as high-purity struvite. Scanning electron microscope revealed that LDO acted as seeded surfaces that significantly reduced struvite nucleation barrier by controlling local supersaturation and interfacial energy. Moreover, the recovery is stable across wide pH ranges (5.0–10.0), attributable to the buffering capacity of Al in LDO X . Finally, the feasibility of NH 4 -N and PO 4 -P recovery was successfully applied to real aquaculture wastewater. This study offers an effective strategy to enhance mineral dissolution-precipitation for resource recovery.
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
PubMed
高影响因子
Membranes
·
2023
·Vol. 13
·期 8
·726
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IF 4.2
Yuanyuan Yu,Qin Zeng,Haoquan Zhang,Maoqin Ao,Jingmei Yao,Chun Yang,Svetlozar Velizarov,Le Han
Competition for the migration of interfering cations limits the scale-up and implementation of the Donnan dialysis process for the recovery of ammonia nitrogen (NH4+-N) from wastewater in practice. Highly efficient selective permeation of NH4+through a cation exchange membrane (CEM) is expected to be modulated via tuning the surface charge and structure of CEM. In this work, a novel CEM was designed to form a graphene oxide (GO)-polyethyleneimine (PEI) cross-linked layer by introducing self-assembling layers of GO and PEI on the surface of a commercial CEM, which rationally regulates the surface charge and structure of the membrane. The resulting positively charged membrane surface exhibits stronger repulsion for divalent cations compared to monovalent cations according to Coulomb’s law, while, simultaneously, GO forms π–metal cation conjugates between metal cations (e.g., Mg2+and Ca2+), thus limiting metal cation transport across the membrane. During the DD process, higher NH4+concentrations resulted in a longer time to reach Donnan equilibrium and higher NH4+flux, while increased Mg2+concentrations resulted in lower NH4+flux (from 0.414 to 0.213 mol·m−2·h−1). Using the synergistic effect of electrostatic interaction and non-covalent cross-linking, the designed membrane, referred to as GO-PEI (20) and prepared by a 20 min impregnation in the GO-PEI mixture, exhibited an NH4+transport rate of 0.429 mol·m−2·h−1and a Mg2+transport rate of 0.003 mol·m−2·h−1in single-salt solution tests and an NH4+/Mg2+selectivity of 15.46, outperforming those of the unmodified and PEI membranes (1.30 and 5.74, respectively). In mixed salt solution tests, the GO-PEI (20) membrane showed a selectivity of 15.46 (~1.36, the unmodified membrane) for NH4+/Mg2+and a good structural stability after 72 h of continuous operation. Therefore, this facile surface charge modulation approach provides a promising avenue for achieving efficient NH4+-selective separation by modified CEMs.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Lei Zhou,Dian Wang,Jiayu Yu,Hongyi Zhang,Hang Dong
Nitrogen recovery from urine and CO 2 utilization are both vital for achieving a circular economy and mitigating climate change. Divided engineering solutions have been proposed to address either problem, but there is still a lack of integrated technologies to simultaneously tackle the two tasks. We demonstrated CO 2 -driven ion exchange for nitrogen recovery (CIXNR) from urine and evaluated the process in Malawi. By comprehensively studying the ion exchange chemistry using a proton-form weak acid cation exchanger (WAC-H), we revealed the suppressed adsorption capacity caused by counterion releasing. Regulating aqueous pH optimized the WAC-H capacity, particularly, by the natural buffering capacity provided by bicarbonate in the hydrolyzed urine. CO 2 regeneration achieved over 75 % nitrogen recovery in a multi-cycle test with synthetic hydrolyzed urine. A higher CO 2 pressure resulted in faster regeneration kinetics due to a lower aqueous pH and higher proton concentration gradient. Our field outreach activity in Malawi indicated future research demand in adapting the system for resource-limited, rural, and no-electricity areas. We envision this study to inspire more integrated solutions to tackle both circular economy and climate actions and call for more field outreach activities to facilitate urine technology adoption in developing countries.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Jia-tao Xiang,Jun-ting Li,Xiong Zhang,Han Zhang,Shao-hui Ren,Shi-hong Zhang
This study focused on the development of a novel process of H2O2/FeSO4 preoxidation combined with wet flue gas desulfurization (WFGD) postabsorption for simultaneous desulfurization and denitrification, and recovery of sulfur and nitrogen from flue gas. The results show that when no oxidant is added, the denitrification efficiency by WFGD is only 5.3%, while under the H2O2/FeSO4 preoxidation, the desulfurization and denitrification efficiency can reach 99.9% and 83.6%, respectively. When the liquid/gas ratio reaches 18 L·m–3, the desulfurization efficiency is nearly 100%, and the denitrification efficiency can reach 90.6% due to the increased liquid/gas contact area and improved heat and mass transfer. The absorption process of SO2 and NOx involves both physical and chemical absorption, which is dominated by physical absorption, and the absorption characteristics are multilayer absorption. The desulfurization products CaSO3 and CaSO4, and the denitrification products Ca(NO2)2 and Ca(NO3)2, are absorbed by the CaCO3 slurry. The Aspen Plus process simulation results show that the desulfurization and denitrification efficiencies are 99.5% and 89.6%, respectively, and the concentrations of SO2 and NOx in the flue gas are 21.4 mg·m–3 and 41.5 mg·m–3, respectively, which meet the ultralow emission standards. In addition, the H2O2/NO molar ratio, oxidation temperature, and SO2 concentration have an important effect on the NO conversion, which then affects the denitrification efficiency.
研究领域:
环境工程
·
化学工程
·
过程模拟
✓ 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）