CHEMOSPHERE
·
2023
·
IF 8.8
Le Zhang,Yong Liu,Jianlong Wang
The oxidation of ammonium (NH 4 + ) to dinitrogen (N 2 ) with high selectivity and high efficiency is still a challenge. Herein, a novel sunlight induced persulfate (PS)-based AOPs process (MgO/Na 2 SO 3 /PS/ hv ) was proposed by introducing solid base (MgO) and hydrated electron (e aq − ), to selectively oxidize NH 4 + to N 2 , with high selectivity and high efficiency at a wide range of pH value. The deprotonation of NH 4 + into NH 3 by MgO and the generation of •OH and SO 4 −• by PS activation were responsible for the high efficiency of NH 4 + oxidation. The buffering capacity provided by MgO to proton released from PS activation made the NH 4 + oxidation possible at a wide pH range. The e aq − from the Na 2 SO 3 / hv process was the main active specie to reduce NO 2 − and NO 3 − (NO x − ) into N 2 , responsible for high N 2 selectivity of NH 4 + oxidation. 100% NH 4 + could be oxidized within 30 min, and N 2 selectivity exceeded 96% at the initial pH range of 3–11 and the initial concentration of NH 4 + of 30 mg N/L. This work could offer an efficient AOPs process for selective NH 4 + oxidation, which is promising for the chemical denitrification of wastewater ….
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Xinyu Liu,Jianlong Wang
The efficient elimination of ammonia nitrogen (NH 4 + -N) from the specific wastewater and selective oxidation to nitrogen gas are the most desirable purposes of wastewater treatment, but still remains a challenge. Herein, we presented a cobalt-based catalyst (Co-VB 12 -C) as a novel heterogeneous catalyst, which was fabricated via the co-pyrolysis of poly (2,6-diaminopyridine) and vitamin B 12 . Co-VB 12 -C were successfully prepared to construct a facile heterogeneous Co-VB 12 -C/PMS/Cl system and achieve effective removal of NH 4 + -N and high selectivity to nitrogen gas in acidic and neutral pH. Co-VB 12 -C had superior catalytic capability, reusability, and stability. The role of catalyst, PMS, Cl - , and pH value was investigated and the corresponding mechanism was proposed, which revealed that Cl•-mediated oxidation reactions made predominant contribution to NH 4 + -N transformation. This system is a facile alternative technology for removing ammonium from high saline wastewater.
研究领域:
环境科学
·
催化化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Yuanzhong Lin,Shuang Liu,Yuxin Zeng,Wenqing Guo,Tao Guo,Lifeng Yin,Yunrong Dai
The oxidative nitrate (NO 3 − ) and reductive ammonium (NH 4 + ) constitute the common nitrogen pollution in water. However, the high energy barrier of the comproportionation reaction makes it challenging for the deammoniation and denitrification reactions to occur simultaneously. This study evaluated the performance of simultaneous deammoniation and denitrification under vacuum ultraviolet (VUV) irradiation. The results demonstrate that the reduction reaction of NO 3 − and the oxidation reaction of NH 4 + conform to the pseudo-first-order reaction kinetics, with respective kinetic constants of 0.012 min −1 and 0.002 min −1 . The presence of Cl − and SO 4 2− inhibits the reduction of NO 3 − , while HCO 3 − and CO 3 2− promote NO 3 − reduction and NH 4 + oxidation. The reaction mechanism of simultaneous NO 3 − and NH 4 + removal was proven through free radical capture and electron spin resonance (ESR) experiments. It was determined that NO 3 − was reduced to NO 2 − , NH 4 + , and N 2 by hydrated electrons (e aq – ) in turn. While the free hydroxyl radical (·OH) produced by direct photolysis of water by VUV was identified as the key to the oxidation of NH 4 + . When NO 3 − and NH 4 + coexist, they can capture e aq – and ·OH, respectively, thus avoiding the quenching of the two highly active species. Thus, energy waste is avoided and nitrogen removal efficiency is improved. The process study shows that the adjustment of the NO 3 − and NH 4 + ratio and the control of process conditions are essential for the synchronous conversion of nitrate and ammonium.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Yingjie Xu,Hongying Xia,Qi Zhang,Wuchen Cai,Guiyu Jiang,Libo Zhang
Germanium-containing dust as an intermediate by-product in the process of zinc hydrometallurgy , which often contains a large number of heavy metal substances. Due to the constraints of economic benefits and process technology, green and efficient treatment of germanium-containing dust is always a great challenge. In this work, XRD , ICP-OES, XPS , SEM and other characterization methods were used to analyze the existing state and quantity of main substances in germanium-containing dust. It was found that the occurrence state of germanium was closely related to sphalerite . At the same time, longer reaction time would lead to continuous hydrolysis of silicate, which would eventually affect the recovery of zinc, germanium and lead and the fixation of toxic substances. Therefore, the ultrasonic enhanced ammonium persulfate oxidation process was proposed to control the waste of resources and environmental pollution caused by the accumulation of germanium-containing dust. The final results showed that more than 95% of zinc and 89% of germanium were efficiently recovered, and heavy metals such as arsenic and cadmium were fixed in the liquid, and then concentrated in the purification and impurity removal stage. The residue after reaction is high-grade lead sulfate residue, which can be returned to the lead smelting system for recycling. In summary, the ultrasonic-enhanced ammonium persulfate process eventually makes all substances in germanium-containing dust harmless and resource treatment.
研究领域:
冶金学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Shasha Huang,Tianjiao Liu,Yunxiao Liu,Yongxin Duan,Jianming Zhang
APS is a cheap and eco-friendly oxidant which enables one-step extraction of nanochitin (NCh) from fishery wastes. However, it is challenging to improve the preparation efficiency and NCh quality simultaneously, owing to the uneven or uncontrollable oxidation . Herein, we propose a simple and controllable way to isolate chitin nanofibers (ChNFs) from squid pen by gradient heating activated (GHA)- ammonium persulfate (APS) oxidation. Compared to the isothermal activated (ITA)-APS oxidation, our strategy reduced the mass ratio of squid pen to APS from 1:45 to 1:6 and reaction time from 15 h to 8 h. Meanwhile, the as-prepared ChNFs exhibited high yield (91.5 %), light transmittance (98 % at 500 nm), crystallinity index (96.9 %), and carboxyl content (1.53 mmol/g). GHA-APS oxidation involved multiple continuous heating and isothermal stages. The former stimulates a moderate activation of APS and enhances the oxidation rate, while the latter provides a duration for surface chemistry. This non-isothermal heating facilitates the continuous decomposition of APS at a relatively high and consistent rate, thereby enhances its oxidation efficiency. Furthermore, green assessments indicate this method is simple, time-saving, eco-friendly and cost-effective. Overall, this work introduces a novel perspective for the industrial extraction of high-efficiency and high-quality nanomaterials .
研究领域:
生物材料学
·
环境科学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 9
·5139-5155
·
IF 3.809
Ye Shounuan,Yu Hou-Yong,Wang Duanchao,Zhu Jiaying,Gu Jiping
Textile manufacturing industries produce large amounts of viscose fiber wastes (VFW), causing serious environmental pollution. This study presents an acid-free approach to prepare spherical cellulose nanocrystals (SCNs) with carboxyl groups from industrial VFW by one-step hydrothermal ammonium persulfate (APS) oxidation. Novel double-response surface methodology was employed to optimize the reaction conditions. A maximum yield (37.89%) of carboxylated SCN was obtained at reaction time of 4 h, APS concentration of 1 M and temperature of 80 °C, while the SCNs showed gradual size reductions along with increase of carboxyl contents as reaction time and APS concentration increased. Interestingly, it was possible to obtain carboxylated SCNs in only 2 h of reaction with an increase of 16.5% in the crystallinity index, which was attributed to efficient swelling of cellulose chains and oxidation interaction of surface groups under hydrothermal condition. Compared with SCN-2 h, the crystallinity index and maximum degradation temperature of SCN-10 h were improved by 5.5% and 17.9 °C, respectively. Moreover, SCN-10 h exhibited excellent emulsifying capacity to stabilize soybean oil/water Pickering emulsion droplets and emulsion volume were increased with decreased mean diameter of emulsion droplets as SCN-10 h concentration increased. These results indicate that VFW is an attractive source to produce carboxylated SCNs by APS oxidation, making SCN extraction as value-added alternatives to recycle this waste. Such carboxylated SCNs have great potentials as green food Pickering emulsion stabilizers and nanofillers in high-performance composites.
研究领域:
材料科学
·
环境科学
·
绿色化学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·Vol. 14
·期 1
·120918
·
IF 7.2
Jianjun Sun,Liuyang Dong,Tianfu Zhang,Peilun Shen,Dianwen Liu
Copper slag (CS) contains high-value metals (Fe, Co, Cu, and Zn), but traditional mineral processing has high energy consumption and poor cost-effectiveness. To tackle such problems, the present research puts forward an innovative method where Ag + -catalyzed ammonium persulfate (APS) oxidation enhances low-temperature H₂SO₄ curing and water leaching of valuable metals in CS. Process mineralogy analysis, thermodynamic evaluation, single-variable experiments, and a range of characterization methods were employed to elucidate the CS features, verify process feasibility, evaluate metal leaching rates, and reveal Ag⁺'s leaching enhancement mechanism. Results show that 96.59 % Fe, 90.36 % Co, 95.12 % Cu, and 94.28 % Zn were leached from CS. Compared with the traditional H 2 SO 4 curing process, their leaching rates increased by 3.85 %, 6.58 %, 19 %, and 6.16 %, respectively. Meanwhile, the curing temperature decreased from 200 °C to 80 °C (120 °C reduction), and H₂SO₄ consumption fell by 10 %. Mechanistic analysis reveals that Ag⁺ enhances leaching through two pathways: First, it catalyzes APS decomposition to generate ·SO₄⁻ with high oxidizing activity. These radicals significantly accelerate the oxidation of sulfide minerals and low-valence iron-based minerals, driving reactions to more thorough completion and promoting formation of more water-soluble metal sulfates. Second, Ag⁺ transforms the cured slag's microstructure from initial dense, smooth state to crisscrossing crack network extending into particle interiors. This evolution not only provides channels for inward diffusion of H 2 SO 4 and APS (facilitating deep oxidation) but also creates favorable conditions for outward migration of water-soluble metal sulfates into the leachate. This method offers a low-energy, sustainable approach for large-scale CS utilization.
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产品关联
DOI
高影响因子
TALANTA
·
2018
·
IF 4.244
Guitao Jie,Qian Zhou,Guifen Jie
In this study, a novel strategy for amplified electrochemiluminescence (ECL) detection of DNA was proposed based on excellent ECL activity of graphene quantum dots (GQDs) coupled with multiple cycling amplification technique. A new type of graphene QDs with well ECL property and uniform size were firstly synthesized, then the graphene QDs were assembled on the electrode by poly (diallyldimethylammonium chloride) (PDDA)-graphene oxide (GO) nanocomposites, which could greatly improve ECL signal and stability of QDs. A novel signal-on ECL biosensor for DNA analysis was designed by using ECL quenching of gold nanoparticles (NPs) to graphene QDs combined with endonuclease–aided cyclic amplification strategy. As a result, the proposed strategy can be conveniently expanded to other biosensing application, especially in clinical diagnoses.
研究领域:
分析化学
·
生物化学
·
纳米技术
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）