SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Liuyang He,Lixin Lv,Suresh C. Pillai,Hailong Wang,Jianming Xue,Yongfei Ma,Yanli Liu,Yulin Chen,Li Wu,Zulin Zhang,Lie Yang
Iron/copper bimetallic nanoparticles based sludge biochar (Fe/Cu-SBC) was prepared by using a modified co-precipitation route. The Fe/Cu-SBC system prepared was subsequently applied to activate periodate (IO 4 − ) to degrade diclofenac sodium (DCF) by using UV light at room temperature (25 °C). The physicochemical properties of both SBC and Fe/Cu-SBC such as morphology, physical properties, crystal structures and functional groups were examined. The type and number of surface functional groups were found to be increased and the catalytic performance was improved by the modification of Fe/Cu bimetallic nanoparticles. The influence of various parameters to evaluate the catalytic efficiency such as periodate (PI) concentration, dosage of catalysts, UV power, initial pH and coexisting anions were investigated. Under the optimized conditions (pH 6.9, UV-power 60 W, PI concentration of 5 mM and 0.1 g Fe/Cu-SBC), it was observed that 99.7% of DCF was degraded with a pseudo-first-order kinetics reaction constant 9.39 × 10 −2 min −1 . The radical scavenging experiments showed that IO 3 radicals were the predominantly reactive oxidants in the Fe/Cu-SBC/UV system. Therefore, this investigation provides a feasible alternative for the degradation of PPCPs in wastewater.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Xiaohui Fan,Heng Lin,Jinjin Zhao,Yican Mao,Jiaxing Zhang,Hui Zhang
Activation of peroxymonosulfate (PMS) for organic-contaminated water remediation is a promising strategy. In this study, a sludge-derived biochar (SBC) was prepared as an efficient and low-cost metal-free catalyst to activate PMS for the abatement of bisphenol A (BPA) in water. The results demonstrate that BPA could be rapidly oxidized by the combination of SBC and PMS. Compared with the slight adsorption (8.1%) by SBC alone and limited direct oxidation (2.4%) by sole PMS, the removal efficiency of BPA was boosted to 94.5% within 60 min in the presence of both SBC and PMS. Active species participating in the rapid elimination of BPA were investigated via both chemical quenching experiment and electron paramagnetic resonance (EPR) technique. The results indicate that non-radical rather than radical process plays an important role in BPA abatement in the SBC/PMS system. The electron-transfer non-radical process was further verified by the open circuit potential test. It is proposed that PMS is bound to SBC to form a surface reactive complex (SBC-PMS*), which would abstract the electrons from the adsorbed BPA through the conductive carbon tunnel. The present work provides an alternative of controlling waste by waste.
研究领域:
环境科学
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水处理技术
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
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IF 7.65
Yaoping Hu,Zhijin Gao
Million tons of sewage sludge produced yearly creates a severe pollution problem to environment, and thus needs either to be properly disposed of, or recovered. Here, we demonstrate a value-added utilization of sewage sludge by converting its contained organics into nanosized carbon dots (CDs) with microwave irradiation. This synthetic method, using waste resources as precursors and avoiding the requirement of hazardous reagents and complex procedures, has the great advantage of low cost, environmental friendliness, and easy scalability. The resultant CDs exhibit excellent fluorescence properties with a large quantum yield (QY) of up to 21.7%, higher than the most values of waste-derived CDs. It is found that CDs can serve as a sensitive and selective sensor to detect para-Nitrophenol (p-NP), a toxic pollutant, through fluorescence quenching, giving a linear detection range of 0.2–20 μM and a detection limit of as low as 0.069 μM. Systematic investigations suggest that the inner filter effect (IFE) is the dominant sensing mechanism. Moreover, the practical applications of CDs for p-NP assay in real water samples achieve good results.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2014
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IF 2.93
M. Gong,W. Zhu,H.W. Zhang,Q. Ma,Y. Su,Y.J. Fan
Dewatered sewage sludge was treated with NaOH additive and Ni catalyst in supercritical water in a high-pressure autoclave to examine the effects of separate and combined NaOH additive and Ni catalyst on hydrogen generation . The effects of Ni/NaOH ratio on hydrogen production were also investigated to identify possible catalytic mechanism and interactions. NaOH and Ni, separately or in combination, improved the hydrogen production and hydrogen gasification efficiency. The addition of NaOH additive not only promoted the water–gas shift reaction, but also favored H 2 generation of Ni catalyst by capturing CO 2 . The hydrogen yield of combined catalysts with different Ni/NaOH ratios was higher than the theoretical sum of hydrogen yield from the mixture by 10–33%. The largest hydrogen yield, of 4.8 mol per kilogram of organic matter, which was almost five times as much as without catalyst, was achieved with the addition of 3.33 wt% Ni and 1.67 wt% NaOH. The combined NaOH additive and Ni catalyst also improved the gasification of several other dewatered sewage sludges, increasing the hydrogen yield by four to twelve times that seen without catalyst. Combined NaOH additive and Ni catalyst are effective in dewatered sewage sludge gasification at low temperature.
研究领域:
环境工程
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能源科学
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催化化学
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DOI
高影响因子
WATER RESEARCH
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2022
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IF 13.4
Chen Cai,Xiangfeng Huang,Xiaohu Dai
Centralized sludge treatment plants (CSTPs) are implicated as strong hotspots of antibiotic resistance genes (ARGs). However, the knowledge gap on the fate of intracellular and extracellular ARGs (iARGs and eARGs), and the functionality of resistant hosts limit risk assessment and management of CSTP resistome. Here, the flow of iARGs and eARGs across treatment units and analyses of ARG hosts were systematically explored in three full-scale CSTPs using quantitative metagenomic approaches. We found that 29% of sludge ARGs could be removed, with iARGs being dominant in the produced biosolids. The treatment process significantly affected the variations of iARG and eARG abundance while no significant difference in composition between iARGs and eARGs was observed in CSTPs. 15% of 295 recovered genomes were identified as antibiotic-resistant hosts, among which Actinobacteriota tended to encode multiple resistance. The key functions of ARG hosts were relative to the biological organic removal (e.g., carbohydrates). There also existed relationships between certain resistance mechanisms and functional traits, indicating that ARGs might take part in the physiological process of microorganisms in the sludge treatment. These findings provide important insight into the differential resistome variations and host functionality, which would be crucial in the management of antibiotic resistance in CSTPs.
研究领域:
环境微生物学
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废水处理
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抗菌素耐药性
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宏基因组学
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Xiaoluan Lu,Xiaoqian Ma,Zhen Qin,Xinfei Chen,Limei Chen,Yunlong Tian
An efficient method of synergetic dechlorination and reduction of heavy metals risk is crucial for the clean resource utilization of sewage sludge (SS) and polyvinyl chloride (PVC). In this work, SS was upgraded to hydrochar using co-hydrothermal carbonization (HTC) with PVC at different mixing ratio (30─70%) at 230 °C. Transformation behaviors of chlorine and heavy metals in hydrochars, along with fuel properties, were evaluated. The results illustrated that Mn and Zn could be effectively removed during co-HTC and low ratio addition of PVC was beneficial for reducing the toxicity of Ni and As. Meanwhile, compared with the HTC of single PVC, co-HTC with SS could further improve the dechlorination efficiency (69.49─81.35%). Particularly, the blending ratio of SS to PVC at 7:3 showed high fuel ratio and HHV (13.58 MJ/kg) with desirable combustion performance. These findings offered a potential approach to convert SS and PVC into clean solid fuel.
研究领域:
环境科学
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能源工程
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Chenyu Wang,Biao Gui,Chaoyue Wu,Chao He,Lucheng Li,Xiaolong Ling,Xiaojun Zuo
Hydrothermal carbonization (HTC) is a promising technology for sewage sludge (SSL) utilization. However, the yield and performance of hydrochar need to be further improved produced when SSL is used as a feedstock must be improved further. Herein, a process combining physicochemical pretreatment , namely, Fenton oxidation (FO) and HTC was developed for SSL utilization. Moderate oxidation was found to improve the yield and performance of the produced hydrochar. The product distribution, yield, and properties of the hydrochar produced using the proposed combined process were compared with those of the hydrochar produced via direct HTC treatment. The pretreatment affected the surface structure and organic composition of SSL and promoted the carbonization of the intermediate products. Thus, compared with the yield of hydrochar (50.7 %) obtained via the direct HTC treatment, the yield of the hydrochar obtained using the combined process increased to 55.0–65.2 % (depending on the pretreatment condition). Hydrochar properties were enhanced using the combined process, and the energy density of hydrochar slightly decreased after pretreatment (1.2–13.1 %); however, the energy yields increased by 0.6–30.1 % due to the enhanced hydrochar yield. The carbonization degree of hydrochar improved, the carbon in the feedstock distributed to the hydrochar increased from 33.40 % to 46.09 %. Moreover, the hydrochar showed more distinct pore channels, slightly improving its combustion activity. This study shows the efficacy of the combined pretreatment–HTC process and provides an experimental basis for the combined hydrothermal treatment of SSL.
研究领域:
环境科学
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能源工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2026
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IF 12.5
Jiangtao Meng,Tao Wang,Lei Ren,Jing Wang,Yuanyuan Zhang,Jingkuan Li,Fei Wang
Stage-matched framework reveals fuel-N pathway shifts. • Microwave shifts NH 3 and HCN release to lower temperature regions. • Microwave enriches amines and nitrile precursors in tar at lower temperatures. • Microwave promotes early char deoxygenation and condensation. • Polar O/N activation couples char-N reconstruction with tar-N evolution. Microwave-assisted pyrolysis shows promise for the clean conversion of N-rich biomass, yet its mechanism for regulating nitrogen migration remains unclear. Deashed sewage sludge and protein-derived amino acid models were employed to contrast microwave and conventional pyrolysis. This comparison utilized a reaction-stage-referenced framework based on the characteristic release regions of N-containing gases. Microwave heating did not change the basic nitrogen release pattern, with NH 3 as the dominant product and HCN as the secondary product, but substantially altered the temperature-dependent progression of the fuel-N conversion pathway. Under the present microwave experimental configuration, substantial fuel-N conversion was observed within the measured 190–300 °C range, occurring at lower measured temperatures than under conventional pyrolysis and accompanied by marked changes in O/N-containing structures. Amine intermediates were enriched in tar, and the tar-N fraction increased from about 44% to 87%, driving NH 3 release to lower temperatures. At 300–500 °C, these intermediates further underwent dehydrogenation, cyclization, and nitrilation under microwave effects, forming nitriles and low-carbon mono‑nitrogen compounds and enhancing HCN release around 300 °C. As a result, the characteristic NH 3 and HCN release regions were recorded at lower measured temperatures in the microwave system than in the conventional system. Meanwhile, microwave heating promoted early char deoxygenation and condensation, as reflected by protein-N conversion to pyrrolic-N, pyridinic-N, and nitrile-N, removal of C O and O-C=O groups, reduced interlayer spacing, and enhanced microcrystalline stacking. Tar evolved from heterocyclic and long-chain N-containing compounds toward light aromatics, oxygenated species, and low-carbon nitriles. A three-phase network is proposed wherein tar acts as an intermediate pool connecting char-N reconstruction with NH 3 /HCN release. This study provides mechanistic insights into fuel-N migration during microwave and conventional pyrolysis of N-rich sewage sludge. Download: Download high-res image (180KB) Download: Download full-size image
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DOI
高影响因子
CHEMOSPHERE
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2024
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IF 8.1
Shaoya Li,Yanmei Zhou,Jin Wang,Mengmeng Dou,Qingyun Zhang,Kaili Huo,Chao Han,Jinyang Shi
The disposal and resource utilization of sewage sludge (SS) have always been significant challenges for environmental protection. This study employed straightforward pyrolysis to prepare iron-containing sludge biochar (SBC) used as a catalyst and to recover bio-oil used as fuel energy. The results indicated that SBC-700 could effectively activate persulfate (PS) to remove 97.2% of 2,4-dichlorophenol (2,4-DCP) within 60 min. Benefiting from the appropriate iron content, oxygen-containing functional groups and defective structures provide abundant active sites. Meanwhile, SBC-700 exhibits good stability and reusability in cyclic tests and can be easily recovered by magnetic separation. The role of non-radicals is emphasized in the SBC-700/PS system, and in particular, single linear oxygen ( 1 O 2 ) is proposed to be the dominant reactive oxygen. The bio-oil, a byproduct of pyrolysis, exhibits a higher heating value (HHV) of about 30 MJ/kg, with H/C and O/C ratios comparable to those of biodiesel. The energy recovery rate of the SS pyrolysis system was calculated at 80.5% with a lower input cost. In conclusion, this investigation offers a low-energy consumption and sustainable strategy for the resource utilization of SS while simultaneously degrading contaminants.
研究领域:
环境科学
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能源技术
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催化材料
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Xiaopeng Wang,Lin Gu,Pin Zhou,Nanwen Zhu,Chengxu Li,Hong Tao,Haifeng Wen,Daofang Zhang
The evolution of oxygen-functioning groups in sewage sludge based carbon is influenced by minerals presented in the raw sludge. In this study, the FeCl 3 and polyacrylamide conditioned sludge in real wastewater treatment plant and demineralized sludge were carbonized in the temperature range of 300 °C–800 °C to investigate the roles of temperature and ash components on the interactions between surface groups conversion and crystalline structure evolution. The temperature-dependent ash effect on the conversion of oxygen containing groups was found by using XPS, Boehm titration, XRD and TPR characterization. The phase transfer of hematite to magnetite promoted the formation of hydrophilic organic groups at 600 °C, which may play a significant role on carbon’s adsorptive and catalytic behavior. To gain an in-depth knowledge and understanding, the as-prepared carbon was used as heterogeneous catalyst in persulfate degradation of a model pollutant 2-Naphthol. The use of carbon obtained at 600 °C (MC600) can achieve 88.7% and 47% of 2-Naphthol and TOC removal respectively at neutral pH, far higher than that of MC prepared at 300 and 800 °C. Further research revealed a strong correlation between adsorptive and catalytic efficiency of MC and its mineral structure, surface functional groups as well as operating pH. The formed hydrophilic oxygen-containing groups at higher temperature of MC600 are responsible for 2-Naphthol retention and the hydrogen bonds in siloxane bridges can easily adsorb persulfate. The pH effect on degradation in the presence of persulfate verified the broad pH operation, which is apparently superior than conducting with traditional heterogeneous Fenton process. The quenching experiments and EPR spectrum were further used to detect the oxidative species SO 4 - and HO , and confirmed the catalytic role of MC.
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DOI
高影响因子
WASTE MANAGEMENT
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2021
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IF 7.145
Chenyu Wang,Wei Zhu,Xihui Fan
Supercritical water gasification (SCWG) is considered a promising technology for sewage sludge (SS) treatment and utilization; however, char produced by a side reaction has become a bottleneck in SCWG. In this study, SS and its model compound (10% humic acid) were treated in an autoclave by SCWG at 400 °C for 30 min and by hydrothermal carbonization (HTC) at 250 °C for 300 min. The char yield was 15.4% in SCWG and 41.3% in HTC. The chars were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller (BET) analysis, and elemental analysis. By comparing the properties the char produced by SCWG and the hydrochar produced by HTC, which has been considered a valuable product, the feasibility of using char as an additional product in SCWG was explored. Compared with the char produced by HTC, the char generated in SCWG exhibits a lower BET specific surface area (8.257 and 15.782 m 2 /g) and combustion activity, a higher proportion of small pores (with pore sizes of 1–2 nm), and greater thermal stability. The formation pathway of the two types of chars is related to both dehydration and aromatization; decarboxylation also occurs in char formation during SCWG. Humus was proved to be related to char formation during the SCWG of SS based on experimental results obtained with the model compound. This work provides insights needed to guide follow-up treatments or utilization of the char produced during the SCWG of SS.
研究领域:
环境科学
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能源技术
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DOI
PubMed
高影响因子
CHEMOSPHERE
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2019
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IF 5.108
Hua Wei,Yunong Tang,Tamer Shoeib,Aimin Li,Hu Yang
The preoxidation effects of H 2 O 2 , NaClO, and KMnO 4 on the dewaterability of sewage sludge were compared by analyzing the changes in specific resistance to filtration (SRF), filter cake moisture content (FCMC), extracellular polymeric substance (EPS) fractions and components, and floc properties. The three oxidants varied in oxidation efficiency and exhibited distinctive mechanisms. NaClO not only destroyed sludge flocs and EPSs but also effectively caused cell lysis, resulting in release of a considerable amount of organic matters and subsequently significant deterioration of dewatering performance. The oxidation of H 2 O 2 and KMnO 4 was relatively mild and occurred mainly on the outer layers of the sludge flocs and cell-bound EPSs. By contrast, the SRF and FCMC of the sludge conditioned with a low dose of KMnO 4 were slightly improved, and a fraction of soluble EPS was compressed because of the coagulation effect of the oxidation product MnO 2 . The pH of the sludge conditioned with H 2 O 2 and KMnO 4 showed no considerable change. Meanwhile, NaClO evidently increased the alkalinity of the sludge because of the hydrolysis effect. After the pH of the NaClO-treated sludge was readjusted to 7.0, the partial protonation efficiency slightly alleviated the deterioration of sludge dewatering performance. The preoxidized sludge was then subjected to reflocculation treatment using FeCl 3 , polyacrylamide, and a cationic starch-based flocculant , respectively. The combined treatment of preoxidation and reflocculation showed a high dewatering efficiency owing to their synergistic effect.
研究领域:
环境工程
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水处理
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化学工程
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）