Water
·
2024
·Vol. 16
·期 22
·3235
·
IF 3
Qiao Xu,Fenfen Yan,Yujie Fan,Miao Gong
This work evaluated the alterations in the levels and types of polycyclic aromatic hydrocarbons (PAHs) within both liquid and solid products throughout the process of the catalytic supercritical water gasification of dewatered sewage sludge to examine the catalytic effect of various catalysts and the inhibit reaction pathways. The addition of Ni, NaOH, Na2CO3, H2O2, and KMnO4reduced the concentrations of PAHs, with Ni and H2O2showing the best performance. The concentrations of PAHs, especially higher-molecular-weight compounds in the residues, decreased sharply as the H2O2amount increased. At a 10 wt% H2O2addition, the levels of PAHs in the liquid and solid products were reduced by 91% and 88%, respectively. High-ring PAHs were not detected in the residues as the H2O2amount increased to an 8 wt%. H2O2addition evidently inhibits PAH formation by promoting the ring-opening reactions of initial aromatic compounds in raw sludge and inhibiting the polymerization of open-chain intermediate products. The addition of NaOH + H2O2or Ni + H2O2as combined catalysts significantly lowered PAH concentrations while increasing the H2yield. The addition of 5 wt% Ni + H2O2reduced PAH concentrations in the liquid and solid residues by 70% and 44%, respectively, while the H2yield escalated from 0.13 mol/kg OM to 3.88 mol/kg OM. Possible mechanisms associated with the reaction pathways of these combined catalysts are proposed.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 33
·期 1
·235-245
·
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
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产品关联
DOI
高影响因子
Engineering
·
2025
·
IF 11.6
Gaojun Wang,Zhaofu Liu,Bo Zhang,Lingwei Wang,Qian Li,Rong Chen
To advance sewage sludge (SS) valorization, this study proposed a novel approach that integrated protein recovery from SS with its conversion into a fully bio-based adhesive for plywood production. A thermal-alkaline pretreatment (pH = 12, 90 ℃) followed by acidic precipitation enabled efficient recovery of sewage sludge protein (SSP). Compared to the commonly used sulfuric acid, citric acid partially co-precipitated with SSP, potentially promoting amidation reactions between amino and carboxyl groups during the curing process. This interaction contributed to the enhanced adhesive strength of SSP. Inspired by the catechol-mediated adhesion mechanism of mussel foot proteins, tannic acid (Tan) and Zn 2+ ions were incorporated into the alkali-modified SSP. Covalent and hydrogen bonding occurred through cross-linking between the polyphenolic moieties of Tan and the amide/carbonyl groups of SSP, while Zn 2+ ions served as coordination centers, further strengthening interfacial cohesion. These procedures reassembled the fragmented peptide chains of SSP, resulting in enhanced hydrophobicity, thermal stability, and mold resistance. Under optimized curing conditions (140 ℃, 8 min), the resulting adhesive achieved a wet shear strength of (1.09 ± 0.08) MPa, surpassing the Chinese National Standard (≥ 0.7 MPa) by 55.7%. X-ray micro-computed tomography revealed that 24.1% of the adhesive penetrated the wood micropores during curing, with mechanical interlocking complementing bulk adhesion to improve shear performance. Heat-induced structural reorganization further promoted β-sheet formation and esterification between SSP peptides and Tan, thereby reinforcing the adhesive’s cross-linked architecture. Finally, a preliminary assessment of the process’s economic viability and carbon neutrality potential highlighted its promise for sustainable, engineering-scale implementation.
研究领域:
环境工程
·
生物聚合物科学
·
胶粘剂技术
·
木材科学
·
可持续材料
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产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jun Zhang,Yulan Lu,Qinying Yan,Hongtao Liu,Beidou Xi,Dunqiu Wang
The biodegradation mechanism of fluoroquinolones (FQs) during composting is the key information to accurately assess and effectively control the environmental risk caused by FQs in sewage sludge. This study investigated the biodegradation of two FQs (norfloxacin [NOR] and ofloxacin [OFL]) using a series of sludge composts over a 56-d incubation period. Sludge composts were collected at the mesophilic, thermophilic, and curing phases from the matrix of a pilot-scale sewage sludge composter; spiked with NOR and OFL (each 5 mg/kg); and incubated at 35 (mesophilic), 55 (thermophilic), and 40°C (curing). Compost samples were evaluated by determining FQ concentration, intermediate metabolites, enzymatic activity (laccase, manganese peroxidase, and lignin peroxidase), and bacterial and fungal communities. Results showed that NOR was likely to be predominantly biodegraded via the acetylation route and the routes for OFL in each phase varied, while the main metabolites from both NOR and OFL retained the FQ core structure related to the antibacterial activity. Only manganese peroxidase had a significant correlation with FQ residue during the mesophilic phase. Proteobacteria and Ascomycota were the dominant bacterial and fungal phyla in the incubated sludge compost, respectively, and Pseudomonas was the most involved bacterial genus for FQ bio-degradation in the sludge composts with Exophiala, Dissoconium, Talaromyces as the fungal genera.
研究领域:
环境科学
·
微生物生态学
·
生物降解
·
废物管理
·
抗生素污染
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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
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Yidi Wang,Wei Li,Yongkang Wang,Yusan Turap,Zhentong Wang,Zhe Zhang,Zhou Xia,Wei Wang
The effect of pretreatment technologies and reactor types on conversion efficiency and operating costs of anaerobic co-digestion of food waste and sewage sludge were investigated by 300-day continuous experiments. The volatile solids (VS) removal efficiency increased from 61% to 77% with the application of co-hydrothermal pretreatment of sewage sludge and biogas residue. Deep dewatering reduced the volume of hydrothermally pretreated biogas residue by 85%. When continuous stirred tank reactors (CSTRs) were converted to anaerobic sequencing batch reactors (ASBRs), vS removal efficiencies increased by 6%, attributed to a 1.4–1.6-fold increase in solids retention time (SRT). The bottom drainage of mineralized sludge every 40 days increased ASBR stability. Firmicutes and Methanosphaera dominated the bacterial and archaeal communities, respectively. Operating costs decreased by 14.9 US$/metric ton feedstock by applying ASBRs. Compared to CSTRs, ASBRs achieved higher organic matter conversion efficiency, smaller volume of biogas residue, and lower operating costs.
研究领域:
环境工程
·
废物管理
·
生物技术
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DOI
PubMed
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2018
·Vol. 77
·期 5
·1410-1417
·
IF 1.247
Xu Jinglu,Yu Yang,Ding Kang,Liu Zhiying,Wang Lei,Xu Yanhua
This study converted sewage sludge into a carbonaceous catalyst via pyrolysis and employed it in the ozonation of hydroquinone. The catalyst was characterized by Mössbauer spectroscopy, X-ray photoelectron spectroscopy, temperature programmed desorption, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Intermediate products were detected by gas chromatography–mass spectrometry, and a pathway for hydroquinone degradation was proposed. The results showed that sludge pyrolyzed at 700 °C promoted hydroquinone degradation, compared with commercial activated carbon derived from coal. When the catalyst dose was 0.5 g/L, the hydroquinone (200 mg/L) removal rate reached 97.86% after exposure to ozone (the ozone concentration was 17 mg/L and the flow rate was 50 mL/min) for 60 min. The results indicated that basic groups contributed to the catalysis.
研究领域:
环境科学
·
催化
·
水处理
·
高级氧化技术
·
废物资源化
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DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2014
·
IF 3.828
Huan Liu,Qiang Zhang,Hongyun Hu,Peng Liu,Xiaowei Hu,Aijun Li,Hong Yao
Thermal disposal of sewage sludge is likely to cause serious nitrogen related environmental pollution since it contains considerable amounts of nitrogen, the species of which are quite different from those in coal. Considering that lime (CaO) is a widely applied chemical conditioner for sewage sludge dewatering, this study investigated the catalytic role of conditioner CaO in nitrogen transformation during sewage sludge pyrolysis in a drop-tube/fixed-bed furnace at 873 K, 1073 K and 1273 K, respectively. Model compounds were also used to further clarify the mechanisms involved. According to the results, conditioner CaO increased the fraction of more stable protein-N as well as amine-N. The solid phase reactions produced CaC x N y , thus enhancing the nitrogen retention in char. Correspondingly, decreased relative ratio of nitrates-N/nitrites-N and oxygenated organics in sludge conditioning contributed to less NO emission. Meanwhile, conditioner CaO promoted the conversion of HCN to NH 3 , as well as the deamination of proteins, amine, and other N-containing compounds in tar and char, leading to increased NH 3 generation. Subsequently, CaC x , the decomposition product of CaC x N y , captured NH 3 , driving down the final production of NH 3 . In addition, Ca(OH) 2 hindered the transformation of nitrile-N in char to HCN, decreasing HCN generation. CaO reacted with HCN, further reducing its releasing amount. CaC x N y derived from different sources decomposed to produce a very large amount of N 2 . These indicate that reusing conditioner CaO is a promising strategy for reducing the productions of NO x precursors efficiently and increasing the formation of non-polluting N 2 dramatically.
研究领域:
环境科学
·
能源与燃料
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Pengyu Xiao,Xianliang Yi,Minghuo Wu,Xue Wang,Simeng Zhu,Bixia Gao,Yang Liu,Hao Zhou
Periodate (PI)-based advanced oxidation processes are a newly discovered approach for effective pollutant elimination . In this study, we demonstrated that biochar obtained from pyrolysis of anaerobic sewage sludge without any pretreatment can be used for PI activation. The biochar obtained at 800 °C (SBC-800) exhibited the best PI activation capacity using acid organic II (AO7) as substrate. The PI activation was strongly dependent on pH and exhibited the highest AO7 removal rate at pH 3.0. Meanwhile, the anti-interference capacity with common wastewater components and reusability of the SBC-800/PI system were confirmed. Combined with the results of chemical quenching, reactive oxygen species (ROS) trapping, X-ray photoelectric spectroscopy (XPS), electrochemical and density function theory (DFT)-based calculations, singlet oxygen production and electron transfer mediated by the SBC-800-PI complex were the dominant AO7 oxidation mechanisms . This study provides easily prepared catalysts for PI activation and paves the way for solid waste recycling and reuse.
研究领域:
环境科学
·
化学工程
·
废物管理
·
水处理
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DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2026
·
IF 6.7
Jiayuan Bao,Bibo Huang,Rui Zhang,Zehua Zhao,Chenyu Wang
Ten-cycle aqueous-phase recirculation induced stage-specific product responses. • Secondary-char yield increased from 12.70% to 15.93% after recirculation. • Oil-phase yield rose from 28.52% to 60.40% with compositional restructuring. • Recirculation increased hydrochar peak combustion temperature to about 393 °C. • Process-water reuse created trade-offs between fuel and adsorption performance. Hydrothermal carbonization generates an organic-rich aqueous phase (AP) whose recirculation can modify the reaction medium and subsequent product formation. However, how aqueous phase recirculation (APR) coordinates product formation remains unclear. This study conducted ten-cycle APR during HTC to evaluate product yields, carbon partitioning, hydrochar characteristics and oil phase composition. Hydrochar yield increased from 57.86% to 60.54% after the first recirculation, whereas secondary char yield increased from 12.70% to 15.93%. The oil phase yield rose from 28.52% to 60.40%, accompanied by marked compositional redistribution. The relative abundances of fatty acids and hydrocarbons decreased from 18.20% to 0.35% and from 11.99% to 0.90–1.86%, respectively, while nitrogen-containing heterocycles and higher-molecular-weight compounds became enriched. Despite limited changes in bulk elemental composition, hydrochar underwent surface deoxygenation and carbon-skeleton reconstruction, increasing its peak combustion temperature from approximately 314 °C to 393 °C. Its adsorption applicability nevertheless declined with further recirculation, and the hydrochar obtained after the first recirculation provided the best balance between fuel and adsorption performance. The oil phase shifted from acids and hydrocarbons towards nitrogen-containing heterocycles and higher molecular weight compounds. Multivariate analyses further associated oil-phase compositional complexity with hydrochar structural stabilization and functional differentiation. These responses were stage specific rather than uniformly cumulative, indicating that evolving AP composition selectively regulated intermediate transformation and cross-phase carbon partitioning during each HTC run. APR therefore acts as an in-process reaction regulator that can couple process water reuse with product oriented resource recovery, although additional cycles did not consistently improve hydrochar performance. Download: Download high-res image (196KB) Download: Download full-size image
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DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 4
·2033-2037
·
IF 3.108
Xiaohu Dai,Ying Xu,Yiqing Lu,Bin Dong
One of the key factors hindering the application of anaerobic sludge digestion is the lower biogas production (BP). In this paper, the main constituents of sewage sludge (SS) and model sludge (MS) were reconsidered and a biochemical methane potential assay of sludge was conducted with the effect of different key chemical constituents. It was found that the humic matter, metal ions (such as Fe, Ca, and Al), silts were the main differences of constituents between SS and MS, and the interactions between them and easily biodegradable organic matter (EBOM) were the main factors for limiting the BP. Further research indicates that the apparent activated energy of sludge organic solubilisation could be used to suggest the strength of the interactions between non-biodegradable matter and EBOM, and the biodegradability of the EBOM in sludge particulate can be indicated by surface site density. This study can provide a new path for enhancing the BP per unit of organic matter and enlighten environmental scientists to develop more effective methods for improving the anaerobic sludge digestion.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Yu-jie Wang,Yi Yu,Hua-jun Huang,Cheng-long Yu,Han-sun Fang,Chun-huo Zhou,Xin Yin,Wei-hua Chen,Xin-chun Guo
The treatment of sewage sludge (SS) is an environmental problem worldwide. In recent years, hydrothermal carbonization (HTC) of SS for hydrochar (HC) has attracted extensive attention. This study preliminarily explored the microwave-assisted HTC of SS for the first time. Increasing the reaction temperature (150–250 °C) and reaction time (0–120 min) resulted in a decrease in the HC yield, and it gradually increased with the rising solid–liquid ratio (0.03–0.25 g/mL). Compared with raw SS, the HC products possessed higher aromaticity, carbonization degree, porosity, and polarity, and lower content of soluble nutrients (N/P/K) and leachable heavy metals (Cu, Zn, Pb, Cd, Cr, and Ni), indicating a lower risk of nutrient and heavy metal loss. Attention should be paid to the total contents of Zn and Cd in HC exceeded the permitted value for use in cultivated land with edible crops. The use of CaO as a catalyst improved the yield of HC, made the HC and process water (PW) weakly alkaline, and further passivated the heavy metals in the HC. In the case of H 3 PO 4 , although the conversion of SS was enhanced (lower content of volatile organic matter in HC), the contents of soluble nutrients (N/P/K) in HC/PW increased, and the migration of Zn and Cd into process water was enhanced. The HCs obtained in this study had poor combustion properties, but higher ignition temperatures than raw SS. PW must be properly treated or recycled because it still contained high contents of organic matter and nutrients. This fundamental study provides basic insights into the microwave-assisted HTC of SS.
研究领域:
环境科学
·
能源工程
✓ 已验证
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）