CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Nanhang Dong,Ruiqiang Huo,Ming Liu,Lisheng Deng,Zhengbing Deng,Guozhang Chang,Zhen Huang,Hongyu Huang
Chemical looping gasification (CLG) provides a novel approach to dispose the sewage sludge. In order to improve the reactivity of the calcined copper slag , NiO modification is considered as one of the good solutions. The copper slag calcined at 1100 °C doped with 20 wt% NiO (Ni20-CS) was used as an oxygen carrier (OC) in sludge CLG in the work. The modification of NiO can evidently enhance the reactivity of copper slag to promote the sludge conversion, especially for sludge char conversion. The carbon conversion and valid gas yield ( V g ) increase from 67.02% and 0.23 m 3 ·kg −1 using the original OC to 78.34% and 0.29 m 3 ·kg −1 using the Ni20-CS OC, respectively. The increase of equivalent coefficient ( Ω ) facilitates the sludge conversion and a suitable Ω value is determined at 0.47 to obtain the highest valid gas yield (0.29 m 3 ·kg −1 ). A suitable steam content is assigned at 27.22% to obtain the maximum carbon conversion of 87.09%, where an acceptable LHV of 12.63 MJ·m −3 and V g of 0.39 m 3 ·kg −1 are obtained. Although the reactivity of Ni20-CS OC gradually decreases with the increase in cycle numbers because of the generation of NiFe 2 O 4- δ species, the deposition of sludge ash containing many metallic elements is beneficial to the sludge conversion. As a result, the carbon conversion shows a slight uptrend with the increase of cycle numbers in sludge CLG. It indicates that the Ni20-CS sample is a good OC for sludge CLG.
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Lan Liang,Guanyi Chen,Ning Li,Hengxin Liu,Beibei Yan,Yanshan Wang,Xiaoguang Duan,Li'an Hou,Shaobin Wang
Active sites on catalyst surface play significant roles in oxidative species formation. The work focused on the regulation of main active sites on catalyst surface and oxidative species formation. Herein, sewage sludge (SS)-red mud (RM) complex biochar (SRCB) and N -functionalized SRCB (NSRCB) were served as activators of peroxymonosulfate (PMS) for sulfanilamide (SMX) degradation. Specially, NSRCB-1 showed excellent catalytic performance with 97.5% removal of SMX within 110 min. Additionally, the effects of N incorporation on the reconstruction of N species, conversion of intrinsic Fe species and ketonic C O groups in SRCB were studied systematically. Both radical (hydroxyl radicals ( OH), sulfate radicals (SO 4 − ) and superoxide radical (O 2 − )) and non-radical (electron transfer and singlet oxygen ( 1 O 2 )) pathways were confirmed by quenching experiments, electron paramagnetic resonance (EPR) testing and electrochemical measurements. Ketonic C O groups, pyridinic N and pyrrolic N were responsible for non-radical pathway in SMX degradation process. Besides, Fe(II) modulated by N -doping was the main actives site for radicals generation. The contribution of active sites on catalyst surface to oxidative species formation provided fundamental basis for practical water treatment in PMS process.
研究领域:
环境科学
·
催化化学
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DOI
PubMed
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 3.9
Balaji Panchal,Jinxi Wang,Yuzhuang Sun,Kai Bian,Cunliang Zhao,Qiaojing Zhao,Bangjun Liu
Lipase from Burkholderia species immobilized onto novel mesoporous polymeric ionic liquids (MO(Poly)C n –BLE) could be utilized as a low–cost biocatalyst for the lipase-catalyzed synthesis of free fatty acid esters from dried municipal sewage sludge. To assess this, this investigation has focused on three main parts of this process: (i) the development of a series of large surface polymer synthesis; (ii) mesoporous polymeric biocatalyst preparation using lipase from Burkholderia sp. immobilization onto MO(Poly)C n , and supports for this alongside Mesoporous polymer ionic liquid–1–bromooctane–lipase from Burkholderia sp. enzyme (MO(Poly)C 18 –BLE) were characterized using FT-IR, SEM, XPS , N 2 , and TGA ; (iii) Response surface methodology was used to determine the optimal conditions for ester production from municipal sewage sludge lipids using a central composite design. Four process variables were assessed at three levels; a total of 13 experiments were performed to study the effects of the lipids: ethanol molar ratio, catalyst concentration, reaction time, and temperature on the ester’s yield. A 91.25% ester yield was obtained under optimal conditions: a 1:12 molar ratio of municipal sewage sludge lipid to ethanol, 225 wt% MO(Poly)C 18 –BLE, 5 h reaction time, 45 ℃ reaction temperature, and a constant 150 rpm agitation. This novel biocatalyst synthesis method and ester production process from municipal sewage sludge lipids may provide ecological and economic support for industrial biodiesel production in the future.
研究领域:
生物化学
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环境科学
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工业生物技术
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DOI
高影响因子
WASTE MANAGEMENT
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2019
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IF 5.431
Xiangdong Meng,Xiaoji Liu,Qunxing Huang,Huaping Gao,Kangrou Tay,Jianhua Yan
As a phosphorus-rich material, low-temperature combustion sewage sludge ash (LTCA) contains over 9 wt% content of phosphorus (P) and a large proportion of impurities, especially the content of Fe arrives at 14.59 wt%. To fully utilize LTCA as a fertilizer, this study investigated a procedure for P recovery from LTCA via struvite crystallization with fewer impurities. The adsorption characteristics of P and Fe by cation exchange resin (CER) were explored by simulating using the macroscopic parametric equation Thomas model. Optimum purification conditions for P-rich leachate by cation exchange column method were determined. Results showed that approximately 97.21 wt% of P was extracted from LTCA at HCl concentration of 0.8 M and liquid/solid ratio of 20.0 ml/g. More than 90 wt% of impurities could be detached by making P-rich leachate flow through cation exchange bed filled by CER at 300 ml/h. The macroscopic parametric equation Thomas model could clearly describe the adsorption characteristics of Fe in P-rich leachate by CER. Theoretical basis for purification of high concentration Fe in P-rich leachate by CER was provided. Approximately 84.04 wt% of total P in LTCA was recovered as struvite crystal which had low concentrations of heavy metals (5.96 mg/kg for Cr, 45.21 mg/kg for Cu, 29.67 mg/kg for Ni, 2.24 mg/kg for Pb, and 290.6 mg/kg for Zn) and could be eco-friendly for agricultural application. X-ray diffraction and SEM-EDS analysis validated the formation of struvite.
研究领域:
环境科学
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农业科学
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化学工程
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DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2022
·
IF 7.968
Shuai Guo,Lidong Liu,Xin Guo,Tiecheng Liu,Xingcan Li,Guangyu Li
Municipal sewage sludge poses environmental and health risks, and thus, requires proper disposal using pyrolytic techniques. However, these techniques are hindered by the production of NH 3 and HCN (NO x precursors) by the sludge. Hence, a comprehensive understanding of NH 3 and HCN formation during sludge pyrolysis is required to minimize its NO x footprint. As sludge N mainly occurs in proteins forms, its transformations can be modeled using amino acids. Here, we aimed to the study the mechanism by which carbohydrates influence the formation of NO x precursors during sludge protein pyrolysis at different temperatures using glutamic acid , tyrosine, and histidine as protein models and cellulose and lignin as carbohydrate models. During pyrolysis, the release of NH 3 and HCN was promoted by high temperatures and inhibited by carbohydrates. Despite this inhibitory effect, the results suggested that the release of NH 3 should be considered for samples rich in aliphatic amino acids. For glutamic acid and tyrosine, NO x precursor formation was inhibited by N fixation in coke under the action of volatiles produced during carbohydrate pyrolysis. For glutamic acid, adding cellulose and lignin increased the coke-N content by 25.32% and 44.73% at 700 ℃. For histidine, this effect was ascribed to the ring-opening reactions induced by the free radical products of carbohydrate decomposition and the enhanced transfer of N-containing compounds to tar after ring-opening recombination. Further, heterocyclic-N within tar increased to 69.12% due to lignin-histidine interactions at 700 ℃. The results of this study can assist in regulating sludge protein pyrolysis intended for minimizing the production of NO x precursors.
研究领域:
环境科学
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化学工程
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废物管理
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产品关联
DOI
高影响因子
Journal of Cleaner Production
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2022
·
IF 11.072
Yongkui Yang,Xiao Luo,Jie Zhang,Xiaoke Ma,Peizhe Sun,Lin Zhao
The effects of co-pyrolyzed sewage sludge–coconut fiber biochar on heavy metal stabilization and antibiotic adsorption capacity have not yet been thoroughly investigated. The present study found that Zn and Cd levels were remarkably reduced in the acid-soluble and reducible fractions in sludge after co-pyrolysis with coconut fiber , whereas their levels increased significantly in the residual fraction, thereby reducing the ecological risk of biochar. Kinetics and Freundlich models of the adsorption of ciprofloxacin (CIP) onto biochar indicated chemisorption and multilayer processes. Negative enthalpy (ΔH 0 ) and Gibbs free energy (ΔG 0 ) values indicated that CIP adsorption was an exothermic and spontaneous reaction. The synergistic mechanisms of heavy metal stabilization and CIP adsorption of this biochar are caused by the formation of crystal structures, complexation of functional groups, electrostatic interactions, and pore filling. The sewage sludge–coconut fiber biochar reduces the risk posed by heavy metals and has demonstrated a higher capacity for adsorbing CIP from water.
研究领域:
环境科学
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土壤修复
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污染控制
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产品关联
DOI
高影响因子
Environmental Science-Water Research & Technology
·
2021
·Vol. 7
·期 9
·1563-1575
·
IF 4.251
Xuan-Yuan Pei,Hong-Yu Ren,De-Feng Xing,Guo-Jun Xie,Guang-Li Cao,Jia Meng,Nan-Qi Ren,Bing-Feng Liu
There is an urgent need for the development of efficient and economical persulfate activators in persulfate-based advanced oxidation processes for wastewater treatment. Accordingly, in this work, sewage sludge from a wastewater treatment plant was carbonized at different pyrolysis temperatures in the range of 400–800 °C via a one-pot synthesis method, which was used to activate peroxydisulfate (PDS) for the degradation of sulfamethoxazole (SMX). Among the samples, biochar pyrolyzed at 800 °C (BC800) showed the best catalytic performance for the removal of SMX (85.3% in 60 min reaction). In the initial pH range of 5.0–11.0, PDS could be activated (0.75 g L−1) efficiently by BC800 for the degradation of SMX. Combined with electron paramagnetic resonance (EPR) spectroscopy, quenching experiment, steady-state kinetics experiment and electrochemical results, the degradation of SMX in the BC800/PDS system was proposed to be a degradation mechanism involving electron transfer as the main pathway. Through the analysis of the intermediates, the possible SMX degradation pathways were predicted. This study provides new insights into the mechanism for the sewage sludge-derived biochar activation of peroxydisulfate and its potential applications for the treatment of SMX wastewater.
研究领域:
环境科学
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化学工程
·
废水处理
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产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2023
·
IF 6
Yuting Wu,Yadong Wang,Peiao Chen,Yang Yang,Ziyue Tang,Yingquan Chen,Haigping Yang,Hanping Chen
In order to reduce nitrogen emissions during municipal sewage sludge (MSS) pyrolysis, the effects of co-pyrolysis of MSS with biomass and the second adsorption of KH 2 PO 4 -modified biochar were investigated. It was found that co-pyrolysis with cellulose inhibited the conversion of nitrogen into pyrolytic gas, and increased the N content in pyrolytic biochar. And the nitrogen fixation rate increased with cellulose addition increasing. Besides, compared with different biomass, MSS co-pyrolysis with 30% sugarcane bagasse had the optimal effect on nitrogen fixation (39%). Moreover, KH 2 PO 4 -modified biochar addition increased the second adsorption of nitrogenous volatiles and fixed nitrogen into oxides-N. The total nitrogen fixation rate reached maximum (47.65%) at 5% KH 2 PO 4 impregnation. Thus, it is an effective nitrogen fixation method that MSS co-pyrolysis of 30% sugarcane bagasse with the second absorption of 5% KH 2 PO 4 -modified biochar. This study provided an effective solution to improve the treatment of municipal sewage sludge by pyrolysis technology.
研究领域:
环境科学
·
能源与资源工程
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产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Lu Xiaoluan,Ma Xiaoqian
The reduction of heavy metal (HM) risk while realizing energy utilization of sewage sludge (SS) remains an important challenge for SS treatment. The effects of pretreatment and additives (citric acid (CA), ferric chloride (FC), and fulvic acid (FA)) were explored based on co-hydrothermal carbonization (co-HTC) of SS and bamboo (BO). The results showed that the use of FC and FA pretreatment was beneficial in reducing the potential ecological risk of HMs and total concentration of Cu, Cr, and Ni. However, in terms of fuel properties, compared to pretreatment, additives were more beneficial in improving the fuel ratio and the high heating value (HHV). Specifically, among all samples, the maximum values of fuel ratio (0.49), HHV (12.85 MJ/kg), and combustibility index (8.00) were all achieved by employing different additives. It was worth noting that FC could not only improve fuel ratio but also obtain a low risk index (14.38) when used as an additive. Therefore, although pretreatment was more efficient in reducing the risk of HMs, additives could improve the fuel properties while alleviating the HMs risks to a certain extent. These findings contributed to the optimization of the HTC process of SS.
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Ying Li,Zhiquan Yang,Hongguo Zhang,Xiaowen Tong,Jinna Feng
An increasing amount of sewage sludge is produced by wastewater treatment plants worldwide. Therefore, the disposal of sewage sludge is one of the vital environmental issues currently. In the present work, we developed an alternative strategy of converting sewage sludge into porous activated carbon (SAC), and then synthesized a magnetically separable MnFe 2 O 4 -SAC heterogeneous catalyst through an environmentally friendly method. Several characterization techniques such as XRD, FTIR, SEM and XPS indicated the evidence of MnFe 2 O 4 nanoparticles successfully sticking to surface of porous SAC. The MnFe 2 O 4 -SAC composites exhibited stable and excellent catalytic activity in activating persulfate (PS) for the degradation of Orange G (OG) throughout the wide pH range of 3–9, and could be recycled by a magnet without any loss. The activation energy was calculated to be 14.94 kJ mol −1 , indicating that the OG degradation in MnFe 2 O 4 -SAC/PS process required moderate activation energy. The results of heavy metals leaching experiments revealed an excellent stability of the MnFe 2 O 4 -SAC catalyst. Possible reaction mechanism in MnFe 2 O 4 -SAC/PS system was also discussed in detail.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Shuanghui Deng,Houzhang Tan,Xuebin Wang,Xuchao Lu,Xiaohe Xiong
Addition of sludge into biomass is an alternative method to capture alkali metals and obtain biomass good combustion conditions. The ash fusion characteristics of sewage sludge (SS), petrochemical sludge (PS), wheat straw (WS), and series of the SS/PS and WS blends in different blending ratios were investigated in this study. The mineral matter transformations during the co-firing of SS/PS with WS were examined. Results indicate that the addition of SS/PS can raise the ash fusion temperatures of WS ash, and the ash fusion temperatures of most SS/PS–WS ashes are higher than those of WS ash. The SS/PS-WS ashes have different mineral matters and microstructures in different blending ratios after the co-firing of SS/PS with WS. It is found that the mineral matters in the SS–WS ash are silicates, silicon dioxide and ferric oxide with high melting points , while the matters in the PS–WS ash are phosphate, manganese aluminate, silicon dioxide, and aluminum nitride with high melting points. The results obtained in this study are not only useful for biomass-fired power stations looking for alternative co-firing fuels but reduce ash deposit formation and agglomeration in biomass-fired boiler.
研究领域:
能源与环境科学
·
材料科学
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DOI
高影响因子
Applied Sciences-Basel
·
2021
·Vol. 11
·期 12
·5522
·
IF 2.679
Changjin Liang,Shaomin Lin,Guiwen Liu
Featured ApplicationDue to the particularity of the source, the sludge can be fired into biochar ceramsite without adding other auxiliary materials, and can be used as the padding of constructed wetland.AbstractBiochar ceramsite was prepared from residual sludge at different temperatures. Specific surface area, compressive strength, and toxic leaching tests were used to compare the properties. Through tests and scanning electron microscopy (SEM), it was found that with the increase of preparation temperature, the ceramsite showed higher porosity, larger specific surface area, and better compressive strength. The leaching amount of toxic heavy metals is low when the temperature is higher than 650 °C. According to X-ray diffraction (XRD) analysis, the main component of sludge is quartz. There were amounts of iron and aluminum in sludge, which were the main reason for its good adsorption efficiency. Through the adsorption experiment on Cr(VI), it was found that the adsorption efficiency of the ceramsite on Cr(VI) was better at low pH, and the adsorption isotherm fitted well with Langmuir and Freundlich types. The adsorption process had both monolayer adsorption and multilayer adsorption, and the adsorption process was in line with the pseudo-second-order kinetics.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）