JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Jian Ke,Yuhui Ge,Qiulian Yang,Yanhua Liu,Pau-Loke Show,Ruixin Guo,Jianqiu Chen
Excess sludge disposal and management has become a global issue of scientific and public concern owing to its high yield and toxicity. In this study, for the first time, we prepared industrial and livestock sludge-derived photocatalysts using dyeing sludge and swine sludge as raw materials, respectively, using a facile pyrolysis coupled ball-milling process without additives. The photocatalytic performances of the two types of photocatalysts were evaluated using sulfamethazine as the target contaminant. The surface morphology and functional groups of the catalysts were analyzed using field-emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy . The sulfamethazine removal rate was 91.5 % under optimal conditions. Degradation intermediates were detected, and a possible degradation pathway was proposed. Major reactive oxygen species in the photocatalytic systems were investigated using electron spin resonance spectroscopy and radical trapping experiments. The results revealed that·O 2 – and h + played main roles in the degradation of SMZ. Furthermore, a pilot-scale experimental setup was designed and manufactured to realize pilot-scale production. Economic analysis of the pilot-scale experiment suggested that the developed photocatalysts are comparatively suitable for practical applications.
研究领域:
环境科学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2013
·
IF 3.258
Ruikun Wang,Jianzhong Liu,Yujie Yu,Junhu Zhou,Kefa Cen
Urbanization has generated large volumes of municipal wastewater sludge (sludge for short) that threaten the environment and human health. As such, utilization of the sludge in a cost-effective manner is an important concern. The sludge, as a carbon-containing material, can be made into coal-sludge slurry (CSS) by mixing it with pulverized coal. However, the slurryability of the raw sludge is relatively poor due to the abundance of hydrophilic groups in the sludge and its loose floc structure. In this study, modification of the sludge with calcium oxide (CaO) showed positive effects on the sludge slurryability. The characteristic viscosity of the coal raw-sludge slurry (R-CSS) was 1635.3 mPa s. After modification of the sludge with 2 wt.% CaO for 24 h, the CSS viscosity decreased to 1184.4 mPa s. The hydrophobic group (C C and C H) content of the sludge increased from 61.5% to 74.9% as the CaO dosage increased from 0% to 4%, and the zeta potential increased from –55.1 eV to –36.2 eV. The optimum CaO dosage for improved slurryability was found to be 2 wt.%. Compared with R-CSS, the coal modified-sludge slurry (M-CSS) showed lower yield stress, weaker pseudoplastic and thixotropic behaviors, and poorer static stability.
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
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Siyang Li,Jinxi Feng,Shuanghong Tian,Shenyu Lan,Chao Fan,Xiaosheng Liu,Ya Xiong
For the first time, paint sludge waste (PS) was used as a pore forming agent in the preparation of sewage sludge derived carbon (SC). The tuning role and mechanism of PS for characteristics of SC were explored. It was found that a sludge carbon (SC PS-Zn ) with rich macro-, meso- and micro- porous could be produced by one-step pyrolytic process of sludge in the presence of PS and ZnCl 2. Its surface area could reach as high as 680.5 m 2 g −1 as 88.4 times and 4.8 times of sludge carbon without addition of PS and ZnCl 2 (SC) and only addition of ZnCl 2 (SC Zn ) , respectively. The macro- pores fabricated by PS provided much inner-space for ZnCl 2 to generate meso- and micro- porous, leading to a hierarchical porous structure. SC PS-Zn showed a high adsorption capacity of 685.4 mg g −1 for Chrysophenine, which is 1.3 and 1.7 times that of SC PS and SC Zn respectively. The adsorption difference could be simply attributed to the fact that the great molecules were difficult to enter micro- pores of SC Zn . It was also found that the difference was also dependent on orientation of Chrysophenine, which was related to pH value of solution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Jinte Zou,Fengfan Yu,Jiyang Pan,Bingjun Pan,Shuyun Wu,Mengjie Qian,Jun Li
This study presents a novel strategy to accelerate the start-up of aerobic granular sludge (AGS) system and ensure the nutrient removal during cultivation. This new method consists of preparing the chitosan-based sludge aggregates outside the reactor and then seeding the reactor with such sludge aggregates. To prepare chitosan-based sludge aggregates, chitosan was dissolved in acetic acid solution acting as a cationic flocculant to bind negatively charged sludge together, and then the dissolved chitosan was in situ precipitated by readjusting pH to form stable sludge aggregates. The chitosan-induced charge neutralization and water-insolubility of chitosan were the two main reasons for the super-rapid formation of chitosan-based sludge aggregates. The as-prepared chitosan-based sludge aggregates had a much lower sludge volume index at 30 min (SVI 30 ) (90.1 mL/g) than the original sludge (SVI 30 = 328.0 mL/g). They also had some AGS-like characteristics such as large particle size (1300 μm) and fast settling velocity (23.8 m/h). Consequently, short settling time can be achieved and excessive biomass wash-out can be avoided in the rapid start-up of AGS system with chitosan-based sludge aggregates as inoculant, which was beneficial to accelerating sludge granulation while maintaining nutrient removal. Additionally, the abundances of filamentous bacteria and Candidatus Accumulibacter and the content of extracellular polymeric substances increased during cultivation, which could also contribute to the AGS formation. By seeding chitosan-based sludge aggregates in the anaerobic/oxic sequencing batch reactor , complete granulation was rapidly achieved in 10 days, and good removals of nitrogen and phosphorus was obtained after 14–18 days of cultivation.
研究领域:
环境工程
·
污水处理
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xian Yang,Liuting Zeng,Jinjia Huang,Zhihua Mo,Zhijie Guan,Shuiyu Sun,Jialin Liang,Shaosong Huang
The high moisture content of sludge is a key factor limiting its subsequent treatment and disposal. Herein, a novel method of MnFe 2 O 4 -biochar (MFB) activated peroxymonosulfate (PMS) combined with tannic acid (TA) was conducted to improve sludge dewatering . The effects of different concentrations of MFB, PMS, and TA on waste activated sludge (WAS) dewaterability were investigated. The water content of sludge cake dropped to 40.80% when the initial pH was 5.0, and the concentration of PMS, MFB, and TA was 0.64 mM/g DS, 100 mg/g DS, and 0.12 mM/g DS respectively, demonstrating that MFB/PMS/TA could effectively enhance sludge dewaterability. Analyzing the changing of sludge properties and characterizing MFB confirmed that the enhancement of sludge dewaterability occurred in two phases. First, TA accelerated the valence transformation of Fe and Mn to promote PMS activation, which strengthened the oxidation capacity of the system. Second, TA complexed and precipitated protein to enhance the compressibility and dewaterability of sludge. Furthermore, MFB/PMS/TA treatment could increase the calorific value of treated sludge, and after the combined treatment, the sludge biochar also had a better pore structure, indicating that the sludge after the combined treatment posed a good prospect of resource utilization. These findings provide a novel strategy for the practical application of achieving efficient sludge deep dewatering, providing a valuable reference for downstream sludge utilization .
研究领域:
环境工程
·
水处理
·
废物管理
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Wei Wei,Xingdong Shi,Lan Wu,Xiaoqing Liu,Bing-Jie Ni
Primary sludge (PS) and Waste activated sludge (WAS) as two main sludge streams in wastewater treatment plants are commonly anaerobically co-digested, which though may be differently affected by pretreatment . Previous work has found that calcium peroxide (CaO 2 ) pretreatment effectively enhanced anaerobic digestion of WAS. However, the feasibilities of this strategy on PS anaerobic digestion and co-digestion of WAS and PS are still unclear. Herein, this work provided new insights into these systems. Biomethane potential test demonstrated that CaO 2 pretreatment at 0.02–0.26 g/g-volatile suspended solids (VSS) promoted anaerobic digestion of PS. Then the feasibility of CaO 2 pretreatment for improving anaerobic co-digestion of PS and WAS mixture was confirmed, with the highest improvement in methane production, VSS destruction and sludge reduction being approximately 37.4%, 38.9% and 19.9%, achieved at 0.14 g/g-VSS of CaO 2 . Process modelling analysis revealed that CaO 2 pretreatment increased both degradable faction and actually degraded fraction in sludge mixture. The changes of sludge characteristics via pretreatment and key enzyme activity in sludge anaerobic co-digestion system demonstrated that increased CaO 2 concentration resulted in increased soluble organics release from sludge mixture in the pretreatment stage and inhibited activity of coenzyme F 420 responsible for methanogenesis . Further mechanism investigation disclosed that OH − , O 2 − and OH were main contribution factors, and the order of their contributions were OH − > O 2 − > OH. This work laid the theoretical foundation and provided guidance for the practical application of CaO 2 pre-treatment technology .
研究领域:
环境工程
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Jingyang Luo,Wenxuan Huang,Qin Zhang,Wen Guo,Yang Wu,Qian Feng,Fang Fang,Jiashun Cao,Yinglong Su
The effects of different hypochlorite types (namely Ca(OCl) 2 and NaOCl) on the waste activated sludge (WAS) anaerobic fermentation, and microbial community and activity were investigated. The results indicated that both Ca(OCl) 2 and NaOCl contributed to volatile fatty acids (VFAs) production by simultaneously enhancing the solubilization, hydrolysis and acidification processes. The maximal VFAs was respectively 1379.5 (at 10 d) and 1621.5 (at 8 d) mg COD/L at the optimal dose of NaOCl and Ca(OCl) 2 while it was merely 157.4 (at 6 d) mg COD/L in the control. However, the Ca(OCl) 2 might affect the anaerobic process in a continuous mode while the NaOCl was relatively transient, which caused distinctive influences on the microbial structure and activity, and subsequently VFAs production in WAS fermentation systems. Moreover, Ca(OCl) 2 treatments showed advantages over NaOCl on WAS dewatering and VSS reduction, implying the superiority of utilizing Ca(OCl) 2 as additives for WAS disposal.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Xiaoping Liu,Yunbo Zhai,Zhixiang Xu,Yun Zhu,Yin Zhou,Zhexian Wang,Liming Liu,Fashen Liang,Wanying Ren,Yu Xie,Caiting Li,Min Xu
Natural deep eutectic solvents (NADES) coupled with hydrothermal treatment was innovatively proposed to process waste activated sludge for sustainable production of 5-methylfurfural (5-MF) and enhanced dewaterability. The yield of 5-MF up to 11.54 kg/t volatile solids (VS) with a NADES dosage of 2.0 mL, hydrothermal temperature of 180 °C and holding time of 30 min. The decreased capillary suction time (CST) and bound water content indicated that NADES with hydrothermal treatment substantially improved the dewaterability of sludge. The variations of sludge physicochemical properties and extracellular polymeric substances (EPS) compositions revealed that NADES disrupted the structure of sludge biopolymers. Density functional theory (DFT) calculations indicated that NADES weakened the hydrogen bond strength between EPS components, and thus promoted the solubilization of proteins and polysaccharides. Besides, transition state analysis showed that NADES also lowered the energy barrier of polypeptide hydrolysis and carbohydrates dehydration reactions for the production of 5-MF.
研究领域:
环境科学
·
化学工程
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Siqi Tong,Dan Chen,Xinbai Jiang,Zhixiang Xu,Xiaodong Liu,Jinyou Shen
A novel composite biochar synthesized from Fenton sludge (FS) and sewage sludge (SS) was employed to catalyze persulfate for the removal of 1-H-1,2,4-triazole (TZ). The optimized conditions for the synthesis and operating process were identified through response surface methodology as follow: SS/FS mass ratio = 5:1, catalyst dosage = 0.9 g L −1 and PDS concentration = 0.5 g L −1 . The removal efficiencies of TZ, TOC and organic nitrogen were found to be as high as 97.6%, 80.33% and 100%, respectively, with the addition of Fe 3 O 4 -doped biochar in persulfate catalytic system. Besides, Fe 3 O 4 -doped biochar exhibited superior stability and tolerance to wide range of pH (2–12), temperature (15–45 °C) and co-existing substrate. The reactive oxygen species, which resulted in the catalytic degradation of TZ followed the order of SO 4 ∙− > ∙OH > O 2 ∙− > 1 O 2 , were identified by electron spin resonance and quenching tests. It demonstrated that the radical pathway accomplished with non-radical pathway contributed to the enhanced degradation of TZ, which was further identified by electrochemical experiments. Moreover, the possible degradation pathway of TZ was ascertained and proposed through DFT calculation and LC-MS analysis. These findings illustrated that the novel magnetic biochar would be a promising persulfate catalyst for the treatment of refractory organic matters. In addition, it also provided a new alternative method for the resource utilization of FS and SS.
研究领域:
环境科学
·
化学工程
·
废水处理
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Di Wu,Zhiming Zhang,Zhuodong Yu,Liang Zhu
Food to microorganisms (F/M) ratio is one of the most important factors affecting microbial growth and pollutant removal in biological wastewater treatment system. For stability of aerobic granular process, optimal range of F/M ratio and a maneuverable F/M ratio control method via quantitative sludge discharge were investigated in this study. Results showed that stable aerobic granules were achieved with good settleability, high pollutant removal efficiency and microbial diversity when F/M ratio was controlled at 0.4–0.5 gCOD/gSS d. In addition, a maneuverable F/M ratio control method via quantitative sludge discharge was developed to verify the feasibility for optimization of F/M ratio. By this method, aerobic granules cultivated with the F/M ratio of 0.4 ± 0.02 gCOD/gSS d had better pollutant removal performance and stable structure with higher protein-like components in EPS. This study further revealed the importance of F/M ratio in the stability of aerobic granular sludge process.
研究领域:
环境工程学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Xiaoping Liu,Yunbo Zhai,Yun Zhu,Zhixiang Xu,Liming Liu,Wanying Ren,Yu Xie,Caiting Li,Min Xu
The dewatering and resource recovery of waste-activated sludge (WAS) seemed to be two contradictory processes due to the high moisture content induced by the extracellular polymer substances, which mainly consist of proteins and polysaccharides. Natural deep eutectic solvents (NADESs) were proposed to synergistically enhance dewaterability and biopolymer release of WAS. It showed that NADES with low-temperature pretreatment can significantly improve the dewaterability and release of valuable resources. With the addition of 1.0 mL of NADES combined with 60 °C thermal treatment for 120 min, the capillary suction time (CST) of sludge significantly decreased from 75.9 ± 7.5 to 30.5 ± 1.6 s, and 11.83 mg/L of the total amino acids (AAs) was obtained. The protein and polysaccharide contents were increased to 876.48 and 213.42 mg/L, respectively. This study indicated that NADES combined with low-temperature pretreatment is a green, cost-effective, and environmentally friendly method to improve sludge dewaterability and resource recovery simultaneously. The theoretical calculation results suggested that the generation of NADES···AAs aggregates is an exothermic reaction and proceeds nonspontaneously. A good correlation is also found between the theoretically calculated free-energy change and the concentrations of AAs. On the basis of this study, the biopolymers from WAS can be recovered as value-added resources, enabling a recycling concept within the circular economy vision. The theoretical calculation can be used to guide future experiments for screening highly selective and effective NADES toward resource recovery from WAS.
研究领域:
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Yuxuan Xing,Jingchun Huang,Zhenqi Wang,Wei Hu,Minghou Xu,Yu Qiao
This study focused on the effect of oxygen (0–15 %) and 5 % CaO addition on the organic-S control and transformation behavior during pyrolysis (400–600 °C) of sludge under the conditions relevant to smoldering combustion. The results show that oxygen inhibits the total emission of gaseous sulfur (decreased by 25.6–36.9 %). At low temperatures (<500 °C), oxygen enhances the oxidation of aliphatic-S, aromatic-S/thiophene-S, and sulfide-S, leading more sulfur retains in the form of sulfone-S and sulfate-S in char products, also migrates to water-soluble products (especially sulfone-S). At high temperatures (>500 °C), the formed sulfur species in char products mainly further decompose into water-soluble sulfone-S, and partially generate SO 2 . After the addition of CaO during oxidative pyrolysis, the synergistic promotion effect on the sulfur fixation in char products is found, mainly due to the generation of more amount of stable sulfone-S and sulfate-S in char products. This leads to a decrease in gaseous sulfur by 12.4–14.6 % and an increase in sulfur content of char products by 31.3–202.9 %.
研究领域:
环境科学
·
能源工程
✓ 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）