Review
Environmental Sciences
Yankai Liang, Rui Wang, Wenquan Sun, Yongjun Sun
Summary: This article analyzes the composition and properties of municipal sludge and examines the factors affecting its dewatering performance. It introduces various chemical conditioning methods and systematically analyzes the principles and applications of existing sludge conditioning technologies. It emphasizes the importance of developing a more appropriate combination of sludge conditioning and dewatering processes and optimizing the dewatering process by developing new efficient and environmentally friendly sludge conditioning agents.
Article
Engineering, Chemical
Sijia Lu, Xiaoliang Li, Xing Zheng, Gang Tang, Tong Liu, Yanchun Ke, Bao Liu, Hua Wu
Summary: A PbO2 plate electrode was synthesized and optimized for the electrochemical treatment of waste activated sludge. The electrochemical treatment improved the dewaterability and reduced the concentration of suspended solids in the sludge. The use of chemically reduced graphene oxide (RGO) modified PbO2 electrode enhanced the production of hydroxyl radicals (& BULL;OH) and improved the removal of sludge components. The addition of NaCl improved the electrochemical performance of sludge treatment.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Engineering, Environmental
Boran Wu, Hewei Li, Kun Zhou, Ningrui Yu, Qinqin Xu, Xiaoli Chai, Xiaohu Dai
Summary: This study aims to improve the dewaterability of waste-activated sludge (WAS) by using crystallization to drive the evolution of water occurrence states. The formation of CO2 hydrate in WAS was found to significantly enhance its dewatering performance. Additionally, the dissociation of hydrates could be used to recycle CO2 gas and reduce chemical consumption in the dewatering process. The research also revealed that the crystallization of water led to changes in the water occurrence state, resulting in improved water-solid separation. These findings provide a novel strategy for enhancing the dewatering performance of waste-activated sludge and increasing its environmental friendliness.
Article
Engineering, Environmental
Bingbing Lan, Ruofei Jin, Guangfei Liu, Bin Dong, Jiti Zhou, Defeng Xing
Summary: The study utilized sodium periodate as an advanced oxidation agent to regulate the EPS of waste activated sludge, in combination with APAM as a flocculant, leading to significantly improved sludge dewatering performance.
WATER ENVIRONMENT RESEARCH
(2021)
Article
Engineering, Environmental
Changtao Chen, Tao Zhang, Li Lv, Yanxiao Chen, Wenxiang Tang, Shengwei Tang
Summary: The use of ionic liquid [EMIM][OTf] as a conditioner significantly improves the dewatering performance of waste activated sludge (WAS) by reducing moisture content. The mechanism involves the destruction of EPS structures, inactivation of microbial cells, and conversion of large flocs into small particles and biopolymers. Additionally, the negative charges of WAS are neutralized, weakening electrostatic repulsion between flocs, and [EMIM][OTf] can be recycled multiple times.
Article
Engineering, Environmental
Hamidreza Masihi, Gagik Badalians Gholikandi
Summary: The study demonstrated that TAMK functions as a physical and chemical conditioner for WAS conditioning and dewatering, improving filtration efficiency and resistance. The cost of using TAMK is relatively low, making it an economical, inexpensive, and effective option for sludge treatment.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Environmental
M. Ruiz-Hernando, S. Vinardell, J. Labanda, J. Llorens
Summary: The study showed that ultrasound treatment can improve the rheological and dewatering properties of waste activated sludge, but the implementation cost is high and has a significant impact on economic balance. Techno-economic analysis revealed that increasing electricity revenue and reducing biosolids disposal costs are crucial factors to make ultrasound treatment economically attractive.
Article
Engineering, Environmental
Boran Wu, Hao Wang, Xiaohu Dai, Xiaoli Chai
Summary: This study investigated the impact of removing EPS-complexed cations on the spatial distribution of EPS and its influence on particle size distribution, fractal dimension, interfacial free energy, and water occurrence states of WAS. The results confirmed that dispersed EPS adhering layers led to higher fractal dimension but lower space filling degree of bio-flocs.
Article
Environmental Sciences
Yujie Tan, Ruiliang Zhang, Xueqin Lu, Chengxin Niu, Guangyin Zhen, Gopalakrishnan Kumar, Youcai Zhao
Summary: Sludge management is a critical challenge due to complex compositions and poor dewaterability. Fe2+-activated persulfate oxidation has been proven effective in enhancing sludge dewatering, with potential benefits for sludge drying efficiency, anaerobic biodegradation behaviors, and sludge recycling. The study proposes a new sludge disposal route that includes enhanced dewatering using Fe2+/S2O82- and subsequent drying-incineration or anaerobic digestion, providing a novel, self-sustainable strategy for sludge management, reutilization, and safe disposal.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Review
Environmental Sciences
Michal Hyrycz, Marek Ochowiak, Andzelika Krupinska, Sylwia Wlodarczak, Magdalena Matuszak
Summary: Mechanical sludge dewatering is an essential step in municipal wastewater treatment to reduce sludge generation and transportation cost. This article discusses the theory of flocculation, sewage sludge, and its dewatering process. It explores the mechanisms, kinetics, and classification of flocculants, as well as the impact of various parameters on the efficiency of flocculation and dewatering. Experimental studies on different types of sludge are compared, and the literature review provides insights into the progress and future directions in this field.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Chemical
Qiyun Feng, Kangying Guo, Yue Gao, Beibei Liu, Qinyan Yue, Weijie Shi, Chunhui Feng, Jizhu Zhou, Guorui Wang, Baoyu Gao
Summary: This study optimized the preparation conditions of polysilicate ferric, polysilicate aluminum ferric, and polysilicate aluminum ferric magnesium and investigated their performance in sludge dewatering pretreatment. The results showed that polysilicate improved sludge dewatering performance through adsorption bridging effect and charge neutralization.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Engineering, Environmental
Boran Wu, Hao Wang, Yunbin He, Xiaohu Dai, Xiaoli Chai
Summary: The cell membrane structure has a significant influence on the dewatering performance of waste-activated sludge, but there is still debate on the optimal extent of cell lysis. This study used non-chemical methods such as sonication, cyclic freezing-thawing, and DMSO amendment to lyse microbial cells and found that the extent of cell lysis had limited impact on the water occurrence states of the sludge.
Article
Environmental Sciences
Hewei Li, Chunjiang Li, Kun Zhou, Wei Ye, Yufei Lu, Xiaoli Chai, Xiaohu Dai, Boran Wu
Summary: Due to the complex compositions and origins of waste-activated sludge (WAS), the physiochemical properties of sludge affect its dewaterability and there is a complex interaction between these properties, making it difficult to identify the controlling factors on sludge dewaterability. This study proposes the use of an artificial neural network (ANN) model to predict the dewatering performance of WAS under different conditioning schemes based on multiple physiochemical properties and conditioning operation parameters. The established ANN model shows satisfactory stability and accuracy, providing valuable insights for improving the operation of sludge dewatering processes.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Environmental Sciences
Baodan Jin, Jintao Niu, Lan Wang, Jianguo Zhao, Yu Li, Long Pang, Miao Zhang
Summary: The study demonstrated that the novel oxidant SDIC combined with microorganisms enhanced the performance of waste-activated sludge anaerobic fermentation. This combination resulted in increased release, extraction, and hydrolytic acidification efficiency of organic substances in the sludge. Additionally, SDIC treatment influenced the activity of various enzymes and affected the microbial communities in the sludge fermentation process.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Biotechnology & Applied Microbiology
SungJu Im, Hee-Joong Kim, Hojung Rho, YeonKwon Kim
Summary: This study investigates the effect of physical change factors in a thermal hydrolysis reactor on the dewatering capacity and solubilization, aiming to reduce the sludge quantity produced from wastewater treatment. By adjusting factors such as sludge amount, slope degree, stirring speed, and residual oxygen quantity, the study identifies optimal conditions for achieving the highest dewatering capacity and efficiency. The findings provide insights into utilizing sludge based on its characteristics.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2022)
Article
Engineering, Chemical
Yunfei Yu, Xue Yang, Chenchen Zhang, Jie Chen, Wei Lin, Jianqiang Meng
Summary: This study reports an environmentally friendly and simple approach for preparing double-network (DN) ion gel membranes with high strength and excellent gas separation performance. By optimizing crosslinking density, mass ratio, and the type and content of free ionic liquid, the mechanical and gas separation properties of the DN membrane are improved.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Si-qi Jiang, Qiang Gao, Xi-guang Li, Chao-zhu Deng, Jun Qiu, Xiang-nan Zhu
Summary: A dual-strengthening pretreatment method is proposed to remove PVDF more efficiently and enhance the leaching of LiCoO2. Experimental results show that dual-strengthening pretreatment can effectively remove PVDF and significantly improve the leaching efficiency compared to single pretreatment methods.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Zengchi Hu, Xiaoyu Wang, Xiaohui Zhang, Xue Li, Jiangbin Xia
Summary: The rapid fabrication of high-performance composite membranes based on CMPs using simple and low-cost methods is challenging. In this study, three CMPs-based composite membranes were rapidly fabricated with adjustable size using unidirectional diffusion synthesis. The microstructural design enhanced the rejection rates of the membranes and they showed strong hydrolytic resistance, thermal stability, and acid-base resistance. Electrostatic adsorption and the adjustable microstructures significantly varied the repellence of the membranes to different charged molecules.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Farzaneh Rouhani, Matineh Ayedi, Nasser Safari
Summary: Introducing defects into porous metal-organic frameworks is important for improving their adsorption performance. Quasi-MOFs, an underutilized variant of large-scale, fundamentally deficient MOFs, have been found to have substantial amounts of unsaturated metal sites to offset the drawbacks of MOFs. In this study, a quasi-MOF was produced using a water-stable MOF and demonstrated significantly improved phosphate adsorption capability due to the presence of defect sites.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Valentin Reungoat, Morad Chadni, Louis M. M. Mouterde, Fanny Brunissen, Florent Allais, Helene Ducatel, Irina Ioannou
Summary: This study focuses on the recovery of sinapic acid using liquid-liquid extraction assisted by a hollow fiber membrane contactor from an aqueous feed obtained through the hydrolysis of mustard bran. The screening of solvents of different chemical nature showed that all tested solvents had an extraction efficiency of more than 80% for pH < 5. Four solvents were selected for use in the hollow fiber membrane contactor, and the volatile solvents showed higher mass transfer coefficients compared to non-volatile solvents. The extraction efficiency was intensified by increasing the initial concentration of sinapic acid and the feed-to-solvent ratio. CPME was found to have optimal recovery efficiency at a phase ratio of 8:1, yielding 0.9 g of sinapic acid per liter of CPME used.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Takahiro Sakamoto, Takafumi Hanada, Hayate Sato, Mayu Kamisono, Masahiro Goto
Summary: The emergence of the battery society has led to a high demand for battery metals, resulting in a strain on their supply. This study introduces a novel technique using a hydrophobic deep eutectic solvent (DES) for leaching and recovering battery metals from low-grade nickel laterite ores. The DES enables selective leaching and recovery of the metals, offering a promising pathway for the extraction of critical battery metals.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Rongrong He, Jiarui Chen, Chunyao Zhang, Dan Lu, Lin Zhang, Tao He
Summary: Researcher has developed a method to quantify the charge density in nanofiltration (NF) membrane separation layer and applied it in NF membranes that can separate Mg2+ and Li+. The results showed that overcompensated amine groups played a major role, and there was a linear relationship between charge density and coating bi-layers or PAH layers.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Zhijian Zhang, Min Chen, Zhe Lin, Zhichao Yang, Yafeng Du, Zhihui Chen, Zhenhao Yang, Kongyin Zhao, Ligang Lin
Summary: Membrane technology plays an important role in molecular/ion separation processes, but faces challenges such as membrane fouling. This study introduces a new ion-crosslinking method to fabricate copper alginate hydrogel membranes with improved mechanical strength and antimicrobial capabilities. The membranes exhibit excellent separation performance and enhanced long-term molecule/ion separation through improved anti-swelling properties. Molecular dynamics simulations and life cycle analysis highlight the pore structure and environmental friendliness of the hydrogel membranes. These findings provide valuable insights for developing sustainable hydrogel membranes with stable performance and high separation efficiency.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Dongmei Liu, Aiying Guo, Yanling Qi, Zhixin Ji, Hongjuan Li, Zhiwei Zhang, Xinyue Zhang, Kunze Wu, Aijun Cai
Summary: In this study, a stable magnetic Mg/Mn-layered double oxide-doped biochar composite (MgMnLDO-MBC) was prepared and successfully used for the removal of antibiotics and bacteria from wastewater. The composite exhibited enhanced surface areas, adsorption sites, and free radicals, leading to improved catalytic activity. The effects of different factors on the removal efficiency were evaluated, and the composite showed good reusability.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Feng Wang, Zhaoyong Bian, Yaru Zhang, Wenchao Yu, Qiang Zhang, Hui Wang
Summary: In this study, a nanofibrous layered structure of Ff-Ti3C2Tx-Co3O4 was prepared by self-assembling nanofibrous Co3O4 with lamellar fluorine-free MXene (Ff-Ti3C2Tx). The Ff-Ti3C2Tx-Co3O4 exhibited excellent catalytic activity for degradation, resistant to ionic interference, and maintained high removal efficiency of sulfamethoxazole (SMX) in municipal wastewater. The rapid SMX degradation involved fast electron transfer in redox cycles with PMS and the generation of 1O2 via PMS ->center dot O2 -> 1O2. This work provides new insights into antibiotic degradation mechanisms and electron transfer based on PMS activation.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Weipeng He, Jiacheng Luo, Yujie Wu, Tianhao Luo, Chen Tang
Summary: This study comparatively evaluated the role of cationic, anionic, and nonionic polyacrylamides (PAMs) in ballasted flocculation of clay suspensions under different aluminum sulfate (AS) coagulant dosages. The selection of PAMs and AS dosage had a significant influence on the size and shear resistance of ballasted floc aggregates.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Lixian Wang, Lizhi Zhao, Didi Si, Zhixin Li, Huiqin An, Hui Ye, Qingping Xin, Hong Li, Yuzhong Zhang
Summary: Metalloporphyrin-based nanozymes integrated with poly (vinylidene fluoride) membrane show high catalytic activity and reusability for the decolorization of Congo Red dye in continuous flow process.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Yongfei Ma, Chenyu Zeng, Yongzhen Ding, Jiayi Tang, Ondrej Masek, Zhikang Deng, Rui Mu, Zulin Zhang
Summary: In this study, sludge-derived biochar (SBC) was functionalized with various iron salts to enhance its adsorption ability for sulfamethoxazole (SMX) and magnetic collection performance. Ball milling was further employed to treat the optimal iron salt functionalized SBC (MSBC), resulting in ball milled SBC (BMSBC) with improved adsorption performance for SMX. The dominant driving mechanism for SMX adsorption onto BMSBC was confirmed to be multiple physicochemical forces, including 7C-7C conjugation, pore filling, H-bonding, Fe-O complexation, and electrostatic interactions. BMSBC exhibited favorable adsorption ability for SMX in actual waters and could be easily collected within 1 min due to its magnetic sensitivity.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Jinglin Tan, Xiaohui Mao, Wenjihao Hu, Hongbo Zeng
Summary: This study investigates the influence of PDMS chain architectures on surface properties and reveals that PDMS coatings with looped structures exhibit superior hydrophobicity, self-cleaning, and water sliding compared to coatings with linear structures. Additionally, both looped and linear PDMS coated stainless steel mesh/polyester fibers show efficient separation of oil/water mixture.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Engineering, Chemical
Wei-Liang Chen, Chih-Chia Cheng, Chien-Hsing Lu, Jem-Kun Chen
Summary: This study designs a novel sandwich-structured capacitor that reduces the absorption time of pollutants using dielectrophoresis force. By coating graphene oxide on polystyrene microspheres as adsorbents and encapsulating them within the capacitor, the adsorption rate is significantly enhanced. Additionally, frequency manipulation allows for the recycling of adsorbents and concentration of dyes, minimizing secondary pollution.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)