Article
Agricultural Engineering
Pengfei Wan, Ying Liu, Quandi Zhang, Li Jiang, Heping Chen, Wenzhou Lv
Summary: Candida Tropicalis was used to improve the dewaterability of activated sludge (AS) by degrading EPS in AS, resulting in a decrease in protein, polysaccharide, and hydrophilic amino acids in EPS. The yeast degraded macromolecular organics into smaller molecular ones and direct addition of yeast to AS was more effective in EPS degradation. Addition of 0.75 g/L of wet yeast cells and 24 h of aeration enhanced the dewaterability of AS with a reduction in CST and MLSS. After 30 days of operation, lab-scale continuous SBRs reduced CST and MLSS of AS. FTIR spectroscopy showed a decrease in hydrophilic functional groups. This study presents a new approach for in-situ reduction of AS in wastewater treatment plants.
BIORESOURCE TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Wanqing Ding, Wenbiao Jin, Xu Zhou, Qinhui Yang, Chuan Chen, Qilin Wang
Summary: This study investigated the dewaterability of anaerobic granular sludge (AGS) by Fe(II)-PDS conditioning, finding that Fe(II)-PDS conditioning can enhance dewaterability by breaking down EPS layers and microbial cell structures, releasing bound water and facilitating sludge re-flocculation. Protein was identified as the primary component in AGS and showed a strong correlation with dewaterability.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Green & Sustainable Science & Technology
Haochi Zhang, Dejin Zhang, Yujun Zhou, Di Fang, Chunhong Cui, Jianru Liang, Bo Zhou, Mingjiang Zhang, Jiansheng Li, Lixiang Zhou
Summary: This study found that bioleaching was not effective for anaerobically digested sludge (ADS) compared to undigested sludge (UDS). The specific resistance to filtration of ADS increased during bioleaching, and the pH value of ADS remained unchanged at 7.97, while it decreased to 2.98 for UDS. Added Fe2+ was not detected as an energy source for ADS. Higher alkalinity and unavailable Fe2+ in ADS hindered the growth of Acidithiobacillus species. Aeration significantly deteriorated the dewaterability of ADS through bioleaching, with a drastic increase in sludge pH and slime EPS content.
Article
Environmental Sciences
Yun bei Li, Jun li Song, Qian jing Yao, Ze xu Chen, Yi Wei, Hai long Li, Meng xiao Wang, Bing jing Wang, Jia min Zhou
Summary: Increasing dissolved oxygen concentration can enhance bioleaching efficiency, improve sludge dewatering performance, and facilitate the removal of heavy metals. Additionally, the degradation of EPS and sludge floc fragmentation play vital roles in the bioleaching process.
Article
Geochemistry & Geophysics
Xudong Zhang, Peng Ye, Yajun Wu, Zhen Guo, Yuan Huang, Xingtao Zhang, Yuncong Sun, Haiqiang Zhang
Summary: Municipal sludge, a by-product of urban sewage treatment with high water content and difficulty in deep dewatering, was treated with an acid-microwave method to improve its dewatering ability. Short-term microwave radiation was found to be beneficial for dewatering, but prolonged treatment time led to deterioration of the performance. Acid-microwave treatment could significantly improve the release efficiency of polysaccharide in sludge.
Article
Environmental Sciences
Xiaoran Li, Yafei Shi, Xi Zhou, Lu Wang, Huiqin Zhang, Kewu Pi, Andrea R. Gerson, Defu Liu
Summary: The study examined the impact of a composite conditioner, Fe2+/SPS combined with phosphogypsum, on sludges with varying organic and solid contents. Results showed that oxidation played a major role in conditioning, especially for higher organic matter content. Changes in phosphogypsum significantly affected the optimal molar ratio and dosage of Fe2+/SPS, with sludge containing more solids requiring higher Fe2+/SPS dosage for stronger oxidation.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Rong Deng, Jiahao Lai, Zonghao Liu, Bing Song, Huan Liu, Dandan Chen, Gancheng Zuo, Zhen Yang, Fanyue Meng, Tingting Gong, Min Song
Summary: This research proposes a hypothesis for the co-disposal of sludge and coal slime to improve dewaterability. by utilizing the beneficial role of coal slime as a filter assist and CaO2 enhanced system. The results showed that under optimal conditions, the capillary suction time, specific resistance to filtration, and water content decreased significantly. The Fe2+/CaO2/coal slime combined system was proved to have a promising application prospect in enhancing sludge dewaterability.
Article
Environmental Sciences
Xia Song, Aijiang Yang, Xia Hu, A-Ping Niu, Yang Cao, Qingqing Zhang
Summary: The contamination of water resources and food chain by Sb bearing tailings in abandoned antimony mines is a significant problem. Microorganisms and extracellular polymeric substances (EPS) produced by bacteria were found to play a crucial role in tailing leaching and reaction speeding. This study investigated the leaching pattern of Sb from Sb bearing tailings using Acidithiobacillus ferrooxidans and analyzed the mechanism of EPS in the leaching process of Sb. Various techniques were employed to characterize the generation behavior of EPS during bioleaching and the changes of EPS functional groups before and after leaching. The findings provide insights into the biogeochemical cycle of Sb and the reduction of risk associated with high-valent antimony.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Environmental
Fang Zhang, Ding-Kang Qian, Zi-Qian Geng, Kun Dai, Wei Zhang, Mark C. M. van Loosdrecht, Raymond Jianxiong Zeng
Summary: The hydrolysis of alginate, a main component of extracellular polymeric substances (EPS) in waste-activated sludge, is crucial for enhancing methane production. The alginate-degrading consortia (ADC) showed a significant increase in methane production and biological methane potential, indicating the importance of alginate in EPS for methane recovery. Future research should focus on investigating the microbial changes in ADC for stable digestion of waste-activated sludge.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2021)
Article
Environmental Sciences
Peng Yang, Dandan Li, Weijun Zhang, Jing Ai, Sainan Peng, Dongsheng Wang, Fengguo Cui
Summary: The study demonstrated that organic acids chelated ferrous ions can significantly enhance sludge dewaterability, leading to improved dewatering performance through the activation of NaClO.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Review
Engineering, Chemical
Yanfeng Jiang, Fuyan Gao, Ning Zhang, Jianxin Li, Meijuan Xu, Yuejun Jiang
Summary: Municipal sludge is a byproduct of wastewater treatment with pathogens, heavy metals, and other pollutants. Its high organic content and low toxicity make it suitable for energy utilization, but its high moisture content poses challenges for harmless disposal and resource utilization. Mechanical dewatering is the main method used, but it doesn't meet rigorous requirements, highlighting the need for deep dehydration technology.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Environmental
Xiaoran Li, Yafei Shi, Kewu Pi, Andrea R. Gerson
Summary: This study investigated the kinetics and oxidation process of Fe(II)-activated sodium persulfate (SPS) treatment on waste activated sludge (WAS). It was found that both proteins (PN) and polysaccharides (PS) followed pseudo-first-order kinetics during the treatment, with preferential oxidation of EPS proteins over EPS polysaccharides. The oxidation rates of PN and PS were higher in granular sludge (GS) compared to raw sludge filtrate (RSF). Additionally, a portion of the sodium persulfate was consumed in the GS solution, reducing the number of effective free radicals for EPS degradation. The mass balance of PN and PS indicated a significant degradation effect of Fe(II)-SPS conditioning on EPS in WAS.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Jing Ai, Zhiyue Wang, Dionysios D. Dionysiou, Ming Liu, Yun Deng, Mingyue Tang, Guiying Liao, Aibin Hu, Weijun Zhang
Summary: The study utilized Fe(II)-sulfite oxidation and polyacrylamide flocculation (F/S-PAM) treatment to remove the bound water in waste activated sludge and improve sludge dewaterability. The radicals generated by F/S could decompose EPS, releasing bound water, while PAM caused re-flocculation of disintegrated sludge flocs, enhancing sludge filterability.
Article
Agricultural Engineering
Zhe Liu, Jingwen Wang, Shumin Zhang, Yiwen Hou, Jiaxuan Wang, Min Gao, Xingdu Chen, Aining Zhang, Yongjun Liu, Zhihua Li
Summary: The formation characteristics of algal-bacteria granular sludge (ABGS) under different light intensities were investigated. It was found that stronger light favored the improvement of sludge characteristics and nutrient removal performances during the growing stage, while weaker light ensured stable operation of the system during the mature stage. The dominant bacterial genus in mature ABGS cultured under low light intensity was Zoogloe, and different algal genus were dominant.
BIORESOURCE TECHNOLOGY
(2023)
Review
Biotechnology & Applied Microbiology
Wolfgang Sand, Axel Schippers, Sabrina Hedrich, Mario Vera
Summary: This article summarizes some recent discoveries related to bioleaching microorganisms, including phylogeny, chemical pathways, surface science, biochemistry, anaerobic metabolism, cell-cell communication, molecular biology, and biofilm lifestyle. These findings contribute to a better understanding of their lifestyle and may open up new possibilities for synthetic biology applications.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2022)
Article
Agricultural Engineering
Yinping Xiang, Meiying Jia, Rui Xu, Jialu Xu, Lele He, Haihao Peng, Weimin Sun, Dongbo Wang, Weiping Xiong, Zhaohui Yang
Summary: This study investigated the impact of the non-antibiotic pharmaceutical carbamazepine on antibiotic resistance genes (ARGs) during anaerobic digestion. The results showed that carbamazepine induced the enrichment of ARGs and increased the abundance of bacteria carrying these genes. It also facilitated microbial aggregation and intercellular communication, leading to an increased frequency of ARGs transmission. Moreover, carbamazepine promoted the acquisition of ARGs by pathogens and elevated their overall abundance.
BIORESOURCE TECHNOLOGY
(2024)
Review
Agricultural Engineering
Weixin Zhao, Tianyi Hu, Hao Ma, Dan Li, Qingliang Zhao, Junqiu Jiang, Liangliang Wei
Summary: This review summarizes the effects and potential mechanisms of biochar on microbial behavior in AD systems. The addition of biochar has been found to promote microbial colonization, alleviate stress, provide nutrients, and enhance enzyme activity. Future research directions include targeted design of biochar, in-depth study of microbial mechanisms, and improved models.
BIORESOURCE TECHNOLOGY
(2024)
Review
Agricultural Engineering
Christina Karmann, Anna Magrova, Pavel Jenicek, Jan Bartacek, Vojtech Kouba
Summary: This review assesses nitrogen removal technologies in reject water treatment, highlighting the differences in environmental impacts and economic benefits. Partial nitritation-anammox shows potential for economic benefits and positive environmental outcomes when operated and controlled properly.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Wei-Hao Huang, Ying-Ju Chang, Duu-Jong Lee
Summary: This study modified pinecone biochar with layered double hydroxide (LDH) to enhance its adsorption capacity for heavy metal and phosphate ions. The LDH-biochar showed significantly improved adsorption capacities for Pb2+ and phosphate, and a slight increase for Cu2+ and Co2+. The LDH layer enhanced the adsorption through various mechanisms.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Chao Song, Fanfan Cai, Shuang Yang, Ligong Wang, Guangqing Liu, Chang Chen
Summary: This paper developed a machine learning model to predict the biochemical methane potential during anaerobic digestion. Model analysis identified lignin content, organic loading, and nitrogen content as key attributes for methane production prediction. For feedstocks with high cellulose content, early methane production is lower but can be improved by prolonging digestion time. Moreover, lignin content exceeding a certain value significantly inhibits methane production.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Sang Min Lee, Ju Young Lee, Ji-Sook Hahn, Seung-Ho Baek
Summary: This study successfully developed an efficient platform strain using Yarrowia lipolytica for the bioconversion of renewable resources into adipic acid, achieving a remarkable increase in production level.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Sefkan Kendir, Matthias Franzreb
Summary: This study presents a novel approach using magnetic separation to efficiently harvest freshwater microalgae, Chlorella vulgaris. By combining pH-induced calcium phosphate precipitation with cheap natural magnetite microparticles, harvesting efficiencies up to 98% were achieved in the model medium.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Ishaq Kariim, Ji-Yeon Park, Wajahat Waheed Kazmi, Hulda Swai, In-Gu Lee, Thomas Kivevele
Summary: The impact of reaction temperature, residence time, and ethanol: acetone on the energy compositions and yield enhancement of biocrudes was investigated. The results showed that under appropriate conditions, biocrudes with high energy and low oxygen content can be obtained, indicating a high potential for utilization.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Xiyue Zhang, Xiyao Li, Liang Zhang, Yongzhen Peng
Summary: Intermittent aeration is an innovative approach to enhance nitrogen removal in low carbon-to-nitrogen ratio municipal sewage, providing an efficient strategy for the continuous plug-flow AOA process.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Xu Yang, Mahmoud Mazarji, Mengtong Li, Aohua Li, Ronghua Li, Zengqiang Zhang, Junting Pan
Summary: This study investigated the impact of magnetite on the nitrogen cycle of pig manure biostabilisation. The addition of magnetite increased N2O emissions and decreased NH3 emissions during composting. It also increased the total nitrogen content but should be considered for its significant increase in N2O emissions in engineering practice.
BIORESOURCE TECHNOLOGY
(2024)
Review
Agricultural Engineering
Ty Shitanaka, Haylee Fujioka, Muzammil Khan, Manpreet Kaur, Zhi-Yan Du, Samir Kumar Khanal
Summary: The market value of microalgae has exponentially increased in the past two decades, thanks to their applications in various industries. However, the supply of high-value microalgal bioproducts is limited due to several factors, and strategies are being explored to overcome these limitations and improve microalgae production, thus increasing the availability of algal-derived bioproducts in the market.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Martin Kerner, Thorsten Wolff, Torsten Brinkmann
Summary: The efficiency of using enriched CO2 from flue gas for large-scale production of green microalgae has been studied. The results show that the use of membrane devices and static mixers can effectively improve the CO2 recovery rate and maintain the suitable pH and temperature during cultivation, achieving a more economical and sustainable microalgae production.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Rui Ma, Ji Li, Rd Tyagi, Xiaolei Zhang
Summary: This review summarizes the microorganisms capable of using CO2 and CH4 to produce PHAs, illustrating the production process, factors influencing it, and discussing optimization techniques. It identifies the challenges and future prospects for developing economically viable PHAs production using GHGs as a carbon source.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Bing Wang, Peng Zhang, Xu Guo, Xu Bao, Junjie Tian, Guomin Li, Jian Zhang
Summary: The addition of zeolite in the co-composting of chicken manure and straw significantly reduced the emissions of ammonia and N2O, and increased the nitrate content. Zeolite also promoted the abundance of nitrification genes and inhibited the expression of denitrification genes.
BIORESOURCE TECHNOLOGY
(2024)
Article
Agricultural Engineering
Rohit Dey, Franziska Ortiz Tena, Song Wang, Josef Martin Messmann, Christian Steinweg, Claudia Thomsen, Clemens Posten, Stefan Leu, Matthias S. Ullrich, Laurenz Thomsen
Summary: This study investigated the operation of a 1000L microalgae-based membrane photobioreactor system for continuous secondary wastewater treatment. The research focused on a green microalgae strain called Desmodesmus sp. The study aimed to understand key trends and optimization strategies by conducting experiments in both summer and winter seasons. The findings showed that maintaining low cell concentrations during periods of light inhibition was beneficial for nutrient uptake rates. Effective strategies for enhancing algae-based wastewater treatment included cell mass recycling and adjusting dilution rates based on light availability.
BIORESOURCE TECHNOLOGY
(2024)