Article
Environmental Sciences
Benedict C. Krueger, Geoffrey D. Fowler, Michael R. Templeton
Summary: Thermal processes such as pyrolysis or combustion offer complete destruction of pathogens and energy recovery from faecal sludge. This study compared faecal sludge samples from different sanitation technologies and found that characteristics like calorific values and ash concentrations vary widely within technology groups, influencing the feasibility of thermal treatment processes. The study highlights the importance of considering the source of faecal sludge in the development of such processes and provides crucial knowledge for further advancements.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Biotechnology & Applied Microbiology
Chea Eliyan, Jennifer McConville, Christian Zurbrugg, Thammarat Koottatep, Kok Sothea, Bjorn Vinneras
Summary: Choosing appropriate sustainable treatment technologies involves satisfying user requirements, quality standards, and specific socio-technical constraints. This study used a locally adapted multi-criteria assessment to investigate faecal sludge treatment technologies in Phnom Penh. The research identified seven primary and thirteen secondary treatment technologies, and through a series of screening and assessments, co-composting was found to be the most suitable option based on health criteria. However, vermicomposting and black soldier fly larvae composting ranked highest when economic return on investment and lower treatment class were prioritized. The study highlights the importance of considering secondary treatment options in early planning for faecal sludge management in low- and middle-income countries.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Engineering, Environmental
Matthew Mamera, Johan J. van Tol, Makhosazana P. Aghoghovwia
Summary: Biochar is a valuable treatment option for faecal sludge management, as it has the potential to significantly reduce organic and inorganic contaminants in soil and improve water retention. This study found that pinewood biochar applied at rates between 5 and 20 t/ha showed high removal efficiencies for bacteria and nitrates/phosphates.
Article
Green & Sustainable Science & Technology
Hannah Larissa Nicholas, Keith H. Halfacree, Ian Mabbett
Summary: Full-scale pyrolysis of faecal sludge is a reliable technology for safe pathogen removal and biochar production, which can enhance crop productivity. Faecal sludge biochar has the potential to improve acidic, low nutrient soils and crop yield, especially in developing countries. However, little research has been conducted on public acceptance of faecal sludge biochar as a soil enhancer. The study found that males and older age groups were more likely to have a positive perception of faecal sludge biochar.
Article
Environmental Sciences
Richard Tokwaro, Swaib Semiyaga, Charles B. Niwagaba, Anne Nakagiri, Jotham Ivan Sempewo, Chimdi C. Muoghalu, Musa Manga
Summary: This study aimed to determine the effectiveness of black soldier fly larvae (BSFL) in treating faecal sludge (FS) from pit latrines under different conditions and to evaluate the quality of the residue left after treatment. The results showed that the optimum feeding rate, larval density, and moisture content were 50 mg/larvae/day, 1.33 larvae/cm(2), and 60%, respectively. The reduction efficiency at optimum conditions was 72% and 66% for FS from lined and unlined pit latrines, respectively. Therefore, BSFL can be applied for effective treatment of FS from pit latrines in informal urban settlements, while generating high-quality residue and providing an additional value chain in faecal sludge management.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2023)
Article
Environmental Sciences
Dirk Dirix, Francesca Rossi, Harald van der Hoek
Summary: This article discusses an action-research process in the city of Toamasina, Madagascar, which improved emptying, transport, and treatment services for fecal sludge and created a profitable private service provider called Clean Impact.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Energy & Fuels
Quattara N. S. Christiane, Emmanuel Amankwah, Edward A. Awafo, Soumaila Sodre
Summary: Burkina Faso faces challenges in managing organic waste, especially faecal sludge, due to inadequate sanitation infrastructure. This study demonstrates the potential of biogas technology in sustainably managing faecal sludge and other organic wastes, resulting in energy recovery and organic fertilizer production for agriculture. The research findings indicate that biogas production from different combinations of waste materials, particularly faecal sludge, can effectively address sanitation issues, provide energy, and enhance agricultural productivity.
Article
Environmental Sciences
Chea Eliyan, Jennifer R. McConville, Christian Zurbruegg, Thammarat Koottatep, Kok Sothea, Bjoern Vinneras
Summary: This study provides baseline data for effective faecal sludge management (FSM) planning in Phnom Penh, aiming to incentivise sustainable management and resource recovery. The study reveals that Cheung Ek and Kob Srov wetlands are the major recipients of faecal sludge in Phnom Penh, with annual volumes of 18,800 m(3) and 13,700 m(3) respectively. The faecal sludge in Phnom Penh contains valuable resources such as nitrogen, phosphorus, and energy, but further investigations are needed to determine appropriate treatment options for resource recovery.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Environmental Sciences
Amour Seleman, Sara Gabrielsson, Richard Kimwaga
Summary: The study highlighted the importance of well-designed toilet facilities in unplanned urban settlements for safe desludging of faecal sludge containment. Analysis showed that design features such as partially lined pits, lack of containment access holes, and presence of solid wastes can negatively impact the containment strength and potential for safe desludging. Only 54.8% of containments studied had faecal sludge that could be desludged using mechanized or hand pumps. To enhance safe desludging, urgent attention is needed on key design features and usage practices such as fully lined pits, mandatory presence of access holes, and limitations on solid waste entering the pits in Dar es Salaam.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Green & Sustainable Science & Technology
Shirish Singh, Mohammed Ali Ibrahim, Sumeet Pawar, Damir Brdjanovic
Summary: This study highlights the major barriers limiting the adoption and reuse of FS co-compost in agriculture, including health risks, bad odor, and socio-cultural beliefs.
Article
Engineering, Environmental
Mohammadreza Kamali, Tejraj M. Aminabhavi, Luis A. C. Tarelho, Rens Hellemans, Joren Cuypers, Isabel Capela, Maria Elisabete V. Costa, Raf Dewil, Lise Appels
Summary: The study showed that acclimatization of activated sludge with pinewood biochar significantly enhanced the biodegradation rate of phenol. The presence of biochar led to increased specific biodegradation rates and improved microbial colonization and growth, demonstrating the positive effects of biochar in the treatment of synthetic effluents.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Environmental Sciences
Chea Eliyan, Jennifer McConville, Christian Zurbrugg, Thammarat Koottatep, Kok Sothea, Bjorn Vinneras
Summary: To achieve the universal target of 'safely managed sanitation' set out in UN Sustainable Development Goal 6, the world needs to increase its rate of progress. One way to promote safer faecal sludge management is to shift to a more circular system with nutrient recycling, but this carries the risk of heavy metal accumulation in the environment. This study analyzed the concentrations of heavy metals in faecal sludge and found that while all elements analyzed were within permissible limits for land application, Hg and Zn concentrations exceeded certain limits for organic fertilizer and compost.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2024)
Article
Chemistry, Analytical
Sirui Tong, Shuping Zhang, Haoxin Yin, Jiaxing Wang, Minzi Chen
Summary: This study evaluated the co-hydrothermal treatment combined with pyrolysis of rice straw and sewage sludge to produce biochar, aiming to reasonably dispose of sewage sludge as a resource and avoid secondary pollution. Results showed a synergy between rice straw and sewage sludge during the co-HTP process, leading to slightly higher biochar yield than predicted values. The co-HTP process also promoted the increase of aromaticity and stability of biochar, with a significant increase in specific surface area. Additionally, the process decreased the total concentrations of heavy metals in biochar and helped immobilize heavy metals to reduce environmental risks.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2021)
Article
Agronomy
H. Larissa Nicholas, Aisling Devine, Iain Robertson, Ian Mabbett
Summary: Full-scale pyrolysis of faecal sludge in developing nations is an emerging technology for pathogen removal and biochar production. This study found that applying faecal sludge biochar to acidic, sandy soil significantly increased tomato yield and plant height. The combined treatment of biochar and fertilizer showed the highest yield increase.
Article
Environmental Sciences
N. Chandana, Bakul Rao
Summary: In India, the second phase of the ODF initiative has begun to sustain millions of toilets, but to achieve this goal, significant knowledge gaps and variations in fecal sludge characteristics must be addressed. The study found that fecal sludge characteristics change with age, with older sludge requiring longer treatment time and higher costs. The research can help practitioners establish or modify fecal sludge treatment systems based on variations in characteristics at the town level in India.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Engineering, Environmental
Rong-Gui Zhu, Chang-Gui Pan, Feng-Jiao Peng, Chao-Yang Zhou, Jun-Jie Hu, Kefu Yu
Summary: This comprehensive survey investigated the occurrence, bioaccumulation, and trophic magnification of parabens and their metabolite 4-HB in a marine food web. Results showed that parabens were the predominant pollutants in marine organisms, with significant bioaccumulation from sediments. The estimated trophic magnification factor indicated biomagnification for MeP and trophic dilution for 4-HB. Overall, the risks for humans consuming marine organisms were found to be low.
Article
Engineering, Environmental
Andres F. Torres-Franco, Deborah Leroy-Freitas, Cristina Martinez-Fraile, Elisa Rodriguez, Pedro A. Garcia-Encina, Raul Munoz
Summary: Anaerobic and microalgae-based technologies have emerged as sustainable alternatives for municipal wastewater treatment. However, the presence of viruses in the treated wastewater is a major concern for reuse applications. This study assessed the ability of these technologies to reduce viruses during secondary wastewater treatment. The results showed that all technologies were effective in reducing the concentration of viruses, with microalgae-based treatment exhibiting the highest potential for reducing the disinfection requirements of treated wastewater.
Article
Engineering, Environmental
Young Gwang Kim, Sae Yun Kwon, Spencer J. Washburn, Scott C. Brooks, Ji Won Yoon, Lucien Besnard
Summary: The study uses Hg isotope ratios to identify the sources and exposure pathways of mercury in bivalves, finding that dissolved Hg phases in the water column are the primary source and exposure pathway to bivalves. This provides new insights into using bivalves as bioindicators for sediment quality monitoring.
Article
Engineering, Environmental
Hui Geng, Ying Xu, Rui Liu, Dianhai Yang, Xiaohu Dai
Summary: This study investigates the effect of cation exchange resin (CER) on the sequential recovery of hydrogen and methane from anaerobic digestion (AD) and the corresponding mechanisms. The results show that CER can simultaneously enhance the production of hydrogen and methane by promoting the solubilisation, hydrolysis, and acidification of organic matter. Additionally, CER facilitates effective contact between bacteria and organic particulates and reduces the energy barrier for mass transfer during methane production. The study also reveals changes in the microbial community structure and metagenomics during the AD process.
Article
Engineering, Environmental
Xiaojing Lin, Zhan Jin, Shunfeng Jiang, Zhiquan Wang, Suqing Wu, Ke Bei, Min Zhao, Xiangyong Zheng
Summary: Dehumidification combined with addition of absorbent resin supplement (ARS) was used to achieve rapid evaporation of non-pretreated urine, resulting in high water evaporation efficiency and nutrient recovery.
Article
Engineering, Environmental
Yangli Che, Chaoran Lin, Shen Li, Jiao Liu, Longhai Zhu, Shilei Yu, Nan Wang, Haoshuai Li, Mutai Bao, Yang Zhou, Tonghao Si, Rui Bao
Summary: Hydrodynamic processes play a crucial role in the transmission of sediments, microbial assembly, and organic carbon redistribution in the ocean. Through experiments and analysis, we found that hydrodynamics shape the assembly of microbial communities and control the redistribution of different sourced organic carbon, thereby influencing microbial-mediated biogeochemical transformation.
Article
Engineering, Environmental
Chao Chen, Yu Yang, Nigel J. D. Graham, Zhenyu Li, Xingtao Yang, Zhining Wang, Nadia Farhat, Johannes S. Vrouwenvelder, Li -an Hou
Summary: The fouling of seawater reverse osmosis membranes is a persistent challenge in desalination. This study monitored the operational performance of a desalination plant for 7 years and the fouling development in different areas of membrane modules. The findings showed that operational performance declined over time and fouling mainly occurred at the feed side of the modules, with the highest microbial diversity. Keystone species like Chloroflexi and Planctomycetes played an important role in maintaining community structure and biofilm maturation. Polysaccharides, soluble microbial products, marine humic acid-like substances, and inorganic substances contributed to fouling. Overall, biofouling had a significant impact on membrane fouling after 7 years of operation.
Article
Engineering, Environmental
Dan Li, Jieyi Sun, Yibo Fu, Wentao Hong, Heli Wang, Qian Yang, Junhong Wu, Sen Yang, Jianhui Xu, Yunfei Zhang, Yirong Deng, Yin Zhong, Ping'an Peng
Summary: Sulfidation-oxidation treatment of magnetite (Fe3O4) enhances the production of dark center dot OH, which can efficiently degrade dissolved organic matter (DOM) and accelerate carbon cycling.
Article
Engineering, Environmental
Cheng Yu, Kaijun Wang, Kaiyuan Zhang, Ruiyang Liu, Pingping Zheng
Summary: This study implemented a microaerobic-aerobic configuration in a full-scale municipal wastewater treatment facility and investigated the effects on sludge characteristics, pollutant removal, microbial community, and granulation mechanisms. The results showed successful transition from flocculent-activated sludge to well-defined AGS after two months of operation. The primary pathways for pollutant removal were simultaneous nitrification, denitrification, and phosphorus removal. Moreover, the incorporation of internal separators induced shifts in the flow pattern, which promoted granulation.
Article
Engineering, Environmental
Zhe Zhang, Shaoyang Hu, Guangrong Sun, Wei Wang
Summary: Halogenated aromatic disinfection byproducts (DBPs), such as halogenated phenols, have garnered widespread attention due to their high toxicity and prevalence. This study reports on the analysis, occurrence, and cytotoxicity of a group of emerging halogenated aromatic DBPs, known as halogenated polyhydroxyphenols (HPPs), in drinking water.
Article
Engineering, Environmental
Shengyue Chen, Jinliang Huang, Peng Wang, Xi Tang, Zhenyu Zhang
Summary: Accurate prediction of river water quality is crucial for sustainable water management. This study introduces wavelet analysis and transfer learning techniques to assist LSTM modeling, proposing a newly coupled modeling approach that improves short-term prediction of river water quality.
Article
Engineering, Environmental
Bang Du, Xinmin Zhan, Piet N. L. Lens, Yifeng Zhang, Guangxue Wu
Summary: Efficient anaerobic digestion relies on the cooperation of different microorganisms with different metabolic pathways. This study investigated the effects of different operational modes and the addition of powdered activated carbon (PAC) on ethanol metabolic pathways. The results showed that the SBR mode and the presence of CO2 facilitated ethanol metabolism towards propionate production, while the CFR mode with extended solids retention time enriched Geobacter. Adjusting operational modes and PAC addition can modulate anaerobic ethanol metabolism and enrich Geobacter.
Article
Engineering, Environmental
Wanfa Wang, Si-Liang Li, Jun Zhong, Yuanbi Yi, Fujun Yue, Zenglei Han, Qixin Wu, Ding He, Cong-Qiang Liu
Summary: This study compares the carbon biogeochemical processes in karst and non-karst regions within large thermal stratified river-reservoir systems. The results demonstrate that karst reservoirs have a reduced potential for carbon emissions and highlight the importance of considering geologic settings to improve accuracy in regional and global CO2 emission estimates.
Article
Engineering, Environmental
Chunxia Jiang, Zelong Zhao, Dong Zhu, Xiong Pan, Yuyi Yang
Summary: This study analyzed the occurrence and distribution of antibiotic resistance genes (ARGs) in different environmental media of the Yangtze River using metagenomics. Core resistome dominated by multidrug resistance genes was found in all samples, while rare resistome dominated by various resistance genes was more prevalent in plasmids. Specific bacteria were identified as hosts for both core and rare resistomes, with high clinical concern ARGs found in the rare resistome. Particle-associated environment provided the most ideal conditions for resistome hosts. This study provided insights into the genetic locations of ARGs and the community assembly mechanisms of ARG hosts in freshwater environments.
Article
Engineering, Environmental
Yu Zhang, Yongtao He, Linchun Jia, Lei Xu, Zheng Wang, Yueling He, Ling Xiong, Xumeng Lin, Hong Chen, Gang Xue
Summary: By synergizing organic carbon source, thiosulfate, and zero-valent iron, efficient mixotrophic denitrification of oligotrophic secondary effluent can be achieved. Thiosulfate plays a vital role in promoting TN removal efficiency, while corrosion of Fe0 releases OH- to neutralize H+ from thiosulfate-driven denitrification, creating a suitable environment for denitrification. The coordination of thiosulfate and Fe0 maintains the dominance of Thiobacillus for denitrification.