Non-negligible greenhouse gas emissions from non-sewered sanitation systems: A meta-analysis

Self Cite

Nutrient recovery and recycling are of great importance in sustainable development. Blackwater (BW) refers to wastewater from toilets, which contains feces, urine, water, and toilet paper from flush toilets. The highly concentrated nutrients of blackwater could be collected through source separation and treated adequately to recover nutrients efficiently and economically. The review intends to give an overview of the characteristics of BW and different techniques to recover nutrients and other valuable products. A number of these technologies are currently under development or being tested at laboratory or pilot scale. The perspective for blackwater nutrient recovery technologies is very positive due to their great potential. For application of source-oriented sanitation infrastructure and systems, there is still a long way to go for development of commercial technologies and valuable products.

Section: Discussionmentioning

confidence: 99%

Nutrient recovery technologies for management of blackwater: A review

Wang

Chen

et al. 2023

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“…Diarrhea caused a substantial disease burden in China, especially in rural areas and west China, where sanitation conditions are relatively poor. However, a significant decrease in the prevalence of diarrheal disease since the founding of the People's Republic of China was observed, which was a result of the implementation of many public and nonpublic health measures, including providing clean water supplies and improving latrines and sanitation in rural and poor areas (Cui et al, 2018;Lu, 2019;Cheng et al, 2022). STH was once a major parasitic disease that endangered the health of a large portion of the rural population in China.…”

Section: Discussionmentioning

confidence: 99%

Health Benefits of Improved Latrine in Rural China

Shang

Li²,

Wang³

et al. 2022

Proper sanitation facilities promote health because they allow people to dispose of their waste appropriately. Since the founding of the People’s Republic of China, the Chinese government has been committed to improving water and sanitation. The coverage of sanitary latrines in rural China reached more than 70.0% in 2022. Using published literature, open data, and national statistics, this study evaluated the health effects of improved latrines in China. A search strategy aimed at collecting all latrine improvement-related community intervention research in China from 1990 to 2021 was designed and implemented. Incidences of three diseases—schistosomiasis, diarrheal disease, and soil-transmitted helminths (STH)—were used as indicators of health benefits. The relationship between adjusted relative risk (RR) and coverage of sanitary latrines in the study area was examined using a log-linear model. Overall, 411 incidences of the three diseases before and after community intervention were extracted from 74 qualified articles. The results demonstrated the importance of promoting access to sanitary latrines in disease prevention and control in China. The overall estimates revealed mean reductions of 60% for diarrhea risk, 42% for schistosomiasis risk, and 65% for STH risk compared to no intervention. In addition, increasing sanitary latrine coverage was negatively correlated with RR in China, indicating that populations with high sanitary latrine coverage were less likely to be affected with water, sanitation, and hygiene-related diseases.

“…Minde et al (2013) pointed out that if 1 kg of wood is burned in traditional cookstoves, it generates approximately 318 g of C. However, if biogas is used, each household saves the consumption of 3 metric ton of firewood annually. Biogas technology for FS treatment can combat environmental challenges such as spread of diseases, eutrophication, acidification, air pollution, and climate change issues (Cheng et al, 2022).…”

Section: Environmental Benefitsmentioning

confidence: 99%

Insights into the anaerobic digestion of fecal sludge and food waste in Tanzania

Kilucha

Cheng

Minza

et al. 2022

Self Cite

With the increasing demand for renewable energy and environmental protection, biogas technology has attracted considerable attention around the world. Fecal sludge (FS) is rich in organic matter, and it contains high concentrations of excreted pathogens that cause gastro-intestinal infection. In Tanzania, fecal sludge management from on-site sanitation systems poses a threat on environmental safety. This study aimed to assess the feasibility of the use of anaerobic digestion (AD) for the treatment of FS and the production of biogas as renewable energy to achieve multiple benefits in Tanzania. For the experiments, FS and food waste (FW) were used as feedstock, and rice straw-derived biochar (RSB) was added as an additive to improve biogas production. The mesophilic anaerobic digestion resulted in a methane yield of 287.5 ml/g VS for FS + FW co-digestion and 396 ml/g VS for FS + FW + RSB co-digestion. At ambient temperature (20–26°C), the system produced a methane yield of 234 ml/g VS for FS + FW co-digestion and 275 ml/g VS for FS + FW + RSB co-digestion. Three different scenarios (digester with volumes of 4, 100, and 400 m3, respectively) and strategies for FS treatment by AD in Tanzania were proposed and analyzed. These treatments can produce methane volumes of 1.95, 49.5, and 199.5 m3 with pay-back periods of 3, 5, and 15 years and net present values of + 28, +1,337, and +52,351 USD, respectively. The calculations also showed that the heat value from the produced biogas and energy needed to heat the digester at 26–37°C resulted in energy balance values of + 0.012, + 0.53, and + 2.22 GJ/day for the 4, 100, and 400 m3 digester volumes, respectively.