The study characterized the changes in physico-chemical properties and bacterial community structure during mesophilic anaerobic digestion (AD) of pit latrine sludge. The sludge was sampled from six different pits six times at an interval of 40 days. Standard techniques were used to assess the changes in pollution indicators including COD and faecal coliforms. Metagenomic DNA from a composite sample from the six pits’ sludge was then extracted at Days 0, 14 and 35 and directly sequenced followed by analysis of the microbial structure using the Ribosomal Database Project tools. Multivariate analyses were used to identify the main determinants of microbial community structure during the digestion process. AD significantly reduced the levels of pollution indicators (p < 0.05). Total solids, volatile solids and COD were reduced by 17–27%, 52–79%, and 42– 63%, respectively. The indicator pathogenic microorganisms FC and E. coli were reduced by 34–54% and 35–60%, respectively. The reduction in terms of COD and BOD were, however, not sufficient to satisfy the standards for safe disposal into the environment. Proteobacteria were the most dominant bacterial phylum in the undigested sludge (24.1%) and were significantly reduced to 2.5% at the peak of the AD (Day 14) up until Day 35. Firmicutes significantly increased (p < 0.05) from 22.4% to 28.8% at Day 14 before being reduced to 11.6% at Day 35. This study contributes to our understanding of AD of pit latrine faecal sludge through mesophilic AD as a baseline study, and helps to inform future research on mesophilic AD.
The objective of this study was to characterise the physical and chemical properties of human faecal sludge from various pit latrines in relation to the differences in usage and management practices of each pit over time. Physico-chemical parameters were measured from the sludge collected from the top layers of six different pit latrines that were sampled six times at an interval of 40 days. Data were also collected on pit user habits and management practices. Multivariate statistical analyses were carried out to determine the variations in sludge physico-chemical characteristics among the pits and the associations between these and user habits and management practices. The results showed that the sludge characteristics from the six pits were significantly different from each other (global test sample statistic (R): 0.862 and p < 0.002). This study also indicated that user habits were important determinants of pit sludge characteristics. This study scientifically contributes to knowledge on how pit management and usage practices determine the potential value and quality of pit latrine sludge for various anaerobic digestion applications for resource recovery. The findings also contribute the knowledge required for the management and treatment of pit latrine sludge, adoption and adaptation of new treatment technologies for local use.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.