Comparative risk of pit latrine sludge from unplanned settlements and wastewater in Mzuzu City, Malawi

Abstract

Most developing countries use existing knowledge and infrastructure for wastewater in the treatment, reuse and disposal of faecal sludge. There is need to have a clear picture of the risk faecal sludge poses in relation to wastewater if effective treatment, disposal and reuse systems are to be implemented. Little work has been done to quantify the risk faecal sludge poses in relation to wastewater in a localized setting. This study quantifies the comparative risk of faecal sludge from pit latrines in unplanned settlements in Mzuzu City and wastewater. A total 80 sludge samples were obtained from 20 pit latrines in five unplanned settlement Laboratory characterisation was performed for Organics (chemical oxygen demand and biochemical oxygen demand), nutrients (total ammonia nitrogen and total phosphorus) and pathogens (Escherichia coli and helminth eggs) were determined through laboratory analyses. Documentation review was used to get wastewater characteristics. The study found a higher risk (comparative risk >1; p < 0.0001) for organics and nutrients in pit latrine sludge as compared to wastewater. Pit latrine sludge was found not to pose significantly higher public health risk from both E. coli (comparative risk <1; p < 0.0001) and helminth eggs (comparative risk < 1; p < 0.165) than relation to wastewater.

Electrochemical Disinfection in Water and Wastewater Treatment: Identifying Impacts of Water Quality and Operating Conditions on Performance

“… 12 , 47 Because cCOD concentration can exceed 1000 mg L –1 in wastewaters, organic carbon can often constitute the majority of oxidizable species in treated waters. 32 , 73 , 74 In addition to high levels of carbonaceous oxidant scavengers, many treatment contexts also display high levels of ammonia.…”

“…Similar to conventional disinfection systems, electrochemical disinfectant demand and system performance are strongly connected to water quality components, most significantly carbonaceous chemical oxygen demand (cCOD) and ammonia (Table ). ,, cCOD is a measure of the carbonaceous, oxidizable pollutants in the treated water and serves as an easily quantifiable analogue of oxidizable organic carbon in the system. , In electrochemical disinfection, the oxidant is generated at the surface of the electrode and then diffuses into the bulk solution where the majority of pathogen inactivation occurs. , However, as electrochemically generated oxidants lack inherent selectivity toward pathogens, the cCOD present in solution can scavenge the oxidant and lower the effective disinfectant dose. , Because cCOD concentration can exceed 1000 mg L –1 in wastewaters, organic carbon can often constitute the majority of oxidizable species in treated waters. ,, In addition to high levels of carbonaceous oxidant scavengers, many treatment contexts also display high levels of ammonia.…”

Effect of Project Control Practices on the Performance of Building Construction Companies in Uganda: A Case Study of the City of Kampala

“…In the context of Uganda, a developing country with a burgeoning construction sector, the need for effective project control practices becomes even more pronounced. Like many other developing nations, Uganda has challenges such as limited financial resources, weak infrastructure, and evolving regulatory frameworks [15]. Project control practices offer a tailored solution to address these challenges by fostering a disciplined approach to project management.…”