Toilet chemical additives and their effect on faecal sludge characteristics

Eugene Appiah-Effah; Godwin Armstrong Duku; Bismark Dwumfour-Asare; Isaac Manu; Kwabena Biritwum Nyarko

doi:10.1016/j.heliyon.2020.e04998

Toilet chemical additives and their effect on faecal sludge characteristics

Heliyon. 2020 Sep 23;6(9):e04998. doi: 10.1016/j.heliyon.2020.e04998. eCollection 2020 Sep.

Authors

Eugene Appiah-Effah¹, Godwin Armstrong Duku², Bismark Dwumfour-Asare³, Isaac Manu¹, Kwabena Biritwum Nyarko¹

Affiliations

¹ Regional Water and Environmental Sanitation Centre, Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, Kumasi Ghana.
² Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, Kumasi Ghana.
³ Department of Environmental Health and Sanitation Education, University of Education Winneba, Asante-Mampong Campus Ghana.

Abstract

This study investigated the effects of two mostly improvised chemical additives, calcium carbide and lambda super 2.5 EC (LSEC), on the physico-chemical and microbial characteristics of faecal sludge from toilets. The quality of faecal sludge was assessed before and after application of the chemical additives in an experimental setup of ten different treatment units including a control, and treatment replicates. The initial characteristic of the faecal sludge was slightly acidic with high content of slowly degradable organic matter. The experimental control without additives after 30 days showed reduction in BOD₅, COD, helminth eggs and sludge mass by a maximum of 30%, 34.7%, 99.8% and 55% respectively. Similarly, calcium carbide additive reduced the BOD₅, COD, helminth eggs and the mass of the faecal sludge by 47.4%, 48.3%, 99.6% and 61% respectively. Also, LSEC additive reduced BOD₅, COD, helminth eggs and the mass of the sludge by 40.6%, 47.9%, 95.9% and 58% respectively. The two additives showed significant treatment effect on the faecal sludge although the level of treatment could not meet the regulatory discharge limits for the key quality parameters assessed including sanitisation. The study is still a grey area and more research is recommended to enrich the findings.

Keywords: Biodegradation; Calcium carbide; Characterisation; Environmental engineering; Environmental health; Environmental management; Environmental pollution; Faecal sludge; Helminth eggs; Lambda-cyhalothrin; Mass loss; Microbiology; Public health; Public toilet; Sanitisation; Toilet additive.