Interaction between suspended and settled solid particles in cassava wastewater

摘要

Cassava (Manihot Esculenta, Crantz) is a very important staple food in most developing countries.udDuring its processing into cassava flour or garri, wastewaters are generated and are indiscriminatelyuddischarged into the public sewers or into the environment and in some cases; the fermentedudwastewater is usually poured into latrines with the aim of degrading sewage. This study is aimed atudfinding out the interaction between the suspended solids and settled solids of cassava wastewater.udCassava wastewater was collected from a cassava processing plant at Ogige main market in Nsukkaudtown and monitored for 14 days. Half of the samples collected were left unstirred and the other halvesudwere continuously stirred. The parameters monitored include biochemical oxygen demand (BOD5),udsuspended solids, coliform, cyanide and pH. Results showed that there was a 73.4, 27.5 and 99.9%udreduction in the settled solids for BOD5, suspended solids and coliform bacteria respectively, for theudstirred samples while there was a 97.8, 44 and 99.9% reduction in the settled solids for BOD5,udsuspended solids and coliform bacteria respectively, for the unstirred samples. Overall, the unstirredudsamples performed better than the stirred samples with respect to BOD5 and SS removal. The result ofudthis work will guide sanitary engineers in the selection of influent parameters for the effective design ofudtreatment units.