Title:
BIOPHYSICOCHEMICAL EFFICIENCY OF A LOCALLY DESIGNED SEWAGE SYSTEM FOR TREATMENT OF IMPACTED WATERS OF SOMBRIERO RIVER IN NIGER DELTA, NIGERIA

Authors:
Edward Moore*, Godwin Udom, Nnaemeka Ngobiri, and Leo Osuji, Nigeria

Abstract:

The efficiency of a locally designed sewage treatment plant was tested, using untreated sewage water samples from Sombriero River in the Niger Delta region of Nigeria. A two-week field reconnaissance campaign was carried out in order to identify areas to be sampled, and delimit hot spots of open river defecation. Composite samples were thereafter collected within an interval of four weeks (on weekly basis). All biological and physicochemical parameters were determined according to standard analytical methods for examination of water and wastewater. The efficiency in the removal of the sewage load was found to be significantly high (P ≤ 0.05) as corroborated by the evaluated indicator parameters, which showed an average removal efficiency of >70%; PO4-P (phosphorus as phosphate) removal recorded the highest efficiency of 98.6%. Dissolved Oxygen (DO) for the untreated sewage water ranged from 3.1 - 3.8mg/l (with an average DO of 3.45mg/l±0.31); while Biochemical Oxygen Demand within 5 days (BOD5) was in the range of 1.2 - 1.4mg/l, with an average of 1.33±0.1mg/l in the untreated sample. The treated sample gave an average DO and BOD5 values of 4.83±0.17mg/l and 2.20±0.26mg/l respectively. An acidic pH range of 5.1 – 5.7 measured in the untreated sewage water similarly transformed to a near to neutral pH range of 6.4 - 7.1, after treatment. The treatment plant also demonstrated substantial efficiency in enhancing the metabolic activities of indicator organisms, as evidenced in the population densities of Escherica coli, Streptococcus spp., Clostridium spp., Total coliform, and Fecal coliform (in Most Probable Numbers per 100 Millilitres). On the strength of its overall efficiency and environmental friendliness, the locally designed plant can be deployed in-situ for the treatment of the impacted hot spots of the Sombriero River. Also, due to the high human fecal contamination detected in this work, there is an urgent need for government and development stake holders in the oil rich Niger Delta to adopt sanitation security models that would guarantee critical infrastructures which discourage open sea defecation and promote healthy living conditions in the rural riverine communities. Such critical interventions by government and stakeholders in the Niger Delta should include, inter alia, the provision of toilet amenities and the immediate development and deployment of this locally designed treatment plant.