Proximate Analysis and Bio-Digestion of Cattle Abdominal Waste for the Production of Organic Fertilizer

Abstract

Biodigestion of cattle abdominal waste from a slaughterhouse in Owerri West Local Government Area Imo state was studied. It was stabilized in a mobile biodigester for the production of quality fertilizer through the activities of microorganisms. Clean plastic bags were used to collect influent and effluent samples in replicate, stored and transported in iced coolers to the laboratory for analyses. Standard laboratory methods were used for sample analyses which focused on Nitrogen, Phosphorus, Potassium, pH, Organic matter, Moisture content, Organic carbon, and Carbon/Nitrogen ratio from pre-digested and digested samples as parameters of interest. Periodic sampling from biodigester was carried out at interval of 0 week (pre-digested samples- PDS), 2 weeks (digested samples1- DS1) and 5 weeks (digested samples 2 -DS2) for parameters investigated. Statistical Package for the Social Sciences (IBM- SPSS(C)) version 19.0, statistical package for windows and MS Excel was used in the analysis of data. The test of homogeneity of variance in means of the variables was carried out using the one-way ANOVA. Further structure detection was made with means plot. Results obtained on pre-digested influent show that Nitrogen varied between 2.03-2.06% (2.01±0.05), Potassium varied between 1.25-1.32mg/kg (1.28± 0.02), and Phosphorus varied between 1.45-1.54mg/kg (1.50±0.02). Carbon/Nitrogen ratio was constant at 20, Moisture content varied between 73.50-80.50% (78.00±1.56), Organic matter varied between 67.42-70.86% (69.05±0.70), Total organic carbon varied between 39.20-41.20% (40.15 ±0.46), and pH varied between 6.30–6.50 (6.41±0.04) respectively. In the digested effluent, Nitrogen varied between 1.40-1.66% (1.53±0.04), Phosphorus varied between 1.20–1.26mg/kg (1.23±0.01), Potassium varied between 1.10-1.17 mg/kg (1.13±0.01), pH varied between 7.20–7.45 (7.32±0.04), Total organic carbon varied between 25.20-29.88% (27.60±0.66), Carbon/Nitrogen ratio was constant at 18, Organic matter 43.34-51.39% (47.48±1.14), and Moisture content varied between 86.10-95.36% (90.88±1.23) respectively. General results show that there was significant inequality among the variables examined [F(12.50) > Fcrit (4.03)] at P=0.05. Total organic carbon, Organic matter and Moisture content were most responsible for the observed heterogeneity.