Potentials of Biogas Generation from Mixture of Three Substrates, Water Hyacinth, Cassava Peels and Cow Dung- Wh+Cp+Cd

The potentials of biogas generation from mixtures of three substrates, water hyacinth, cassava peels and cow dung was evaluated using standard microbiological techniques. The results revealed that the combination of the three substrates without starter culture recorded zero milliliter biogas production in the first 5 days with optimum yield of 300mls, 600mls and 715mls for 1kg, 2kg and 3kg weight of the mixture respectively within 25 days while the digester with starter culture yielded optimum biogas production of 475mls, 650mls and 820mls respectively in 1kg, 2kg and 3kg weight within 25 days. The total viable bacterial and fungal counts from the substrate slurry of the WH + CP + CD was 7.55 x 108cfug-1 and 2.35 x 104cfug-1 before digestion respectively and 4.10 x 105cfug-1 and 1.20 x102 cfug-1 after digestion respectively without starter culture. The digester with starter culture gave 7.68 x 108cfug-1 and 3.35 x 104cfug-1 for bacteria and fungi respectively before digestion and 5.25 x 105cfug-1 and 2.20 x 102cfug-1 respectively for bacteria and fungi after digestion. Optimum and total biogas produced from the treatments KEY WORDS:  BIOGAS, WATER HYACINTH, CASSAVA PEELS and COW DUN

Evaluation of Total Hydrocarbon (THC) levels in oil polluted coastal areas of South Eastern Nigeria

Analysis of water, sediment and biota for total hydrocarbon (THC) levels five months after the Mobil oil spillage in the coastal areas of Cross River State, South Eastern Nigeria, was carried out. THC levels in water, sediment and biota samples were determined by colorimetric method after extraction with distilled n-hexane. Result showed elevated THC mean levels in water (149+81.11 mg/l), sediment (339.2 + 245.7 mg/kg) and biota (198.9 + 50.08 mg/kg), indicating a polluted environment. THC levels in water at all sampling locations were above 10mg/l being the maximum recommended limit of FEPA. In sediment and biota, THC values exceeding 100mg/kg and 25mg/kg, respectively, were observed, indicating that sediment and biota were highly impacted. THC levels in water correlated significantly (r = 0.632) with THC levels in the sediment (P = 0.05). Bioconcentration factors (BCFs) in 70% of the water samples were higher than unity. Although there was low BCF in about 70% of sediment samples, BCF in water significantly correlated (r = 0.689) with BCF in sediment (P = 0.05), indicating that the more the THC levels in the water column in relation to sediment, the more the biota were impacted. Key Words: Oil spillage, Total hydrocarbon, Bioconcentration factor, Polluted environment, Coastal Areas. [Global Jnl Environ Sci Vol.2(1) 2003: 1-9