Traditional Coping Mechanism and Environmental Sustainability Strategies in Nnewi, Nigeria
Nnewi is situated some 30 kilometres South East of Onitsha in Anambra State in the southeastern part of Nigeria. This highly commercial town has undergone rapid urbanisation and industrialisation within the past two decades, since the end of the 1967–1970 Nigerian civil war. The Igbo community of the study area had traditionally employed bioconversion methods and other indigenous technology to process or recycle bio and non-degradable wastes. Industrialisation has enjoyed priority status in this locality as a requirement for modernisation and economic progress. The rapid urbanisation, aggressive industrialisation, and the attendant uncontrolled population growth have had a deleterious impact on the environment. There is now a wide range of industrial wastes that are released daily into the environment. Effects of these activities on the socio-cultural practices of the people, plant genetic resources and the environment are highlighted. In addition to palliative measures suggested here, a call is made to revisit the successful indigenous waste treatment and management technology formerly practised by the Igbo community. The importance of combining modern biotechnological approaches with the indigenous technology, norms and practices of Nwewi people to effect suitable waste treatment and management, as well as improving the living habits and the education of the people about their environment, is recommended.
Bioremediation of crude oil polluted soil by the white rot fungus, Pleurotus tuberregium (Fr.) Sing.
Bioremediation has become an attractive alternative to physicochemical methods of remediation of polluted sites. White rot fungi (WRF) are increasingly being investigated and used in bioremediation, because of their ability to degrade an extremely diverse range of very persistent or toxic environmental pollutants. The white rot fungus, Pleurotus tuberregium, was examined for its ability to ameliorate crude oil polluted soil. This was inferred from the ability of the polluted soil to support seed germination and seedling growth in Vigna unguiculata, at 0, 7 and 14 days post treatment. Results obtained from the present study showed that bioremediation of soil contaminated with crude oil was possible, especially when the fungus had been allowed to establish and fully colonize the substrate mixed with the soil. There were significant improvements in % germination, plant height and root elongation values of test plants, when seeds were planted 14 days post soil treatment. At 1 to 5% crude oil pollution, % germination values were comparable with the values in control plants in the 14 days treatment, and significantly higher than values obtained in the day 0 treatment. Also, at the highest level of crude oil pollution (15%), there was about 25% improvement in % germination value over the 0 day treatment. This trend of improvement in values was also observed for plant height, root elongation and biomass accumulation as well as decreased total hydrocarbon content.
The effect of a crude oil spill on cereals
Abstract A break in an oil pipeline in mid-winter caused oil to travel underground over a distance of about 850 m. Oil moved upwards through cracks in the frozen soil, especially during recovery attempts. The contamination in the affected area varied considerably both horizontally and vertically. Oil contamination and damage to the soil structure due to the clean-up efforts caused serious yield decreases during the next summer. In subsequent growing seasons oil was the major factor in reducing yields. Total above-ground dry matter and grain yield were affected similarly by oil pollution; even very small amounts of oil (less than 0·2% by weight) in the 0–30 cm or 0–90 cm depth reduced yields considerably. Oil reduced the available N content of the soil and markedly reduced water uptake by wheat from contaminated layers or from below such layers. Problems in reclaiming soils with oil contamination below the topsoil are discussed.