Environmental Science/Studies

This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical soundings (VES) and 9 induced polarization soundings (IPS) data were acquired using Schlum-berger array technique. Three aquifer units were delineated across the study area. The resistivity of the first, second and third aquifer layers varies from 0.2 to 1569 ohm-m, 0.5 to 904 ohm-m and 0.4 to 665 ohm-m respectively, while depth to the top of first, second and third aquifer varies respectively from 0.7 to 151.5 m, 1.4 to 305.5 m and 12.9 to 452.9 m. The depth to the first aquifer layer is shallow (less than 5 m) in the coastal area which makes this area to be highly vulnerable to anthropogenic pollution while their proximity to Atlantic Ocean makes them susceptible to saline water intrusion. In all the three aqui-fer units, the coastal area, Agbabu and other few locations in the mainland are characterized by low resistivity values (below 60 ohm-m) indicating possible presence of brackish or saline water. IP sounding results showed that all the low resistive layers in the mainland are characterized by clayey materials. The integration of VES and IPS results enabled the delineation of the saline water lateral extent across the study area. There is a strong direct correlation (r² = 0.8564) between location distance from the saline water source and depth to saline water in the study area. This can therefore serve as a predictive model to determine depth to saline water at any location within the saline water zone in the study area.

Dumanquillas Bay is a body of saltwater and the major source of food located in the Southern Mindanao. It has been observed that marine resources and fish catch in the area are declining. This study assumed that fishing practices affect the decline of marine and fish catch in the bay. A study on the documentation of fishing practices in the area is reported here. Key informant interview (KII), focus group discussion, direct observation and document archival were used. Twenty-three (23) fishing practices were observed in the area. Based on R.A. 10654 or the Philippine Fisheries Code, five (5) fishing practices were identified in the bay which are illegal. These are “pahulbot sa lalum”, “pahulbot sa mabaw”, “panubli”, “panguryente” and “troll” that destroys sea grasses, coral reefs and the sea beds. The illegal fishing practices identified poses a threat to the marine resources. It implies weak implementation of fishing policies among the LGU’s and other concerned government instituti...

... Project for water supply and sanitation: Improve the services for poor people m the strategy of Project in years 90. [2] Le The Thu, Nguyen Van Ba and Nguyen Van Hiep, 1993. ... UMNET, No 2, 94. [16] Nguyen Cong Hao and Nguyen Cuu Thi Huong Giang, 1994. ...

Mining activities have several impacts on the environment. In our study, emphasis was given to assess biodiversity in one of the leading iron ore mining sites of Bailadila-Kirandul Iron Ore Mines (KIOM) of Dantewada District, South Bastar of Chhattisgarh. Habitat fragmentation, loss and deforestation are highly prevalent in the area. However, the study reveals high species richness of 110 and 253 plant species in core and buffer zone respectively. Canopy cover was found to be within 10 to 40% and in places in the buffer zone canopy cover with > 40% was recorded. Species diversity index indicates the instability of vegetation structure in the area with indices of 1.44 in core and 1.88 in buffer zone. Although species richness is high, about 10 floral species (7 herbs, 3 trees) are recorded under REET (Rare Endangered Extinct Threatened) species while locally endangered floral species are 6 and locally critically endangered are 4. Similarly, 208 faunal species belong to 10 faunal g...

ABSTRACT This chapter presents preliminary results regarding ethene removal from waste gases with a conventional trickling filter. It also discusses the possibility of adding an organic solvent as an ethene vector to increase the sorption of ethene. Biological waste-gas treatment can be an alternative for physico-chemical treatment, but the use of biological systems may become critical, as the organic compound becomes less water soluble. Experiments are carried out in a continuously operated lab-scale trickling filter. The trickling filter consists of a rectangular shaped plexi-glass column. The preliminary results show that the biomass growth on the packing material could be enhanced by loading the trickling filter with a secondary ordinary carbon source through the liquid circuit. The use of a solvent to increase the sorption of ethene is probably not possible, because ethene shows a low solubility in organic solvents. In addition, the use of a solvent to increase the sorption of ethene is probably not possible, because ethene shows also a low solubility in organic solvents.

Abstract Our empirical material based on interviews with influental actors in environmental policy in Finland suggested that possible future climatic changes illustrates the greatest single environmental threat on a global scale. The influential actors did not hesitate to consider as an issue of high certainty a kind of man-induced climate change. In mapping out social resources among actors to tackle climatic risks we have utilizised a teleological reasoning of rational action as an ideal model.

Abstract With industrial development comes increasing amounts of hazardous wastes and a simultaneous depletion of raw materials. The storage of hazardous solid and liquid wastes at dump sites presents a serious health and safety risk to the community, and other disposal methods are required. It seems prudent to consider wastes as a resource, which can be detoxified and converted to usable products. One such waste from industrial effluents is chromium. The application of ion exchange for chromium reclamation from effluents is reviewed. However, the main type of chromium waste is sludges from plating plants containing up to 20% Cr2O3. There are thousands of tons of this sludge in storage throughout the world. The methods of detoxification of the sludge are reviewed. The most effective method is probably the oxidation of Cr(III) followed by washing-out of chromic acid or sodium chromate. The solution obtained in the washing operation can be directly re-used in a plating plant. The most important step of the process is oxidation of Cr(III) to Cr(VI). The are few wet reactions which are practical for the conversion of Cr(III) to Cr(VI). The most promising method is oxidation by air at 850–900°C.