Waste material from urban areas is a major environmental concern and landfill application is a frequent method for waste disposal. The leachate from landfills can, however, negatively affect the surrounding environment. A bioreactor cascade containing submerged biofilms was used to treat newly formed (< 1 year old) leachates of the Jbel Chekir landfill located southwest of Tunis, Tunisia. A preliminary analysis indicated a highly biodegradable portion of the leachate substances (BOD5/ COD = 0.4). The treatment system and performance was investigated at different organic loading rates. Results obtained during this study indicated a significant reduction in organic matter between 60 to 90% of Total Organic Carbon. The main bacterial genera responsible for removal of organic carbon in the leachate consisted of the genera Bacillus, Actinomyces, Pseudomonas and Burkholderia. The bacterial isolates inoculated into raw leachates further reduced TOC concentrations. TOC was reduced by Pseudomonas isolates by 70%. Actinomyces and Bacillus isolates reduced TOC by 69% and Burkholderia isolates resulted in the greatest TOC reduction of 77%. Consortia of the bacterial isolates reached TOC yield of about 84%.

The present study was conducted to study of some microbial pollution indicators such as - total count, total coliforms, fecal coliforms, E.coli and fecal streptococci from water and sediment of Al-Hilla River in middle of Iraq. Samples were collected over a period of twelve months from March, 2010 to February, 2011.The results showed variation in the number and density of microbial indicators between seasons and study sites. A highest number of bacterial pollutants recorded through spring and summer seasons. Many environmental factors affect the bacterial indicators such as solar radiation, temperature, water flow and organic matter. The present study showed high variation in quantitative and qualitative of bacterial indicators, also they could be used as a bio-indicator for pollution of both water and sediment in Hilla River.

Soil and water assessment Tool is used to model the hydrology of a mountainous catchment in tropical Africa. Land cover and soil characteristics for the catchment were used to determine initial model parameters that were later adjusted during a calibration process. The model was calibrated and validated against measured stream flow. Although the model performed satisfactorily for simulating monthly river flows based on SWAT model calibration guidelines, it fell short of capturing daily peak flows. Average error on prediction of daily peak flows was -19.8%, while the median error was 10.8%.Overall, the average simulated daily peak flow was 2.6cms less than the corresponding observed daily peak flow, indicating a model tendency to under predict the magnitude of peak events. The inability of the model to capture peak flows was found to be the main limiting factor for its performance.