Environmental and Microbial Investigation on the Dredged Sediment Soil of Diyala River in Iraq

摘要

Background and Objective: Pollution of water resources is a major risk to human health and water quality throughout the world. This in turn has led to a renewed interest in protecting the environment and has focused attention on the concept of environmental monitoring and site characterization, including an evaluation of the physical, chemical and biological factors that impact on the environment. The objective of this work was to determine the effect of Rustumiya Sewage Plant on the water and sediment quality of Diyala River in Iraq. Materials and Methods: This study comprised the isolation and identification of some pathogenic bacterial species using Bio-chemical tests, the coliforms enumeration was achieved by appropriate cultural media provided with suitable chemical indicators. Also, heavy metal ions concentration was identified using Flame Atomic Absorption Spectroscopy (FAAS). However, one-way analysis of variance by Statistical Package for the Social Science (SPSS) program (Version 19.0) was employed for the statistical analysis. Results: The results show certain pathogenic bacterial groups, including Clostridium perfringens, Pseudomonas aeruginosa, Salmonella sp., Shigilla sp. and Vibrio cholera that were isolated from six locations of sewage wastewater and dredged sediment of Diyala River. The numbers of total coliforms, total faecal coliforms and total viable count reached 120×106 cell mL–1. Some of biological and physiochemical parameters were also determined such as: Biochemical oxygen demand, chemical oxygen demand, total suspended solids, total dissolved solids and electrical conductivity. Concentration of Zinc, Nickle, Copper, Cadmium and Lead ions were measured in examined samples. Ni ions concentration was (101.7±1.2 mg kg–1) in sediments and Cd ions concentration was (0.09±0.0 mg L–1) in water. Conclusion: The extracted results revealed that Diyala River water and its dredged sediments contained high concentrations of both pathogenic bacteria and toxic heavy metals, which indicated the lack of efficient sewage treatment processes.