Assessment of Bahr El-Baqar Drain and its Environmental Impact on Manzala Lake in Egypt

Abstract

Polluted drains are considered one of the most important dangerous elements for the surrounded aquatic environment. The use of polluted water from drains outfalls in fish farms and agricultural lands has a very dangerous environmental effect on plants, soil, and groundwater. Over a year period starting May 2018, 75 water samples were collected from bahr El-Baqr drain outlet, Manzala wetland and Manzala Lake to examine and classifies it water quality and evaluates its suitability for reuse in safe irrigation. Based on physical, chemical and bacteriological results obtained, the calculated water quality index (WQI) classified Bahr El-Baqr drain as poor drainage water, while gradual improvement recognized at the end of wetland stages specially in subsurface follow basin and Manzala Lake as medium quality that attributed most probably to self-purification and dilution concepts. Out of 200 bacterial isolates, 29.8% and 70.2% were recovered from Bahr El-Baqar drain and all wetland station sites, respectively. Identified bacterial strains were verified using 16S-rDNA and all nucleotide sequence data were submitted to the NCBI GenBank database, USA and gained their accession numbers. The bioinformatics analysis supported the analytical data and the correlation coefficient matrix between physicochemical and bacteriological pairs recorded several positive and negative significant relationships. The study recommended continuous treating domestic wastewater and directing it to locations distant from direct disposal in Lake Water and pointed out its possible reuse in cultivating cereal, industrial and fodder crops of economic importance to mitigate health problems outbreaks or any aquatic ecosystem disorders.