Biological Assessment of Water Toxicity and Fertility of Wastewater Omer Bek Drain Discharging into Receiving Water of the River Nile in Egypt | ||||
| Journal of Environmental Sciences. Mansoura University | ||||
| Article 5, Volume 47, Issue 3.4, June 2018, Page 129-144 PDF (1.15 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/joese.2018.158376 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| Ghada S. Abou-El Wafa; Sara S. Ibrahim; Mohammad I. Abdel-Hamid | ||||
| Botany Department, Faculty of Science, Mansoura University, Egypt | ||||
| Abstract | ||||
| Water toxicity and fertility of a drain wastewater discharging wastewater directly to the Damietta branch of the River Nile were seasonally investigated from winter to autumn, 2016. Nutrient enrichment bioassays to define the algal growth limiting nutrients, their bioavailability and heavy metal toxicity of the sampled water, were carried out with the ISO standard test alga Pseudokirchneriella subcapitata. The algal growth potential (AGP) test exhibited a wide range of growth potential ranging from 0.4 mg.l-1 to 19.42 mg.l-1 algal dry weight. At drain, mixing and recovery stations the algal growth was mainly limited by heavy metals toxicity with inhibition percent at day 14 of growth (%I14) ranged between 27.9 and 58.6 while at the upstream reference station, %I14 ranged between 20 and 37.The algal growth was also limited by N and P depending on site and season. In all seasons, but only at drain station, the expected Chl. a was significantly higher than the observed Chl. a, however, the reverse was held true for other sampling stations during this study. The relationships between the chemically analyzed nutrients (P and N) and their bioavailable concentrations were greatly affected by heavy metal toxicity. The results indicated that the observed chlorophyll a showed significant correlations with TDP(r=0.82), while the expected chlorophyll a correlated significantly with NH4-N(r=0.73). The algal growth potential test proved a sensitive and reliable mean to assess water fertility and toxicity of polluting drains and the receiving waters. | ||||
| Keywords | ||||
| Drainage water; Algal growth potential (AGP); Eutrophication and heavy metal | ||||
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