Response of microalgae from mud-flats to petroleum hydrocarbons in the presence of nitrogenous fertilizer effluents

Untreated industrial waste (effluent) from out-fall of the National fertilizer company of Nigeria (NAFCON) was found to be weakly alkaline with a pH of 7.8. Total dissolved solids and sulphate were relatively high with levels of 2052 and 1599 mg/l, respectively. Nitrogen as ammonia was high in comparison to nitrate nitrogen. Phosphate was also found to be low in concentration. Using indigenous microalgae and aeration, there was a reduction in nutrients; NH4 +, NO3 -, PO4 3- and SO4 2-. However, in the presence of the hydrocarbon, there was delayed nutrient uptake. The consequence of this response was the observed reductions in chlorophyll content, biomass, etc. There was however a quick recovery in theoiled systems