Determination of Nutri-chemical and Biological Content of the Wastewater Drains from Cement and Associated Factories in Port Harcourt, Nigeria

Abstract

This study was designed to ascertain the level of Nutri-chemical and microbial load of the drain water around the cement industry, gas tank farm and other associated activities in the Iwofe by Eagle cement road (now Dangote). This was premeditated by the industrial activities and high employment rate within the study area. Three sample points for each station made up of three composite samples were made labelled R, S, T selected based on distance from target cement factory (100m, 250m and 400m respectively) and corresponding control points of Rc, Sc and Tc respectively were used. The Nutri-chemical parameters of pH, DO, NO3-, PO43-, SO42-, NH4+ were determined using Horiba pH meter, Modified Azide or Winkler Method, Ultraviolet Spectrophotometric Screening Method, Stannous Chloride Method, Turbidimetric method and the Phenate method respectively (all parameters measured in mg/l except pH in units). Result showed the following ranges for pH, DO, NO3-, PO43-, SO42-, NH4+ were 7.14±0.01-7.22±0.01, 0.00±0.00-0.58±0.26, 4.45±0.06-4.75±0.08, 5.10±0.23-6.30±0.30, 0.40±0.12-0.90±0.20 and 2.68±0.36-3.70±0.22 respectively. The microbiology parameters studied were THB, TCB and FCB determined by the Spread plate, MPN and MPN but with ranges of (4.5± 35355-6.5±28284) x 105 Cfu/ml; 4000±412-5500±648 MPN/100ml and 3450±69-4050±153 MPN/100ml respectively. The results showed that pH, nitrates and sulphates were within regulatory limits (WHO, NSDWQ, FEPA, NESREA, USEPA, SON etc) but DO, phosphate and ammonia are much above allowable limits by these regulatory agencies which poses great danger to both ground water and water usage for other beneficial uses. The one way ANOVA and t-test showed no significant variations (p<0.05). Water bacteriology showed high level pollution from fecal waste which must be checked to avoid water borne diseases and epidemics. The concentrations of THB, TCB and FCB were well above permissible limits but most importantly, their mere presence is an indication of pollution and contamination of the water body. Government should as a matter of urgency carry out post treatment of the abandoned waste dump and monitor the indiscriminate human waste dump around the drains by providing public toilets around busy and industrial areas creating jobs and revenue at minimal cost to the notary public.