PHYSICOCHEMICAL PROPERTIES AND HEAVY METAL PROFILES OF TREATED AND UNTREATED EFFLUENTS FROM TWO CHEMICAL INDUSTRIES IN ABEOKUTA

Abstract

Samples of untreated and treated effluent were collected on hourly basis forming a composite sample from Midland Galvanising Company (MID GAL) and Industrial project International (IPI) respectively. Grab samples were also collected from nearby streams where the effluents were being discharged and also to the river in which the streams flows into. All the samples were preserved appropriately and physicochemical parameters and heavy metal concentrations of the samples were carried out using standard method for water and effluents analysis (Ademoroti, 1996). The result of the physicochemical determinations for the samples had the suspended solids (mg/l) ranged from 0.89 to 3.99, the total solids had its value ranged from 2.00 to 28.06mg/l, dissolved solids had its values ranged from 0.28 to 24.65mg/l, volatile solids had its values ranged from 0.01 to 10.99, the pH of the sample had its values from 3.35 to 10.99, the conductivity of the sample extended from 120 to 13,100~s/cm, some of the samples had no acidity detectable with its greatest values in the others as 2000mg/l, the alkalinity had its values ranged from 15.00 to 680mg/l, BOD had its value from 0.45 to 1.40mg/1 in the samples while COD had its values extended from 4.00 to 414.00ppm, the DO values in mg/l extended from 3.66 to 5.04 and the total phosphate values in the samples in mg/l were 0.74 ± 0.006,0.25 ± 0.006, 1.53 ± 0.006, 1.00 ± 0.006 , 0.09 ± 0.006 ,0.26 ± 0.006, 1.26 ± 0.006 in Ogun river, treated effluent from IPI, untreated effluent from IPI, sample from stream close to MIDGAL , treated effluent from MID GAL , untreated effluent from MIGDAL company and sample from stream close to IPI company respectively. The heavy metal profile of the sample had no traces of cobalt, Nickel, Arsenic and Cadmiun samples analysed. Iron had its concentration in ppm extending from 0.42 to 11.72 ppm , Manganese was absent from Ogun river, treated effluent from MIDGAL and blank sample, Zinc concentration had values from 0.63 to 198.70 ppm no traces of copper in samples from Ogun river, stream close to MID GAL company , Stream close to IPI company, treated effluent from MID GAL company and the blank sample. Lead was absent in ogun river , treated effluent from IPI stream close to MIDGAL, Stream close to IPI , Untreated effluent from IPI and the blank sample. There were no traces of selenium in river close to MIGDAL, Stream close to IPI and blank sample but selenuim, had its presence in Ogun river, treated IPI effluent, untreated effluent from MIDGAL, treated effluent from MID GAL untreated effluent from IPI .