INVESTIGATION OF LINEAR RELATIONSHIPS BETWEEN PERMANGANATE VALUE (PV), BIOCHEMICAL OXYGEN DEMAND (BOD) AND CHEMICAL OXYGEN DEMAND (COD) OF TEXTILE EFFLUENT OBTAINED FROM LAGOS, NIGERIA

Uwidia, Ita Erebho 

Department of Chemistry, University of Benin, Benin City, Nigeria

Abstract

Textile effluents have been known to exhibit high toxicity. Effluent discharges from textile industries contain organic and inorganic pollutants which migrate into ground waters, surface waters and other parts of the ecological system. This is hazardous to public health. Linear relationships between permanganate value (PV), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of textile effluent from a textile industry in Lagos State were investigated. The aim was to establish an empirical relationship which will be useful for rapid prediction of organic and inorganic pollutant concentrations in effluents discharged into the environment. The range of values obtained for parameters studied were: PV (469.60 ± 0.28 - 746.40 ± 0.36) mg/L, BOD (584.30 ± 0.21 - 885.00 ± 1.07) mg/L and COD (2012.13 ± 0.63 - 2984.00 ± 0.84) mg/L respectively. Linear relationships for the parameter pairs such as PV/BOD, BOD/PV, PV/COD and COD/PV were investigated using the above values. The validity of the linear regression equations were tested with the test data results analysed and the following relationships were obtained: BOD = 1.0862PV + 58.817, PV = 0.8078BOD + 30.431, COD = 3.5918PV + 273.46 and PV = 0.2295COD + 49.015. Also the correlation coefficients "r" for the parameter pairs (i.e. PV/BOD, BOD/PV, PV/COD and COD/PV) were: 0.937, 0.937, 0.908 and 0.908 respectively. The interrelationship established between the parameter pairs suggests that anyone of the pairs is good enough to represent the pair in predicting pollutant concentrations in textile effluent discharges. 

Keywords: Textile effluents, permanganate value (PV), biochemical oxygen demand (BOD), chemical oxygen demand (COD), parameter pairs, linear relationship.