Correlating biochemical and chemical oxygen demand of effluents – A case study of selected industries in Kumasi, Ghana

Abstract

The study aims at establishing an empirical correlation between biochemical oxygen demand (BOD 5 ) and chemical oxygen demand (COD) of effluents from selected industries in the Kumasi Metropolis to facilitate speedy effluent quality assessment or optimal process control. Hourly effluent samples were collected for an 8-h period three times per week for analysis of the principal parameters BOD 5 and COD, using the Standard Methods for the Examination of Water and Wastewater. Measured BOD 5 and COD of the effluents were above the required discharged guideline of 50 mg/l and 250 mg/l, respectively, specified by the Environmental Protection Agency, Ghana. These levels of BOD 5 and COD of the wastewaters could pose potential pollution to the waterbodies in which they are discharged since untreated. Results also indicate that the degree of common variation between the two variables COD and BOD 5 is highly positive for the effluents from Ghana Brewery Limited (GBL), Guinness Ghana Limited GGL) and Coca-Cola Bottling Company of Ghana (Coca-Cola), thus, the variables are correlated. However, the degree of common variation between the variables was low for the effluent from the Kumasi Abattoir. The fitted equations were GBL, y = 0.6558x -270, r = 0.93; Coca-Cola, y = 0.3536x + 113.6, r = 0.81; GGL, y = 0.225x + 1343.7, r = 0.83; Kumasi Abattoir, y = 0.1331x + 54806, r = 0.22) with x and y representing COD and BOD 5 , respectively. The BOD 5 /COD ratio for the wastewater from the selected industries can also be approximated to the gradient of their respective fitted equations, i.e. GBL, 0.66; Coca-Cola, 0.35; GGL, 0.23. The fitted equations for GBL, Coca-Cola and GGL can be used to facilitate rapid effluent assessment or optimal process control by these industries once the chemical oxygen demand is measured.

Bioremediation of refinery wastewater using immobilised Burkholderia cepacia and Corynebacterium sp and their transconjugants

“…There a lot of investigations on the effect of inoculation and subsequent transfer of cata-bolic genes on in situ biodegradation in soils and bioreactors as demonstrated in the present study, such as: Di Giovanni et al 38 demonstrated transfer of the IncP-1L plasmid pJP4 from Ralstonia eutropha JMP134 to indigenous soil bacteria when high concentrations of 2,4- Diya'uddeen et al 30 reported that the minimum amount of dissolved oxygen necessary for normal life in an aquatic environment is about 2 mg/L, 41 and the discharge of high organic matter containing waste waters into water bodies results in the excess consumption of oxygen by the bacteria. This is oxidation of the effluent, thus depleting oxygen from the water faster than it dissolves back into the water from the air.…”

“…This is oxidation of the effluent, thus depleting oxygen from the water faster than it dissolves back into the water from the air. 41 In addition, oxygen availability is important because the end products of chemical and biochemical reactions in anaerobic systems often produce aesthetically displeasing colours, tastes and odours in water. 8 Phenol is one of the major pollutants found in refinery effluents.…”

Application of Central Composite Design approach for dairy wastewater treatment by electrocoagulation using iron and aluminum electrodes: modeling and optimization

“…Oxidation of effluent by bacteria results in depletion of oxygen in water, faster than oxygen gain from air. This problem leads to inadequate maintenance of higher life forms [10]. Additionally, wastewater consisting excessive amount of fats and oils can cause the formation of surface films and shoreline deposits and can lead to environmental degradation when discharged to water media [11].…”

The interaction of a naturally occurring membranous collagen with high-saline dye solutions – mechanistic features from unusual multi-step biosorption

“…In aquatic environments, the minimum amount of dissolved oxygen for normal life is about 2 mg/L [3]. The discharge of wastewater containing dyes into water bodies can result in depleting oxygen and production of toxic sub products, such as hydrogen sulphide (H 2 S).…”