Empirical Regression Model for Biochemical Oxygen Demand Removal in Solar Enhanced Waste Stabilization Ponds

Consequent on the findings that a Solar Enhanced Waste Stabilization Pond (SEWSP) will increase treatment efficiency thereby reduce the large land area requirement; hence, this study aims at developing an empirical regression model for the prediction of the efficiency of Biochemical Oxygen Demand removal of the SEWSPs for sewage treatment. SEWSPs were constructed of varying sizes made of metallic tank with inlet and outlet valves, and a solar reflector to increase the incident sunlight intensity. Physio-chemical and biological characteristics of the wastewater samples were collected from different points (inlet and outlets) of the SEWSPs were examined for a period of two months. The examined parameters were: Efficiency of BOD removal in %, Efficiency of E Coli removal in %, Dissolve Oxygen in mg/l, Efficiency of COD removal in %, Efficiency of Suspended Solid removal in %, Temperature in0C, Detention Time in days and coliform. Discussions were made revealing the relationship between the depth of the SEWSP and treatment efficiency.An empirical correlation model predicting the efficiency of BOD removal for the SEWSP was developed thus y = - 0.292X1 – 0.1011X2 + 0.876X3 + 0.148X4 – 0.087X5 +0.012X6 + 22.939 together with a MATLAB solver for easy computation

Lube Oil Recycling: Environmental and Economic Implications

This study presents a practical investigation on the reuse of spent lubricating oil as its indiscriminate disposal by the various users daily constitutes a serious pollution problem in the environment. In carrying out this work, samples of various used lubricating oil collected at different locations were analyzed for their physical and chemical composition, to ascertain their suitability for use as fuel in the cement factory. The examined parameters gave average values of 9.4686 kcal/kg, 96 oC, 18.48, 24 oC and 7834.5 kg/m3 for caloric value, flash point, viscosity, pour point and ash content respectively. The results were compared with those of low fuel oil, used in the cement factories. Consequently, a trial burn was conducted which gave mean values of 133.7 mg/m3, 1.7 ppm, 112.3 mg/m3, ﹤25.0 mg/m3, 20.0 mg/m3, ﹤0.1 mg/m3, ﹤6.8 mg/m3 and 371.2 ppm for SPM, CO, THC, SO3, NO3, H2S, NH3 and CO3 respectively. The results obtained clearly showed that the used lubricating oil has chemical composition, calorific value and other physical properties that are comparable to those of low pour fuel oil. The results obtained from the trial burn conducted in the various cement factories, reveal that, the use of used lubricating oil as fuel in cement factories is environmental friendly and economically viable technique of disposing used lubricating oil