THE EFFECTS OF INDUSTRIAL EFFLUENTS ON THE WATER QUALITY OF ABA RIVER IN SOUTH-EASTERN NIGERIA

This study examines the effect of industrial effluents on the water quality of the Aba River. In order to achieve this, a total of six water samples were collected each season and was analysed for different wastewater characteristics of temperature, water pH, Conductivity, Alkaline, Chloride, BOD5, COD, DO, TS, THC, TDS, Zn, Cd, Fe, Pb, Cr, Total Coli-form and E-Coli. Using APHA Standard Analytical Method, the results shows that during dry season, temperature, pH, Chloride and Zn values were found to be lower than NESREA Standard. While TS, THC and Total Coli-form values were found to be higher than NESREA standard in dry season

An adjoint for likelihood maximization

The process of likelihood maximization can be found in many different areas of computational modelling. However, the construction of such models via likelihood maximization requires the solution of a difficult multi-modal optimization problem involving an expensive O ( n 3 ) factorization. The optimization techniques used to solve this problem may require many such factorizations and can result in a significant bottleneck. This article derives an adjoint formulation of the likelihood employed in the construction of a kriging model via reverse algorithmic differentiation. This adjoint is found to calculate the likelihood and all of its derivatives more efficiently than the standard analytical method and can therefore be used within a simple local search or within a hybrid global optimization to accelerate convergence and therefore reduce the cost of the likelihood optimization.