Degradation of Aqueous Diethanolamine (DEA) solutions using UV/H2O2 Process

Aqueous diethanolamine (DEA) solutions are commonly used for the absorption/scrubbing of acidic gases (CO2 and H2S) from natural gas apart from its wide applications in the formulations of consumer chemicals namely, soaps, shampoos, emulsifiers etc. During these processes high concentrations of DEA are released into the atmosphere in the form of waste water/effluents causing a severe pollution to the environment. Hence these stable organic compounds need to be treated/degraded/mineralized before being released into the atmosphere. Hence in the present research an attempt was made to employ UV/H2O2 based advanced oxidation process for the degradation of DEA. Experiments were conducted using a synthetic solution of DEA with a concentration range of 500 - 2000 ppm. The other variables used for the DEA degradation experiments were, the initial concentrations of H2O2, pH and the temperature. Experiments were conducted in a glass reactor, using UV lamp (8W) as radiation source. The DEA removal efficiencies were estimated based on the TOC measurements. Based on the experimental results the optimum conditions for the maximum removal efficiency were obtained by using the Box-Behnken Response Surface Methodology (RSM). A quadratic regression model was developed to represent the present experimental results on the degradation efficiency as a function of the variables. The experiments conducted based on the estimated optimum conditions showed a satisfactory agreement with the predicted values.