Modelling and optimization based Control of dissolved oxygen for Industrial effluents in semibatch Fermenter

Abstract

Effluents from industries such as textile, distillery, bone wash, paper newlineand paint pose serious environmental hazard and leads to health problems. newlineGovernment and other environmental agencies have coordinated efforts to newlinecombat or neutralize the adverse effect on human beings, animals and plants newlineby proper treatment prior to disposal. The first stage in treatment of such newlineeffluents is aeration. Arbitrary aeration of effluents in many industries has newlinebeen recorded leading to effluents with odour. Dissolved oxygen is an newlineimportant parameter in the aeration process of effluents to be controlled. newlineExperimental setup for batch process was fabricated with a speed adjustable newlineagitator in a semi batch reactor. It consist of lark hygiene fermenter, effluent newlinestorage, rotameter, Dissolved Oxygen probe (DO), stirrer, control valve and newlinepersonal computer. The 1.5 litre semi batch reactor has provisions for newlineadjustment of air flow, temperature and speed of stirrer. Fresh effluent was newlinediluted with water to obtain various concentrations ranging from 10 to 100 newlinepercent in steps of 10 percent. One litre of fresh effluent of known newlineconcentration was charged into the semi batch fermenter from storage tank 1 newlineusing a peristaltic pump. The dissolved oxygen was monitored using an online newlinedissolved oxygen probe interfaced to a PC. At time t = 0, purified air was newlinesuddenly metered through a rotameter at a rate of 1 lpm. newlineThe dissolved oxygen was monitored and recorded for ten newlineconcentrations and three speeds (135, 145, and 155 rpm) with time till newlinesaturation. Based on the data generated different models for the aeration newlineprocess with dissolved oxygen as controlled variable have been studied newline