DEVELOPMENT OF COST MODEL FOR RATIONAL DESIGN OF UASB UNIT IN DISTILLERY WASTE WATER TREATMENT

Abstract

Treatment system with UASB reactor as a main unit has become very popular treatment method for distillery wastewater, because of its effectiveness in treating high strength distillery wastewater and its economic advantages. Developed in the Netherlands in the late seventies (1976-1980) by Prof. Gatze Lettinga - Wageningen University, UASB (Upflow Anaerobic Sludge Bed) reactor was originally used for treating wastewater from sugar refining, breweries and beverage industry, distilleries and fermentation industry, food industry, pulp and paper industry. Conventional sewage treatment technology requires high investment in terms of capital and OMR costs along with considerable skill in their installation, operation and maintenance. Under the complex socio-economic environment of developing countries, the choice of technology for distillery wastewater treatment is a crucial decision in view of the availability of limited funds and, for such purposes, the designer is called upon to select a suitable method of wastewater treatment, which could be capable of meeting the environmental quality objectives and giving the desired level of treatment before the wastewater is discharged to water bodies or on land as fertigation. In a tropical country like India, anaerobic processes have a promising future in distillery wastewater treatment. During past three decade or so, much of research work on UASB reactor has been carried out towards its start up and treatment potential as applied to different types of wastewater. An ideal technology for distillery wastewater treatment will be one which satisfies requirements of efficient treatment and keeps financial constraints intact. The cost effective modeling of various treatment systems has attracted the attention of researchers for a long time. However, with a poorly understood performance of UASB reactor in distillery wastewater treatment, its cost model is not available in the literature so for. In the present study, distillery waster treatment system with UASB reactor process has been considered for the purpose of the cost effective modeling. 111 Performance of UASB reactor has been studied in much detail regarding hydraulic behavior of fluid flow and biochemical kinetics inside the reactor. But the cost effective model still remained unanswered for UASB unit in distillery wastewater treatment system. In the view of the same performance evaluation of UASB reactor in distillery wastewater treatment has been carried out. On the basis of minimum cost worked out for the different design volumes, a cost equation relating minimum cost per unit volume to design volume has been developed for circular UASB reactor. It is seen that UASB systems along with post-treatment units tend to minimize total area of land required for distillery wastewater treatment system. It is revealed that a significant amount of saving can be achieved by employing the rational design of UASB system in distillery wastewater treatment. Jr. addition, as the rationally designed UASB system with post-treatment unit tend to minimize the land area to a great extent and are also not dependent upon external. power intensively. The quality of treated wastewater coming out from reactor is satisfactory, when compared to other conventional treatment units regarding public health, ecology, and aesthetic. The effluent coming out is nutrient rich for the agricultural farming. The methane as side product of the biochemical reactions taking place inside the reactor, is used for power generation and heating of boilers. Because of these factors, there is enormous scope of application of UASB reactor in distillery wastewater treatment system. Thus, it is expected that the present study will yield a cost effective design of UASB system for distillery wastewater treatment system.