ASSESSMENT OF WASTE MANAGEMENT STRUCTURES FOR TEA FACTORIES IN KENYA: A CASE STUDY OF NYANSIONGO TEA FACTORY

Abstract

Waste management is a great challenge in most processing industries in Kenya. This study was specifically carried out to establish the effectiveness of the waste management system in tea processing factories in Kenya with a case study of Nyansiongo tea factory. The study identified the types and sources of solid, liquid and thermal wastes generated during tea production mainly through observations, the identified solid wastes at every stage of tea production were then sampled and weighed and their weights recorded, the wastewater was also sampled and analysed empirically for BOD, COD, PH and electrical conductivity, boiler data was also collected and analysed to determine the efficiency of the boiler. Solid waste in Nyansiongo tea factory was found to be 0.01% of the total tea production. The highest amount of waste was generated from the withering stage due to spillages, while the least amount of waste was generated at the offloading area. Solid waste generated from the factory is poorly disposed; the waste is not segregated (different types of wastes are not disposed separately). Wastewater was generated due to the cleaning processes at the factory. The major cleaning which was done weekly generates about 40 m3 of wastewater and minor cleaning which is done daily generates about 10m3 of wastewater. The wastewater was analysed empirically and the results indicated that BOD5 levels measured 150 mg/L against the National Environment Management Authority recommended maximum discharge limits of 30 mg/L while the COD levels measured 505.5 mg/L against the NEMA recommended maximum discharge limits of 50 mg/L. The calorific value of the wood fuel used at the factory was determined using a bomb calorimeter and the data was used in calculating the efficiency of the boiler. The boiler efficiency was found to be 76. 83% which could be improved by harnessing the energy that is lost through the flue gas and the piping system. It was found that dry flue gas generated the highest amount of heat loss at 13.7% and the least amount of heat loss was 0.32% due to moisture in the fuel.