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 carriedout to establish the effectiveness of the waste management system in tea processing factories in Kenya with a casestudy of Nyansiongo tea factory. The study identified the types and sources of solid, liquid and thermal wastesgenerated during tea production mainly through observations, the identified solid wastes at every stage of teaproduction were then sampled and weighed and their weights recorded, the wastewater was also sampled andanalysed empirically for BOD, COD, PH and electrical conductivity, boiler data was also collected and analysed todetermine the efficiency of the boiler. Solid waste in Nyansiongo tea factory was found to be 0.01% of the total teaproduction. The highest amount of waste was generated from the withering stage due to spillages, while the leastamount 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 generateddue to the cleaning processes at the factory. The major cleaning which was done weekly generates about 40 m3 ofwastewater and minor cleaning which is done daily generates about 10m3 of wastewater. The wastewater wasanalysed empirically and the results indicated that BOD5 levels measured 150 mg/L against the NationalEnvironment Management Authority recommended maximum discharge limits of 30 mg/L while the COD levelsmeasured 505.5 mg/L against the NEMA recommended maximum discharge limits of 50 mg/L. The calorific valueof the wood fuel used at the factory was determined using a bomb calorimeter and the data was used incalculating the efficiency of the boiler. The boiler efficiency was found to be 76. 83% which could be improved byharnessing the energy that is lost through the flue gas and the piping system. It was found that dry flue gasgenerated the highest amount of heat loss at 13.7% and the least amount of heat loss was 0.32% due to moisturein the fuel.