Positive environmental management via waste minimisation in a textile washing factory

Abstract

Textile and garment Industry is an important industry sector in the Sri Lankan economy. The finishing part comprises the final step in textile processing and it is known as a sector with high polluting potential. In the textile washing sector considerable quantities of water is used only once usually and is discharged without any recovery. To stay competitive this industry needs to be modernized and definitely needs better performance in the environmental management sector. This project was limited to looking at the environmental management aspects and that too with only a single pollutant stream -water. The sector of the textile industry considered is the textile washing industry. A garment washing plant is analyzed with the objective of promoting water recycling and waste minimization practices. Initially typical practices were reported, followed by a water balance for the system . Results of the water audit presented here forms the first essential element of the waste minimization process. Water stream is considered from the inlet to the exit, and the consideration is given to methods of conservation possible of this valuable natural resource while obtaining the optimal use in the process. The time that water was assumed to be a limitless low-cost resource has already passed. Today there is an increasing awareness of the danger to the environment caused by over-extraction and use of water. There is now considerable incentive to reduce both consumption and waste water production. The selection of the washing industry was selected for this study under that consideration. This industry sector today uses significant quantities of water and most of the factories neither utilize waste minimization nor water recycling techniques. The waste treatment methods are also not adequate. Thus there is a tremendous potential on savings on one hand and a need on the other hand. It was shown that it is feasible to utilize groundwater after treatment. Manganese is not appearing to be a major problem. The problem chemical appears to be the presence of iron. Iron can be removed from groundwater using several operations. This eliminates the transport of water from outside and serves many environmental needs such as reduced traffic, removing reliance on outside sources and events etc. A pilot plant was constructed in the laboratory and four methods of iron removal were analyzed. Ozonation was studied as a method of reducing this wastage. In this manner there would be a reduced demand on the freshwater resource as well as reduced discharge of effluents. Thus the situation would lead to a facility whereby the waste minimization has taken place and a facility with positive environmental management. It has been shown that this technology offers many advantages to the industry including the recycling option. Ozonation in addition provided abilities to provide the required input quality as well in addition to being able to reduce COD, BOD and the most importantly Color of effluents. It was seen that processes are carried out with less attention being paid to the overall efficiencies but only towards meeting production targets and/or meeting deadlines. The feasibility of recycling waste water was shown. The practice of this would be a major improvement on the current environmental performance.