Coir industry is one of the important traditional cottage industries widely spread over South India. The case of Coco products, a small-scale industry located in Gubbi, Tumkur District, Karnataka, India, which is in the coir fibre production, is considered. Coconut husk is the basic raw material of the industry. Tumkur district happens to be one of the prominent coconut growing areas in the state. The speciality of this region is that edible copra is obtained from coconut. The coir fibre extracted from the husk is used in local bedding, mat and mattings, rubberized coir mattress, yarn and rope making etc. The byproduct of this industry is coir pith. 

In the process of extraction of coir fibre from husk, generally about 1/3rd of it is obtained as fibre and 2/3rd of it is obtained as coir pith. Coir pith with a range of interesting properties finds various applications. Coir pith has a high lignin (31%) and cellulose (27 %) content and a carbon-nitrogen (C/N) ratio of 104: 1. (Shekar, 1999). Coir pith also has a very high water holding capacity of 5 to 6 times its weight. It should be noted that coir pith is very stable because of the presence of high percentage of lignin. Hence coir pith left to itself takes decades to decompose. Studies by various institutions have resulted in methods to speed up the process of decomposition (lignin reduction) by fungal/microbial culture. The decomposing or composting of Coir pith is done near agriculture fields, in heaps generally by the Pleurotus sojarcaju species an edible mushroom, which takes around 35-45 days. Composted Coir pith is used along with organic supplements in crop fields in horticulture and floriculture. It is also used as a rooting and growing medium for certain ornamental flowering plants. Decomposed coir pith is also used as hydroponics systems for  growing roses and vegetables under controlled conditions. The coir pith in sterilized condition finds use in  mushroom  cultivation and floriculture. The coir pith also finds application as an alternative for 'Peat Moss' the extraction of which has been banned in most of the European countries .It also finds application as a mulching material for grape vine.

Coir pith has a calorific value of 3975 k cal/kg, close to 4200 k cal/kg of coal. It can also be used as fuel briquettes with  the ash content almost 1/10th of coal. A proper methodology or technology for briquetting coir pith is yet to be developed for manufacturing a commercially viable product.

Here in our case, on an average a husk weighs about 300 g, 80-85 g is obtained as fibre and around 200 g is obtained as coir pith. Further on an average 5000 husks are defibred per day, which yields 1000 kg (1 ton) of Coir pith per day while around 5-6 tons is composted or decomposed in batches for every 35-45 days depending upon the requirement. As mentioned earlier, out of the rest of coir pith, some quantity is sterilized and dispatched to be used chiefly in floriculture. Thus, the coir pith, which was once a waste and had a disposal problem, has a commercial value.  Infact today it is even being exported to other countries by some other units and has both internal and external market. Finally, we have arrived at cleaner and eco-friendly as well as profitable method of disposing the byproduct-Coir pith.

Key words:
Coir pith, composting, decomposing, briquetting, mushroom cultivation

Sudhira H.S. is currently a student of third semester, Bachelor of Engineering degree course in Environmental Engineering. This is an eight semester course and is scheduled to be over by August 2002.  Sudhira was recently awarded the second place in the order of merit in the International Essay Competition on 'Choice of Technology for Sustainable Development of Developing Countries', held on behalf of the World Congress on 'Sustainable Development' held at Calcutta, India during January 20-23, 2000.  Sudhira has also worked as a Summer Fellow of the Indian Academy of Sciences, Bangalore during July - September, 1998. During this period he worked under Prof. Raghavendra Gadagkar, Chairman, Centre for Ecological Sciences, Indian Institute of Science, Bangalore on a joint project on 'Methods of Estimating Bird Diversity - Evaluation of Three Different Methods in Man-made Ecosystem'.

Ann Jacob is a student currently in her 3rd semester Bachelor of Engineering degree course in Environmental Engineering. She is involved in a project of the Environmental Protection and Research Institute (EPRI) in Hyderabad on vehicular pollution in Hyderabad City. Ann Jacob has published a paper on sustainable development.