The National Institute for Interdisciplinary Science and Technology (NIIST)-Thiruvananthaupram has developed a clean bioprocess for the extraction of quality coir fibre from coconut husk.

This biological method carries out separation of fibres from their matrices by a process of cementing compounds with localised microbial growth and enzyme production.

This microbiological process converts degradable plant components into soluble compounds, a spokesman for NIIST, an affiliate of the Council of Scientific and Industrial Research (CSIR).

METHANE-RICH

Anaerobic reactor (that which facilitates a chemical reaction without the presence of oxygen) removes chemical oxygen demand (COD) from liquid and recovers it as methane-rich biogas.

That the bioprocess not only converts all organic pollutants emanating from the extraction process to methane but also facilitates its recovery as an energy source, is an added advantage.

Quality coir fibre can also be used for processing of natural fibres like jute, banana, and pineapple leaf.

MAJOR CONCERN

However, retting leads to extensive pollution of water bodies. Environmental pollution, methane and sulphide emission and water contamination are associated with conventional retting.

It is a major concern that retting areas are almost devoid of higher aquatic life. Retting also leads to destruction of fisheries in these areas.

Given the above circumstances, it is found that biological methods shall be preferred to mechanical and chemical routes for extracting fibres of good quality from the embedding matrix.

RETTING PROCESS

Kerala produces the best quality coir fibre in the world. Better quality white fibre is extracted from fresh coconut husks after a decaying process called “retting.”

Husk retting is carried out by immersing coconut husks in lakes, rivers and ponds for a period ranging from six months to one year.

During retting, materials of the husk which bind fibres together are degraded and fibres are loosened. Further extraction is simple and hence it yields fibre with polished surface properties.

MOSTLY IMPORTED

Most of the coconut fibre being used by the industry is at present imported from the neighbouring States where fibre is extracted from chemically-treated raw coconut husks using machines.

Retting causes chemicals that stick on the fibre to get dissolved in water. According to studies, retting has caused large-scale destruction to fish wealth of backwaters and other water bodies in the coastal areas of the State.

The foul smell associated with retting has also been objected to by the coastal communities.