Chitosan of shrimp as a adsorbing agent in the treatment of effluents from the chemical industries.

What is it about?

Chitosan, a copolymer of B-(1-4)-D-glucosamine, is a polysaccharide derived from chitin, B-(1-4)-N-acetyl-D-glucosamine, which is found in abundance in nature. The main commercial sources of chitin are shrimp, lobster and crab waste. Shrimp have an average of 6% chitin, and crabs, from 15 to 20%, and the chitin/chitosan production process generates effluents with a high concentration of total solids. The conversion of chitin into chitosan can be carried out through an alkaline hydrolysis, which can cause incomplete deacetylation, and also in a depolymerization of variable lengths, resulting in chitosans with different degrees of deacetylation and different molar masses, which determines their applications. The objective of the present work is the production of chitin and chitosan from waste from the fishing industry, and the study of their use as coagulating and adsorbing agents in the treatment of effluents. The work consists of the following steps: obtaining chitin on a pilot scale, from shrimp and crab residues; converting chitin from different types of raw materials into chitosan; use of chitin/chitosan as a coagulating and adsorbing agent in the treatment of effluents from the food industry (organic matter and dyes), metal ions and petroleum and their derivatives. For the characterization of the chitosan produced, in addition to the analysis of the proximate composition, the viscosimetric molar mass and the degree of deacetylation of chitosan are determined, parameters that define the applicability of the biopolymer.

Featured Image

Why is it important?

The waste generated during fish processing (skins, heads, bones and viscera) can total 60-70% of the raw material, and for the heads they represent approximately 20% of the fish. In search of technologically viable alternatives, to take advantage of these residues, several products can be obtained, and the use of these would increase the companies' revenue and reduce environmental problems.