Utilization of Shrimp Shell Waste as Matrix Controller by Using Ionotropic Gelation Method in Slow Release Fertilizer Based on Environmental Conservation

The Availability of shrimp waste in Indonesia is huge, especially in shrimp pond areas. However, it has not been utilized optimally and caused environmental pollution. The weight of shrimp waste reaches 30%-40% of its weight. Most of the shrimp waste is dominated with shrimp shells. Shrimp shells containing 60% -70% chitin. It will produce 15-20% yield of chitosan synthesized from chitin. On the other hand, the use of fertilizer continues to increase. Fertilizer is an essential nutrient for plants if lack nutrients to make plants can't grow normally. Preparation of chitosan as matrix controller begins from shrimp shell synthesis which is obtained by deacetylation method with the highest deacetylation degree of 74.5% and the optimum deacetylation is 71.2%. The SEM test which shows the thickening and rougher structure of the fertilizer surface, fertilizer coated by macrospheres has a thickener and coarser surface so as to inhibit the release of elements inside. The shrimp shell waste based coating is able to inhibit the release of NPK contained in the fertilizer. The occurrence of ionic crosslinking shown by the presence of N-H groups and -P=O on material.