Shrimp is a member of the phylum Arthropoda, sub-phylum Mandibulata and belong to the class Crustacea. The entire body is made up of sections that covered by the framework outer or exoskeleton of chitin and substance horn or reinforced by calcium carbonate limestone material. In shrimp waste, contained a biopolymer called chitin (poly N-Acetyl Glucosamine). Deacetylation of chitin will produce a more potent compounds, namely chitosan or poly [β-(1-4)-2-amino-2-deoxy-D-glucopyranose] or D glukosamina, with a certain degree of deacetylation. Chitosan lot of utilization, as in the fields of pharmaceuticals, health, agriculture and industry. Chitosan can also be used as coagulants and flocculants in water treatment (Mu’minah, 2008)
The process of isolation of chitin from shrimp shells can be broadly divided into two, demineralization (mineral removal) and deproteinasi (protein removal). If chitin is processed further using a concentrated alkaline solution it will produce a new product that is chitosan. Chemically, chitin and chitosan can be considered a derivative of cellulose with the hydroxyl group at C-2 atom is replaced by cellulose asetamida and free amine groups. If the hydroxy group at C-2 atom is replaced by cellulose asetamida group, the compound formed is chitin. But if the hydroxy group at atom C-2 cellulose is replaced by the free amine compound formed is chitosan (Mia, 2007).
Chitosan has amine group of the N element is very reactive and alkaline. The principle of chitosan coagulation is an ion exchange where the amine salt formed by reaction of amines with acid to exchange protons owned by electron metal contaminants that are owned by the nitrogen (N). Chitosan is one example of the polyelectrolytes. Polyelectrolytes is part of a special polymer that can be ionized and have the ability to make the occurrence of flocculation in a liquid medium (Agus, et al, undated). Utilization of chitosan in water pengolaha caused this compound acts as a chelating compound for pemisahkan heavy metals from the solution (Mu’minah, 2008).
Below is Making way Chitosan (Mu’minah, 2008):
• Shrimp Waste Samples
Dried shrimp waste samples consisting of the skin of the body in the puree.
• Isolation of Chitin from Shrimp Waste
• Disappearance Protein
At this stage the protein from shrimp waste is separated by introducing 50 g of shrimp waste powder into 500 mL of NaOH 3.5% w / v, and heated at 650 C for 2 hours, stirring constantly using a magnetic stirrer. Subsequently the mixture is cooled and filtered with a filter cloth. The residue is filtered, washed with water until neutral and then rinsed with aquades. Neutral residue which is dried in an oven crude chitin with a temperature of 650 C for 24 hours and weighed.
• Removal of Mineral
Shrimp waste has been eliminated protein is inserted into a solution of 1 M HCl at room temperature with a ratio of 1:15 w / v for 1 hour. Crude chitin incorporated into the solution slowly. Stirring process conducted over the magnetic stirrer. The reaction was filtered using a filter cloth. The filtered residue was washed with water until neutral and then rinsed with aqua dm. Neutral residue, which is coarse chitin, dried in an oven with a temperature of 650 C for 24 hours and weighed.
• Preparation of Chitosan
Chitin isolation results put into a beaker containing a solution of NaOH 50% w / v for 4 hours at temperatures of 1000 C with a ratio of 1:10 w / v. The mixture is stirred using a magnetic stirrer, temperature constant cultivated. The results of chitin extract is filtered using a filter cloth. Residue which is chitosan, washed with water until neutral and rinsed using aquades. Chitosan was dried in an oven with a temperature of 650 C for 24 hours.
1. Agus Widodo, Mardianh, dan Andy Prasetyo. Potensi Kitosan dari Udang sebagai Koagulan Logam Berat Limbah Cair Industri Tekstil. Jurusan Teknik Kimia, Institut Teknologi Sepuluh November (ITS) Surabaya.
2. Mu’minah. Aplikasi Kitosan sebagai Koagulan untuk Penjernihan Air Keruh. Tesis Program Studi Kimia ITB 2008.
3. Mia Ledyastuti. Sintesis dan Karakterisasi Membran Berbasis Kitosan dalam Aplikasi Fuel Cell. Tesis Program Studi Kimia ITB 2007.