Biological decalcification method in process for preparing chitin

Abstract

This invention discloses a method for biologically removing Ca during preparation pf chitin. The method comprises: mixing Aspergillus niger with one of chitin-containing material, saccharide, starch or starch-containing carbohydrate, fermenting in a container equipped with stirrer at 28-40 deg.C, 0.1-0.3 MPa and pH value of 5-7, introducing asepsis wind with a flux of 400-700 m3 / h, stirring, terminating fermentation when the pH value is lower than 2.5 and the chitin content is lower than 10%, discharging, solid-liquid separating, washing the solid with water and drying to obtain chitin. The method has such advantages as no need for inorganic strong acid, no secondary pollution, low water and energy consumption, no waste liquid, little wastewater and little pollution. The obtained chitin has high quality. The method can effectively recover and utilize the byproducts, thus has a high profit.

Description

technical field [0001] The invention relates to a chitin production method, in particular to a biological decalcification method in the chitin preparation process. Background technique [0002] Due to its wide application and huge market demand, chitin and its derivatives have been industrialized. my country is a big chitin producing country, and the production enterprises are mainly distributed in the coastal areas. The main products are glucosamine, and most of them are small and medium-sized enterprises with an annual production scale of 100-1000 tons. The total annual domestic output is about 5,000 tons, which currently accounts for more than 80% of the global output. However, while the above-mentioned products are earning foreign exchange for the country's exports, they are also causing secondary pollution to the environment. As people pay more and more attention to chitin and its derivatives, the secondary pollution caused by the production of its low-end product - c...

AI Technical Summary

Problems solved by technology

Although the chitin production wastewater by the acid-alkali method has been treated for many years, despite the high cost, not only can not completely recycle a large amount of animal protein, pigments, oils and other resources, but also cannot achieve standard discharge, which has become a constraint to the sustainable development of the chitin industry. one of the bottlenecks

[0004] The reason is that the key point for the discharge of chitin production wastewater by the acid-alkali method is the chloride ions in the acid leaching waste liquid, because the existence of a large number of chloride ions reduces the recovery value of other by-products and hinders the subsequent biological treatment of wastewater , and because it itself cannot be biodegraded, if it is discharged into the environment, it will degrade the quality of the environmental water body, and its own existence will also increase the measured value of COD

Therefore, there are many disadvantages in using hydrochloric acid to remove calcium or minerals in chitin-containing raw materials.