Chitins and chitosans for the removal of total ammonia of aquaculture effluents

摘要

This study aimed to evaluate efficiency of adsorption of chitins of marine and freshwater shrimps, three commercial chitosan and chitosan produced in laboratory in the removal of total ammonia synthetic effluents with different initial concentrations of ammonia and natural aquaculture effluents. The adsorbents were characterized in relation to degree of deacetylation, specific surface area and porosity, surface characteristics of particles, chemical composition and semicrystalline structure. Were performed adsorbent dosage effect tests in different initial concentrations of ammonia of the synthetic effluent and in removal of total ammonia effluents aquaculture per adsorption. All dosages of commercial chitosans 1 and 2 tested removed 100% at the smaller initial concentration of ammonia (0.09 mg L-1). The samples of marine shrimp chitin, freshwater shrimp chitin, commercial chitosan 3 and chitosan obtained in the laboratory were not efficient in the process of adsorption of ammonia from synthetic effluent. The removal of total ammonia from aquaculture effluents 1 and 2 was immediate (100%), which is related to the greater surface area of the adsorbent. Commercial chitosan 2 proved to be more efficient in the process of adsorption of total ammonia, removing up to 94.33% of ammonia from synthetic wastewater with initial concentration 7.35 mg L-1.