Study On The Biodegradability Of Amine Collectors

With the development of mineral industries, the pollution caused by flotation agents is more and more serious. In order to control and prevent the pollution of agents, and provide the theory for the synthesis and reasonable application of flotation agent, six kinds of amine collectors were selected as objects of study. The aerobic biodegradability of amine collectors has been evaluated by the methods of BOD5/CODCr, shaking cultivation and the amount of CO2 produced, and their kinetics models of biodegradability were investigated preliminarily. Making use of multiple linear regression, the relationship between the biodegradability of typical amine collectors and their chemical structure were discusssed. The degradation pathway of amine collectors were analysized by use of infrared spectroscopic analysis.Utilizing the methods of BOD5/CODCr, shaking cultivation and the amount of CO2 produced, the aerobic biodegradability of lauryl amine, octadecylamine, laurtrimonium chloride, lauryl trimethyl ammonium bromide, decane-propyl ether amine and dodecyl propyl ether amine were studied. By means of analyzing the evaluation results synthetically, all of these test substances are biodegradable. Among of them, lauryl amine, laurtrimonium chloride, lauryl trimethyl ammonium bromide and octadecylamine is more easy to be degradated than decane-propyl ether amine and dodecyl propyl ether amine.According to analyzing the situation of study on the relationship between the biodegradability of compounds and their chemical structure, and comparing the parameters of chemical structure and the methods of building model, these parameters, such as EHOMO, ELUMO, Vm, ClogP,μ, and 2X, were selected as the ones of amine collectors. Through the regression analysis, the quantitative structure biodegradability relationships (QSBR) on amine collectors was created, and the biodegradability of amine collectors were predicted. The biodegradability of amine collectors are affected by ClogP and EHOMO markedly.By use of infrared spectroscopic analysis, the biodegradation pathway of amine collectors were analysized. There are two kinds of potential biodegradation pathway for ether amine, the one is the rupture of C-N firstly, and via the oxidation ofωandβ, the ultima metabolites are produced, the another one is the rupture of C-O firstly, and the products are propylamine and fatty acid which is oxidized furthermore. The possible biodegradation pathway for primary amine is the rupture of C-N firstly, the the products are NH3 and aliphatic alcohol which is oxidized furthermore. And quaternary ammonium salt is biodegradated as a result of the rupture of C-N firstly, (CH3)3N and aliphatic alcohol are produced, and aliphatic alcohol is degradated to finalproducts.