Abstract:

The culture and acclimation of mixed bacteria were studied systematically, including refractory and salt-tolerant acclimation, for hypersaline polluted water from chemical factories which is degradated hardly.The results show that during refractory acclimation, if COD_Cr removal rate is as a primary factor, asynchronous domestication should be selected because of its COD_Cr removal rate 72.0%, much higher than that of synchro one.If reagent cost is as a leading factor, the method of rising COD_Cr load is the best choice, whose agentia cost is only 5.78 CNY·（t water）^-1.The method of high COD_Cr load is characterized by the shortest domestication time of 17 d.Concentration of sodium chloride increases from 50 g·L^-1 to 60 g·L^-1 by 2 g·L^-1, the mixed bacteria adapted hypersaline condition of 60 g·L^-1 NaCl after domestication of 20 d, and COD_Cr removal rate increases slightly, by about 1%.The change of bacteria morphology before and after acclimation, observed by SEM, indicates that the mixed bacteria before domestication is uniform size and surface smooth, and mainly consists of cocci and short bacilli; while that after acclimation is surface rough, mainly consists of long bacilli and contains a lot of secretion, which is a result of acclimatizing themselves to hypersaline environment.