羟肟酸类捕收剂的好氧生物降解性评价

Evaluation of aerobic biodegradability of hydroxamic acid collector

采用振荡培养法和CO_2生成量法对苯甲羟肟酸、水杨羟肟酸和N-羟基邻苯二甲酰亚胺的初级和最终好氧生物降解性进行了评价。采用振荡培养法测得的苯甲羟肟酸、水杨羟肟酸和N-羟基邻苯二甲酰亚胺在降解5 d后的初级好氧生物降解率分别为98.95%、97.55%和93.60%;采用CO_2生成量法测得的14 d后的最终好氧生物降解率分别为80.18%、77.78%和95.80%。依据不同评价标准得出3种羟肟酸都具有良好的初级和最终好氧生物降解性,属于易降解类物质。

As is known, in recent years, more and more synthetic chemicals have been adopted in daily life. When the chemicals are released into the environment, the lack of local micro-organisms with enzyme system makes they long-term existence and accumulation. Thus, there comes an ever increasing concern about the biodegrad- ability of synthetic chemicals. Hydroxamic acid is a new kind of organic flotation reagent with a bright prospect in the area of mineral separation. However, so far as we know, few papers can be found reporting the research progress on their biodegradability. This paper takes it as its target to give an evaluation on the three hydroxamic acid collectors, i.e. hydroxamate benzophenone, hydroxamate sali- cylaldehyde and N-hydroxy phthalimide for their primary and final aerobic biodegradability according to the shaking cultivation method and CO2 generation amount method. The results show that the primary aerobic biodegradation rate of a 5-day period is 98.95% （hydroxamate benzophenone ）, 97.55 % （ hydroxamate salicylaldehyde ）, 93.60% （N-hydroxy phthalimide） according to the shaking cultivation method. Whereas the final aerobic biodegradation rate of a 14- day period proves to be 80.18% （hydroxamate benzophenone）, 77.78 % （ hydroxamate salicylaldehyde）, 95.80% （ N-hydroxy phthahmide）. In comparison to the different evaluation methods, all the three collectors turn out to have nice primary and final biodegradability.