Application Of Enzyme In The Inhibitting Of Biological Slime In Circulating-cooling-water-systerm

The biological slime is made up of Extracellular Polymeric Substances(EPS) agglutinated with microbe cells(corpses included) and all kinds of organic or inorganic granules such as clunch and humus.The biological slime may reduce the efficiency of cooling,accelerate the eroding of equipments,increase the running cost of the system and water wastage.The routine method to deal with it is to add with chemic fungicide to restrain the growth of microbes and the forming of the biological slime.But the fungicide may be obstructed by the subsistent biological slime from the microbes in it. In addition,chemic fungicides will pollute the water.The basis of EPS is amylose and protein secreted by microbes,which can be bio-decomposed in nature.So we can decompose the EPS to collapse the biological slime,the microbes in which will be exposed to fungicides in the water.Therefore,we study using enzymes to decompose EPS to wipe off the biological slime in circulating cooling water.In the experimentation we simulate the condition of circulating cooling water and add nutrimental substances to speed up the increasing of the biological slime.We choseα-amylase,cellulase,protease and lysozyme to decompose EPS.We scale the effect of them to desquamate the biological slime by the change of the wet-weights after decomposing,and scale the bio-activity of the biological slime by the oxygen-consuming-speed.The experimentation indicates that there are some effects to use the chosen enzymes to desquamate the biological slime.The effect of cellulose is better than the other three enzymes.At the concentration of 50mg/L,cellulose will make the slime decrease by 10.97% after 22 hours.It is better to use more than one kind of enzymes than a single enzyme.The best effect is striken out by four enzymes together.At the total concentration of 100mg/L,addingα-amylase,cellulase,protease and lysozyme with the quantity proportion of 1:4:12:3 to the water will make the best result,which is 24.30% decreasing after 22 hours.This reagent of enzymes can boost up the effect of fungicide to desquamate the biological slime.The experiment shows that the effect of Bromogeramine to desquamate the biological slime increased by 2~5 percents with the assistant of the reagent of enzymes.Otherwise,the same quantity of fungicide put in water,enzymes make the bio-activity of the biological slime a little higher.It shows us that the enzymes have destroyed the configuration of the biological slime,and make the microbes hidden in it exposed to the water.