Study role of ozone at biocorrosion control in water transfer from copper mines

Microbial corrosion or a kind of corrosion affected by biological agents could be defined as an electrochemical process which in this process, microorganisms are able to initiate, facilitate or encourage the corrosion process without any change in its electrochemical nature and of course microorganisms attached to surfaces which are called biofilms, have a principal role in this phenomenon and may be the necessary factor for proceeding the reactions. Damages due to biocorrosion result in consuming high expenses to substitute and fix the equipment and metal installations in most industries.One of the cases of biocorrosion has occurred in the water supply pipes from Khatoon Abad water well to Kerman Sarcheshmeh copper mine which in order to control this phenomenon , the water sample exist in the water supply pipelines was studied from the biological view and it was found that the development of biocorrosion is due to the presence of sulfur corrosive bacteria in the transferred water , according to the result of performed experiments on the water sample , the identified and separated species , was sulfolobus bacteria which has different enzymatic activities and as a result of these activities a considerable amount of sulfur accumulates on the cell surface. Then in order to prevent the reduction of sulfate and so controlling the biocorrosion phenomenon ozone adding method were studied and the rate of sulfolobus bacteria growth was used as a scale to prevent biocorrosion. In the ozone adding method, at pressure less than 0.5 bar for 1 hour , 0.5 bar for 1 hour, 1 bar for half of hour , between 1 bar and 1.5 bar for half of hour, 1.5 bar and 2 bar for 20 minutes , the sample was exposed to ozone gas. For each of pressure which exert, each 15 minutes sampling was done and in pressure with less time, each 10 minutes . Then the samples were incubated in the desired culture medium for 24-48 hours on 27-30°c .Finally specified that ozone adding method on some of times and pressure which exert had been prevented from growth of mentioned bacteria.

Keywords:

Biocorrosion , Biofilm , Sulfolobus bacteria , Ozone adding method