Detection of Microbes in Natural Industrial Cooling Water by Conductometric Method

This paper reports the detections of sulfate reduction bacteria (SRB) and iron bacteria in natural industrial cooling water by conductometric analysis method. Natural industrial cooling water, containing lots of microbes, is special and complex environment where microbes are suitable to grow and multiply under certain conditions of pH, water temperature and sunlight etc. If microbes of cooling water system are excessive, sludge will deposit and then plug pipes, leading to the reduction of cooling water flow and of thermal transmission efficiency. SRB and iron bacteria are the main causes of biofouling formation. To shorten detecting time and improve the accuracy of detection results, it is important to develop quick and accurate detection methods for SRB and iron bacteria in cooling water. The detection method of SRB and iron bacteria in Chinese chemical industrial standard is most probably number methods (MPN) which is to inoculate water samples of different dilution rates into liquid culture medium and place them into incubator tube. The disadvantage of MPN method is long incubating time, for example, of 14 days for iron bacteria and 21 days for SRB. This paper proves the feasibility testing on SRB and iron bacteria using conductance method and the MPN, as an independent method, is used to confirm the results of the conductance method.