Evaluation Of The Environment-friendly Biocide, THPS, Used In The Recycling Cooling Water

In circulating cooling water system, the large increase of microorganism can make cooling water become black and olid and pollute the environment. At the same time, uncontrollable biological growth causes fouling, loss of heat exchange capacity and initiating or accelerating equipment erosion. Furthermore, biological fouling can disable the medicine's functions of avoiding corrosion and scale by isolating medicine to metal. So the harm resulted in by microorganism is as serious as scale and corrosion in circulating cooling water system, and sometime, we can say, the control of microbial bane is initial.The method of controlling biological growth in cooling systems by biocide is common and effective. Nowadays the policy of "Sustainable Development" is insisted, thus whether secondary pollution takes place during the process of biocide's production and the application in industry has become an important factor in evaluating biocide's performance. It is inevitable that environmental friendly biocide shall gradually substitute biocide bringing secondary pollution.Tetrakis(hydroxmethyl) phosponium sulfate(THPS) with the potential benefit for environment is a kind of novel tetra- phosponium sulfate biocide. THPS compared with traditional biocide has the good environment effect. However THPS is freshly used in industry, there is little performance parameters about it. THPS is mainly used in oil-field system as biocide especially in killing the Sulfate Reducing Bacteria(SRB) abroad. In our country there is little application of THPS to practical work and the report on THPS used as biocide is seldom presented too.In this paper evaluating the performance of THPS in the application to cooling water system is done through researching the THPS's performance of killing the microbe existed in the cooling water system. Firstly, through the laboratory static experiments the effect of THPS in killing the most harmful microorganism such as heterotrophic bacteria, Fe-Bacteria, SRB, epiphyte, and alga etc is studied. Secondly, THPS's using condition in cooling system, impact upon the equipments' corosion and the compatibility with other water quality stabilizing agents are studied, and its treatment was compared with the conventional biocides'. Lastly, in the dynamic state emulation experiment, THPS's performace of killing germs in cooling water system is evaluated comprehensively through the method of pulsed treatment and pulsed- batch treatment.According to the results of experiment, The THPS applied in the circulating cooling water system has the characteristics of broad-spectrum, high efficiency and fast bactericidal potence. And it is qualified well with the corrosion or chemical scale inhibitors in common use. In addition it's fish poison is low and it is easily biodegradated. So, THPS Matchs the standard of" ideal biocide". Nowadays the sustaining development is emphasized, so the future of THPS in the application to cooling water system must be bright.