Transformation Of Organic Phosphorus In Circulating Cooling System

Municipal wastewater(MWW) is one of the most important measures to alleviate the global shortage of fresh water resources as power plant circulating cooling system makeup water,which has the advantages of much quantity of water and water-quality stability,but the complex water-quality is the main reason for occurring the system’s scaling,corrosion and microorganism growth.Organic phosphorus is one of the important factors to cause the above problems,and different forms and amounts of organic phosphorus have different influence on scaling and corrosion in the system,but there is no unified conclusion.This article researches regarding simulating reclaimed-water as make-up water which was applied in circulating cooling system,regarding organic phosphorus scaleinhibitor as the sole source of phosphorus,investigating the extraction method of particle organic phosphorus and the effect of the morphology and content of organic phosphorus and its influence on water-quality,scaling and corrosion under different conditions in circulating cooling system.The results show that the recovery rate is highest when the active organic phosphorus and secondary active organic phosphorus(acid)method for the extraction of particle organic phosphorus.The temperature,the concentration ratio(COC)and the additive amount of inhibitors have important transformation influence on dissolved organic phosphorus.The transformation rate of dissolved organic phosphorus increased with increasing the temperature,the concentration ratio and the additive amount,the transformation rate were 83.88 %,77.24 % and 75.72% under 80 ℃,COC5 and 12 mg/L,respectively.The effective utilization of dissolved organic phosphorus decreased,increased the scaling and corrosion rate under the conditions of temperature and concentration.The hardness(H)has important influence on dissolved organic phosphorus,the migration rate of dissolved organic phosphorus to particle organic phosphorus increased with increasing the hardness,the migration rate was 66.54 % under H6.Meanwhile,the scaling and corrosion rate increased and the utilization rate of organic phosphorus decreased.The flow velocity has little migration and transformation influence on dissolved organic phosphorus,increased the flow velocity can improve scaling and corrosion rate in the system.Thus,the temperature of 40 ℃,the flow velocity of 0.6 m/s,the concentration rate of 4,the hardness of 4 and the additive amount of 8 mg/L were the best operation conditions.The research results not only can provide experimental basis and theory reference for power plant operation,but also have important economic and social value by its promotion.