Study Of Effects Of Phosphorus In The Reclaimed-water For The Power Plant Cooling System

In recent years, reciculating cooling water consumption become more and more with the rapid development of the power industry in power plant, it has reached 40% of the total consumption of the global and it continues to grow. But the global water shortage has become one of the main reasons to restrict the development of power industry. The recycled water that comes from the sewage treatment plant has a large amount, a fixed water source and stable water quality, and these recycled water being applied to the power plant cooling systems is going to be one of the important measures to save water. However, the rich nutrients in the recycled water easily lead to the recycled cooling system fouling, corrosion and microbial growth and other problems affecting security due to the recycled water quality. Phosphorus in the recycled water are one of the main factors to result such problems. Therefore it is important to study how the phosphorus impacts the recycled cooling systems.That the forms of phosphorus in recycled water and in sediments, and the method of extracting and determination of the different forms of phosphorus are researched in the paper. The method of extracting and determination of the different forms of phosphorus in the recycled cooling systems and the scale deposition are simulated with that from the recycled water and in sediments. The impact of phosphorus to the scaling of the cycle cooling systems under different operating conditions are analyzed. The results show that the temperature of water and the flow rate of water impact the scaling of the systems particularly. The content of different forms of phosphorus in the scale deposition change constantly when the operating temperature change, Aluminum-bound P(Al-P), the main form of phosphorus in scale, reaches a maximum of 65.75mg/g at 55℃, while it minimize at 40℃, only 11.17mg/g. The flow rate of water has also influenced scaling of the systems, the amount of scale deposition reduce to 0.010g/cm2 from 0.0158g/cm2 when the flow rate increases to 0.354m/s from 0.212m/s. This study is based on the sewage water resource, it will provide theoretical basis for the recycled water widely used to power plant cooling systems, the success of the study will bring great social and economic value.