Influence Analysis On Marine Environmental Capacity Of Power Plant Thermal Discharge In Xiangshan Harbor

In this paper, with an instance of Guohuaninghai Plant, which is at inner XiangshanBay of Ningbo City of Zhejiang Province and has an advanced water-cooling system, theinfluence of coastal plant’s thermal discharge on adjacent water’s environmental capacityloss is studied. Methods such as in situ measurements, indoor analysis, and numericalsimulations are used in the study.By using the three-dimensional unstructured grid finite-volume coastal ocean modelFVCOM, a high-resolution hydrodynamic model system is established to numericallyinvestigate the temperature rise diffusion near Guohuaninghai Plant. Results show that thetotal amount of temperature rise caused by thermal discharge from the plant is about1.4×109m3°C in summer and6×108m3°C in winter. After the total amount of temperaturerise reaches its balance, temperature rise diffusion range of1°C and above is1.5×108m3insummer and6×106m3in winter.At the same time, according to the background data before the construction ofGuohuaninghai power plant and the track monitoring data of6running years, the trend ofmain water quality factors, such as COD, inorganic N and phosphate,was analyzedcomparatively. The result showed that the main pollution factor of this sea area wasphosphate, and the water quality was eutrophicated. Water quality indexes were inaccordance with the secondary standard of water quality, except inorganic N and phosphate.All of the water quality indexes fluctuated in considerable range. It was found that, withadvanced circulation process and discharging amount in control, water quality of the seaarea nearby coastal power plant was not polluted significantly by thermal discharge.The loss of marine environmental capacity caused by coastal power plant thermaldischarge was composed of direct loss of marine environmental capacity induced bycharacteristic factor—temperature rise and indirect loss of marine environmental capacityinduced by secondary factor—water quality changing. The direct loss of marineenvironmental capacity was evaluated monetarily, based on the cost of heat input tomaintain the total amount of temperature rise. The results showed that the interval of loss ofmarine environmental capacity caused by Guohuaninghai power plant thermal dischargewas38657461~90248094yuan in RMB, mainly depending on the direct loss of marineenvironmental capacity caused by thermal discharge.The composition and calculation method of monetary evaluation of marine environmental capacity caused by thermal discharge, given in this paper, is a kind oftheoretical exploration in perfection of research on thermal pollution of coastal power plant.The loss value calculated quantitatively of marine environmental capacity of sea areanearby Guohua power plant offers reference to management of fishery ecologicalcompensation.