Research On The Process Optimization And Kinetics Of The Nitrogen And Phosphorus Removal In Petrochemical Wastewater Treatment

The people's living standards are getting better with the rapid development of social economy. At the same time, the problem of water pollution is getting more and more serious, which is one of the important environmental issues of global concern. The nutrients accumulation and excessive discharge of nitrogen and phosphorus in China these years led to the poor water quality of rivers and lakes, which has had serious impacts on human health. The removals of carbon, nitrogen and phosphorus are the key issues to prevent water quality from getting worse.At present, anaerobic/anoxic/oxic(A~2/O) process is one of the conventional technques in municipal and industrial waste water treatment, and the advanced processes of nitrogen and phosphorus removal have also been studied and developed. With the implementation of new environmental laws and stricter standards of wastewater discharge, many industries and old treatment plants have been transformed. In 2011, the China's Environmental Protection 12 th Five-Year Plan required significant reduction of the total emission of major pollutants, the 8% and 10% cut down of the total emission of chemical oxygen demand and ammonia nitrogen respectively on the basis of 2010, and the securities of urban and rural drinking water. In response to the new laws and standards, the deep analysis of the nitrogen and phosphorus removal process in pollutants' biodegradation is necessary. To achieve optimal operation results, the nitrogen removal process in original biochemical treatment was adjusted and reformed. By the optimization of operational parameters in actual production, sampling and calculating the process, the targets of this research were achieved. The main results are as follows.(1) By adjusting the process and optimizing the operational parameters, the removal rate of carbon, nitrogen and phosphorus is 80%, 80% and 92.24%, respectively.(2) The balance rate of carbon, nitrogen and phosphorus is 97.82%, 98.05% and 96.19%, respectively, and the system had long-term stability.(3) The problem about the competition of carbon source and the phosphorus absorption influenced by nitrates were solved, which ensured the processes of denitrification, phosphorus release, nitrification and phosphorus absorption.(4) The kinetic constants and calculation models of each process were determined, which has been proved to be applicable.