Research On The Treatment Process Of High-concentration Coal-to-liquid Wastewater

This study aims at the characteristics of high COD,high oil substances,high phenol,high ammonia nitrogen and sulfur compounds in the wastewater of coal-to-oil industry of XX company.separately using the activated sludge process,A2 / O,two stage three of A/O process can satisfy the practical problem,research and development with phenol oil recovery and the combination of the two levels of A/O process,based on phenol oil recovery process operation and process parameters optimization result is analyzed,two levels of A/O process operation and process parameters optimization effect analysis to determine the best operating condition of sewage treatment,and for this kind of wastewater chroma processing has carried on the preliminary discussion and the suggestion,The implementation of this project has reference significance for similar sewage treatment operation.The main conclusions of this study are:(1)To XX company as an example of the high concentration coal should first after preprocessing,phenol oil recovery wastewater preliminary to remove most of the raw sewage CODcr,ammonia nitrogen and phenolics,prevent with abnormal individual indicators of water quality of high impact on downstream biochemical post,for the follow-up to lay a solid foundation for the operation of the biological system.(2)for the high concentration of coal-to-oil wastewater,phenol oil recovery and pretreatment must be carried out in the early stage to ensure that the biochemical system treatment reaches the standard.This study based on the engineering examples,phenol oil recovery unit,through a series of process parameter adjustment and optimization,to achieve carbolic oil recovery plant effluent CODcr acuities were 5000 mg/l,ammonia nitrogen acuities were 180 mg/l,total phenol 500 mg/l or less,sulfide 180 mg/l or less goal,at the same time for phenol oil recovery unit in operation,processing of coal oil wastewater treatment efficiency and optimum operating conditions,solve the biochemical system unstable water quality,water distribution difficult key problem.(3)Through the engineering application of phenol oil recovery device and two-stage A/O process in the treatment of coal-to-oil wastewater,the CODcr is no more than 60mg/l and ammonia nitrogen is no more than 12mg/l in the wastewater discharge,and the PH is between6 and 9.Color 80 times the target.In this study,through comparison of actual engineering operations,the final field experiment shows that for the treatment of high concentration coal-to-oil wastewater,only the combination of A/O and phenol oil recovery process after technical modification can achieve the purpose of effluent quality standard discharge.Biochemical water distribution is the key to ensure qualified phenol oil recovery and pretreatment effluent.By adjusting the homogenous water quantity and water quality of the tank,the effluent water quality can be guaranteed with sufficient sludge concentration in the aeration tank.After the primary and secondary hypoxia+ aerobic treatment,the effluent self-flow reaches the coagulation sedimentation tank.Through the addition of polyaluminium chloride to the tertiary sedimentation tank and coagulation sedimentation tank for physicochemical treatment and the reduction of chromaticity,the standard discharge of coal-to-oil wastewater can be achieved.