Pilot Scale Test Of Lurgi Coal Gasification Wastewater Treatment By Biological Process

Over the past years, as the development of coal-chemical engineering industry, the issue of wastewater discharge volume augmenting, complex quality and low treatment efficiency is becoming increasingly obvious and water pollution pricks up. If the wastewater discharged directly without any treatment or to insufficient levels of treatment,it will pollute receiving waters around gas production companies and even be harmful to groundwater.This paper generalizes the sources, characteristics of coal-chemical engineering industry wastewater, presents research and application situation in treating such kind of wastewater. Also, this paper carried out a detailed analysis on the quality of wastewater from Yima Gasification Plant Lurgi gasifier, especially analysized the COD, nitrogen, phosphorus and phenol components. Through pilot experiment on-site for Lurgi gasifier wastewater treatment, this paper studied the efficiency of the BioDopp biochemical process for treating Lurgi gasifier wastewater in depth, and focused on discussing the changes of wastewater main indicators and causes before and after biochemical treatment during the experiment. Moreover, this article systematically studied the pathway and balance of the substances at the stable phase of the pilot experiment, analyzed the nitrogen removal mechanism by BioDopp Biochemical Process for treating Lurgi gasifier wastewater in detail, demanstrated the occurance of the simultaneous shortcut nitrification-denitrification process, even calculated the proportion of nitrification and denitrification process. Effects of dissolved oxygen and temperature on the performance and target pollutants removal were conducted, and control and effect factors for engineering application were proposed.The main conclusions are drawn as follows: The debugging and operating practice of the pilot experiment on-site for Lurgi gasifier wastewater treatment by BioDopp Biochemical Process shows that this technique is reliable and economically reasonable. Practical operation demonstrates that the average removal efficiencies of COD, ammonia nitrogen, total phenol and total oil are 98.45%, 99.30%, 99.90% and 99.32%, respectively. The effluent quality is good enough to meet the standard of design requirement. The nitrogen removal process is the coexistence of several nitrogen removal pathways including shortcut nitrification-denitrification. The removal efficiency of total nitrogen reaches at 71.5%, in which 57.77% was achieved by shortcut nitrification-denitrification. This BipDopp process has advantages as small-land use,steady operation,low expenses and high-level inflexibility.The results of this study can be used as significantly theoretical guidance in the development and practice of the Lurgi coal gasification wastewater biochemical treatment, as well as playing a very good and exemplary role in guiding the future operation and other related wastewater treatment projects design and debugging.