| Coking wastewater is a typical industrial wastewater with high COD,high phenol,high ammonia nitrogen containing aromatic compounds and heterocyclic compounds.It is a problem in the field of industrial wastewater treatment that coking wastewater treatment technology has not achieved a breakthrough research progress for a long time,because the high biodegradable organic matter content in coking wastewater,which has Biological toxicity and high ammonia nitrogen.After the promulgation and implementation of the new Coking Chemical Industry Pollutant Emission Standard(GB16171-2012),it is difficult for most coking and steel enterprises to reach the discharge standard within the affordable input and operation and maintenance costs,which is also the focus of the future environmental engineering and science fields.Thus,the purpose of this study is to solve the above problems.In this study,after researching the progress of domestic and foreign technology,and comparing the treatment effects of similar sublimation processes,the biochemical process of improved low-oxygen oxidation ditch(QSYB)has high sludge concentration,aeration energy saving,non-stop replacement parts,The integrated structure with built-in clarifier has a large proportion of internal circulation and full-mixing process to achieve a lower concentration gradient of pollutant concentration in the pool.It is decided to use this process as the core means to analyze and verify the effect of the process in coking wastewater,in order to obtain Effective,low-investment,low operating costs,and easy-to-use process management.According to the trial production,the wastewater from a coking enterprise in Henan was selected as the test object,and the process design plan of the pilot test was formulated,based on that,the work of the pilot site began on August 20,2017.Many problems were found during the continuous operation from September to November in2017,according to the conclusion,the pilot test was interrupted due to the temperature drop.The pilot test was restarted since the weather recovered in April 2018,according to the problems that were found before,the process was adjusted and acid precipitation was increased,it helps to solve the problem that the oily lipids in the coking wastewater and a large amount of highly difficult-to-degrade biphenyl,phenol and polycyclic aromatic hydrocarbons cause foam overflow and the effluent CODcr fails to meet the expected target.After continuous pilot test from May to November 2018,the data were summarized and analyzed.The average values of the effluent indicators and removal rates were:CODcr 156.3 mg/L,removal rate 96.6%,ammonia nitrogen 4.0 mg/L,removal.The rate was 98.6%,the volatile phenol was 0.25 mg/L,the removal rate was99.97%,the cyanide was 0.17 mg/L,and the removal rate was 99.16%.Except for CODcr slightly exceeding the standard,it basically meets the indirect emission standards of the newly-built enterprises in Table 2 of the Coking Chemical Industry Pollutant Emission Standard(GB 16171-2012),which basically achieves the expected target of this pilot,and provides a good quality in-depth treatment of influent water for zero discharge of industrial water in the future,it saves energy and chemicals consumption after subsequent deep treatment,and plugging of filters,ultrafiltration,sodium filtration,RO membrane,etc.due to excessive water inflow.The total cost of the pilot test is 5.09 yuan/m~3,and the power consumption is 3.04yuan/m~3,accounting for 59.7%of the total cost.This is due to the small water volume,the high power of the equipment,or the substitution of larger equipment without the flow adapter.After large-scale application,the estimated power consumption is about2 yuan/m~3±,and the estimated total cost is 4 yuan/m~3±.It has broad prospects for further research and engineering application. |
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