| At present, the pollution problem is turned more and more serious. And environment protection has become one of focuses cared by people and government. Plenty of organic wastewater produced by industry is threatening people's health. Therefore, it is of significance to develop new technology for wastewater treatment.Coal gasification wastewater is produced in the process of coal gas cooling, washing and purification. The wastewater quality is very complex and it comprises maily of phenols, a number of hydrocarbons, including heterocyclic compounds and cyanides as well as ammonium and sulphur containing compounds.Before further utilization of coal gasification wastewater or before its introduction to the sewer,it must be purified to reduce the concentration of all phenols and COD.This study is a new way to treat coal gasification wastewater with TAME dephenolization, lignite pyrolysis char adsorption and Fenton reagent catalytic oxidation.The results show that, under the conditions that in 298 K , the phase ratio of TAME to wastewaterl is 6,the concentration of phenols in wastewater is reduced from 5720mg/L to 263mg/L,and extaction ratio of phenols is 95.4%.This method obtains a number of useful chemicals.After absorbed during 30 min by lignite pyrolysis char (520℃, 200 g·L-1, l-2mm), the removal ratio of COD of wastewater can get 49.5%. It finds a new way for the further utilization of lignite pyrolysis char, and it is unnecessary to renew or activate for used chars.With Fenton reagent as catalytic oxidation, under the conditions of 75℃, 0.6g/L Fe2+, 7.5g/LH2O2,the removal rate of COD of coal gasification wastewater is 95.16%.
|
PDF Full Text Request