A Study Of Chemical Remediation On 1,2,4-Trichlorobenzene In Groundwater

With the acceleration of economic development and urbanization,industrial site reuse and urban redevelopment always have to deal with all the contaminated soil and groundwater,which posed a significant threat to human health,due to the land use history.Our study,based on the cooperation project between Nanjing University and Dupont Company,was carried out in former Longxi Chemical Plant in Luhe,Nanjing.1,2,4 Trichlorobenzene was targeted as the contaminant of concern in our study according to the sampling results in the site.As In-situ chemical oxidation technology is a commonly used technique in site remediation,this paper discussed removal effect of 1,2,4-TCB by hydrogen peroxide,sodium sulfate and these two-mixed oxidant under the catalytic condition.By changing the value of the influential factors(temperature&pH)in the experiment,the best conditions for site remediation application were then determined.The fluorescent brighteners PF,produced by the former chemical plant,were then added to testify whether their existence made a difference on the removal effect of the contaminant.Such results could then provide reference for this technique’s applicability to the Luhe site where PF existed.Finally,1-D sand column simulation was conducted to study the degradation effect of the contaminant using In-situ chemical oxidation technology.Two kinds of antioxidants are subject to effects of temperature and pH;adding a venue exists the remnants of plant production products optical brighteners PF has some influence on oxidation rate does not affect oxidative tendency.The experimental results showed:1.Individual usage of both oxidants and mixed usage can remove 1,2,4-TCB completely;2.The oxidation efficiency of both oxidants will be influenced by temperature and PH,more specifically,for hydrogen peroxide,the oxidation efficiency will decrease with the increasing PH,while for sodium sulfate,the efficiency will be maximized under the mildly acidic and mildly basic condition;3.The fluorescent brighteners PF,existed in the site due to the manufacturing history,has an impact on the oxidation efficiency when added into the laboratory experiment,with hydrogen peroxide’s oxidation efficiency decreased and sodium sulfate’s efficiency increased.Furthermore,1-D sand column simulation validated certain degradation effect of in-situ chemical oxidation.It can be then concludes that in-situ chemical oxidation is an effective method to remediate the site and the results in this paper can provide reference for future field application.