Experimental Study On The Reduction Of Chlorinated Hydrocarbons By Zero-Valent Iron/Zinc Reduction

A chlorinated hydrocarbon refers to an organic substance formed by a chlorine element replacing a hydrogen element in a hydrocarbon.Chlorinated hydrocarbons are generally biohazardous and are the class of compounds of major interest in relevant standards in major countries and regions of the world.The chlorinated hydrocarbons entering the environment will eventually enter the water and soil through various routes,and the repair of chlorinated hydrocarbons in water and soil is one of the hot spots in recent years.Among the many repair techniques,the use of zero-valent iron reduction degradation is considered to be an environmentally friendly,cost-effective treatment.In this paper,the effects of parameters such as top air-liquid ratio,headspace equilibration time and equilibrium temperature on the analysis of target materials were investigated by reducing the degradation of trichloroethylene and other organic compounds by Nano-iron,and screening the instruments suitable for the separation of the components studied.Conditions;the matrix effect in the organic component test by gas chromatography-mass spectrometry was evaluated,and the solution containing sodium chloride(inorganic salt),methanol(organic),passivated Nano-iron(zinc)and the like was investigated.The degree of influence of the detection of the components.The results show:1.When the gas-liquid ratio is 1:1,the equilibrium temperature is 80 C and the equilibrium time is 50 min,good sensitivity can be obtained for the analysis of the target.There is a good linear correlation in the range of 50-1000 g/L,and the detection limit is between 1.54-11.70 g/L.2.In the initial concentration of trichloroethylene is 20 mg/L,the amount of Nano-iron added is 2.0 g/mg,and the ratio of head-air to liquid is 1:1,Nano-iron has nearly 60% TCE in the first half hour.Degradation;the removal rate of trichloroethylene in the reaction to 180 min reached 98.58%.The process of Nano-iron reduction and degradation of trichloroethylene conforms to quasi-first-order reaction kinetics.3.In the detection of organic matter in complex systems,the effect of matrix effect on the measurement results should not be neglected;in the actual sample detection,the results should be corrected by matrix.