有机污染场地原位化学氧化高压旋喷修复试验

EXPERIMENTAL STUDY ON IN-SITU CHEMICAL OXIDATION HIGH-PRESSURE ROTARYSPRAY REMEDIATION OF ORGANIC CONTAMINATED SITES

原位化学氧化高压旋喷修复技术在有机污染场地修复工程中具有广阔的应用前景。以某复合有机污染场地修复工程为依托,通过现场影响半径试验确定了该场地的高压旋喷最佳施工参数,经过室内小试研究了氧化药剂投加比与污染物初始浓度对修复效果的影响,并通过中试规模工程应用确定了该场地氧化药剂的最佳投加比。结果表明:该场地的高压旋喷最佳施工参数为旋转速度15 r/min,喷嘴直径2.5 mm,注药压力25 MPa,提升速度15 cm/min;NaOH活化过硫酸钠的复配型氧化药剂的修复效果良好,氧化药剂投加比越低,污染物初始浓度越高,则污染物去除率越高;当氧化药剂投加比增加到5%时,中试规模工程应用区域内的各有机污染物浓度均可降至修复目标值。研究结果可为相关工程实践提供新思路。

In-situ chemical oxidation high-pressure rotary spray remediation technology has broad application prospects in the remediation of organic contaminated sites.Based on the remediation project of a compound organic contaminated site,the field impact radius test was conducted to evaluate the optimal construction parameters for a high-pressure rotary jet.The indoor pilot test was used to study the impacts of the oxidant dosing ratio and the initial concentration of pollutants on the remediation effect,and the engineering pilot scale application was operated to identify the best oxidant dosing ratio for the site.The results showed that the best construction parameters of the high-pressure rotary jet at the site were rotation speed of 15 r/min,nozzle diameter of 2.5 mm,injection pressure of 25 MPa,and lifting speed of 15 cm/min.The composite oxidant of sodium persulfate activated by sodium hydroxide has good repair effect.The lower the dosage ratio of oxidant and the higher the initial concentrations of pollutants,the higher the pollutant removal rate;when the dosing ratio of oxidant increased to 5%,the concentrations of organic pollutants in the application area of the pilot scale project were reduced to the target values of remediation.The research results have high engineering reference value.