Kinetics and physicochemical studies of surfactant enhanced remediation of hydrocarbons contaminated groundwater

摘要

Kinetics and physicochemical studies of surfactant enhanced remediation of hydrocarbons contaminated groundwater were investigated for efficiency and effectiveness. 10% pollution was simulated in the laboratory by contaminating groundwater samples with crude oil, automatic gasoline oil (diesel) and domestic purpose kerosene (DPK) in replicates of five. Physicochemical properties of the hydrocarbons contaminated groundwater samples and a control sample were investigated before and after treatments. Total petroleum (TPH) hydrocarbon as target contaminant was monitored periodically to assess the extent of the remediation process. TPH was determined by molecular spectrophotometry technique. Other physicochemical parameters such as pH, turbidity, alkalinity, dissolved oygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), condutiivity, ammonia, nitrate, phosphate, salinity, total dissolved solids (TDS), total suspended solids (TSS) and total solids (TS) were obtained using standard methods while heavy metals levels were determined by atomic absorption spectrophotometry. Different kinetics models were tested to determine the appropriate kinetics model. The pseudo-first order kinetics is established with rate constant as 1.80×104; 1.78×104; 1.53×104mg?1Lh?1for crude oil, diesel and kerosene respectively at 30°C. At the end of the remediation after 6h there was 89.11%; 93.21%; 87.76% reduction in TPH as crude oil, diesel and kerosene for the treated samples in that order. The application of surfactant enhanced remediation using sodium dodecyl sulphate is found be very efficient, effective and rapid in reducing total petroleum hydrocarbon as crude oil, kerosene and diesel as target contaminants. There is the need for post-treatments after remediation for most of the physicochemical parameters are impaired and do not meet the Guideline and Standards for Environmental Pollution Control in Nigeria set by Federal Ministry of Environment and World Health Organization for drinking water and agricultural uses in order to make them fit for these purposes.