Remediation of phenol contaminated soil using persulfate activated by ball-milled colloidal activated carbon

The degradation of phenolic compounds through persulfate (PS) activation is a valuable approach for soil/ groundwater remediation. Several reports have been made related to PS activation and contaminant degradation using carbo-catalysts; however, there is no detailed study on soil remediation by colloidal activated carbon. This study demonstrates the phenol (PhOH) degradation efficiency in spiked and field-contaminated soils by a novel and low-cost ball-milled colloidal activated carbon (CAC(BM)) catalyst. The CAC(BM)/PS system exhibited outstanding degradation performance for PhOH in both spiked and field-contaminated soils. Optimum condition for degradation of 5.63 mmol PhOH kg soil(-1) was achieved at 2.5 mg CAC(BM) g soil(-1), 5 mM PS, and a solid-liquid ratio of 1:5 at 25 ? in the wide pH range of 3-11. Radical scavenger experiments and electron spin resonance (ESR) spectroscopy revealed that both radical (& BULL;OH and SO4 & BULL;-) and non-radical (O-1(2)) species were involved in the CAC(BM)/PS system. PhOH degradation in soil phase followed several degradation pathways, resulting in various intermediate byproducts such as acetic acid, maleic acid, p-benzoquinone, fumaric acid, and ferulic acid as analyzed by ultra-high-performance liquid chromatography with mass spectroscopy (UPLC-MS). The CAC(BM)/PS system showed a promising potential in the remediation of organic-contaminated soil.

Automated summary

The activation of persulfate (PS) with ball-milled colloidal activated carbon (CAC(BM)) is an effective method for the degradation of phenolic compounds in soil. The CAC(BM)/PS system showed outstanding degradation performance under optimal conditions and was efficient in both spiked and field-contaminated soils.