Solvent-based washing as a treatment alternative for onshore petroleum drill cuttings in Thailand

Solvent-based washing as a treatment alternative for onshore petroleum drill cuttings in Thailand

Optimization

Activated carbon

Gasoline

Petroleum transportation

Organic solvents

Ethylene

Infill drilling

Ethylene glycol

Washing

Recycling

Incineration

Activated carbon treatment

Rock drills

In Thailand, onshore drill cuttings (DC) contaminated with total petroleum hydrocarbon (TPH) are currently transported off-site for incineration, causing high transportation cost and potential leakage to the environment. To address the issues, we develop solvent-based washing as a greener alternative for onshore DC remediation, focusing on solvent selection, washing process optimization, and solvent recovery. The results showed that ethyl lactate (EL) was the best green solvent for DC washing, compared to water, ethylene glycol, and ethyl acetate. Based on response surface methodology assisted with central composite design, the maximum TPH removal of 87.1% was achieved from 4 mL g1 liquid-to-solid ratio, 14 min washing time, and 80 rpm stirring speed, and the TPH removal rate by EL fitted well with the second-order reaction (R2 = 0.9774). Furthermore, the spent EL was successfully recycled by simple and low-energy adsorption using granular activated carbon (GAC). With the sufficient GAC dosage, TPH could be completely removed from the spent EL without impairing the original EL properties. Moreover, the recycled EL exhibited its successful reuse in the subsequent DC washing process. These findings suggest that solvent washing accompanied with solvent recovery by adsorption could be a novel and greener remedial scheme for onshore DC management. 2020 Elsevier B.V.

718

Science of the Total Environment

2020

Poyai, Thaksina

Getwech, Chiratthakan

Dhanasin, Phanachit

Punyapalakul, Patiparn

Painmanakul, Pisut

Chawaloesphonsiya, Nattawin

journalArticle

489697

10.1016/j.scitotenv.2020.137384