Project Overview
A Kuwait refinery generating 800 m³/day of spent caustic (NaOH) from LPG merox treating was sending all spent caustic off-site to hazardous waste contractors at significant cost. The caustic contained sulfides (~3,000 mg/L), disulfides, phenols (~800 mg/L), and mercaptans — incompatible with the refinery's existing biological ETP without pre-treatment.
The Challenge
Off-site hazardous disposal carried both cost and supply-chain risk. The high-strength sulfide/phenol load could not enter the biological ETP without shock-loading it and triggering compliance failures downstream.
WFS Solution
WFS designed a dedicated wet-air oxidation (WAO) plant with caustic neutralization, sulfide oxidation to sulfate, and phenol destruction to CO₂ and water. Effluent was polished by activated carbon before being released to the existing ETP as a benign feed.
Technologies Applied
- ▸Wet Air Oxidation (WAO)
- ▸Caustic Neutralization
- ▸Activated Carbon Polishing
- ▸Integrated ETP Pre-treatment
Results Achieved
Performance Outcomes
- ✓>99.99% sulfide destruction
- ✓COD knocked down from 180,000 mg/L to 150 mg/L before ETP
- ✓>99.8% phenol removal
- ✓$4.2M/year saved in hazardous-waste contractor fees
Your Project Could Be Next
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