Treatment of wastewater containing o-phthalic acid by polymer adsorbent

The removal and recovery of o-phthalic acid (o-PA) from 1,4-dihydroxyanthraquinone industrial wastewater by adsorption with macroreticular polymeric adsorbent NDA-404 was studied. The results show that ≥ 99% of o-PA and CODCr can be removed as a result of adsorption by NDA-404, and > 99.8% of it can be washed out by desorbent. Over 90% of o-PA in the washout liquor can be crystallized after acidification and concentration with purity of ≥ 99.6%. Both o-PA and CODCr in the adsorption effluent are < 100 mg/L. The treated water can be recycled as wash water or discharged after neutralization.