Experimental and modeling study of pure terephthalic acid (PTA) wastewater transport in the vadose zone

Abstract

PTA wastewater discharged from a factory was selected as the research object in this project and CODcr was selected as the characteristic pollution factor. Static adsorption and soil column leaching experiments of silty clay and clayey soil were carried out to study the adsorption, bio-degradation and dispersion coefficient of CODcr in PTA wastewater. Hydrus-1D was used to build the convection-diffusion model to demonstrate the migration of PTA wastewater in the vadose zone. The results indicate that silty clay and clayey soil in the vadose zone can adsorb, degrade and impede the contaminants in PTA wastewater; however, the coefficient of adsorption and degradation were very low, they were down to 0.0002 L g(-1), 0.0003 L g(-1) and 0.0097 d(-1), 0.0077 d(-1) for silty clay and clayey soil, respectively. Under the virtual condition that, wastewater in the sewage pool is 5 m deep, CODcr concentration is 4000 mg L(-1), vadose zone is 21 m, PTA wastewater will reach the phreatic surface after 20.87 years. When wastewater in the sewage pool is 7 m with other conditions unchanged, after 17.18 years PTA wastewater will reach groundwater. The results show that there is a higher pollution risk for groundwater if we do not take any anti-seepage measures.

Improved anaerobic degradation of purified terephthalic acid wastewater by adding nanoparticles or co-substrates to facilitate the electron transfer process

“…1,2 However, PTA wastewater, which is composed of high concentrations of terephthalic acid (TA), benzoic acid (BA), isophthalic acid (IPA), p-toluic acid, acetic acid and methyl acetate, is massively generated from PTA manufacturing industries and subsequently results in severe environmental pollution. 3 In recent years, anaerobic treatment methods have been gradually introduced into PTA wastewater treatment plants due to their several advantages, e.g. lower nutrient requirements, less surplus sludge production and additional energy generation in the form of methane-rich biogas.…”

Studies on the Solubility of Terephthalic Acid in Ionic Liquids

“…Nowadays, PTA is produced by the catalytic liquid-phase oxidation of p-xylene in acetic acid, in the presence of air, using a manganese or cobalt acetate catalyst. In 2011, global PTA capacity reached 28.8 million tons, with China being the main world producer [2].…”