Solid phase aerobic digestion of high strength organic wastewater using adsorbent polymer gel

A novel solid phase aerobic digestion process for high strength organic wastewaters using adsorbent polymer gel particles was developed. Characteristics of organic removal and water evaporation were investigated using laboratory scale experimental apparatus. It was found that the removal rate of organic pollutants adsorbed on polymer gels increased with the increase in organic concentration of wastewater and the temperature. The maximum rate of organic removal was as high as 10 kg-TOC.m⁻³.d⁻¹ at about 50°C, but the elevated temperature beyond 50°C hindered the rate of organic removal and thus CO₂ evolution rate. Mineralization of organic matters to CO₂ was decreased as well. The mineralization of organic matters was in the range of 65% to 81%, corresponding to a temperature of 30 to 50°C. The increased temperature and air feed rate accelerated the water evaporation. Water evaporation rate was well estimated from the previously reported formulation and the mass transfer coefficient. Based upon the experimental results in the present study, a mathematical model was set up and used to simulate a optimal operating conditions to accelerate the mineralization of organic pollutants and to evaporate the wastewater.