Effect of interactions during co-combustion of organic hazardous wastes on thermal characteristics, kinetics, and pollutant emissions

Thermal disposal of organic hazardous wastes (OHWs) in a rotary kiln is an effective method to destroy organic pollutants and reduce the volume, but the complex interactions between various OHWs may result in sharp degradation on combustion performance and the increase in gaseous pollutants emission. Herein, three typical types of OHWs (i.e., pesticide waste, dyeing waste, and organic resin waste, labeled as HW1, HW2, and HW3, respectively) were chosen and thermally co-treated, and the co-combustion characteristics, kinetics, and gas evolutions were systematically studied. A strong positive interaction between HW1 and HW2 was found between 440 and 680 degrees C possibly due to the catalytic effect of Fe (III) and alkali metals in HW1. The experimental DTG peaks of mixtures at 480 degrees C were advanced by 60 degrees C compared with the calculated ones, resulting from the volatiles combustion of HW2 and the catalytic effect from Fe2O3 formed during the combustion. The decrease of ignition temperature of mixtures was found helpful for stable combustion, while the decrease of burnout temperature during co-combustion of HW2 and HW3 exhibited the potential to reduce the clinker ignition loss.

Automated summary

Thermal disposal of organic hazardous wastes in a rotary kiln is effective in destroying organic pollutants, but interactions between different wastes can affect combustion performance and gas emissions. Experimental results showed positive interactions between different types of wastes, which can be beneficial for stable combustion.