Exploratory studies on incineration of carbaryl waste.

A hazardous waste stream, generated during the manufacture of carbaryl (1-naphthyl-n-methylcarbamate), an insecticide, was explored for assessing its suitability for incineration. The physico-chemical characteristics such as proximate analysis (moisture, volatile matter, fixed carbon and ash), ultimate analysis (carbon, hydrogen, nitrogen, sulphur and oxygen), calorific value and the heavy metal content of the waste indicated that carbaryl waste was suitable for incineration. The incineration experiments were conducted in a bench-scale (25 mm ID, 450 mm long) quartz reactor at various operating temperatures (800 to 1200 degrees C) at a fixed gas-phase residence time of two seconds. Results of the experiments showed that carbaryl waste could be effectively incinerated at a temperature of 1200 degrees C with a gas-phase residence time of two seconds. The destruction and removal efficiency (DE) at these operating conditions was > 99.99% for carbaryl, which was monitored as a principal organic hazardous compound (POHC). The ash generated at these operating conditions was subjected to the Toxicity Characteristic Leaching Procedure (TCLP) and was found to be non-toxic in nature.