Microwave Oven for Improved Biological Solids Determination

This paper describes the evaluation of the use of microwave power to evaporate the water from biological solids in the suspended solids analysis for wastewater treatment plants. When microwave power was applied to the sample at a level of 1.8 watts per gram of water a constant weight was achieved in twelve minutes. This compares with sixty minutes drying time in the conventional test where thermal ovens are utilized. Solids results from microwave oven drying were more precise than the results from drying with a thermal oven.