The Potential Applications of Using Compost Chars for Removing Environmenal Pollutants from Solution

Municipal compost sample was pyrolyzed to produce compost char as a sorbent for removing the herbicide atrazine from solution. The compost-based char was compared with an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N2. In contrast, when the corn stillage was pyrolyzed under N2, the yield was only 22%. The corn stillage char was activated by stream vapor, and yielded a N2-BET surface area of 439 m/g, which was much greater than the maximum compost char surface area of 72 m/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of corn stillage activated carbon. This similarity could have resulted from the initial organic materials being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermal stabile when compared with the raw materials. In addition, the microorganisms endemic to compost might have increase the microporosity of the compost, which would not have measured by the N2-BET method. Overall, the experimental results suggested that the compost sample in current study was relatively stable material thermally for producing a char, and that it has the potential as a feed stock for making high-quality activated carbon.