Iranian Researchers Discover Method to Improve Process of Producing Compost from Garbage

The research to study the effect of biochar on the composting process of the organic fraction of municipal solid waste (OFMSW) was carried out by Omid Hassanzadeh Moghimi, a UT graduate in environmental planning major under the supervision of Gholamreza Nabi Bidhendi, a professor at UT's Faculty of Environment.

“Using biochar or charcoal for soil amendment as an additive in the composting process, even at low doses (1% by weight), can increase the quality of compost by reducing the nitrogen reduction rate during the process. The main objective of this study was to investigate the effect of biochar on the composting process of the organic fraction of municipal solid waste (OFMSW) under real conditions,” Nabi Bidhendi said about the project.

The professor said that different doses of biochar (1%, 3%, and 5%) were mixed with compost piles to evaluate the variation of temperature, moisture content (MC), organic matter (OM), carbon (C), nitrogen (N), C/N ratio, and heavy metal (HM) contents in comparison with the control treatment (with 0% biochar addition).

Nabi Bidhendi went on to say that the results of the study showed that the compost piles combined with different doses of biochar had higher MC. The use of biochar as an additive, even at low doses (1%), was able to increase the compost quality through the reduction of N losses during the composting process. The highest reduction of OM during the composting process was observed in the control pile (without biochar addition) by 48.06%, whereas biochar affected the biodegradability of OM and prevented the reduction of nutrients during the composting process under real conditions. The contents of HMs (Pb, Zn, Ni, Cd, and Cu) showed a significant reduction in all of the compost piles combined with biochar in comparison with the control treatment.

“Considering that in terms of all compost quality indicators, the piles combined with biochar can regarded as high standard product, the composts obtained from combining the OFMSW with different biochar doses have desirable features to be used as an amendment agent to improve agricultural soil quality,” he further said.

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