Improving Quality of Municipal Solid Waste Compost through Mg-Modified Zeolite

Developing materials to improve the efficiency of fertilizers and increase their performance is one of the main areas of research in the agricultural science. To the best of our knowledge, this is the first time that Mg-modified zeolite is used for modification of composting process of urban organic solid waste. Natural zeolite was clinoptilolite with a particle size smaller than ۲۵۰ μm modified with MgCl۲.۶H۲O salt. Different ratios (i.e. ۵, ۱۰, and ۱۵% , on a weight basis) of natural and/or Mg-modified zeolite were used to modify the Municipal Solid Waste (MSW) compost. Experimental results revealed that the pH of the final compost product with the Mg-modified zeolite was effectively buffered at ۷.۷. Furthermore, in comparison to the control treatment (without zeolite), the compost with natural and Mg-modified zeolite showed ۳۲.۱۳ and ۴۱.۲۵% reduction in electrical conductivity, respectively. Ammonium retention of the compost containing ۱۵% natural and Mg-modified zeolite was increased by ۶۴.۵۱ and ۱۱۰.۱۰%, respectively. Metals mobility test of the matured composts also revealed that adding zeolite, especially the Mg-modified zeolite, could decrease the mobility of Cu, Pb, Zn, Fe, Ni, and Mn metals. The most decrease in the mobility of metals was observed in Cu, which was about ۴۴.۱۶ and ۴۷.۸۲%, in the compost with the natural and Mg-modified zeolite, respectively.

کلیدواژه ها:

Ammonium retention ، Composting ، Conductivity reduction ، instead of Composting ، Metals mobility.