ZHANG Xuehong, YU Ronghao, LIU Liheng , WEI Chunzhong , ZENG Si
2026, 46(1): 88-95.
To evaluate the potential of industrial-scale pyrolyzed sludge biochar ( ISB) as a soil amendment , the effects of ISB content( mass ratio of ISB to soil ; CK , 2. 5% , 5. 0% and 10. 0%) on soil leaching characteristics are investigated through soil column leaching experiments. Meanwhile , the leaching kinetics of nutrients are an- alyzed by first-order kinetic equation , double constant equation , parabolic equation and Elovich equation. Mo- reover , the Nemero composite index method and soil heavy metal environmental capacity method are selected to evaluate the fertility level and heavy metal environmental capacity of the soil after leaching , respectively. The results show that pH of leaching solution show a decreasing trend with the content of ISB. The levels of nutrients such as dissolved organic carbon ( DOC) , TN , NH3 -N , TP , K , Ca , and Mg in leaching solution have a signifi- cant positive correlation with the content of ISB. The content of ISB increases the concentrations of Zn , Fe , and Mn in the leaching solution , while the concentration of Pb shows a decreasing trend with the content of ISB. The release behavior of DOC , TN , NH3 -N , TP , K , Ca and Mg is a complex process controlled by a combina- tion of multiple factors , such as precipitation/dissolution , adsorption/desorption , complexation/dissociation , and intra-particle diffusion. The fertility level of the soil after leaching increases from 0. 59 to 1. 02 with the con- tent of ISB , while the level of the environmental capacity of heavy metals decreases from 1. 004 to 0. 995. In conclusion , ISB possesses the potential to be used as a soil conditioner , and its content is recommended to be not higher than 10. 0% .