highly significantp < 0.01
(3) Range analysis and variance analysis The range and variance analysis of the residual proportions of Cu and Zn over 30 days ( Tables 3 , 4 ) revealed that the primary and secondary influencing factors were in the order of activated carbon addition (C) > C/N (B) > moisture content (A): activated carbon addition had the largest range (Cu: R = 17.6, Zn: R = 17.1) and the impact reached a highly significant level (p < 0.01); C/N followed closely (Cu: R = 8.5, Zn: R = 9.2), with the impact reaching a significant level (p < 0.05); moisture content had the least impact (Cu: R = 3.9, Zn: R = 1.8), with significant effects only on Cu (p < 0.05).