... Based upon the changes in different chemical pools of heavy metals in sludge due to metal spiking and incubation, it appeared that bio-oxidation of organic carbon and consequent acidification effected ... **, * and NS indicate significance at P = 0.01, 0.05 and non-significant difference between pairs, respectively 3.3 Effect of metal spiking and incubation on chemical pools Heavy metal spiking and ... of toluene was 3.2 Chemical pools of heavy metals Among various chemical pools, major portion of metals in unspiked sludge occurred in the residual fraction (F5 ) followed by F3 , F2 , F4 , and...