Vermiremoval of heavy metal in sewage sludge by utilising Lumbricus rubellus

► Increment of heavy metals after removal due to excretion from earthworms itself (within the interval of week ten to fifteen). ► Heavy metal mass balance in vermitechnology/vermicomposting process. ► Application of Lumbricus rubellus is limited in earthworms' biotechnology area. ► Mixture of urban sewage sludge and spent mushroom compost (SMC) as feed material. ► Regression coefficient (R2=0.8305) between SMC and earthworms' growth rate.