This book gives a comprehensive discussion on the removal of heavy metal ions from electroplating wastewater sludge using acid dissolution. Hydrochloric acid, nitric acid and aqua regia solutions were used to dissolve the metals at various reaction conditions. Metals that were tested include Silver, Aluminium, Copper, Tin, Iron, Nickel and Zinc. The optimal recovery values obtained for the above metals were 99.5%, 72.6%, 99.6%, 55.4%, 19.4%, 4.97% and 6.4% respectively. The dissolution process was greatly influenced by the reagent type and reaction temperature. Results obtained were optimised with a statistical software called DOE PRO, where a dissolution model of each metal species was obtained. All models showed good confidentiality and can be used as a tool for future studies for metal extraction from wastewater sludge.

Vasanthi Sethu is a lecturer in the Department of Chemical and Environmental Engineering, University of Nottingham Malaysia Campus. Her research interests include biosorption technology, wastewater treatment, sludge treatment and heavy metal reclamation, recycle and re-use.