Kutty, S.R.M. and Ezechi, E.H. and Khaw, S.G. and Lai, C.L. and Isa, M.H. and Salihi, I.U.  (2016) Copper removal from biological treatment system using modified adsorbent derived from groundwater treatment plant sludge and rice husk.  Jurnal Teknologi, 78 (5-3).  pp. 53-57.  ISSN 01279696