Use of a natural mineral for the removal of copper and nickel from aqueous solutions to reduce heavy metal content of precipitation sludges


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Cagın V., Moralı N., Imamoglu I.

JOURNAL OF RESIDUALS SCIENCE & TECHNOLOGY, vol.4, pp.45-54, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 4
  • Publication Date: 2007
  • Journal Name: JOURNAL OF RESIDUALS SCIENCE & TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.45-54
  • Middle East Technical University Affiliated: Yes

Abstract

A major disadvantage of precipitation removal of heavy metals is the disposal of sludge having a high concentration of heavy metals, sometimes requiring disposal in hazardous waste landfills. A sorption based polishing step using natural sorbents; following precipitation may be feasible to avoid costly disposal of hazardous sludge. This study investigates the applicability of the use of a natural zeolite, namely clinoptilolite, obtained from a Western Anatolian deposit, in removing copper and nickel from aqueous solutions. Maximum achievable capacities were found as 0.31 meq Cu2+/g and 0.32 meq Ni2+/g for as-received, and 0.55 meq Cu2+/g and 0.43 meq Ni2+/g for conditioned clinoptilolite samples, respectively. Use of clinoptilolite for the removal of Cu2+ from precipitation effluents holds more potential for the purpose of meeting discharge standards. Metal removal mechanisms are also investigated via examination of exchangeable cations (Na+, K+, Mg2+, Ca2+) in the aqueous phase.