Comparison of Ion-Exchange Resins and Biosorbents for the Removal of Heavy Metals from Plating Factory Wastewater

Abstract

The NCP (Neurospora crassa gene expressed in the periplasmic space) is a recombinant Escherichia coli expressing the Neurospora crassa metallothionein gene within the periplasmic space. The NCP has been shown to remove heavy metals from solutions containing low concentration of heavy metals. In this study, the ability of NCP to remove heavy metals from wastewater was compared to the commercial sorbents Duolite GT-73, IRC-718, and BIO-FIX. Three process wastewater streams, acid/alkali, chromate, and cyanide, were tested at their original pH and near neutral pH. In addition to other contaminants, the wastewaters contained metals including Cd, Cu, Ni, and Ag. NCP was most efficient in removing the heavy metals from wastewaters at near neutral pH. Chromium removal per gram of IRC-718 at pH 2.05 was an order of magnitude higher than any other sorbent in either pH-unadjusted or pH-adjusted samples. Duolite GT-73, IRC-718, and BIO-FIX had similar efficiency in removing heavy metals from the pH-adjusted wastewater. When the sorbents were tested for removal of part per billion levels of 109 Cd, NCP demonstrated the highest percent removal. These results suggest potential treatment strategies for metalcontaminated wastewaters involving pH adjustment and primary treatment with a commercial sorbent followed by polishing with NCP.

Biomass Adsorbent for Removal of Toxic Metal Ions From Electroplating Industry Wastewater

“…Heavy metal pollution around plating factories has been associated with the expansion of the plating industry in developing countries (Morgan &Lee, 1997 andBrower et al, 1997).…”

Staphylococcal Surface Display of Metal-Binding Polyhistidyl Peptides

“…Bacterial sequestration of toxic metals has previously been investigated using nonengineered bacteria (23), but recombinant DNA technology offers the possibility of improving the metal binding capacity of the bacteria. Such engineered bacteria have in fact been evaluated for removal of Cd 2ϩ from actual factory wastewater (2). Periplasmic expression of a Neurospora crassa metallothionein in Escherichia coli generated cells that were superior to bacteria with cytoplasmic metallothionein localization in terms of metal ion adsorption (29).…”

Synthesis of Poly(hydroxamic Acid)‐Poly(amidoxime) Chelating Ligands for Removal of Metals from Industrial Wastewater

“…Overall, the extraction of heavy metal was very good from cyanide wastewater. NCP (Neurospora crassa gene expressed in the periplasmic space) removed heavy metals from solutions containing heavy metals 6 . Three process wastewater streams such as acid/alkali, chromate and cyanide were tested and NCP was noted to be removing the heavy metals from Heavy metals % Extraction wastewaters at near neutral pH.…”

“…Although known to be quite effective in treating industrial effluents, chemical coagulation induces secondary pollution due to the addition of chemicals. Heavy metal precipitation also produces intractable sludge that must be treated and disposed of often at high cost 6 . Therefore the need for an effective methodology to overcome this drawback is essential to treat industrial effluents.…”