Treatment of heavy metal-bearing wastewaters using activated carbon
- West Virginia Univ., Morgantown, WV (United States). Dept. of Civil and Environmental Engineering
- Norit Americas, Inc., Atlanta, GA (United States)
Two synthetic wastewaters (1 mg/l/Pb-10 mg/l phenol; 1 mg/l Pb-1 mg/l TCE) were treated using granular activated carbon (GAC) columns. Several process cycles (wastewater treatment-regeneration) for each wastewater were conducted. The study carbon, Hydrodarco (HD) 4000, was a lignite based carbon. Regardless of the organic contaminant, column performance parameters based on Pb removal were relatively constant: bed volumes at breakthrough ranged from 625 to 870, X/M at exhaustion ranged from 1.60 to 2.59 mg Pb/g carbon, carbon usage rate ranged from 0.500 to 0.668 g carbon/l of wastewater treated, the degree of column utilization ranged from 78--91%, and the Pb desorption efficiencies ranged from 74--100%. Phenol desorbed during the base rinse portion of the regeneration procedure as well as during the first several bed volumes of the subsequent treatment run. The high column pH was due to the base conditioning step that follows the acid desorption step of the regeneration procedure. Phenol ionizes at high pH and the ionic form of phenol is not as adsorbable as the nonionic form. TCE did not desorb to any great extent during the regeneration procedure. After 2,930 BVs of Pb-TCE wastewater, TCE had not broken through. The TCE surface loading at this point was 7.67 mg TCE/g carbon. The waste concentration factor (WCF) increased from 37.5--53 from the first to the third run. The WCF after the third run was similar to the WCF`s that are typically reported for membrane and ion exchange processes. Simultaneous removal of organics and heavy metals is feasible provided that the organics contaminants do not desorb at the extreme pHs experienced during regeneration for heavy metals. If desorption does occur, the portion of the column effluent with an acceptable concentration of organics can be recycled to the column influent.
- OSTI ID:
- 257059
- Report Number(s):
- CONF-950952-; TRN: IM9631%%265
- Resource Relation:
- Conference: 12. annual international Pittsburgh coal conference, Pittsburgh, PA (United States), 11-15 Sep 1995; Other Information: PBD: 1995; Related Information: Is Part Of Twelfth annual international Pittsburgh coal conference: Proceedings. Coal -- Energy and the environment; PB: 1248 p.
- Country of Publication:
- United States
- Language:
- English
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