Complex mixtures of hazardous chemicals such as @entity2555 ( @entity2556 ) in contaminated soil and groundwater can have severe and long-lasting effects on health. The evidence that these contaminants can cause adverse health effects in animals and @entity1 is rapidly expanding. The frequent and wide-spread occurrence of @entity2556 in groundwater makes appropriate intervention strategies for their remediation highly desirable. The core objective of this research was to assess the ability of a clay-based composite to sorb and remove toxic contaminants from groundwater at a wood-preserving chemical waste site. Treatment efficiencies were evaluated using either effluent from an @entity11896 ( @entity11896 ) or a bioreactor (B2). The effluent water from these units was passed through fixed bed columns containing either an organoclay composite or granular activated @entity505 . The sorbent columns were placed in-line using existing sampling ports at the effluent of the @entity11896 or B2. Individual one-liter samples of treated and untreated effluent were collected in Kimax bottles over the course of 78 h (total of 50 samples). Subsequently each sample was extracted by solid phase extraction methodology, and @entity211 ( @entity212 ) and @entity2556 concentrations were quantitated via GC/ @entity15 . Columns containing porous organoclay composite, i.e. sand-immobilized cetylpyridinium-exchanged low-pH @entity6638 clay (CP/LPHM), were shown to reduce the contaminant load from the @entity11896 effluent stream by 97%. The concentrations of @entity3014 ( @entity3015 ) and @entity212 were considerably reduced (i.e. >99%). An effluent stream from the bioreactor was also filtered through columns packed with composite or an equivalent amount of GAC. Although the composite reduced the majority of contaminants (including @entity3015 and @entity212 ), it was less effective in diminishing the levels of lower ring versus higher ring @entity2556 . Conversely, GAC was more effective in removing the lower ring @entity2556 , except for @entity12683 and @entity212 . The effectiveness of sorption of @entity212 from the @entity11896 effluent by the composite was confirmed using a @entity212 -sensitive adult hydra bioassay previously described in our laboratory. The findings of this initial study have delineated differences between CP/LPHM and GAC for groundwater remediation, and suggest that GAC (instead of sand) as the solid support for organoclay may be more effective for the treatment of contaminated groundwater under field conditions than GAC or CP/LPHM alone. Further work is ongoing to confirm this conclusion.

Porous organoclay composite for the sorption of @entity2555 and XXXX from groundwater.

@entity1 :: ('9606', 'Species') :: ['humans'] @entity211 :: ('MESH:D010416', 'Chemical') :: ['pentachlorophenol'] @entity11896 :: ('MESH:D014869', 'Disease') :: ['OWS', 'oil-water separator'] @entity2555 :: ('MESH:D011084', 'Chemical') :: ['polycyclic aromatic hydrocarbons'] @entity212 :: ('CHEBI:8058', 'Chemical') :: ['PCP'] @entity3014 :: ('MESH:D001564', 'Chemical') :: ['benzo[a]pyrene'] @entity2556 :: ('CHEBI:33848', 'Chemical') :: ['PAHs', 'PAH'] @entity3015 :: ('CHEBI:29022', 'Chemical') :: ['BaP'] @entity6638 :: ('MESH:D001546', 'Chemical') :: ['montmorillonite'] @entity12683 :: ('MESH:C031721', 'Chemical') :: ['naphthalene'] @entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity15 :: ('MESH:D009103', 'Disease') :: ['MS']
@entity211 :: (MESH:D010416,Chemical) :: ['pentachlorophenol']
