ABSTRACT
T o v a lid a te th e A sR T tech n o lo g y u n d e r na tu ra l co n d itio n s , a field d e m o n s tra tio n w a s c o n d u c te d a t an a rsen ic co n tam in a ted landfill in M aine. A series o f fo u r co lu m n s w as evalua ted . T h e g lass co lum ns w e re 59 cm lo n g and 7.5 cm in d iam eter. T h e co lum ns w ere filled w ith a 1:1 (w /w ) ra tio o f iron and silica sand. S ilica sand w as used b ecau se it w as show n to hav e little cap ac ity fo r a rsen ic ad so rp tio n . O ne co lu m n w as filled w ith sand only as a co n tro l. T w o c o lu m n s w e re filled w ith th e J. T. B ak e r iro n and o n e w as filled w ith th e C o n n e lly -G P M iron. A nox ic g ro u n d w a te r fro m th e site w as p u m p ed th ro u g h th e co lu m n s a t a c o n s tan t flow ra te . T h e g ro u n d w a te r a t th e site had co n sis ten t ch em istry w ith a b o u t 3 2 0 ppb arsen ic [A s (III)] , 48 p p m iron , and 3 30 ppm su lfa te . T h e o p e ra tio n a l p a ram e te rs o f each co lum n are listed in T ab le 1. T he field ex p erim en t la s ted fo r 56 days and ran con tinuously . T h e effluen t o f th e co lu m n s w a s sam pled fo r arsen ic , iron (fe rro u s and to ta l) , and sulfate.
