Arsenic Removal from Groundwater

Application: Filtration with enhanced coagulation for arsenic removal from groundwater
Capacity: 158,400 GPD (600 m3/d)
Commissioned: May 2002

Challenge
Arsenic is an element that occurs naturally in the earth’s crust. However, arsenic can also be contrib-uted from industrial sources such as semiconductor manufacturing, pesticides, refining operations and wood preservatives. All of these sources can lead to increased arsenic levels in groundwater.

Consuming groundwater that has high levels of ar-senic has been linked to skin damage and circulato-ry problems, as well as increased cancers. For this reason, the US EPA has reduced the Maximum Con-taminant Level (MCL) for arsenic in drinking water from 50 ppb to 10 ppb.

At a site in the southern US, groundwater was found to contain 250 to 360 ppb of arsenic from industrial sources. Faced with the responsibility of treating the contaminated groundwater, the site owner investigated arsenic removal technologies to reduce the high levels of arsenic to < 10 ppb.

Solution
ZeeWeed* ultrafiltration membranes were selected over other arsenic removal technologies for round-water remediation at this site. GE provided a con-tainerized ZeeWeed system consisting of a ZeeWeed process tank and an ISO container with all of the required process equipment (e.g. pumps, blowers, chemical feeders).

Pilot testing has demonstrated that ZeeWeed im-mersed ultrafiltration membranes with enhanced coagulation can reduce arsenic concentrations in one simple, integrated process to below that of the MCL designated by the US EPA.

Within a few months, the ZeeWeed system had al-ready treated 1.5 million gallons of groundwater, bringing arsenic levels to < 5 ppb. Today, the system continues to produce drinking water quality effluent which consistently surpasses the US EPA’s Maxi-mum Contaminant Limit for arsenic.