Monitoring of a pilot GFO filter for removal of low-concentration arsenic in water

Abstract

Many water treatment plants (WTPs) were designed to remove ammonia, iron, and manganese simultaneously\ud using biofilters. In some cases (especially in the Pianura Padana area, in Italy) such plants were designed without\ud a specific treatment stage for arsenic removal because its concentration in the groundwater (i.e. 10 to 20 μg/L)\ud was lower than the previous maximum contaminant level (MCL) of 50 μg-As/L; therefore, specific treatments for\ud arsenic removal must be introduced or upgraded in WTPs. In this work, the results of a 19-month monitoring\ud campaign are reported for a pilot granular ferric oxide (GFO) filter installed in an Italian WTP as a polishing\ud stage. The aim was to investigate the performance of GFO with low arsenic concentrations. The results show\ud that, if the groundwater arsenic concentration is close to the MCL, GFO treatment can be cost effective (approximately\ud 80,000 bed volumes have been treated). It was confirmed that GFO can be effective for the removal of\ud both As(III) and As(V) species

Water Safety Plan for drinking water risk management: the case study of Mortara (Pavia, Italy)

“…DWTP monitoring to highlight critical issues, with the addition of laboratory and/or field tests (so-called experimental performing tests), should be adopted as a routine procedure for the "good management" of a DWSS. The scientific literature (Vieira et al, 2008;Lamrini et al, 2014) reports interesting studies on the optimization of different DWTPs with "targeted upgrading" (Sorlini et al, 2015b) and operative cost saving (Sorlini et al, 2015c) for DWSSs that must respect more stringent limits for specific pollutants, i.e., arsenic (Sorlini et al, 2014;Collivignarelli et al, 2016).…”