Many water treatment plants (WTPs) were designed to remove ammonia, iron, and manganese simultaneously using biofilters. In some cases (especially in the Pianura Padana area, in Italy) such plants were designed without a specific treatment stage for arsenic removal because its concentration in the groundwater (i.e. 10 to 20 µg/L) was lower than the previous maximum contaminant level (MCL) of 50 µg-As/L; therefore, specific treatments for arsenic removal must be introduced or upgraded in WTPs. In this work, the results of a 19-month monitoring campaign are reported for a pilot granular ferric oxide (GFO) filter installed in an Italian WTP as a polishing stage. The aim was to investigate the performance of GFO with low arsenic concentrations. The results show that, if the groundwater arsenic concentration is close to the MCL, GFO treatment can be cost effective (approximately 80,000 bed volumes have been treated). It was confirmed that GFO can be effective for the removal of both As(III) and As(V) species.
Monitoring of a pilot GFO filter for removal of low-concentration arsenic in water
COLLIVIGNARELLI, MARIA CRISTINA;CANATO, MATTEO;SORLINI, SABRINA;CROTTI, BARBARA MARIANNA
2016-01-01
Abstract
Many water treatment plants (WTPs) were designed to remove ammonia, iron, and manganese simultaneously using biofilters. In some cases (especially in the Pianura Padana area, in Italy) such plants were designed without a specific treatment stage for arsenic removal because its concentration in the groundwater (i.e. 10 to 20 µg/L) was lower than the previous maximum contaminant level (MCL) of 50 µg-As/L; therefore, specific treatments for arsenic removal must be introduced or upgraded in WTPs. In this work, the results of a 19-month monitoring campaign are reported for a pilot granular ferric oxide (GFO) filter installed in an Italian WTP as a polishing stage. The aim was to investigate the performance of GFO with low arsenic concentrations. The results show that, if the groundwater arsenic concentration is close to the MCL, GFO treatment can be cost effective (approximately 80,000 bed volumes have been treated). It was confirmed that GFO can be effective for the removal of both As(III) and As(V) species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
