Soluble arsenic removal at water treatment plants

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.

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Survey on full-scale drinking water treatment plants for arsenic removal in Italy

Water Practice & Technology ◽

10.2166/wpt.2014.005 ◽

2014 ◽

Vol 9 (1) ◽

pp. 42-51 ◽

Cited By ~ 16

Author(s):

S. Sorlini ◽

F. Gialdini ◽

M. C. Collivignarelli

Keyword(s):

Drinking Water ◽

Water Treatment ◽

Arsenic Removal ◽

Ferric Hydroxide ◽

Drinking Water Treatment ◽

Chemical Precipitation ◽

Ionic Form ◽

Ionic Exchange ◽

Water Characteristics ◽

Water Treatment Plants

Arsenic in drinking water causes severe health effects and it is widely diffused in groundwater around the world. This paper presents the results of a survey about the main arsenic removal technologies employed in Italy and the main features in the management of real treatment plants. 19 drinking water treatment plans were involved in this study. The specific aspects analysed in this survey were: type of technologies applied in the drinking water treatment plants (water characteristics, ionic form of As in raw water, etc.), technical aspects (chemical dosage, treatment steps, hydraulic load, retention time, etc.), operational aspects (backwashing, media regeneration, management of residues, etc.) and costs of these technologies. In Italy, the main technologies employed are chemical precipitation (10 plants) and adsorption with granular ferric hydroxide (GFH) (six plants). Two of these plants employ both chemical precipitation and GFH. Moreover, there are some applications of adsorption on titanium dioxide (two plants), reverse osmosis (two plants) and ionic exchange (two plants).

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Water Decontamination at Water Treatment Plants. A New Approach

Chemistry for Sustainable Development ◽

10.15372/csd2020212 ◽

2020 ◽

Keyword(s):

Water Treatment ◽

Water Decontamination ◽

New Approach ◽

Water Treatment Plants

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Determination of natural radionuclides in waste generated in the potable water treatment plants of the Zona da Mata of the state of Pernambuco- Brazil

Brazilian Journal of Radiation Sciences ◽

10.15392/bjrs.v7i2a.763 ◽

2019 ◽

Vol 7 (2A) ◽

Author(s):

Adriana Muniz De Almeida Albuquerque

Keyword(s):

Water Treatment ◽

Potable Water ◽

Natural Radionuclides ◽

The United States ◽

Radioactive Material ◽

Human Consumption ◽

Radiological Protection ◽

Natural Occurrence ◽

Water Treatment Plants ◽

Potable Water Treatment

The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the presence of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Studies have shown that the stages of purification are quite effective in removing the radionuclides contained in water. The removal is due to co-precipitation of the radionuclides with the suspended materials and the precipitated material is accumulated and characterized as a Technologically Concentrated Natural Occurrence Radioactive Material (TENORM) by the United States Environmental Protection Agency (USEPA). This residue can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U, Th and the K-40 were determined in the residues generated at the Potable Water Treatment Plants – PWTPs in six municipalities of Pernambuco. The results obtain corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiological protection standards established.

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