Italy's First Large Scale Municipal Arsenic Removal Water Treatment System

Culligan (USA) and Zilio S.p.A have provided Acqualatina S.p.A. with Italy’s first large scale water treatment system designed to remove Arsenic and other contaminants from municipal water supplies. The Culligan system, which is the largest installed in Italy and one of the largest municipal systems in Europe designed for Arsenic removal, was inaugurated on January 31 in Aprilia, a town in the province of Latina in the Lazio region of Italy. It will enable residents to draw potable water from municipal waterworks in compliance with new Italian regulations that took effect at the beginning of January.

The inauguration of the facility follows the expiration of exemptions for certain contaminants in drinking water. Among the main contaminants for which exemptions had previously been granted were Arsenic and Vanadium. These elements frequently occur naturally in the region’s water as a result of particular geological formations that release the contaminant ions directly into the water as it flows through deep aquifers.

Following the issuance of a public tender, Acqualatina awarded Culligan a contract to design and provide a municipal water treatment system that would reduce these contaminants in compliance with the new and more stringent regulations. The new maximum permissible value for Arsenic is 10 micrograms per litre, and 50 micrograms per litre for Vanadium.

"With this system, which I remember is the largest in Italy and one of the largest in Europe, it has been possible to be within the limits of Arsenic concentration in the water, as established by law regulations since 28 December 2012," said Giuseppe Addessi, President of Acqualatina S.p.A. "This is not to brag,” said Mr. Addessi, “but a simple fact: today we succeeded in reaching the admissible limits of Arsenic in the water requested by the law, in respect of citizens more than to comply what the European Community stated."

”Culligan is delighted to have supported Acqualatina on this important water quality project. Culligan has extensive experience in treating drinking water and we are currently working with many other communities across Italy to help meet the new drinking water standards for Arsenic. Culligan is able to offer large plants, such as this one for Acqualatina, but also has packaged individual solutions from under sink cartridge removal systems for household through to skid mounted systems for hotels and office complexes” said Laurence Bower, Senior Vice President EMEA, Culligan.

Prior to designing the system for Acqualatina, Culligan had demonstrated success in providing treatment to remove Arsenic and other contaminants (Fluorides and Vanadium) from water in the municipality of Cisterna (Latina) and Anzio (Rome), as well as 15 units to ACEA for Optimal Territorial ambits No. 2 for Rome area and No. 4 for Frosinone area, such as to other private companies for water supply to other municipal waterworks in the Lazio region.

For the Acqualatina project, Culligan partnered with Arsenic treatment specialists Zilio S.p.A and the process of adsorption by means of an Arsenic and Vanadium removal mineral was selected. The mineral employed has a particular affinity with these elements, causing them to bind to the porous surface of the minerals.

The water to be treated is drawn from six water wells with an average Arsenic concentration of 12 µg/l, with a maximum flow rate of 600 litres per second. Once treated, the water is conveyed to a storage and recovery tank.

The Culligan system consists of four filtration lines assembled in a clover configuration, to allow for easy management and simple control, while ensuring high filtration efficiency. Butterfly valves with a pneumatic actuator are installed in a 20 foot container, which also houses the local control unit. This configuration is extremely compact, with all sensitive components protected from any atmospheric damage by the specially designed container, which also enables relatively rapid relocation if necessary at a future time.

The installation includes a colorimetric analyser for Arsenic, designed to monitor, through a customisable program, the concentration of Arsenic in the raw water, in the treated water, and at the various phases of the process. To maximise the efficiency of the minerals, the system also incorporates an automatic chemical pre-treatment.

“The successful results were achieved thanks to both the expertise of the Acqualatina staff, who provided precise indications throughout the planning stage and were extremely attentive at every stage of the installation and testing, and to Culligan’s extensive experience in the design and realisation of countless systems utilising a wide variety of different processes. Drawing on laboratory and field tests conducted, we are able to offer our clients solutions specifically designed to meet their technical and economic requirements,” said Lauro Prati, Director Commercial & Industrial Italy, Culligan.