First and second rainwater treatment polluted by heavy metals.

With the entry into force of Legislative Decree no. 152/2006 (Consolidated Environmental Law) the various types of wastewater are regulated in particular art. 113, dedicated to the "run-off rainwater" and to the "Rain Water" where the following is specified:
- for the prevention of hydraulic and environmental risks, the Regions, after consulting the Ministry of Environment, regulate the forms of control of waste water run-off discharges from separate sewage systems, and when it is required that rainwater run-off from other separate pipelines , are subject to particular requirements, including any authorization;
- the Regions also regulate the cases in which it may be required that the first rain and washing waters of the external areas are conveyed and properly treated in purification plants for particular cases in which, in relation to the activities carried out, there is a risk of run-off from the uncovered waterproof surfaces of hazardous substances or substances that create damage to the achievement of water quality objectives.
In any case, the discharge of meteoric water into groundwater is forbidden and, in addition, meteoric waters not regulated according to paragraph 1 (Point A) are not subject to restrictions or prescriptions.

The individual Regions, according to the National Regulations, are therefore delegated to the specific regulation of run-off rainwater, with particular reference to the "regulation of the forms of control of discharges of rainwater from separated sewage systems", and the possibility to subject them to "specific requirements, including any authorization".

Some Regions, in particular Lombardy, Puglia and Veneto, have begun to regulate also the waters of "second rain", when they come from areas where activities with a high probability of pollution are carried out. The volumes of water to be treated are calculated on a case-by-case basis by the Competent Authority; while the first rain water goes, after specific treatment in the public sewers, the second rainwater should always be destined to a surface water body, with possible chemical-physical treatment if coming from potentially polluting activities.

EMS Water Technology Srl , in addition to the design and supply of standard systems for the treatment of first rain water made with prefabricated monobloc elements in high-strength concrete, has developed a line of "Modular chemical treatment plants" for the complete purification of first and second rain water contaminated in particular by heavy metals , coming from industrial areas of metal processing and storage or from waste treatment plants.

The implants of chemical-physical type CFP series P offered by EMS Water Technology Srl using chemical and physical technologies in a succession of stages to remove the pollutants in the form of for purified water sludge having limits of acceptability content within the limits prescribed by current ative norm. With the use of special reagent mixtures, appropriately studied according to the polluting products to be treated, separation is obtained by gravity of the harmful substances (mainly metals in the form of hydroxides and insoluble salts ) present in the first and second rain rainwater mainly consisting of metals in the form of hydroxides and insoluble salts.

The EMS Water Technology Srl plants CFPP series provide for a serious and chemical reaction stages (acidification, coagulation, alkalinization and flocculation) followed by a sedimentation phase with "lamellar packs" for the separation of the insoluble fraction ( chemical sludge ) from the clarified water.
The purified water before being sent to the final delivery is further filtered on filters with mixed sand beds with special zeolites while the sludge is collected and thickened in particular draining bags before final disposal.

The whole process is automatically controlled based on the detection of the meteoric event and all the equipment is designed for intermittent operation based on the rainy phenomena and can be completed with a remote telecontrol system via GSM.