Hectron's solutions for automatic filtration in wastewater treatment plants

Hectron's solutions for automatic filtration in wastewater treatment plants
With water quality standards in wastewater treatment plants becoming more and more stringent, operators need to find efficient, practical and cost-effective filtration solutions. Hectron's two filter series (AG and AS) are increasingly used to meet these requirements. Here are their characteristics and advantages as well as reference projects where they are already used.

Which filtration in a wastewater treatment plant?

The purpose of a wastewater treatment plant is to discharge healthy water from the wastewater that is directed to this equipment. In spite of a pre-treatment to eliminate larg­e waste and some heavy matter, then a biological treatment by activated sludge and a decantation phase, it happens that the output water sometimes contains fine particles in suspension. It is very often at the clarifier outlet that automatic filters must be installed to remove these materials.  This is an excellent technique for small and scattered suspended solids. In addition, it is a fast process that is perfect as a back-up or at the end of the process to ensure that the water discharged is fully compliant. The processes offered by Hectron with the AG and AS automatic filters are perfectly suited to these problems. Moreover, they require no human intervention, almost no maintenance and no consumables to be renewed over time. Finally, their installation is simple, quick and requires little fitting out, even in an existing treatment plant.

Hectron's solutions for filtration in wastewater treatment plants

Two ranges of Hectron automatic filters can be used to filter water in wastewater treatment plants: the AG and AS filter ranges.

The AG automatic filter range

The AG range of filters is recommended for filtration in wastewater treatment plants. They offer automatic operation, low filtration thresholds and do not require consumables. The range of filtration thresholds of these automatic filters goes from 0.5-1 microns to 500 microns. Four models are available in this range (AG 100, AG 200, AG 300 and AG 400): all have a stainless steel casing and a maximum pressure of 5 bar. The maximum flow rate of the AG automatic filters is different according to the models:
  • AG 100: 8 m3/h.
  • AG 200: 45 m3/h.
  • AG 300: 120 m3/h.
  • AG 400: 340 m3/h.
Similarly, the types of inlet/outlet and their diameters are also variable: AG 100: 1" female thread AG 200: 2" female thread, 3" male thread and DN80 flanges AG 300: 3" male thread and flanges of DN100 and DN150 AG 400: DN100, DN150, DN200 and DN250 flanges There are many examples of wastewater treatment plants with automatic filters of this type. One example is the Ginestous Garonne wastewater treatment plant of Toulouse Métropole where OTV Veolia has installed an AG400 filter with 200 micron filtration to filter industrial water at the clarifier outlet in a new methanisation unit. The flow rate provided by this filter is 200 m3/h. On the same principle, the Saindo wastewater treatment plant in Theix in Morbihan has a 400-micron AG200 filter at the clarifier outlet, before lagooning. This is also the case for the Sicoval WWTP in Ayguesvives (31) where a 200 micron filtration is provided by an AG200 automatic filter. With an AG300 automatic filter, we can cite the case of the Geolide wastewater treatment plant in Marseille where Suez (Degremont) installed such equipment to ensure 400 micron filtration at the clarifier outlet with a flow rate that can go up to 70 m3/h.

The AS automatic filter range

For low-pressure networks, the Hectron AS filter range is the one to look for. It includes 3 filter models: AS200, AS300, AS400. The filtration thresholds of these models range from 6 to 400 microns and the maximum permissible pressure is 5 bar. As with the AG range of filters, the differences between models are the maximum flow rate possible and the types and diameters of inlets/outlets. Thus, for the different models, we have:
  • AS 200: 45 m3/h maximum flow rate and 3" male thread and 2" female thread
  • AS 300: 120 m3/h maximum flow rate with DN100 and DN150 flanges
  • AS 400: 340 m3/h maximum flow rate with DN150, DN200 and DN250 flanges
A remarkable example of the use of this type of automatic filter is found at the Laon wastewater treatment plant in the Aisne. On its low pressure network with less than 0.5 bar, Suez (Lyonnaise des Eaux) has installed an AS200 filter at the outlet for use in industrial water. Filtration is provided at 500 microns.