Wastewater

What is wastewater?

The Water Resources Act (WHG) defines wastewater as the water contaminated by domestic, commercial, industrial, agricultural, or other use and thereby altered in its properties, as well as the water collected from precipitation running off from the area of built or paved surfaces. Although many companies in Germany operate their own wastewater treatment plants, the majority as well as private consumers must discharge wastewater into the public sewer system. The Wastewater Ordinance specifies the requirements that must be met before the wastewater is discharged into the public network. Charges, the so-called wastewater levy, are also imposed for this.

What happens to our wastewater in the public sewer network?

In Germany, municipalities have sewage treatment plants for wastewater recycling. These do not sufficiently eliminate organic micropollutants such as active pharmaceutical ingredients, pesticides, chemical residues, microplastics, viruses and bacteria. The treated water is discharged into surface waters where it affects water quality in the presence of micropollutants. The substances removed from the wastewater are transferred to the sewage sludge.

Sustainability aspect: How can the amount of wastewater in water treatment be reduced?

Wastewater levies and water withdrawal charges are intended to encourage the careful use of water as a raw material. Many companies therefore rely on the reuse of wastewater, which then has to be carefully treated. The other recurring use in Germany is the use of treated wastewater for agricultural irrigation. The micropollutant aspect should not be lost sight of here, as this endangers soil and groundwater. In countries with water stress and water scarcity like Spain, water-saving measures and alternative water resources are of much greater importance than in Germany.

Herco offers sustainable, water-saving systems to reduce the amount of wastewater in the operational water treatment preventively.

This means:

• Two-stage reverse osmosis systems with concentrate circulation enable a yield increase from 70 % to approx. 87 - 90 %. Because of water and energy savings (use of pumps with variable frequency drive) the additional acquisition costs are redeemed after only half a year.
• Water treatment by means of nanofiltration is also well suited as a treatment stage for the RO concentrate.
• Water treatment plants with process water (i.e. wastewater) or surface water as feed water instead of drinking water

See our webinars "Reducing wastewater by nanofiltration" and " Reduce wastewater with a concentrate staged reverse osmosis! - UO S7 KR" as well as " Decrease wastewater on existing systems UO-D BW FU".