Festive opening CarbonBlue

CarbonBlue- Heerlen

On 19 July 2018 the new CarbonBlue solar park was opened festively. This project is an initiative of World of Walas (www.worldofwalas.com). ‘In cooperation with 18 innovative partners, CarbonBlue solar park offers a holistic and integral solution to reduce the costs of energy, transfer to cleaner sources of energy while simultaneously improving the financial, ecological and social performances. Boasting over 3,500 solar panels and various business models, CabonBlue meets approximately 36% of the energy needs for Carbon6, produces approximately 900,000 kWh a year and reduces the emission of CO2 by over 400,000 kg a year.’ Or so the Carbon6 website says.

Helophyte filter

Our part in all this is that we were asked to design and build a helophyte filter. A request we are more than happy to comply with! A fine project enabling us to use both expertises, Aqua-Flora® and gabions.

But what exactly is a helophyte filter? A helophyte filter is an artificially laid wetland in which waste water, grey water and rain water is purified until it is no longer detrimental to the environment. We manage to do so using waterside plants and marsh plants. Contrary to what many people think, it is not the vegetation itself that is responsible for the purification, but the micro-organisms growing on the roots, stems and leaves. The vegetation merely provides the requisite substrate. The micro-organisms are responsible for breaking down organic materials, approximately 90% of the pollutants. The vegetation itself accounts for approximately 7 to 10%.

Roughly speaking, there are two types of structures, the horizontal flow and the vertical flow helophyte filters. In the horizontal flow the effluent moves horizontally due to gravity, parallel to the surface, without surface water. In wetlands constructed in vertical flow, the effluent (logically) moves vertically from the planted layer downwards through the substrate and to the outside.

We decided to combine two types of structures of helophyte filters. We used aspects of the horizontal as well as the vertical flow structures. That means we designed an innovative structure in which we allow the effluent to move between three different layers, but also make sure that the micro-organisms have enough time to break down the waste water by allowing it to settle in one layer long enough before flowing onwards to another. We used the gabions as a sediment basis and for creating the difference in height. A layer of sand and gravel is used as a filter bed.


Known for their absorption of heavy metals and their purifying capacity, we chose to use Caltha palustris, Iris pseudacorus, Acorus calamus, Lythrum salicaria, Lysimachia thyrsiflora, Sparganium and Filipendula ulmaria. We will place them in the spring of 2019.


The opening itself was a spectacular happening with actors who seemed to have come straight from the coal mining era, but with a modern twist focused on the future. In addition, there were various speakers, a market where all sorts of sustainable initiatives and products were put on display and of course a network event where all partners were able to showcase their products and services.