Posted on March 31, 2015
Cleaning water of pollutants is an ongoing challenge for communities across the globe. Along with this is the need to find cost-effective and sustainable methods to remove ever-increasing amounts of contaminants from diverse bodies of water.
Waterclean Technologies, a subsidiary company of Kauri Park Nurseries, has developed a system utilising suspended floating wetlands for treatment of polluted waterways. These wetlands can be designed to architecturally enhance a waterway.
Floating wetlands represent an industry breakthrough with benefits including:
- proven-effective performance
- minimal environmental impact
- flexibility in shape and design
- zero land use
- retrofit to existing assets
- beautification of unsightly waterways
- waterway architecture
- provides an ecosystem for establishment of aquatic and bird life
Floating wetlands provide the perfect environment for pollutant digesting microbes and bacteria to bio-remediate water that is laden with nitrates, phosphates, heavy metals and other pollutants.
Floating wetlands are constructed from a plastic matrix, which is a fibrous material extruded from waste plastic and moulded into sheets.
Several sheets are joined together to create thick mattress-like slabs. These mattresses are injected with polystyrene to create flotation and can be linked together to create huge floating islands.
Wetland plants are then placed within holes drilled into the mattresses. While the mattresses float on the waterway, the plants send their roots into the water to uptake nutrients. It is these plant roots combined with the fine filaments of plastic in the floating islands, that attract microbes which feed on waste nutrients in the water.
The nutrients are broken down and are mostly converted into nitrogen gas or into minute amounts of solid waste.
The floating islands were originally designed for municipal sewage settling ponds but now are used in ponds and waterways. They are often used to beautify unsightly wastewater or storm water ponds and streams and rivers, require no maintenance, and can be cut to fit any size or shape.
Another key advantage is that they also offer a habitat for water birds, fish and other water life.
Rotorua Floating Island
In late March, the New Zealand Institute of Landscape Architects (NZILA) held their annual conference in Rotorua. Kauri Park contributed by way of sponsorship to this conference. Part of the sponsorship package involved several helicopter flights for the architects over a 2ha floating island on Lake Rotorua. This floating island was primarily designed to mitigate nitrate levels in the lake but was also designed to promote the city by way of its unique design in the shape of the word ‘Rotorua’.