Water is essential for all human life. Ensuring access to clean and pleasant tasting drinking water is therefore one of the most important tasks for every society.
The majority of all raw water comes from surface water sources in lakes and water courses. Surface water is exposed more heavily than groundwater to various impurities from the air, plant and animal life, precipitation and the surrounding environment. This also means that the quality of the raw water can worsen rapidly, for example due to heavy rain and flooding.
A modern water treatment plant must therefore be able to handle varying raw water quality with a good and consistent end result. Nordic Water’s product lines offer effective, versatile and reliable technology for separation, sedimentation, sludge treatment, sieving and filtration. In addition, with the DynaSand Filter, we can deliver very compact water treatment plants that provide major savings in expensive floor space.
Within industry, water is used as raw material, rinsing agent and cooling fluid, and for cleaning. For large industrial water users, it is often profitable to invest in their own equipment to treat their raw water, process water and wastewater.
Circuit Water’s product line is employed within many different industries both for raw water treatment, re-use of process water and for wastewater treatment. Effective, energy efficient technology combined with compact, reliable design make Circuit Water’s products the first choice for a number of industrial applications, such as breweries, abattoirs, dairies, canneries, steelworks, paper and pulp.
Municipal wastewater treatment installations are often designed to handle solid particles, organic impurities and nutrients such as nitrogen and phosphorus. In every project, Circuit Water works closely with the client to optimise the solution adapted to local conditions.
Bad odours can cause problems in sewage treatment plants, both for the employees and for those living nearby. The problem occurs primarily in the handling of faeces-saturated screenings and during pre sedimentation.
Circuit Water offers intelligent solutions that solve the odour problem effectively, both by washing the screenings and by hermetically sealing the sedimentation tanks, combined with effective odour-removing carbon filters with a high purification level and a long lifetime.
Every lake is unique. Specific strategies to address a lake’s nutrient enrichment problems must focus on activities in the watershed and, if needed, in-lake restoration techniques. We have found that each lake has a certain amount of pollution that it can handle without human intervention.
The transfer of oxygen from the atmosphere to the top layer of the lake ensures a surface layer of varying depth which keeps nature in equilibrium. Urbanisation drastically increases pollutants into the lakes thus exceeding the capacity the water body can handle on its own and turning the oxidative layer into anaerobic conditions. The AIRE-O2 Aerators have proven time and again that they increase the ability of lakes to survive pollution, increased nutrient levels and eutrification. By providing sub surface aeration with directional mixing, the water moves in a circular pattern around the entire dam and increases in DO levels, the aerators assist nature in returning a healthy state of aerobic equilibrium.
Artificial circulation combined with injected atmospheric oxygen provides increased aeration and oxygen to a pond by circulating the water to expose more of it to the atmosphere. Aeration systems are generally used in shallow water bodies. Artificial circulation disrupts or prevents stratification and increases aerobic habitat. The effect of aeration on algae varies. Subsurface aeration with uni-directional mixing decreases algal biomass, but may also lead to less cyanobacteria (blue-green algae). Some cyanobacteria have gas vacuoles which allow them to regulate their position in the water column. By circulating the water, cyanobacteria may spend more of their time in the dark, reducing their competitive advantage over other kinds of algae. Internal loading of phosphorous may also decline if sediments remain oxygenated. When lake sediments lack oxygen, conditions exist to release phosphorus into the water.
The principal waste-waters associated with mines and quarries are slurries of rock particles in water. These arise from rainfall washing exposed surfaces and haul roads and also from rock washing and grading processes. Volumes of water can be very high, especially rainfall related arisings on large sites. Some specialised separation operations, such as coal washing to separate coal from native rock using density gradients, can produce wastewater contaminated by fine particulate haematite and surfactants. Oils and hydraulic oils are also common contaminants. Wastewater from metal mines and ore recovery plants are inevitably contaminated by the minerals present in the native rock formations. Following crushing and extraction of the desirable materials, undesirable materials may become contaminated in the wastewater. For metal mines, this can include unwanted metals such as zinc and other materials such as arsenic. Extraction of high value metals such as gold and silver may generate slimes containing very fine particles in where physical removal of contaminants becomes particularly difficult.