Hard water is a term used to describe water with a high mineral content, usually referring to multi-valent cations. The most common multi-valent cations are Ca2+ and Mg2+, which are typically present in water with anions such as carbonates, bicarbonates, hydroxides, chlorides and sulphates.
Although there isn’t any evidence of water hardness causing adverse health effects in humans, it can alter the taste of the water and form soap scum when washing clothes, dishes or your body. In industrial settings hardness can cause issues with scaling, usually in the from of calcium carbonate or calcium sulphate, which can destroy pipes, turbines, boilers, and heat exchangers. The risk of scaling increases with pH and temperature, with total dissolved solids (TDS) and total alkalinity also factors to consider when designing against scaling.
Water can be softened through ion exchange, using chemical methods such as lime softening, or by using membranes. As scaling can be a major issue for membranes, it is common for ion exchange or chemical softening to take place before membrane methods such as reverse osmosis (RO). RO will usually also use anti-scalants and will typically require multiple passes to bring the hardness to the desired range. Lime softening can lead to water with a high pH, and ion exchange and lime softening typically produce waste which needs to be disposed of.
Clean TeQ Water’s CIF® (continuous ionic filtration) technology combines physical filtration with ion exchange in a continuous and concurrent process, removing hardness in a single step with a low chemical cost. The process can also remove other undesirable impurities, and can be used in conjunction with our other technologies.
HIROX® (high recovery reverse osmosis) uses CIF® as a pre-treatment for RO, removing ions which cause scaling and allowing higher recoveries (typically 95-99%).