Environmental Water & Waste TreatmentWater Treatment and Acid Rain Remediation

Lime is used to treat potable and industrial water supplies, industrial waste water, liquid wastes, and sewage or animal solid wastes. The lime should be of high purity, with a high calcium oxide level and high chemical reactivity.

Potable Water Treatment

Lime is utilised when treating water to be drunk, by increasing the pH so that bacteria and some viruses are controlled. With the continuing decline in the quality of naturally-occurring water for many reasons (such as denitrification, increased soil carbon dioxide levels and increased nitrogen and sulphur oxides in rain water), water frequently needs to be treated with limestone grades. This treatment remineralises the water, alters the pH level, or reduces the hardness of the water.

Waste Water

Water & Waste Treatment

The use of lime in treating waste water and liquid waste generated in industry is economical, as a direct result of its rapid rate of acid neutralisation and high neutralising power. It is also effective in reducing solids that are dissolved in human waste. Slurried lime solidifies heavy metals suspended in liquid waste, allowing them to be removed by filtration or settling.

Lime kiln dust (ground limestone) and lime itself are furthermore utilised in the treatment of sewage biosolids and animal waste, and industrial sludge and hazardous materials in the form of solids. Lime is used instead of limestone to control the development of viruses and bacteria in human waste, and the sludge produced is converted into a material that can be used in agriculture.

Acid Rain Remediation

Industry, particularly the burning of coal to produce electricity, contributes significantly to air pollution. Rain is produced by the addition of sulphur and nitrogen dioxide to the air, and this effects the pH of any water it comes into contact with. The spreading of calcium carbonate on the water increases the pH, and limits the eutrophication of it. Excess nutrients, such as phosphate and nitrate, are minimised through the addition of Ca ions, and therefore the water is made clearer.