What quantity of coagulant is required to provide clean water for a typical European?
The average European uses approximately 150 litres of water per day which equates to almost 55,000 litres per year. To treat this amount of waste water requires approximately 1.1 kilograms of inorganic coagulant per annum.
How is the use of inorganic coagulants regulated?
The quality of drinking water treated with inorganic coagulants is regulated according to standards published by the European Union and organisations such as the European Committee for Standardisation (CEN). Under these regulations, local water authorities are required to monitor and certify that drinking water is fit for human consumption.
All substances are registered under REACH (the European regulation which deals with the Registration, Evaluation, Authorisation and Restriction of Chemical substances).
What happens to the sludge produced by inorganic coagulants?
When inorganic coagulants react with the impurities in the water, sludge is produced. The coagulant is removed from the water with the sludge. Good quality sludge, which has no trace of toxins, can be used in agricultural applications as fertiliser. Depending on its composition, sludge can also be used as biomass to produce biogas, incinerated, or placed in landfill.
Are there alternatives to inorganic coagulants?
Are inorganic coagulants sustainable?
How long have inorganic coagulants been used in water treatment?
In the modern times, London became the first city to mandate that drinking water should be purified using coagulants, after an outbreak of cholera in 1854. By the start of the 20th Century, scientists better understood the role of inorganic coagulants in water purification and their use spread worldwide. The treatment of waste water with inorganic coagulants started on a large scale in the 1950s.
What is the carbon footprint of inorganic coagulants?
These materials are abundant in the Earth’s crust and can also be derived from the recycling processes of industries such as steelmaking.
Conducted by the Karlsruhe Institute of Technology (KIT) on behalf of INCOPA, the LCA study found that the cradle-to-gate emissions of all coagulants studied averaged 0.106 kg CO2-eq/mole Fe3+ or Al3+. The value is extremely low.
Inorganic coagulants provide a cost-effect, environmentally friendly method of water purification.