Water purification FAQ Frequently Asked Questions
The question library on water related issues
Water purification generally means freeing water from any kind of impurity it contains, such as contaminants or micro organisms.
More information on water treatment chemicals
More detailed descriptions of water purification steps are available here
Bacteria and other microorganisms are removed from water through disinfection. This means that certain substances are added to kill the bacteria, these are called biocides. Sometimes disinfection can also be done with UV-light.
When bacteria are used for water purification there are two sorts of transfer; one of these is aerobic transfer. This means, that bacteria that are oxygen dependent are converting the contaminants in the water. Aerobic bacteria can only convert compounds when plenty of oxygen is present, because they need it to perform any kind of chemical conversion. Usually the products they convert the contaminants to are carbon dioxide and water.
When bacteria are used for water purification there are two sorts of conversion; one of these is anaerobic transfer. This means, that bacteria that are NOT oxygen dependent are converting the contaminants in the water. Anaerobic bacteria can only convert when oxygen levels are low, because they use other sorts of substances to perform chemical conversion. Anaerobic bacteria do not just develop carbon dioxide and water during conversion, but also methane gas. This can be used to keep the machinery that supports the purification going. The anaerobic conversion of a substance requires more steps than aerobic conversion, but the final result is often less satisfactory. After anaerobic conversion usually aerobic bacteria (bacteria that do use oxygen) still need to finish the process, because the water is not clean enough yet.
Fertilizers such as phosphate are removed through addition of another chemical, usually iron. The substances than become solid precipitates, that can be filtered from the water.
Feel free to contact us if you have any other questions