Question

Discuss the advantages and disadvantages of disinfectants for pathogen removal from drinking water

Answer 1

Chlorine:
Advantages: well understood disinfectant capability            
Disadvantages: chlorination by-products, taste and odour issues

Chloramine:
Advantages: no significant by-product issues, less taste and odour issue than chlorinartion
Disadavantages: Considerably less effective than chlorine. not usually practical

Ozone:
Advantages: Strong Oxidant and highly effective disinfectant compared with chlorine. Benefits of destrcution of micropollutants.
Disadvantages: Bromate by-product , increased assimiable organic carbon. Complex, energy intensive and expensive when compared with chlorine.

Chlorine dioxide:
Advantages: More effective than chlorine at higher pH, less taste , odour and by-product issues.
Disadvantages: Weaker Oxidant than chlorine and Ozone. Dose limited by consideratrion of inorganic by-products.

UV:
Advantages: Generally highly effective for Protozoa, bacteria and most viruses and particularly for Cryptosporidium.
Disadvantages: Less effective for Viruses than Chlorine. No residual for disteribution.