Water Disinfection Alternatives

The most used method for the disinfection of water is chlorine gas. This is the most common method used in potable water and sewerage filtration plants in Puerto Rico. It is known that chlorine gas represents a high risk for the health and safety of employees and surrounding communities. This compound also represents risks to the environment and fauna. Due to this, the investigation of different disinfection alternatives was produced to replace the chlorine gas system in the Filtros de Canóvanas plant.
The main goal is to find a viable alternative that is cost-effective and economically competitive, easy to handle and that significantly minimizes the risk of health and the environment. To develop this research, we begin with a literature review of the different methods that exist of disinfecting drinking water. After this analysis, two possible alternatives were selected. These were; sodium hypochlorite, better known as liquid chlorine and calcium hypochlorite, which is in solid form. Following an evaluation of the possible limitations and benefits of each option, taking into account the objectives of the research, it was determined that the best option was to replace the chlorine gas with a liquid chlorine application system.
Liquid chlorine (sodium hypochlorite) is commercially available in different concentrations ranging from 12% to 20% by volume of chlorine in solution. By a jar tests, it was determined that the use of a more concentrated solution is more effective. Representing the best economic alternative and allowing a greater amount of storage while maintaining the same application conditions as the different concentrations. In short, the option more costs beneficial and more effective for the filtration plant.
The design does not require major considerations for the handling of the product. Two 1,000 gallon tanks with a pumping application.

Author(s):

Jomary Torres    
Chemical Engineering
Polytechnic University of Puerto Rico
Puerto Rico

Alexamar Rosario    
Chemical Engineering
Polytechnic University of Puerto Rico
Puerto Rico

Perla Lopez    
Chemical Engineering
Polytechnic University of Puerto Rico
Puerto Rico