Instantaneous Generation of Sodium Hypochlorite and its Applications

Abstract

Sodium hypochlorite (NaClO), also known as simply bleach is used on a large scale for surface purification, fabric bleaching, odor removal and water disinfection. Earlier sodium hypochlorite was widely used in textile industries for fabric bleaching but these days sodium hypochlorite is more important for sanitizer and deodorizer in lavatory bowls and for the purification of water. The advantage of sodium hypochlorite is that the microorganisms cannot build up any resistance to it and after cleaning it leaves no chemical residues on the cleaned surfaces. Microbial activity is the main cause of the spoilage and degradation of food products that’s by in food industries the equipment surface should be maintained cleaned and uncontaminated therefore sodium hypochlorite can be a good option for food industries. One of the strategies recommended by the Pan American Health Organization and the U.S. centers for Disease Control and Prevention to improve access to drinking water is to add hypochlorite to water just before consumption. Commercially sodium hypochlorite is produced using high concentration sodium hydroxide and chlorine gas. Both of these raw materials are highly corrosive and toxic in nature. The cost of centralized manufacturing, packaging, transportation and distribution of and liquid chlorine are relatively expensive and ecologically unsafe operations. The disadvantage of sodium hypochlorite solution is that it is an unstable product and it degrades with time. All household and commercial bleach needs high dilution before use because they are produced at high concentration in range of 3 to 5 % and 5 to 8.5 % respectively. Higher the concentration of sodium hypochlorite in the solution faster is the degradation. Because of continuous degradation, concentration of solution keeps decreasing and because of which it become difficult to decide the actual dilution rate for the application. Electrochlorinators are the best alternative solution for the production of sodium hypochlorite which uses only salt and water as a raw material. Electrochlorinators produced low concentration sodium hypochlorite with higher stability time. These can be designed and fabricated according to the requirement in the various applications. In this innovation sodium hypochlorite is produced through electrolysis of brine solution in the temperature range of 15-25 °C and slightly alkaline pH. To increase the current efficiency for chlorine production, mixed metal oxides coated titanium electrodes are used as an anode. The purpose of this research work was to design and study the various factors effecting the production of sodium hypochlorite using electrochlorinators and compare the cost and stability of commercially and electrochemically produced sodium hypochlorite solution.