Methyl red (2-(N,N-dimethyl-4-aminophenyl) is an indicator dye that turns red in acidic solutions. It is an azo dye and is a dark red crystalline powder. Methyl red is a pH indicator; it is red in pH under 4.4, yellow in pH over 6.2, and orange in between, with a pH of 5.1. Murexide and methyl red are investigated as promising enhancers of sonochemical destruction of chlorinated hydrocarbon pollutants.
Methylene blue is also known as methylthioninium chloride, is a medication and dye. As a medication, it is mainly used to treat methemoglobinemia. It is specifically used to treat methemoglobin levels that are greater than 30% or in which there are symptoms despite oxygen therapy.
Sodium Hypochlorite (NaOCl) is a compound which is composed of a sodium cation (Na+)and a hypochlorite anion (ClO-) that can be effectively used for water purification. It is used on a large scale for surface purification, bleaching, odor removal and water disinfection. Sodium hypochlorite neutralizes sulphur hydrogen gas (SH) and ammonia (NH3). It is also used to detoxify cyanide baths in metal industries. Hypochlorite can be used to prevent algae and shellfish growth in cooling towers.