Novel Water Treatment Processes Based on Hybrid Membrane-Ozonation Systems: A Novel Ceramic Membrane Contactor for Bubbleless Ozonation of Emerging Micropollutants
Generated in specially designed reactors at the moment of use due to short life
A, B, C, D
2.80
Ozone
Ozone is a gas that is generated on-site by passing dry compressed air or pore oxygen across a high voltage electrode
B, C, D
Ozone is applied to water as a gas. Because mass transfer is an important issue, special attention is required for contractor design
2.08
Peracetic acid
Stabilized liquid solution
A, D
Concentrated solution mixed with water to be treated
—
Hydrogen peroxide
Liquid solution
A
Concentrated solution mixed with water to be treated
1.78
Permanganate
Available in bulk as granules
A, B
Added as a dry chemical using a feeder or as a concentrated solution (no more than five percent by weight due to its limited solubility)
1.67
Chlorine, free
Chlorine gas, NaOCl solution
A, D
Gas eductors and various diffuser designs
1.49
Chlorine, combined (chloramines)
Addition of ammonia: anhydrous ammonia gas, ammonium sulfate, and aqua ammonia (20 to 30 percent ammonia solution)
A, D
Gas eductors, dry chemical feeders, and spray jets
—
Chlorine dioxide
Chlorine dioxide gas is produced on-site using a 25 percent sodium chlorite solution. The sodium chlorite solution reacts with the following constituents to form ClO2(g): (1) gaseous chlorine (Cl2), (2) aqueous chlorine (HOCl), or acid (usually hydrochloric acid, HCl)
A
Gas eductors
1.27
Oxygen
Gas and liquid
—
Pure oxygen or the oxygen in air applied using diffusers or other devices
1.23
A = oxidation of reduced inorganic species such as soluble metals, complexed metal species, and destruction of odor causing compounds. B = oxidation of trace organic compounds, color and odor causing compounds, and NOM. C = to improve coagulation. D = used as a biocide to control algae in reservoirs and basins, for disinfection, and to control growth in distributions system.
