Chlorine Dioxide is used as a biocide in a large variety of manufacturing operations to control biofilm and eliminate deposits that can slow down operations or damage equipment. Here are a few examples:
- Paper Manufacturing--Chlorine dioxide is used very effectively as a slimicide and oxidizer for microbiological control on the wet end of paper machines. It controls microorganisms and offensive odors that may adversely affect the quality of the finished product. Additional benefits of chlorine dioxide as a wet-end slimicide/biocide include lower corrosion rates on paper machine metallurgy, extended paper machine runs, reduced frequency of boil outs of stock chests and a more cost effective microbiological control program.
Ultrapure water for Electronics-- Ultra Pure Water (UPW) is used throughout the electronics industry to clean wafers, silicon-based microchips and other very small electronic parts without leaving any residue behind. As electronic components become smaller and line widths shrink, the need for "absolute clean" becomes greater. Small minerals or bacteria (live or dead) can become a conductor of current shorting out chips. This is typically present as Total Organic Carbon or TOC. The primary methods of removing TOC are through the use of activated carbon absorption and hyper-filtration (typically reverse osmosis). The other main method of reducing the residual level of TOC is through applying heat, especially combustion and ultraviolet irradiation, with or without a chemical oxidizer such as persulphate or iron and hydrogen peroxide, or with the use of a catalyst such as platinum or titanium dioxide. Chlorine dioxide helps control algae, bacteria/plankton and biofilm in process piping, and therefore makes an excellent choice for use in applications where environmental performance, reliability and high performance are essential.
Plastics Molding— Chlorine dioxide is an excellent biocide for removing unwanted impurities in water streams used in plastic molding processes without introducing chemical contamination. Biofilm can build up in the molding cooling loops causing slower and inconsistent heat transfer resulting in spoilage and downtime. ClO2 injected into the cooling water will control the biofilm.
Laboratory and Production Equipment Cleaning and Sterilization-- There are two main applications used: CIP (Clean in Place) and SIP (Steam In Place) where steam is used after the manufacturing process to clean reactors, process/blending tanks, other processing equipment, filtration units (which often need to be sterilized) and water and/or chemical piping/lines. Chlorine Dioxide is offered for both types due to high water solubility and ability to decontaminate head space in tanks as a gas.
High Purity Water-- High purity water is required for fluids/medicine injected into the human body and for CIP systems. This market is very closely related to Reverse Osmosis (RO) systems which are used as a pre-treatment before getting to the ultra-pure level. The objective is to reduce variability in process water by removing traces of biomass and organic compound contamination. Water/Steam is used to clean membranes, fluid lines and reservoirs. It is also used in RO membrane systems. High purity water which has been highly filtered and deionized can then be treated with chlorine dioxide.