Bridging the GAPs: Approaches to Treating Water On Farms

Antimicrobial Pesticide Products – Chlor ine Dioxide

Chlorine dioxide (ClO2) is a synthetic, green-yellowish gas and is very different from elementary chlorine. It is most commonly produced by reacting sodium chlorite with an acid:

Chlorine dioxide (ClO2)

water treatment should not exceed this level due to adverse health effects. Chlorite and chlorate are by- products of chlorine dioxide degradation and linked to decreased thyroid function and hemolytic anemia. Example of a chemical product label includes the following text: As an antimicrobial for water systems in horticultural applications. For horticulture applications, this product may be used to disinfect and control biofilm in irrigation and non-potable water at concentrations between 0.25 and 2 ppm available chlorine dioxide. Concentrations and contact times are application specific

Advantages and Disadvantages of Chlorine Dioxide

As with all disinfectants, growers must weigh the advantages and disadvantages. Chlorine dioxide is not as impacted by organic matter, as compared to chlorine. pH does not impact its efficacy as chlorine and does not have to be monitored. It does not create harmful chlorinated by-products such as trihalomethanes. There are various disadvantages to chlorine dioxide use. Salinity will increase in soil as sodium will be a byproduct of chlorine dioxide generation depending on method. Because of its established low concentration by FDA, it has limited use in the field and can be costly. The chemical must be made onsite mixing two separate compounds prior to application.

Antimicrobial Pesticide Products – Peroxyacetic Acid/Peracetic Acid

Peroxyacetic acid (also known as peracetic acid) is a mixture of acetic acid and hydrogen peroxide in water. The chemical has a strong odor with a low pH and dissolves in water to disintegrate to acetic acid and hydrogen peroxide. Peroxyacetic acid has gained popularity as an alternative to chlorine for postharvest washing.

Mode of Action

Peroxyacetic acid is a strong oxidizer and disinfects by oxidizing the outer cell membrane of vegetative cells, as well as yeast and mold spores. The chemical penetrates the outer cell membrane. Once inside the cell, peracetic acid denatures proteins, disrupting cell wall permeability, and oxidizes sulfhydryl and sulfur bonds

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