nutrients & agrichemicals (27)

15 May 2018

Removal of Paclobutrazol from Irrigation Water using Granular Activated Carbon

Grant, G.A., P. Fisher, J.E. Barret, and P.C. Wilson (University of Florida)

Paclobutrazol is a commonly used plant growth regulator for controlling plant height, which has biological activity in the parts per billion range and a half-life in water of over 6 months. Pesticides such as paclobutrazol have potential to accumulate in recaptured irrigation water over time. This recently published article outlines various experiments conducted at the University of Florida where irrigation water containing paclobutrazol was effectively removed using a laboratory-scale granular activated carbon (GAC) filtration system. There is potential that GAC can be used to remediate recaptured irrigation water for a range of agrichemicals relevant to the greenhouse and nursery industry.

Description of research activities

A national team of scientists is working to encourage use of alternative water resources by the nation’s billion-dollar nursery and floriculture industry has been awarded funds for the first year of an $8.7 million, five year US Department of Agriculture – National Institute of Food and Agriculture –Specialty Crop Research Initiative competitive grant.

The team will develop and apply systems-based solutions to assist grower decision making by providing science-based information to increase use of recycled water.  This award from the NIFA’s Specialty Crop Research Initiative is managed by Project Director Sarah White of Clemson University.  She leads a group of 21 scientists from nine U.S. institutions.

Entitled “Clean WateR3 - Reduce, Remediate, Recycle – Enhancing Alternative Water Resources Availability and Use to Increase Profitability in Specialty Crops”, the Clean WateR3 team will assist the grower decision-making process by providing science-based information on nutrient, pathogen, and pesticide fate in recycled water both before and after treatment, average cost and return-on investment of technologies examined, and model-derived, site specific recommendations for water management.  The trans-disciplinary Clean WateR3 team will develop these systems-based solutions by integrating sociological, economic, modeling, and biological data into a user-friendly decision-support system intended to inform and direct our stakeholders’ water management decision-making process.

The Clean WateR3 grant team is working with a stakeholder group of greenhouse and nursery growers throughout the United States.

For example, at the University of Florida graduate student George Grant is collecting data on removal of paclobutrazol, a highly persistent plant growth regulator chemical, from recirculated water using granular activated carbon (GAC) filters. This is being done in both research greenhouses and in a commercial site. The GAC filters can remove more than 90% of chemical residues, and are proving to be a cost-effective treatment method.