These experiments agreed with some reports of the effects of AOP water treatment reported in the literature, while some results did not or were inconclusive.
Despite being made of “off-the-shelf” components, our water treatment systems
functioned to the manufacturer’s standards and the combination of Ozone/UV devices deployed here succeeded in creating the AOP under most conditions relevant to greenhouse operation. The systems were equally effective when employed in a standard growth cycle and showed differing levels of efficacy against low levels of chemical contaminant after single and double passes of treatment. It was evident that ozone treatment required different pre-treatment or a different method of application to deal with the surfactants in commercial formulations of herbicide.
Our method of measuring UV dosage using the OWL meter was reliant on flow rates that were preset into the device. The lowest flow rate available on the device was 2.5L/min, roughly four times faster than we were able to apply flow through the system.
In the future, it would be beneficial to more accurately measure the UV dosage applied to the irrigation solution using specialized sensors or actinometry rather than estimating the dose. Despite not knowing the exact output the UV lamps, the estimated dose was 8-fold higher (400 vs 50 mJ cm2 s-1) than the dose required for ozone destruction in a recirculating salmonid culture reported by Summerfelt et al. 2004. The parameters of the water used for the two studies was comparable though Summerfelt et al. had higher concentrations of dissolved organic carbon, lending credibility to the belief that the AOP systems was in fact a true AOP.
The dissolved oxygen sensor used was not reliable in the presence of ozone.
Unfortunately, oxygen concentration after ozone had dissipated was not a recorded metric, though one would have to extrapolate the oxygen concentration during the time where ozone was still present in the solution. A workaround to this would be to seal water samples, apply UV light to speed the decomposition of ozone, and then test levels of dissolved oxygen.
During both plant production trials, absence of plant mortality and any incidence of disease or nutrient malnutrition were noted. Plants directly next to the emitters in the ozone treatment group during the plant growth trials exhibited minor ozone damage while no damage was found in the AOP treatment. This is an important consideration for growers, as the protection from off-gas damage at the emitters in AOP treatment
systems is paired with the lack of residual ozone applied in ozone only systems.
The Lemna minor bioassay showed that both AOP and O3 treatments were sufficient to return all parameters except plant number to baseline. The time taken to do this was concurrent with the irrigation timing of the plant growth trials suggesting that incorporation of these treatments in-line with an irrigation system would suffice as a treatment option for controlling low concentrations of chemical contaminants. At the doses found relevant to detrimental plant health, the treatment options were not able to remediate the irrigation solution due to a variety of reasons such as excess surfactant and ozone demand versus the sizing of the systems.
Due to the success of the testing of both glyphosate and paclobutrazol, further testing of the doses to be used in the salvia mortality trial were not conducted using the prototype testbed until the final salvia mortality trials had begun. Due to the cost of acquiring four different pumps during the last months of the trial, it was not possible to swap the pumps used for the final trial. The frothing caused by the static mixers installed in the system to improve ozone saturation also increased the degree of foaming caused by the glyphosate, indicating the need for a surfactant removal pre-treatment step as a requirement for efficient AOP pre-treatment of wastewater. Options for accomplishing this pretreatment include activated carbon, biofilters, and slow sand. As the project was limited by both time and budget constraints, it was not possible to replicate the final trial under parameters which would have permitted more a more accurate study.
For the final trial, a second control group was added in order to separate the effects of the irrigation systems from the effects of the pesticide challenge. This second
group allowed the detections of intermediate responses between plants affected and not affected by glyphosate when treatment was applied to the irrigation solution. Few
differences were seen in plant metrics when watered using subirrigation and AOPs though an increase in flower number and root length in the AOP treated Begonia x heimalis may suggest influence of dissolved oxygen, nutrient influence, or other factor which the study was not observed.
Further examination of systems with appropriate pre-treatment measures and access to instrumentation with the ability for accurate measurement of precise AOP facets (hydroxyl radical production, accurate ORP sensors etc.) would further
characterize the function of AOP systems necessary for complete remediation within the period of an irrigation regime (single-pass).
References
Aboulhassan, M. A., Souabi, S., Yaaoubi, A. and Baudu, M. 2006. Removal of surfactant from industrial wastewaters by coagulation flocculation process. International Journal of Environmental Science and Technology 3, 327-332.
Adams, C., Wang, Y., Loftin, K. and Meyer, M. 2002. Removal of Antibiotics from surface and distilled water in conventional water treatment processes. Journal of Environmental Engineering. 126(3), 253-260. DOI: 10.1061/~ASCE!0733-9372~2002!128:3~253!
Agathokleous, E., Kitao., M. and Kinose, Y. 2018. A review study on ozone phytotoxicity metrics for setting critical levels in asia. Asian Journal of Atmospheric Environment 12. 1-16. DOI: oi:5572/ajae.2018.12.1.001
Ahmed, A. K., Cresswell, G. C., and Haigh, A. M. 2000. Comparison of sub-irrigation and overhead irrigation of tomato and lettuce seedlings. Journal of Horticultural Science &
Biotechnology 75. 350-354. DOI: https://doi.org/10.1080/14620316.2000.11511249 Andreozzi, R, Caprio, V., Insola, A. and Marotta, M. 1999. Advanced oxidation processes
(AOP) for water purification and recovery. Catalysis Today. 53, 51-59.
DOI: 10.1016/S0920-5861(99)00102-9
Argo, W.A. and J.A. Biernbaum. 1995. The effect of irrigation method, water-soluble fertilization, preplant nutrient charge, and surface evaporation on early vegetative and root growth of poinsettia. Journal of American Horticultural Science. 120, 163-16.
Amrhein, N., Deus, B., Gehkre, P. and Stienrucken H. C. 1980. The site of the inhibition of the shikimate pathway by glyphosate. Plant Physiology 66, 830-834.
Assalin, M. R., De Moraes, S. G., Queiroz. S. C. N., Ferracini, V. L and Duran, N. 2010.
Studies on degradation of glyphosate by several oxidative chemical processes:
Ozonation, photolysis and heterogeneous photocatalysis. Journal of Environmental Science and Health 45, 89-94.
Barrett-Lennard, E. G., Leighton, P. D., Buwalda, F., Gibbs, J. J., Armstrong, W., and Thomson, C. J. and Greenway, H. 1988 Effects of growing wheat in hypoxic nutrient solutions and of subsequent transfer to aerated solutions 1- Growth and
carbohydrate status of shoots and roots. Australian Journal of Plant Physiology 15, 585-595.
Beltran, F J. 2004. Ozone Reaction kinetics for water and wastewater systems. Lewis Publishers New York.
Bennett, W.F. 1996. Nutrient deficiencies and toxicities in crop plants. APS Press, St. Paul, MN, USA.
Bolton, J. R., Bircher, K. G., Tumas, W. and Tolman, C. 2001. Figures of merit for the technical development and application of advanced oxidation technologies for both electric and solar driven systems. Pure and Applied Chemistry. 73(4) 627-637.
DOI: 10.1351/pac200173040627
Britt, A. B. 1995. Repair of DNA damage induced by ultraviolet light. Plant Physiology. 108:
891-896. DOI: 10.1104/pp.108.3.891
Bultynck, L. and Lambers, H. 2004. Effects of applied gibberellic acid and paclobutrazol on leaf expansion and biomass allocation in two Aegilops species with contrasting leaf
elongation rates. Physiologia Plantarum, 122: 143-151.
DOI: 10.1111/j.1399-3054.2004.00383.x
Burgess, T., Hardy, G. E., McComb, J. A. and Colquhoun, I. 2008. Effects of hypoxia on root morphology and lesion development in Eucalyptus marginata infected with Phytophthora cinnamomi. Plant Pathology. 48(6). 786-796. DOI: 10.1046/j.1365-3059.1999.00395.x Cabiscol, E., Tamarit, J. and Ros, J. 2000. Oxidative Stress in bacteria and protein damage by
reactive oxygen species. International Microbiology. 3, 3-8.
Canada Water Act SOR/2012-139. 2012. Government of Canada. Accessed: 12 Aug 2019.
http://laws-lois.justice.gc.ca/eng/acts/c-11/page-2.html#h-8.
Çakmakçi, R., Donmez, F., Aydin, A. and Sahin, F. 2006. Growth promotion of plants by plant growth-promoting rhizobacteria under greenhouse and two different field soil conditions.
Soil Biology and Biochemistry. 38, 1482-1487. DOI:10.1016/j.soilbio.2005.09.019 Cayanan, D. F., Zheng, Y., Zhang, P., Graham. T. and Dixon, M. 2008. Sensitivity of
five container-grown nursery species to chlorine in overhead irrigation water.
Hort Science 43, 1882-1887.
Chameldes, W. L. 1989. The Chemistry of Ozone Deposition to Plant Leaves: Role of Ascorbic Acid. Environmental Science Technology. 23, 595-600. DOI: 10.1021/es00063a013 Chen, J., Loeb, S., and Kim, J. 2017. LED revolution: fundamentals and prospects for UV
disinfection applications. Environmental Science: Water Research and Technology 3. 188-202. DOI: DOI: 10.1039/c6ew00241b
Chérif, M., Tirilly, Y. and Belanger, R. 1997. Effect of oxygen concentration on plant growth, lipidperoxidation, and receptivity of tomato roots to Pythium F under hydroponic conditions. European Journal of Plant Pathology. 103, 255-264.
DOI: 10.1023/A:1008691226213
Chevrefils, G., Caron, E., Wright, H., Sakamoto, G., Payment, P., Barbeau, B. and
Cairns, B. 2000. UV dose required to achieve incremental log inactivation of bacteria, protozoa and viruses. Public service publication for Trojan Industries (London, ON, Canada).
Chiang, Y. P., Liang, Y. Y., Chang, C. N. and Chao, A. C. 2006. Differentiating ozone direct and indirect reactions on decomposition of humic substances. Chemosphere 65. 2395-2400.
Copes, W., Chastagner, G.A. and Hummel, R.L. 2003. Toxicity Responses of Herbaceous and Woody Ornamental Plants to Chlorine and Hydrogen Dioxides. Plant Health Progress.
DOI: 10.1094/PHP-2003-0311-01-RS.
Davis, J. C. 1975. Minimal dissolved oxygen requirements of aquatic life with emphasis on Canadian species: A review. Journal of the Fisheries Research Board of Canada 32, 2295-2332.
De Loe, R., Kreutzwiser, R., and Ivey, J. 2001. Agricultural Water Use in Ontario. Canadian Water Resources Journal 26. 17-42. DOI: 10.4296/cwrj2601017
Degenhardt, D., Humphries, D., Cessna, A. J., Messing, P., Badiou, P. H., Raina, R., Farenhorst, A. and Pennock, D. J. 2012. Dissipation of glyphosate and
aminomethylphosphonic acid in water and sediment of two Canadian prairie wetlands.
Journal of Environmental Science and Health 47, 631-639. DOI:
10.1080/03601234.2012.668459
Deloitte Consulting. 2009. The impact of ornamental horticulture on Canada’s Economy.
Canadian Ornamental Horticulture Alliance.
DeVincentis, A. J., Brumfield, R. G., and Gottlieb, P. 2015. Cost Analysis of Using Recycled Water in Container Production: A Case Study of Southern New Jersey.
HortScience 50, 1196-1201.
Donahue, N. M., Drozd, G. T., Epstein, S. A., Presto, A. A. and Kroll, J. H. 2011. Adventures in ozoneland: down the rabbit-hole. Physical Chemistry. 13, 10848-10857.
Douki, T., von Koschembahr, A.and Cadet, J. 2007. Insight in DNA repair of UV-Induced Pyrimidine dimers by Chromatographic Methods. Photochemistry and Photobiology.
93: 207-215. DOI: 10.1111/php.12685
Dramm Corporation. 2014. Dissolved Oxygen in the Greenhouse (white paper).
http://www.dramm.com/media/Dissolved%20Oxygen%20in%20the%20Greenhouse.pdf Dumroese, R. K, Pinto, J. R., Jacobs, D. F., Davis, A. S., and B. Horiuchi. 2006.
Subirrigation reduces water use, nitrogen loss and moss growth in a container nursery. Native Plants Journal 7, 253-263.
Ehret, D. L., Menzies, J. G. and Helmer, T. 2005. Production and quality of greenhouse rose in recirculating nutrient systems. Scientia Horticulturae 106, 103-113.
Ferreira, J. F. S., Simon, J. E. and Janick, J. 1994. Developmental studies of Artemisia annua: flowering and Artemisinin production under greenhouse and field conditions. Planta Medica 61 167-170.
Ferrarezi, R. S., Weaver G. M., van Iersel M. V. and Testezlaf R. 2015. Subirrigation:
Historical Overview, Challenges, and Future Prospects. Hort Technology 25, 262-276. DOI: 10.21273/HORTTECH.25.3.262
Gottschalk, C., Libra, J. and Saupe, A. 2000. Ozonation of Water and Waste Water: A Practical Guide to Understanding Ozone and Its Application – Second Edition.
10.1002/9783527613342.ch3.
Graham, T. 2001. The effect of nutrient solution ozonation on nutrient balance and lettuce production in a recirculating hydroponic system. Master’s Thesis, University of Guelph,
Guelph, Canada.
Graham, T., Zhang, P., Zheng, Y., and M. A. Dixon. 2009. Phytotoxicity of aqueous ozone on five container-grown nursery species. Hort Science 44, 774-780.
Graham, T., Zhang, P., and M. A. Dixon. 2011. Aqueous ozone in the rootzone: Friend or foe? Journal of Horticulture and Forestry 3, 58-62.
Graham T., Zhang, P., and M. A. Dixon. 2012. Closing in on upper limits for root zone aqueous ozone application in mineral wool hydroponic tomato culture. Scientia Horticulturae 143, 151-156.
Grigoriev, A.I., Sinyak, Yu.E., Samsonov, N.M., Bobe, L.S., Protasov, N.N., and Andreychuk, P.O. 2011. Regeneration of water at space stations. Acta Astronautica 68, 1567-1573.
DOI:10.1016/j.actaastro.2010.05.018.
Hamrick, D. 2003. Ball Redbook, Volume 2: Crop Production: 17th edition. Ball Publishing.
Haughan, P.A., Burden, R.S., Lenton, J. and Goad, J.1988. Inhibition of celery cell growth and sterol biosynthesis by the enantiomers of paclobutrazol.
Phytochemistry 3, 781-787. DOI: 10.1016/0031-9422(88)87016-X
Hillel, D. 2003. Salinity Management for sustainable irrigation: integrating science, environment and economics. The World Bank. Report.
Hoff, J. C. and Akin, E. W. 1986. Microbial resistance to disinfectants: mechanisms and significance. Environmental Health Perspectives 69, 7-13.
Hong, C. X., and Moorman, G. W. 2007. Plant pathogens in irrigation water: Challenges and opportunities. Plant Sciences 24. 189-208.
Huber, M., Canonica, S., Park, G. and von Gunten, U. 2003. Oxidation of Pharmaceuticals during Ozonation and Advanced Oxidation Processes. Environmental Science Technology 37. 1016-1024.
Huff, C. B., Smith, H. F., Boring, W. D. and Clarke, N. A. 1965. Study of Ultraviolet
disinfection of Water and Factors in Treatment Efficiency. Public Health Report. 80(8), 695-705. DOI: 10.2307/4592510
Ikehata, K. and El-Din, M. G. 2005a. Aqueous Pesticide Degradation by Ozonation and Ozone- Based Advanced Oxidation Processes: A Review (Part I). Ozone: Science &
Engineering.
27(2) 83-114. DOI: 10.1080/01919510590925220
Ikehata, K. and El-Din, M. G. 2005b. Aqueous Pesticide Degradation by Ozonation and Ozone- Based Advanced Oxidation Processes: A Review (Part II). Ozone: Science &
Engineering. 27(2) 83-114. DOI: 10.1080/01919510590945732
Jansen, M., Gaba, V. and Greenberg, B. 1998. Higher plants and UV-B Radiation: balancing damage, repair and acclimation. Trends in Plant Science. 3(4), 131-135.
DOI: 10.1016/S1360-1385(98)01215-1
Jensen, R. A. 1986. The shikimate/arogenate pathway: Link between carbohydrate metabolism and secondary metabolism. Plant Physiology 66, 164-168.
DOI: 10.1111/j.1399-3054.1986.tb01251.x
Johnson, M. B. and Mehrvar, M. 2008. Aqueous Metronidazole degradation by UV/H2O2 Process in Single and Multi-Lamp tubular photoreactors: Kinetics and Reactors design.
Indian Engineering and Chemistry Research. 47, 6525-6537. DOI: 10.1021/ie071637v Jones, H. W., and Kliss, M. H. 2010. Exploration life support technology challenges for the
Crew Exploration Vehicle and future human missions. Advances in Space Research 45, 917-928. DOI: 10.1016/j.asr.2009.10.018
Kaleta, J. and Elektorowicz, M. 2012. The removal of anionic surfactants from water in coagulation process. Environmental Technology 34, 999-1005
Kashef, N. and Hamblin, M. R. 2017. Can microbial cells develop resistance to oxidative stress In antimicrobial photodynamic inactivation? Drug Resistance Updates. 31, 31-42.
DOI: 10.1016/j.drup.2017.07.003.
Khadhraoui, M., Trabelsi, H., Ksibi, M., Bourgerra, S. and Elleuch, B. 2009. Discoloration and detoxicification of a Congo red dye solution by means of ozone treatment for a possible water reuse. Journal of Hazardous Materials. 161, 974-981.
DOI: 10.1016/j.jhazmat.2008.04.060
Khalil, A. and Abussaud, B. 2013. Reduction of Escherichia coli bacteria from contaminated water by combining hydrogen peroxide, ozone and ultraviolet light. Water Science &
Technology Water Supply. DOI: 13. 782. 10.2166/ws.2013.064.
Krishnan, S., Rawindran, H., Sinnathambi, C. M. and Lim, J. W. 2017. Comparison of various advanced oxidation processes used in remediation of industrial wastewater laden with recalcitrant pollutants. IOP conference series: Materials Science and Engineering. 26.
DOI: 10.1088/1757-899X/206/1/012089
Langlais, B., Reckhow, D. A., and Deborah, R. B. 1991. Ozone in Water Treatment. Colorado, USA: Lewis Publishers. p. p12–21.
Lazarova, V., Levine, B., Sack, J., Cirelli, G., Jeffrey, P., Muntau, H., Salgot, M. and Brissaud, F. 2001. Role of water reuse for enhancing integrated water management in Europe and Mediterranean countries. Water Science and Technology 43(10): 25-33.
DOI: 10.2166/wst.2001.0571
Lefohn, A. S. and Runeckles, V. C. 1986. Establishing standards to protect vegetation from ozone exposure/dose consideration. Atmospheric Environment 21, 561-568.
Lenton, J. R., Appleford, N. E. J., and Temple-Smith, K. E. 1994. Growth retardant activity of paclobutrazol enantionmers in wheat seedlings. Plant growth regulation 15, 281-291.
Liu, H., Lin, T., Mao, J., Lu, H., Yang, D., Wang, J. and Li, Q. 2015. Paclobutrazol Residue Determination in Potato and Soil using Low Temperature Partition Extraction and Ultrahigh Performance Liquid Chromatography Tandem Mass Spectroscopy. Journal of Analytical methods in Chemistry, 2015, 1-6. DOI: 10.1111/j.1399-3054.2004.00383.x Lucas, M. S., Peres, J. A. and Li Puma, G. 2010. Treatment of winery wastewater by ozone- based advanced oxidation processes (O3, O3/UV and O3/UV/H2O2) in a pilot-scale bubble column reactor and process economics. Separation and Purification Technology.
72, 235- 241. DOI: 10.1016/j.seppur.2010.01.016
Masschelein, W. J. 2002. Ultraviolet light in water and wastewater sanitation. Lewis Publishers, 2002. New York.
Massman, W. J., Musselman, R. C., and A. S. Lefogn. 2000. A conceptual ozone dose- response model to develop a standard to protect vegetation. Atmospheric Environment 34, 745-759.
Mazher, A. M., Abdel-Aziz, N. G., El-Maadawy, E. I., Nasr, A. A. and El-Sayed, M. 2014.
Effect of Gibberellic acid and Paclobutrazol on Growth and Chemical Composition of Schefflera arboricola plants. Middle East Journal of Agriculture Research, 3(4): 782-792.
McDougall, R., Kristiansen, P., and Rader, R. 2019. Small-scale urban agriculture results in high yields but requires judicious management of inputs to achieve sustainability.
Proceedings of the National Academy of Science 116. 129-134. DOI:
10.1073/pnas.1809707115
Melero, J. A., Castillejo, F. M., Botas, J. A., Molina, R. and Pariente, M. I. 2009. Heterogeneous Catalytic Wet Peroxide Oxidation Systems for the Treatment of an Industrial
Pharmaceutical Wastewater. Water Research. 43(16), 4010-4018.
DOI: 10.1016/j.watres.2009.04.012
Miklos, D. B., Remy, C., Jekel, M., Linden, K. G, Drewes, J. E. and Hubner, U. 2018.
Evaluation of advanced oxidation processes for water and wastewater treatment - A critical review. Water Research. 139, 118-131. DOI: 10.1016/j.watres.2018.03.042 Morooka, S., Ikemizu, K., Kamano, H. and Kato, Y. 1986. Ozonation rate of water-soluble
chelates and related compounds. Journal of Chemical Engineering of Japan 19, 294-299 Morvant, J. K., Dole, J. M., and E. Allen. 1997. Irrigation systems alter distribution of
roots, soluble salts, nitrogen and pH in the root medium. Hort Technology 7, 156- 160.
Munoz, P., Anton, A., Nunez, M., Paranjpe, A., Arino, J., Castells, X., Montero, J. I. and Rieradevall, J. 2007. Comparing the environmental impacts of greenhouse versus openfield tomato production in the Mediterranean region. Acta Horticulturae 801, 1591-1596. DOI: 10.17660/ActaHortic.2008.801.197
O’Connor, G. A., Elliot H. A., and R. K Bastian. 2008. Degraded water reuse: an overview. Journal of Environmental Quality 37, 157-168.
Ohashi-Kaneko, K., Yoshii, M., Isobe, T., Park, J., Kurata, K. and Fujiwara, K. Nutrient Solution Prepared with ozonated water does not damage early growth of hydroponically grown tomatoes. Ozone: Science and Engineering. 31(1) 21-27.
DOI: 10.1080/01919510802587523
Oh, B. S., Kim, K. S., Kang, M. G., Oh, H. J. and Kang, J. 2006. Kinetic study and optimum control of the ozone/UV process measuring hydrogen peroxide formed in-situ. Ozone: Science and Engineering 27, 421-430.
Oller, I., Malato, S. and Sanchez-Perez, J. A. 2011. Combination of Advanced Oxidation Processes and Biological Treatments for Wastewater decontamination. Science of the Total environment. 409, 4141-4166. DOI: 10.1016/j.scitotenv.2010.08.061
Government of Ontario. 2006. Ontario Clean Water Act. Ontario, Canada.
OMAFRA. 2002. Nutrient management act. Date Accessed: 2 Mar 2017.
https://www.ontario.ca/laws/statute/02n04#BK61.
OMAFRA, 2014. Guide to greenhouse floriculture production. Date Accessed: 8 Aug 2019. http://www.omafra.gov.on.ca/english/crops/pub370/pub370.pdf
Pannekens, H., Boergers, A., Raab, J., Türk, J., and Dopp, E. (2015). Efficiency of UV-
Oxidation in Removal of Pharmaceuticals from Waster Water Samples and Toxicological Evaluation Before and After the Oxidative Treatment.
DOI: 10.1039/9781782622710-00180.
Parrish, J. 1978. UV-A: Biological Effects of Ultraviolet Radiation with Emphasis on Human Responses to Longwave Ultraviolet Light. Plenum Press. ISBN: 0306311216.
Pardossi, A., Incrocci, L., Massa, D., Carmassi, G., and Maggini, R. 2008. The influence of fertigation strategies on water and nutrient efficiency of tomato grown in closed soilless culture with saline water. Acta horticulturae 807, 445-450.
DOI: 10.17660/ActaHortic.2009.807.63
Pell, E. J., Schlagnhaufer, C. D. and Arteca, R. N. 1997. Ozone-induced oxidative stress:
Mechanisms of action and reaction. Physiologia Plantarum 100L 264-273.
DOI: 10.1111/j.1399-3054.1997.tb04782.x
Pfister, S., Bayer, P., Koehler A., and S. Hellweg. 2011. Projected water consumption in future Global agriculture: Scenarios and related impacts. Science of the Total environment. DOI:10.1016/j.scitotenv.2011.07.019.
Prasad, S., Srivastava, S., Singh, M. and Shukla, Y. 2009. Clastogenic Effects of Glyphosate in Bone Marrow Cells of Swiss Albino Mice. Journal of toxicology. 308985.
DOI: 10.1155/2009/308985.
Proctor, A. D., Ahmedna, M., Kumar, J. V. and Goktepe, I. 2004. Degradation of aflatoxins in peanut kernels/flour by gaseous ozonation and mild heat treatment. Food Additives and Contaminants. 21:786–793. DOI: 10.1080/02652030410001713898
Rahn, R. O. 1997. Potassium iodide as a chemical actinometer for 254nm radiation: use of iodate as an election scavenger. Photochemistry and photobiology. 66(4), 450-455.
DOI: 10.1111/j.1751-1097.1997.tb03172.x
Raub, L., Amrhein, C. and Matsumoto, M. 2001. The Effects of Ozonated Irrigation Water on Soil Physical and Chemical Properties. Ozone: Science and Engineering. 23(1), 65-76.
DOI: 10.1080/01919510108961989
Raudales, R.E., Fisher, P.R. & Hall, C.R. 2017. The cost of irrigation sources and water treatment in greenhouse production. Irrigation Science. 35, 43-54.
DOI: 10.1007/s00271-016-0517-5
Raudales, R.E. et al. 2014. Control of waterborne microbes in irrigation: A Review. Agricultural Water Management. 143, 9-28. DOI: 10.1016/j.agwat.2014.06.007.
Relyea, R. A. 2005. The Lethal Impact of Roundup on Aquatic and Terrestrial Amphibians. Ecological Applications 15, 1118-1124. DOI: 10.1890/04-1291.
Reynolds, P. et al. 2004. Residential proximity to agricultural pesticide use and incidence of breast cancer in the California Teachers Study cohort. Environmental Research. 96(2) 206-218. DOI: 10.1016/j.envres.2004.03.001
Richardson, S and Ternes, T. 2018.Water analysis: Emerging Contaminants and Current Issues. Analytical Chemistry 83, 4614–4648. DOI: 10.1021/ac200915r.
Rijsberman, F. 2006. Water scarcity: Fact or fiction? Agricultural Water Management 80, 5-22.
DOI: 10.1016/j.agwat.2005.07.001.
Roques, S., Kendall, S., Smith, K., Newell Price, P., and Berry, P. 2013. A review of the non- NPKS nutrient requirements of UK cereal and oilseed rape (Figure). Agriculture and Horticulture Development Board.
Rubin, J. L., Gaines, C. G. and Jensen R. 1982. Enzymological Basis for Herbicidal Action of Glyphosate. Plant Physiology 70(3), 833-839. DOI: 10.1104/pp.70.3.833
Sancar, A. Structure and Function of DNA photolyase and Cryptochrome Blue-Light Receptors.
2003. Chemical Reviews. 103(6), 2203-2237. DOI: 10.1021/cr0204348
Sanches, S. Barreto Crespo, M. and Pereira, V. J. 2010. Drinking water treatment of priority pesticides using low pressure UV photolysis and advanced oxidation processes. Water Research. 44, 1809-1818. DOI: 10.1016/j.watres.2009.12.001
San Miguel, A., Faure, M., Ravanel, P. and Raveton, M. 2012. Biological responses of maize (Zea mays) plants exposed to chlorobenzenes. Case study of monochloro-,1,4-dichloro- and 1,2,4-trichloro-benzenes. Ecotoxicology 21, 315-324.
DOI: 10.1007/s10646-011-0792-0
Saunders, L. E., Koontz, M. B, and Pezeshki, R. 2013. Root-Zone Glyphosate Exposure Adversely Affects Two Ditch Species. Biology, 2. 1488-1496.
DOI :10.3390/biology2041488
Schaefer, K., Exall, K. and Marsalek, J. K. 2004. Water Reuse and Recyclingin Canada: A Status and Needs Assessment, Canadian Water Resources 29:3, 195-208.
Schaefer, K., Exall, K. and Marsalek, J. K. 2004. Water Reuse and Recyclingin Canada: A Status and Needs Assessment, Canadian Water Resources 29:3, 195-208.