DOI: 10.6084/m9.figshare.9808271
title: Datasets describing the inactivation of Rhizoctonia solani in fertigation water using regenerative in situ electrochemical hypochlorination

description: This data record consists of seven data files, all in .<b>csv</b> file format.The first file <b>(NH4)2SO4 analysis table 2.csv</b> consists of 16 columns and 16 measured parameters. These include:- <b>Sample:</b> Sample solution of <i>Rhizoctonia solani</i> (<i>R. solani</i>)-<b>Flow rate (ml/min):</b> Flow rate of solutions through the electrochemical flow cell (EFC), measures in millilitres per minute.-<b>Current (A):</b> Electrical current through the EFC, measured in amperes.-<b>Voltage:</b> Applied voltage, measured in volts-<b>pH</b>: pH of <i>R. solan</i>i solution in the EFC-<b>Ammoniacal-N (_x1d741_mol/L): </b>Concentration of ammoniacal nitrogen, a measure of the amount of ammonia in the solution, measured in moles per litre. This variable was not used for analysis to derive the figures in the published article.-<b>Nitrate-N (_x1d741_mol/L):</b> Concentration of nitrate nitrogen, a measure of the nitrogen present which is combined in the nitrate ion, measured in moles per litre.-<b>Chloride (micromol/L): </b>Chloride concentration in EFC <i>R. solani </i>solution, measured in micromoles per litre.-<b>Contact time (min):</b> Contact time of <i>R. solani</i> with the anodes of the EFC, measured in minutes-<b>Chloride (mg/L)</b>: Chloride concentration in EFC <i>R. solani</i> solution, measured in milligrams per litre.-<b>Current density (A/m_)</b>: Amount of electric current flowing per unit cross-sectional area of the EFC, measured in amperes per meter.<br>The second file <b>DSA with combined chlorine and temperature.csv </b>consists of 6 columns and 6 measured parameters. The added parameters in this spreadsheet are:-<b>Total chlorine (mg/L):</b> Concentration of total chlorine in the <i>R. solani</i> solution, measured in milligrams per litre.-<b>Combined chlorine (mg/L): </b>Combined chlorine measurements were determined by subtracting the concentration of free chlorine by that of total chlorine for each sample collected, measured in milligrams per litre.-<b>Temperature (¡C):</b> Temperature of <i>R. solani</i> solution, measured in degrees Celsius.<br>The third file <b>free chlorine generation with increasing current and fertilizer (no pathogen).csv</b> consists of 6 columns and 6 measured parameters. The added parameters in this spreadsheet include:-<b>Fertilizer concentration (g/L):</b> Concentration of fertilizer in the solution in EFC, measured in grams per litre.-<b>Residual Free chlorine (mg/L):</b> Concentration of residual free chlorine in the solution in EFC, measured in milligrams per litre.<br>The additional parameters in the fourth file <b>Inactivation of Rhizoctonia with DSA 20 ppm chloride 0.5 g_L.csv</b> include:-<b>R. solani (CFU/ml):</b> R. solani concentration in the sample, measured in colony forming units per millilitre. -<b>Column 4:</b> Sample solution of <i>Rhizoctonia solani</i> (<i>R. solani</i>)<br>Data files <b>R. solani inactivation with increasing chloride concentration.csv</b>, <b>R. solani inactivation with only presence of chloride.csv</b> and <b>R. solani inactivation without fertilizer or chloride.csv </b>report on the concentrations of <i>R. solani</i> with increasing chloride concentrations, with the presence of chloride only, and in the absence of both chloride and fertilizer, respectively.<br><b>Note:</b> Variables "Column 1", "Column 3" and "Column 4" in the data files above, all refer to the names of the samples collected for the experiment.<br><b>Study background, aims and methods: </b>The capture and re-use of greenhouse fertigation water is an efficient use of fertilizer and limited water resources, although the practice is not without risk. Plant pathogens and chemical contaminants can build up over successive capture and re-use cycles; if not properly managed they can lead to reduced productivity or crop loss. In this study, an electrochemical flow cell (EFC) outfitted with ruthenium dioxide (RuO2) dimensionally stable anodes (DSA) was characterized and evaluated for free chlorine production and <i>Rhizoctonia solani</i> inactivation in both irrigation and fertigation solutions. The aims of the study were to determine if: 1. RuO2 DSAs could be used, <i>in situ</i>, to generate sufficient free chlorine to achieve inactivation of Rhizoctonia solani in a fertigation solution, where the background chloride concentrations are compatible with hydroponic crop production (i.e., below phytotoxic thresholds), and 2) if the free chlorine produced in situ reached phytotoxic thresholds as reported in the literature.The experimental procedures involved culturing <i>R. solani </i>and subjecting the various <i>R. solani </i>solutions to electrochemical treatment, using an electrochemical flow cell system.<br><br><br>