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1 • <br /> SECONTERNATIONAL INCORPORATED <br /> 1 S E C O R K^w.secorcom <br /> 1 Soil Oxidant Demand Procedure <br /> _____ _ Me surement of Potassium Permanganate SOxD —��i�� <br /> ' SOxD analysis using Y g pot ssium permanganate provides an estimate of the soil oxidant demand <br /> for potassium permangar ate. The potassium permanganate soil oxidant demand (SOxD) is <br /> 1 measured using a small r presentative sample of soil, a standard potassium permanganate <br /> solution, and an Ultra Vio at Visible detector (UV-vis) or spectophotometer to measure the <br /> permanganate concentral ion in the treatment water over time. The method is presented below: <br /> ' Triplicate blank samples r controls: <br /> Add 5ml KMn04 standard solution (7.9 g/L) to each of 3 amber VOA bottles <br /> Add 5ml distilled H2O and iortex bottles for 30 seconds <br /> 1 Triplicate samples of eac soil sample: <br /> Add 19 soil to each ambei VOA bottle <br /> Add 5ml KMn04 standard solution (7.9 g/L) <br /> Add 5ml distilled H2O and vortex bottles for 30 seconds - <br /> Allow samples to stand foi 15 minutes before reading in the UV-vis spectrophotometer <br /> ' The analysis can be scaleb up using equivalent proportions. If a larger sample is required, 1 <br /> kilogram (kg) of soil can be used with 5 liters of KMn04 solution and 5 liters of distilled water. <br /> Mixing will have to be done by hand or using a sample roller. The efficiency of mixing will <br /> depend on the containers ivailable to do the mixing in. <br /> 1 Analysis of Samples <br /> ' Dilute samples 1/10 to 1/1 0 for analysis (ie. 100 ul sample in 10ml distilled water) depending <br /> on the intensity of the colot in the reacted solution. Use a 10ml pipette to dispense 10ml distilled <br /> water into a clean VOA bottle. Add the sample, put on the lid, inverted twice and pour the <br /> ' diluted sample into the HAGH UV-vis spectrophotometer tube. If precipitate is observed in the <br /> extracted sample and the tandard used for analysis, filter the sample with a 0.45 pm filter <br /> cartridge or centrifuge at high speed prior to analysis. Set up a standard concentration curve <br /> ' with the standard solution prepared to treat the samples. Prepare standards that are between 0 <br /> and 500 mg/I of KMn04 to quantify the KMn04 in each sample. Wipe each tube with a Kimwipe <br /> if necessary. Both VOA bottle and spectrometer tube should be rinsed between sample sets, <br /> ' but not between replicates f the same set. <br /> Sampling Intervals <br /> 1 Samples that contain high oncentrations of organic matter or clay will have a large soil oxidant <br /> demand. Typical soil samp as that have low organic matter and low or moderate clay <br /> concentrations consume o idant at a more moderate rate. The permanganate solution in <br /> ' samples should be analyze I immediately after addition, within several hours, and after 1, 2, 4, <br /> 6, and 10 days. After apprc ximately ten days the consumption rates have stabilized and the <br /> total soil oxidant demand cc n be estimated from the results. <br /> 1 Samples should be kept in he dark (in the VOA bottle box) <br /> Samples should be shaken vortexed after each analysis. <br /> 1 <br /> ' 5 <br />