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In Situ Technologies
Published in Larry W. Canter, Robert C. Knox, Ground Water Pollution Control, 2020
These successful tests led to the design and construction of the system (Jhaveria and Mazzacca, 1982). The aboveground portion consisted of two activating tanks and two settling tanks. The activated tanks were maintained at 20°C and supplied with air and the following nutrients: ammonium chloride, monopotassium phosphate, dipotassium phosphate, magnesium sulfate, sodium carbonate, calcium chloride, manganese sulfate, and iron sulfate. The levels of the nutrients were adjusted to provide the necessary nitrogen and phosphorus to stimulate in situ degradation. Good results were achieved by the system; removal of organics exceeded 95.9% in the aboveground systems, and the levels of contamination in one of the producing wells fell from 91 ppm of methylene chloride and 54 ppm of acetone, to less than 1 ppm after a year. Similar degradation efficiencies were noted for the monitoring wells. Sludge production was minimal since some of the sludge was recycled from the settling tanks to the activating tanks and some was allowed to pass to the recharge trenches to inoculate the soil with acclimated microorganisms. An independent study by Professor W. W. Umbreit of Rutgers University confirmed that methylene chloride was oxidized by the GDS culture.
Groundwater Remediation
Published in Kathleen Sellers, Fundamentals of Hazardous Waste Site Remediation, 2018
Pretreatment may be required to remove iron and manganese. Options for pre-treatment include precipitation, manganese greensand filters, and the addition of sequestering agents. Fe(II) can be removed by aerating the water, to oxidize the iron to Fe(III). Ferric (Fe(III)) hydroxides precipitate readily at a pH between 7 and 10.61 Aeration will not effectively oxidize manganese below pH 9.5.61 Chemical oxidation (by chlorination or potassium permanganate) may be required to precipitate manganous oxides. Iron and manganese are also removed by the lime softening process used to remove hardness.61 A manganese greensand filter contains a combination of New Jersey glauconite (greensand), manganese sulfate, and potassium sulfate. This mixture contains high levels of manganese oxides. When manganous ion in groundwater contacts the bed, an oxidation-reduction reaction forms insoluble manganese dioxide. The manganese dioxide remains on the filter bed. The bed is periodically reoxidized with permanganate, and backwashed to remove solids. For high levels of manganese in the groundwater, the necessity for frequent maintenance can make the use of manganese greensand filtration infeasible. For additional discussion of iron and manganese removal, see Water Treatment Plant Design.62Sequestering agents are chemicals that can be added to the groundwater to chelate the metal ions and keep them in solution. Sequestering agents are only effective at relatively low concentrations of iron.
Turfgrass Diseases and Nematodes
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
Cultural controls. Since take-all patch is favored by alkaline soils, fertilize with acidifying fertilizers such as ammonium nitrate and ammonium sulfate or use other acidifying compounds such as elemental S at 3 to 5 pounds/1,000 square feet (15 to 25 g/m2). Split the total yearly amount of acidifying compound into several applications so as to maintain a soil pH of around 5.5. Minor elements such as Mn, Mg, and Zn should also be tested and soil applied if deficient. Soil (granular) applications of these nutrients are typically more effective than foliar sprays for take-all suppression. Either spring or fall applications of 2 pounds Mn/acre (5 kg/100 m2) in heavy soils and 6 to 8 pounds/acre (30 to 40 kg/100 m2) in sandy soils have proven beneficial. Patch suppression has followed use of manganese sulfate, ammonium chloride, and ammonium sulfate. Annual applications are usually needed. Acidic soils favor more Mn availability and thus tend to have better disease suppression. Control thatch accumulation and promote rooting by aerifying, topdressing, verticutting, and deep, infrequent irrigation. In situations with chronic infections, replant affected areas with less susceptible grasses, blends, or mixtures of nonhost grasses.
A Review of Low Grade Manganese Ore Upgradation Processes
Published in Mineral Processing and Extractive Metallurgy Review, 2020
Veerendra Singh, Tarun Chakraborty, Sunil K Tripathy
The other consumers, such as chemical, battery, glass, non-ferrous metal industry, etc. use relatively high grade or processed ores. Chemical industry uses high-grade manganese oxide ores to produce potassium permanganate, hydroquinone, manganese sulfate, manganese oxide, manganese chloride, manganese carbonate, manganese phosphate, etc. Most of these plants consume manganese ores with >78% MnO2, <5% SiO2, and <5% Fe2O3. Glass industry uses high-grade manganese oxides ores as a decolourizer. For this purpose, high-grade manganese ore containing >85% MnO2 with <10% Fe is used. In the battery industry, the high-grade manganese dioxide is used as an oxidizing agent or a depolarizer of hydrogen. Variety of ore compositions are used, e.g. (a) natural ore with 72% MnO2, (b) chemically activated manganese dioxide with 85% MnO2, and (c) electrolytic manganese dioxide (EMD) with 90% MnO2 and small amount of iron and should be free from copper, nickel, cobalt, arsenic, chromium, lead, etc. In general, the battery industry consumes manganese ore with 70–90% MnO2 and low Fe (2.5–4%). Manganese metal is used for refining and as an alloying element for aluminum, copper, magnesium, and zinc alloys. These industries use Mn metal with Mn >95%, Si <1%, Fe <2.5%, C < 0.2%, S < 0.005% and P < .1% (IBM Report 2006). The specifications reveal that first choice of all the industries is to get high grade manganese ores as a raw material.
Minreview: Recent advances in the development of gaseous and dissolved oxygen sensors
Published in Instrumentation Science & Technology, 2019
Q. Wang, Jia-Ming Zhang, Shuai Li
The indirect Winkler method uses residual iodine and the replacement of iodine methods. This procedure must be in neutral or weak acid solution. High acidity oxidizes iodide, which promotes the decomposition of sodium thiosulfate. In highly alkaline solution, disproportionate reactions occur with iodine. The surplus iodine method uses excess iodine as reducing substances. The first reaction involves reducing substances and excess iodine, while the remaining iodine with a sodium thiosulfate back-titration, and amount of sodium thiosulfate is used to determine the concentration. The determination of water-soluble oxygen is replaced by the Winkler method. The basic procedure uses manganese chloride and sodium hydroxide to induce manganese hydroxide precipitation, water-soluble oxygen precipitation into a brown precipitate, followed by reaction with sulfuric acid to produce manganese sulfate. Lastly, the potassium iodide is oxidized to iodine, and the resulting iodine is titrated with sodium thiosulfate.