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  2. Anaerobic digestion - Wikipedia

    en.wikipedia.org/wiki/Anaerobic_digestion

    National environmental enforcement agencies, such as the U.S. Environmental Protection Agency or the English and Welsh Environment Agency, put strict limits on the levels of gases containing hydrogen sulfide, and, if the levels of hydrogen sulfide in the gas are high, gas scrubbing and cleaning equipment (such as amine gas treating) will be ...

  3. Bokashi (horticulture) - Wikipedia

    en.wikipedia.org/wiki/Bokashi_(horticulture)

    A soil ball with indigenous worms in soil amended a few weeks previously with bokashi fermented matter. Bokashi is a process that converts food waste and similar organic matter into a soil amendment which adds nutrients and improves soil texture. It differs from traditional composting methods in several respects. The most important are:

  4. Soil vapor extraction - Wikipedia

    en.wikipedia.org/wiki/Soil_vapor_extraction

    Soil vapor extraction (SVE) is a physical treatment process for in situ remediation of volatile contaminants in vadose zone (unsaturated) soils (EPA, 2012). SVE (also referred to as in situ soil venting or vacuum extraction) is based on mass transfer of contaminant from the solid (sorbed) and liquid (aqueous or non-aqueous) phases into the gas phase, with subsequent collection of the gas phase ...

  5. Thermal desorption - Wikipedia

    en.wikipedia.org/wiki/Thermal_desorption

    The volume of gas requiring treatment for indirect fired desorbers is a fraction of that required for a direct fired desorber. This requires smaller air pollution control trains for the gaseous process vent emissions. Some thermal desorption systems recycle the carrier gas, thereby further reducing the volume of gaseous emissions.

  6. Deaerator - Wikipedia

    en.wikipedia.org/wiki/Deaerator

    The treated water falls into a storage tank below the deaerator. [20] [3] Oxygen scavenging chemicals are very often added to the deaerated boiler feedwater to remove any last traces of oxygen that were not removed by the deaerator. The type of chemical added depends on whether the location uses a volatile or non-volatile water treatment program.

  7. Soil gas - Wikipedia

    en.wikipedia.org/wiki/Soil_gas

    Soil gases (soil atmosphere [1]) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. [2] Oxygen is critical because it allows for respiration of both plant roots and soil ...

  8. Biogas - Wikipedia

    en.wikipedia.org/wiki/Biogas

    Biogas in India [101] has been traditionally based on dairy manure as feed stock and these "gobar" gas plants have been in operation for a long period of time, especially in rural India. In the last 2–3 decades, research organisations with a focus on rural energy security have enhanced the design of the systems resulting in newer efficient ...

  9. Food preservation - Wikipedia

    en.wikipedia.org/wiki/Food_preservation

    Burial of food can preserve it due to a variety of factors: lack of light, lack of oxygen, cool temperatures, pH level, or desiccants in the soil. Burial may be combined with other methods such as salting or fermentation. Most foods can be preserved in soil that is very dry and salty (thus a desiccant) such as sand, or soil that is frozen.