In situ or direct dosing water treatment involves mixing and dosing chemical reagents directly into the affected water body for the treatment of a number of issues, instead of pumping water for treatment through a water treatment plant.

Applications

Applications of ''

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

'' water treatment include

acid mine drainage Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines or coal mines. Acid rock drainage occurs naturally within some environments as part of the rock weathering ...

(AMD) treatment,

turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality. Fluids can ...

control, algal control, nutrient pollution control, metal control, disinfection, chlorination, cyanide destruction, pH control, salinity control and lowering dissolved metals. ''In situ'' water treatment is commonly used in the mining industry for a number of applications including the treatment of acid mine drainage and

. ''In situ'' treatment of turbidity is often used for controlling turbidity in stormwater collection ponds at coal mine sites and coal loading facilities especially in Australia and Indonesia. Some municipalities with numerous small water storage reservoirs spread out over a geographical location use ''in situ'' treatment for the control of turbidity. Although rare chlorine has been dosed directly into water bodies for the purpose of disinfection.

Technologies

There are a number of technologies available for the ''in situ'' water treatment. Reagent can be mixed into a slurry in a vertical mixing tank, or similar, and dosed directly into the water body (e.g. a tailings storage facility (TSF) or pond) via a pipeline. Some systems mix the reagent in a tank and spray it into the water body using a spray cannon. Other technologies mix and dose into the water body using a mobile water based floating system. The technology must be selected carefully based on the application and the reagent selected. For example for the treatment of turbidity the flocculant must be evenly dispensed over the surface of the water body to allow it to settle through creating flocs.

References

{{unsourced, date=April 2013 Pollution control technologies Water treatment