Organisms used in water purification

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A flowering water-purifying plant (Iris pseudacorus)
A flowering water-purifying plant (Iris pseudacorus)

At present, several species of water-purifying plants, bacteria, and fish are selected for use in water purification. This, in order to allow the most efficient water purification and/or the creation of a complete ecosystem.

Contents

[edit] Types of organisms

Besides water purifying (which are actually de-nutrifying) plants, extra plants that provide shade and a refuge for fish and extra plants that provide oxygen are needed for certain water purifying plant-based systems so as to create a good environment in which the water-purifying plants and bacteria may survive and thrive [1]. In addition, fish is also added to certain plant-based systems to prevent the attack of pests to the system or to prevent the settlement of unwanted organisms (eg mosquitos).

Off course, depending on the local climate (temperate, subtropical or tropical), different species need to be taken for each situation. To ensure optimum system efficiency (and for environmental reasons as well), indigenous species are usually taken. Indigenous species usually tend to more adapted (and therefore more suited/hardy) to the local environment. The list of the most most common and/or most efficient species (each for their specific field of expertise) is the following:

[edit] Plant species

A water-purifying plant (Iris pseudacorus) in growth after winter (leaves die-off at that time of year)
A water-purifying plant (Iris pseudacorus) in growth after winter (leaves die-off at that time of year)

Plants need to be taken for several waterlayers/depth-zones [2]. This to ensure that a good system is made. 4 layers/water depth-zones are to be determined and used:

  1. A water-depth zone from 0-20cm;
  2. A water-depth zone from 40-60cm;
  3. A water-depth zone from 60-120cm;
  4. A submerged water-depth zone;

[edit] Water purifying (de-nutrifying) plants

  • Nymphea alba; for temperate climates, depth 60-120cm, One of the best plants for water purification
  • Phragmites australis, for temperate climates, One of the best plants for water purification, will escape cultivation and become invasive, is now invasive in many areas
  • Sparganium erectum, for temperate climates, depth 60-120cm, One of the best plants for water purification
  • Iris pseudacorus, for temperate climates, depth 0-20cm, One of the best plants for water purification
  • Schoenoplectus lacustris, for temperate climates
  • carex acutiformis, for temperate climates

[edit] Oxygen-supplying plants

[edit] Shade/refuge-supplying (both free floating and large-leaf) plants

  • Hydrocharis morsus-ranae, temperate climates, depth 40-60cm, One of the best plants for oxygen-supply and shade-supply
  • Nuphar lutea, temperate climates, depth 60-120cm, a good plant for giving shade (floating leaf)

[edit] Fish species

Fish need to be taken for 3 waterlayers/depth-zones. The fish need to be non-predatory in nature This again to ensure that a good system is made. 3 layers/water depth-zones are to be determined and used:

  1. Surface swimming fish
  2. Middle-swimmers
  3. Bottom-swimming fish

[edit] Surface-swimmers

[edit] Middle-swimmers

[edit] Bottom-swimmers

[edit] Bacteria

One of the most important organisms for the water-purification are the bacteria. The bacteria are ideally grown locally (although they might be bought at commercial stores as well). Local growing is preferred to ensure that the bacteria are indigenous and well-adapted to local conditions. The bacteria are grown at home by submerging straw (or other plant material) in water for several days. Bacteria automatically populate it as they arrive from the surrounding atmosphere.

[edit] Extra considerations

For ecologic/self-purifying ponds, de-nutrified soil needs to be taken for the plants to prevent the possible growth of algae. Coconut fibre growing medium is best used to prevent soil from being spread around and to sometimes to let the plants root in.

[edit] Example of a working system

An example of a working system (which combines both oxygen supply, shade-supply, ...) and takes into account the depth zones:

[edit] Plants

[edit] Fish

[edit] See also

[edit] References

  1. ^ Several types of plants required to form a water-purifying pond
  2. ^ Several-depth zones of plants need to be determined