my question is interested in water treatment methods for agricultural uses , depending in which class of treatment methods is more important due to the final uses , Does Bio m phys, or chemical methods???
The treatment process for use of water to Agriculture purpose largely depends on source and nature of pollutants. Ground water with silt as sediments if used under drip irrigation can be treated with physical process- filtration. If the water is degraded with dissolved chemicals or microbial loads beyond critical limit, chemical and biological treatment is recommended..
It depends on the type of irrigation (e,g,: dripping, open/channel, sprinkler irrigation) and also on the characteristics of the soil (especially whether or not the soil has a medium to high level of stable OM). Sediments and particulates will affect the good functioning of dripping and sprinkler irrigation systems whereas the same will not affect open channel irrigation). Therefore, filtration (Physical method) will aid in this context. Chemical and biological treatments of irrigation water has to do with the reduction of bacteria (e.g.: fecal bacteria like E. coli, Shigella, Salmonella) that can be deleterious to human and animal health). The spreading of these via sprinkler irrigation on a crop may pose risks to health hence the need of treating the water with chemicals, or UV light. the chelating action of soil OM will be valuable to retain undecomposed residues and microrganisms that will be degraded by soil microflora.
About 80% of all or our water use is for irrigation. The irrigation approach can make or break our food production system. For crops this will move irrigation to drip irrigation systems which use much less water. For water treatment in drip it is imperative to use filtration. Another issue is pH in areas of alkaline water acidification is important. The ability to add input through the drip lines can include biological and chemical agencies. In terms of subtle energies electro magnetic fields can pulled clumped water making the ability to provide nutrients and inputs much greater. Physical chemical biological and subtle energies are all useful for optimizing our water of crops and pastures.
Since you are intrested in water treatment for agriculture use, i would suggest biological method over physical and chemical, because of less chemical burden( more eco friendly) and more compatible for irrigation purpose. But again it depends on the source of contamination and types of contaminants.
Ultraviolet light is an effective and low cost option for reducing bacteria in water systems. It can leave not chemical trace and is favorable for this regard rather than depending on toxic environmentally damage chlorine.
That is depend on nature of pollutants.... My opinion is the effective method may be combination of three methods. The important final step often biological method.
Let us define the above mentioned question as to whether the main pollution indicator is related to brackish salinity(groundwater), ie, total dissolved solids is greater than 3000 mg / L, which is the best and cheapest method to be applied?