Dear Sir. Concerning your issue about the most effective treatment process for the removal of organic phosphorous (not phosphate ions) from wastewater. The removal of phosphorous from wastewater involves the incorporation of phosphate into TSS and the subsequent removal from these solids. Phosphorous can be incorporated into either biological solids (e.g. micro organisms) or chemical precipitates. I think the following below links may help you in your analysis:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.605.3410&rep=rep1&type=pdf https://www.lenntech.com/phosphorous-removal.htm

https://www.ripublication.com/ijaer16/ijaerv11n5_88.pdf

http://www.environmentalleverage.com/newsletters/Biological%20Nutrient%20removal%20vs%20chemical%20nutrient%20removal.pdf

Thanks

Mr. Ahmed, I know that physico-chemical processes are applied for treating wastewaters that have predominant inorganic pollutants, while organic pollutants can be removed exclusively by biological processes. The organic phosporous is a very good nutrient for bacterias, mainly aerobic bacterias that are able to remove up to 95% of organic pollutants from wastewaters while anaerobic bacterias/processes are used for concentrated slurries. My answer is that the efficient and widely applied process for removing organic phosphorus from wastewaters is not chemical but biological (activated slurry, biofilms, oxidation ponds etc.).

Thanks Dr Isam I appreciate your effort but the main topics of this articles deals with phosphate removal not organophosphorus removal

This article could be useful for finding the best methods of organic phosphorous removal.

Article Advances in enhanced biological phosphorus removal: From mic...

Thanks Dr. Carmen

if we taking about contaminated wastewater with organophosphorous pesticides such Malathion the biological treatment also takes place?

Yes, biological processes were proved to remove very toxic organic pollutants such as pesticides, PAH, PCBs. I don't have any articles available now but you can find if search on keywords. I worked in the past in the projects related to persistet organic pollutants POPs disposal and I found many articles that recommended biological processes as unique methods to decompose such persistent compounds, even above incineration. You have to seach thouroughly, even most toxic organics have specifical microbiota able to eat/decompose them.

Chemical and biological phosphorous treatments are the two main techniques for removing phosphorus from wastewater. Chemical treatment for phosphorus removal involves the addition of metal salts to react with soluble phosphate to form solid precipitates that are removed by solids separation processes including clarification and filtration whilst biological treatment involves culturing of communities of microorganisms in MLSS that have the ability to store intracellular phosphorus on a dry-weight basis, thus subsequent removal of waste activated sludge can produce phosphorus removal efficiencies. Compared with the chemical method, the biological method is relatively efficient, cheap and more environmental friendly. The common element in Enhanced biological phosphorus removal (EBPR) implementations is the presence of an anaerobic tank (nitrate and oxygen are absent) prior to the aeration tank. Under these conditions a group of heterotrophic bacteria, called polyphosphate-accumulating organisms (PAO) are selectively enriched in the bacterial community within the activated sludge. These bacteria accumulate large quantities of polyphosphate within their cells and the removal of phosphorus is said to be enhanced. Generally speaking, all bacteria contain a fraction (1-2%) of phosphorus in their biomass due to its presence in cellular components, such as membrane phospholipids and DNA. Therefore, as bacteria in a wastewater treatment plant consume nutrients in the wastewater, they grow and phosphorus is incorporated into the bacterial biomass. When PAOs grow they not only consume Phosphorus for cellular components but also accumulate large quantities of polyphosphate within their cells. Thus, the phosphorus fraction of phosphorus accumulating biomass is 5-7%. This biomass is then separated from the treated water at end of the process and the phosphorus is thus removed. Thus if PAOs are selectively enriched by the EBPR configuration, considerably more phosphorus is removed, compared to the relatively poor phosphorus removal in conventional activated sludge systems.

Reference links supplied below:

https://en.wikipedia.org/wiki/Enhanced_biological_phosphorus_removal

https://www.pca.state.mn.us/sites/default/files/wq-wwtp9-02.pdf

Mr. Antwi, I understood that the question was not addressed to removal or phosphate ions/salts but of complex organic phosphorous compounds. The chemical treatment leads to precipitation of phosphate salts but the organic compounds are not removed, just affected by hydrolysis and other processes, depending on the chemical reactant. The anaerobic process in anaerobic tank is applicable to fairly thick slurry (humidity max. 90-92%, most frequently of 80- 90%), while the aerobic processes are suitable for treating waste waters. There is much theory on such topic, the biochemical pathways that bacteria use to decompose such complex molecules are very wide and still not enough elucidated. Mr. Ahmed can search and decide what is the best to for his application, probably he could find some chemical processes others than to precipitate phosphate salts. I personally haven't learn about chemical methods to remove phosphorous from complex organic compounds but I'm curious and open to learn more.

Lanthanum Carbonate

Municipal wastewaters may contain 5 to 20 mg/l of total phosphorous, of which 1-5 mg/l is organic and the rest in inorganic. Several biological suspended growth process configurations have been used to accomplish biological phosphorous removal. The following link may also be useful.

https://www.lenntech.com/phosphorous-removal.htm

Regards

The phosphor in effluent wastewater that isn't phosphate is to a very large degree associated with particulate matter and therefore the methods used to achieve low total phosphorus effluent concentrations is filtration aiming to get SS very low. The most common is a sand filter but disc filters are becoming more common. http://technomaps.veoliawatertechnologies.com/hydrotech/en/municipalities.htm#c4998iQr01

Organic phosphorus in wastewater can be precipitated by adding Alum. It will result in the formation of Aluminium hydroxyphosphate precipitate. It will be more effective if precipitated at high DO content, preferably immediately after aeration.

Dr.Henrik - Good link on 'Water Treatment Technologies' (Municipalities).

Thanks

None of the forms of phosphorous are gaseous at normal temperature and pressures so removal has to be accomplished by formation of insoluble precipitate that can be removed by gravity settling.

Organic phosphorous is however less easily removed than ortho-phosphorus -adding aluminum or iron salts after secondary treatment usually results in the best removal. This definitely increases the TDS.

Contact filtration can be employed

Phosphorous can also be removed in biological treatment by means of incorporation into cell tissue.Micro-organisms are able to remove excess amount of phosphorus over that required for growth.