Published by satyam arya, Design Engineer at Geo Miller & Co pvt. Ltd
Is it possible to remove phosphorus from sewage from 19 mg/l to 1 mg/l by biological means?
How? Which biological treatment do you suggest?
Yes is possible, by using ferric chloride in the process between Biological filter and Humus tank. The P will turn from 19 to 1mg/l.
Thank you,
Mangena P
Published by PHETLA MANGENA, Water quality at WEB Bonaire
Yes, we have done this using a membrane bio-reactor process. You may need to use Phoslock if it there is also inorganic P.
Please email me at andrew@waterandoilsolutions.com.au if you would like to know more.
Published by Andrew Tran, Engineer
Enhanced Biological Phophorus Removal or EBPR configurations to activated sludge systems can enhance growth of PAOs,as bacteria that accummulate polyphosphates in large quantities,as they grow on nutrients in waste waters.
EBPR configurations can selectively enrich PAOs,as polyphosphate accumulating systems for enhanced phosphate removal thru growth of microbial biomass in waste waters.
EBPR is anaerobic aerobic system cofiguration,applied to activated sludge.
Reference...Biological phosphorus removal manual..Utrecht,2002.
Wastewater engg. Treatment..Metcalf ,Eddy Inc.,McGraw Hill.Boston
Published by Suresh Kumar.S
Published by Eros Kaw, Biocleaner Inc. - Chief Tech Support
Municipal wastewaters may contain from 5 to 20 mg/l of total phosphorous, of which 1-5 mg/l is organic and the rest in inorganic. The individual contribution tend to increase, because phosphorous is one of the main constituent of synthetic detergents. The individual phosphorous contribution varies between 0.65 and 4.80 g/inhabitant per day with an average of about 2.18 g. The usual forms of phosphorous found in aqueous solutions include:
Orthophosphates: available for biological metabolism without further breakdown Polyphosphates: molecules with 2 or more phosphorous atoms, oxygen and in some cases hydrogen atoms combine in a complex molecule. Usually polyphosphates undergo hydrolysis and revert to the orthophosphate forms. This process is usually quite slow.(i.e., nutrient enrichment due to human activities) in surface waters are primarily due to nitrogen and phosphorus. The most recognizable manifestations of this phenomena are algal blooms that occur during summer. Over-nutrient enrichment results in low dissolved oxygen (DO), fish kills, murky water and depletion of desirable flora and fauna. In some cases toxic algae such as microsystis was found in algal blooms. In addition, the increase in algae increases the need to increase chlorine doses of drinking water, which in turn, leads to higher levels of disinfection by-products (that have been shown to increase the risk of cancer Excessive amounts of nutrients can also stimulate the activity of harmful microbes, such as Pfisteria.Phosphorous removal processes
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.
Phosphate precipitation
Chemical precipitation is used to remove the inorganic forms of phosphate by the addition of a coagulant and a mixing of wastewater and coagulant. The multivalent metal ions most commonly used are calcium, aluminium and iron.
Calcium:
it is usually added in the form of lime Ca(OH)2. It reacts with the natural alkalinity in the wastewater to produce calcium carbonate, which is primarily responsible for enhancing SS removal.
Ca(HCO3)2 + Ca(OH)2 à 2CaCO3 ↓+ 2H2O
As the pH value of the wastewater increases beyond about 10, excess calcium ions will then react with the phosphate, to precipitate in hydroxylapatite:
10 Ca2+ + 6 PO43- + 2 OH- ↔ Ca10(PO4)*6(OH)2 ↓
Because the reaction is between the lime and the alkalinity of the wastewater, the quantity required will be, in general, independent of the amount of phosphate present. It will depend primarily on the alkalinity of the wastewater. The lime dose required can be approximated at 1.5 times the alkalinity as CaCO3. Neutralisation may be required to reduce pH before subsequent treatment or disposal. Recarbonation with carbon dioxide (CO2) is used to lower the pH value.
Aluminium and Iron:
Alum or hydrated aluminium sulphate is widely used precipitating phosphates and aluminium phosphates (AlPO4). The basic reaction is:
Al3+ + HnPO43-n ↔ AlPO4 + nH+
This reaction is deceptively simple and must be considered in light of the many competing reactions and their associated equilibrium constants and the effects of alkalinity, pH, trace elements found in wastewater. The dosage rate required is a function of the phosphorous removal required. The efficiency of coagulation falls as the concentration of phosphorous decreases. In practice, an 80-90% removal rate is achieved at coagulant dosage rates between 50 and 200 mg/l. Dosages are generally established on the basis of bench-scale tests and occasionally by full-scale tests, especially if polymers are used. Aluminium coagulants can adversely affect the microbial population in activated sludge, especially protozoa and rotifers, at dosage rates higher than 150 mg/l. However this does not affect much either BOD or TSS removal, as the clarification function of protozoa and rotifers is largely compensated by the enhanced removal of SS by chemical precipitation.
Ferric chloride or sulphate and ferrous sulphate also know as copperas, are all widely used for phosphorous removal, although the actual reactions are not fully understood. The basic reaction is:
Fe3+ + HnPO43-n ↔ FePO4 + nH+
Ferric ions combine to form ferric phosphate. They react slowly with the natural alkalinity and so a coagulant aid, such as lime, is normally add to raise the pH in order to enhance the coagulation.
Published by Prem Baboo, Researcher at www.researchGate.net
Hi Satyam,
I would like to take up this challenge and propose Makro Organics treatment. We supply a patented, organic certified, plant extract product from South Africa. The product is marketed in UK, EU, South East Asia, UAE, Australia, Pakistan and soon India for the treatment of sewer effluent. In a recent application in Dubai, a independent 3rd party confirmed the results and we managed to reduce the phosphorus from around 5.0 to 0.4 in a limited retention system. We also managed to reduce P from 9.0 to 1.0 in another application on TSE. The treatment offers many other benefits for TSE. dave@makroorganics.com
Published by Dave Gaybba, Managing Director
I can tell you that in an experiment I did during my master thesis, we were using biological treatment with MBBR technology. An anaerobic reactor was followed by an aerobic one (simple PAOs bacteria technology) and as carbon source for the anaerobic we used the carbon in the wastewater. The removal was good, but from 19 mg/l we never went down to 1mg/l; if I remember well it was something around 40-50% removal. Therefore I think you can't achieve that goal ONLY biologically, or at least unless you have a very complex system (maybe lots of Anaerobic/Aerobic couples of reactors with external carbon source, but this solution is a simple and probably wrong idea I had now). And even if you do, I don't think you can grant it always, especially if unwanted nitrification happens in the aerobic reactor.
Published by Francesco Formisano, Process Engineer at AquaOptima AS | Environmental Engineer | Water and Wastewater Treatment
Hi
there are several biological treatments that can be used, but to get it to 1 mg/l you really need to think about chemical precipitation also.
please check the ICEAS SBR's from Xylem
Published by Pedro Mota, Xylem Water Solutions Rugby Ltd. - Site Process Engineer
Enhanced biological phosphorus removal via luxury uptake after an anaerobic step is a well established technology applied at large scale in sewage treatment in the EU in spite of the low COD/TP and BOD/TP ratio's. In practice less than 2 mg/l can be achieved 100% biologically but to ensure maximum 1 mg/l in all conditions also chemical phosphorus precipitation would be needed from time to time.
Published by Bruno Peeters, managing director at Model Engineering
First prize is to use the natural micro-organisms already in the wastewater. This is the whole principal around the biological nutrient removal processes. The choice of which configuration is best for a particular application usually depends on the P to COD ratio, the sludge age, and other factors. The configurations vary from BardenPho, UCT, Johannesburg, Modified Ludzak-Ettinger, and variations of these. A precaution when dewatering the sludge is not to return the filtrate or supernatant back to the head of works as this often contains higher levels of P released by the microorganisms as they come under stress in the de-watering process. Algae sounds very promising, but the algae need to be separated from the treated effluent which could be challenging - may require a DAF process.
Published by Ian Pearson
You have to waste biosolids to get P removal, no matter what kinds of the biological process. To get Bio-P removel to below 1 mg/L, the ratio of COD to TP should be more than 40 and with short sludge ages.
Published by Liang Qiao, Chief Process Specialist at ZJ High New Pty Ltd
I also come to understand that anaerobic-anoxic SBRhas superiority for aerobic -anaerobic ones more widely used
Published by Suresh Kumar.S
Aerobic-anoxic SBR reported with use of nitrates for highly efficient phosphorus removal in wastewater
Published by Suresh Kumar.S
you can use PAO to treat it to 0.2. and then you can treat the biomass to phosphorus as high as 14% to be reused for farming after checking for heavy metals. i hope this helps
Published by Eros Kaw, Biocleaner Inc. - Chief Tech Support
I've been working on phosphorus removal by microalgae and we could less its concentration from 7ppm to 1.75.
Depending on microalgae you choose, yes it can be possible to remove it.
Published by mahsa pishbin
Hi,
You can biologically remove this amount of P if the raw water has sufficient carbon and de-sludge from the process. Because the waste biomass normally contains 1 - 3% of P.
If the raw wtaer has not sufficient BOD, the chemical P precipitation would be economic.
Published by Liang Qiao, Chief Process Specialist at ZJ High New Pty Ltd
Could you please provide me any reference regarding phosphorus removal in waste biomass..
Published by satyam arya, Design Engineer at Geo Miller & Co pvt. Ltd
1,500 mg of algae will consume 18 mg of P. Growing algae is the best biological solution to remove P, provided adequate N is available, about 120 mg of N is required.
Published by Bhaskar Mallimadugula, Kadambari Consultants Pvt Ltd - Director
What is the typical retention times needed microalgae P removal? I am not convinced that the stated methodology would work under current conventional systems.
Published by Antonio Bowers, Mister
Algae growth rates will be from 0.1 to 1 g per liter per day .
Published by Bhaskar Mallimadugula, Kadambari Consultants Pvt Ltd - Director
Sir --- we have been using a 100% pure organic solution to remove phosphorus for about 20 years now. Our product, Solutek has been used by a number of municipal authorities in WWTP for this purpose. We could ship you a sample to trial if you wish.
See.....www.soleco-technology.com
Email me.
Hugh.
Published by E. Hugh Pettman, Employee at Biophysics Research Pte. Ltd.
Dear Huge
Can you provide us with some technical information and efficiency graph on your product Solutek? please email to: antonio.bowers22@gmail
Published by Antonio Bowers, Mister
Biosol has been shown to remove influent phosphorus in the sewer from around 25 mg/L to about 4 mg/L. The phosphorus is precipitated and cannot be detected by the normal analysis means in Australia. This precipitate end up in the sludge. While Biosol's primary application is for odour and corrosion control in sewer systems, phosphorus removal is an additional benefit. Alum is used to remove the remaining phosphorus at the treatment plant.
Published by Ross Chandler, Managing Director
You might be interested in a technique to drop out the P in the wastewater by lowering the pH 2 pts and adding Magnesium (one of the most common elements of sea water). The P will form a ball around an N molecule and precipitate out.
Published by Neal Van Milligen, New Range Power Corp - Manager