I am looking the chemical method to remove the algae from raw water pond to be used as feed water for a reverse osmosis plant. As the algae is making problem in the cartridge filters. So what chemical in what ratio should be poured in pond's water to avoid the growth of algae colonies. Thanks & regards.
Dear S. K. Singh,
CuSO4 treatment will be risky, as we treat the raw water through RO plant for Drinking & industrial uses.
Cobber salts will only solve the problem temporarily. After a while the cobber will be buried in the sediment or complexed by organics.
You can measure the phosphate an the water and sediment and add an excess of iron or aluminium salts to precipate the phosphate.
I donnot think chemical method is good. it introduces pollution again. How about some simple method, like to cover the pond with shading net？ If there is not enough sunshine, the algae will dissaper some days latter.
Dear Tianlong Qiu,
Your suggestion is valuable, We are set to cover our pond by some shed ultimately, But it will take few weeks to complete the job. So for the time being we have to use some Flocculation technique.
Thanks for your valuable suggestion.
Regards.
Could you kindly elaborate? Are we talking fresh water, brine or saltwater?
Yoram
Dear Yoram Gerchman,
I have fresh water from underground well source, with Brackish nature. TDS= 5000-6000 ppm.
Regrads
but can not one act mechanically? can you use a series of filters with mesh network increasingly smaller, until you get to 45micrometer? this of course depends very much on the water flow needed
Dear Mauro Lenzi ,
Thanks for your provoked idea. yes it is possible to arrange the series of mechanical filters/ sieves. But it will involve a booster (Pump) and a lot of manual work to replace or wash the sieves very frequently.
Am I Right?
Regards.
We have studied algae flocculation with cationic polymers, and then either sedimentation of filtration in a rough filter. We have worked in BBM medium (~62 ppm) and I am not sure it work in brackish water as it does not work in 35,000 ppm. I will test our algae (C. vulgaris) at 5,000 ppm NaCl and let you know.
Yoram
Dear Yoram Gerchman,
It would be great pleasure for me to get the results from your experiments.
With Profound Regards.
Muhammad Imran
Certainly, but to obtain the result in such conditions (development of microalgae), a bit of energy must be spent. and I do not believe that chemicals can be used. An alternative would be the use of plankton feeders, e.g. Daphnia, properly inserted.
Best
Attached please find the results of treating Chlorella vulgaris (as a model) with chitosen (10mg/L), with salinity up to 10,000 ppm (NaCl). As you can see the algae flocculate and should be easily removed by simple rough filter. I am not sure if this is economically viable, but maybe as a temporary solution.
Do keep in mind that you probably want to remove access chitosen so it won't clog your membranes, you can try flowing the water through sand-clay filter.
Yoram
The chemical methods for algae removing from pound water was copper sulphate, 0.5mM three times weakly.
Dear Yoram Gerchman ,
Thanks for your shred results. This is a good solution of the problem. As Concern to remove the algae after coagulation, I want to tell you that the manual removal of algal colonies from surface of water becomes very easy when the coagulant works effectively. So the problem will be solved after effective coagulation.
Regards.
Good morning everyone,
I don't know if it can help, but I've read interesting papers about algal bloom and pretreatments strategies you can think of to remove algae organic matter before RO.
Good luck,
Best regards
Article Effect of coagulation on fouling potential and removal of al...
Article Seawater reverse osmosis desalination and (harmful) algal blooms
The algae themselves are not really the problem, as they are easily removed. The main problem is the Algal Organic Matter (including Transparent Exopolymer Particles), which can result in rapid headloss and clogging in media/sand filters as well as membrane filters if coagulation is not performed properly. Maria Kennedy
Glad to be of help Muhammad, and good luck with the project . Please feel free to contact me if you need more information. Maria