I think, following are the key factors that affect coagulation: Type of coagulant, dose of coagulant, characteristics of water such as; type and quantity of suspended matter, temperature, and pH; Time, and mixing methods etc.

Besides, you can find so many stuffs related to this question in google.

Best,

Important parameters such as; temperature, pH, DO, organic matter, characteristics of water, suspended materials and type of coagulant.

Among of a number of factors, the pH of solution and the total dissolved salt (TDS) are the most parameters that effected on the coagulation process.

pH, temperature,

Amount of suspended matter, temperature, PH and type of coagulant.

Dear susmita,

Coagulation is depend on the type of coagulant used, its dose and mass. Further, initial turbidity, TDS and pH of the water and pollutants present in water. Oxidation also a parameter which can affect with the effectiveness of the coagulation process.

I agree with Yohan Mahagamage . When discharging through the dam pH-Eh conditions are changed. oxidation processes take place, etc. In addition, turbulence in a fall from a height also has an effect.

Not an expert on coagulation but besides the vectors mentioned above, have observed that can be not such an straight forward mechanism. Dissolved organic matter can occur on several configuration

(negatively charged, neutral. positive charged, hydrophilic. hydrophobic, different charge densities),coagulants can come with different charge densities; and dissolved gases also can interfere with charge neutralization. So the well known jar test is a very useful tool to determine the best coagulant and coagulation conditions...high NTU waters are easier to cagulate mthan low NTU waters, ake sure to aerate the sample (if from a lake) up to at least 100 +mv (ORP) just in case!...hope this help.

Temperature and pH

thank you, Carlos, I think about it...

Temperature, mixing velocity and coagulant dose.

I made a video on coagulation and jar testing if you want to learn more here: www.amiralansari.com/jartest

Short answer: type and concentration of organics. However, there are many other factors that contribute as well, but not as much. All these factors are interacting which makes it very complicated, e.g. changing the pH of the water changes the contaminant surface charge, the solubility of your coagulant, the primary coagulation mechanism, etc.

Thanks for your contribution I find it very valuable. My objective is to understand why aerated lake water is easier to coagulate. Please see video where the project is explained...Spanish

Air to reduce eutrophication / stratification

https://www.youtube.com/watch?v=_hy13fUIaMw

Carlos Gonzalez,

First, high turbidity does not make coagulation easier. You get better overall performance because higher turbidity waters are easier to flocculate. Flocculation is mostly a physical process with the goal being to bring about contact between particles. Whether or not those particles "stick" will depend on how effective your coagulation step was.

This is purely speculation, but aerating the water, with respect to coagulation, will likely to change something about the chemistry of the water either directly or indirectly (e.g. by increasing biological activity). My guess is that it could be pH and organics related.

Thanks for your comments. In fact here water authorities are finally realizing that makes sense to have a more homogeneous raw water instead of an stratified lakes. Oxygen also reduces metal like Mn and Fe as well as DOC for incorporating into the water column.

Will make sense to run jar tests with aerated water vs non aerated ? We ran chlorine demand and aerated water showed a 25% less chlorine demand.

Graphs shows OPEX reduction before / after lake oxygenation

Interesting contributions by respected colleagues on this discussion

Local news channel reported on the benefits of the oxygenation system, sorry is in Spanish.

Reduction on eutrophication: : https://www.youtube.com/watch?v=_hy13fUIaMw

In fact when a river is used to 'build" a reservoir, is good as a water reservoir, however it makes a huge impact on the natural equilibrium. after the construction, garbage ,sewage is dumped into these lakes exceeding the natural environment to recover by its own tools.

So is a good idea to include an artificial way to oxygenate the water, since we are really artificially contaminating it.

There are several firms that can offer this kind of technology.

Dr. Carlos Gonzalez valuable discussion. thanks

Nice discussion

Interesting contributions by respected colleagues on this discussion

I thank everyone for discussing this issue. It's important for me. in addition to coagulation of organic matter during discharge, there is a decrease in the concentration of trace elements, due to the formation of suspended forms of trace elements. At the same time, there is an increase in the concentrations of almost all macroelements and general indicators. after some time my article will be published in the Journal of Geochemistry, this issue is discussed there. anyone interested, read.

Dear Susmita Pant,

Coagulation can be based on a reaction. So, it probably is affected by the factors impacts on the reaction, such as temperature, the coagulant, the concentrations of the solute and coagulant, etc.

Good luck,

Foroogh

I agree @ Foroogh Khodadadi

Yes, we also investigated this question - how the distribution of organic matter changes over time, in different seasons of the hydrological year. The changes are there, but small, and I cannot explain them yet. The maximum effect we saw when dumping over the dam in the spring. I explain this by the elevation difference, due to which the pH-Eh conditions change.

Temperature, concentration of coagulant, type and nature of coagulant, level and characteristics of colloidal matter to be removed, retention time of dosing, retention time of clarrifier. These are the most common factors.

Many factors effect of colloidal matter such as, nature of coagulant, retention time, concentration of coagulant and the physical properties such as temperature, pH and others.