First of all you should provide information about the type of wastewaer you are going to treat (urban? metal finishing effluents?) and what kind of pollutants you would like to remove (heavy metals? emulsified oils? colour?). NaCl is the most commonly used electrolyte. A nice review is reported in Water 2011, 3, 495-525; doi:10.3390/w3020495; www.mdpi.com/2073-4441/3/2/495/pdf.

Thanks sir for valuable suggestion ....I want to treat paper industry wastewater by electrocoagulation method sir plz give the above link agian i cant able to open it here...Thanks

Dear Dushyant,

Advanced biological treatment provides a far more sustainable alternative for treating paper industry wastewater as opposed to increasing its salinity (by adding NaCl) for electrocoagulation (EC) consuming a lot of electrical energy and producing a lot of EC-sludge.

After recovering fibers (for producing more paper) and conditioning, we convert about 50% of organic pollution to methane (for direct firing in the industry's steam boilers) and remove the remaining pollutants (including lignin, colour) by advanced activated sludge (AAS) technology resulting in clean water to produce more paper.

Is preferable to use electrocoagulation as pretreatment after primary treatment. For paper industry you can reduce inorganic  as well as organic pollutants by chemical precipitation, or/and electrocoagulation and biological treatment (extended aeration).

In any case NaCl is the most cheap and suitable electrolyte.

Dear Elisavet,

Please explain how EC reduces the inorganics (minerals) of the wastewater when it would need the addition of much more minerals (electrolyte) for its own operation? How sustainable would it be to increase the salinity of water?

Dear Dushyant

the link is to this journal:

http://www.mdpi.com/journal/water

and look for the paper

Electrocoagulation in wastewater systems.

Having said that, I agree entirely with Bruno Peteers, as paper mill wastewater can be easily treated via floatation (to recover fibers) and subsequent biological treatment, such as those suggested by Bruno. Many paper mills adopt anaerobic digestion followed by activated sludge processes as standard technology. However filamentous bulking can be experienced in activated sludge processes treating anaerobically pretreated paper mill effluent and this is the reason to adopt a further floatation unit to separate sludge from the final effluent, or an MBR (membrane bioreactor).

Dear Dashyant

Your question was about EC and I don't see why the discussion regarding other technologies is relevant. Roberto gave you a full answer. Please try to google "electrocoagulation and paper"  you find a huge number of papers describing exactly what you are looking for. 

If you use NaCl as an electrolyte, oxidation of chloride ions on anode will lead to formation of oxidative chlroine species that can help in oxidation of dissolved organic matter in addition to coagulation by metal hydroxide species. 

Dear Dushyant Panwar,

there are many electrolytes like NaCl, KCl... ( approximately all salt ), but this technique is not efficient for this type of water  (need energy, chemicals, ..) may be you can use membrane filtration before electrocoagulation treatment,

good luck

Tarik

In EC technique it is recommended to use supportive electrolyte to increase the conductivity of solution and to increase Chloride ions.The addition of NaCl showed that Cl2 and OCl− are the products from anodic discharge when chlorides are present in the solution. The formation of hypochlorous acid, will assist to oxidize the hydrous ferrous oxides producing the active adsorbents such as hydrous ferric oxides with a large surface area.

The most important supporting electrolytes that can be used in wastewater treatment by electrocoagulation are NaCl, Na2SO4 and Na2PO4 to increase conductivity. The most effective one is NaCl where Cl- usuallyoxidizes at the anode to form Cl2 gasand then HOCl acid which is highly oxidizing agent of pollutants.

simply use salt water from the ocean

Please consider that electrocoagulation of wastewater in presence of chloride may produce toxic chlorinated compounds, as you can also read from the answer provided by Nael Yasri. You may try to use ocean water and check the formation of chlorinated compounds.

Here any paper on wastewater treatment with the effect of Napo4 electrolyte plz provides to me 

Yael Nasari has pointed the most important question to be start with. Waste water is not a chemical element, it has characteristic and to be carefully defined both for what is coming in and what is going out (effluent) and under what regulation. most common use is NaCl, it is the cheapest solution too.

Sir, can u provide me the paper related to NaCl causes environmental problem ...plz if possible

Thank you sir..

Dear Dushyant Kumar ,

Of course nothing can be compared to NaCl in electrocoagulation! since it is very cheap and available and the most effective electrolyte. So try adding NaCl (table salt) to your wastewater until it reaches the appropriate conductivity :)

The electrolytes play a major role in the EC process due to the possible formed side products that can increase or decrease the efficiency of the system.

NaCl, This may be explained by the fact that the higher Cl− concentrations related to ability of Cl− to damage any passive oxide film which tends to form on anodes at relatively high potential and limit electrod dissolution.

Yes, generally NaCl is considered a good electrolyte in the case of the electrocoagulation process. But it slightly depends on your effluent what you want to may treat