Sulfate Radicals for Industrial Wastewater Treatment

I am ​currently ​working with ​sulfate ​radicals to ​treat ​industrial ​wastewater ​containing high ​levels of ​metals such as ​nickel, zinc ​and copper. ​

Which sulfate ​radicals are the most efficient in wastewater treatment? Which are the most economical?

Which metals are sulfate radicals best for removing and for which metals should alternative treatment methods be used? ​

Taxonomy

• Metals
• Industrial Wastewater Treatment
• Wastewater Treatment
• Inorganic Chemicals
• Sulfates
• Metals

11 Answers

1. I suggest you use hydrogen peroxide or Ozone system to precipitate these ions by oxidation and converting them to hydroxide ions. zinc hydroxide and copper hydroxide are insoluble or negligibly soluble in water. I have no idea for nickel right now.

    

2. I believe Cu, Ni, Zn all form soluble sulfates < ph7. if NH4+ is present; then this will form soluble complexes, Cu(NH3)4 ++ etc., if you add a lot of lime.

   S= should also precipitate them. I believe CuS & NiS are insoluble in acid solutions.

   2 Comments

   1. pH range 5.0-6.5 , and is  better heavy metal recovery. 

   2. this depends on Temperature..??

3. Dear All,

   Dear We are working in the communities living under poverty line. The ground water is too salty to drink with the contamination of arsenic. The TDS ranges between 2000-2500. Could you please the cheap, affordable and sustainable method/product. 

    

   1 Comment

   1. Slow sand and carbon filtration. High TDS may be due to another reasons. Please check the physical quality of water with a analysis. and upload the same or mail  kgrenil@gmail.com

4. you can also try for Nano filtration for metal removal if water parameter meet nano filtration process. removal of metal in nano reject stream & reject stream treat with lime for metal oxide precipitation.

5. I totally agree with the Jar-test before taking your final decision. Vermiculite was proved as a high potencial for adsorption this kind of metals. Please make sure to find a properly way for the final destination of the sludge.

6. You need a very dilute Sulphuric acid , and sodium/ calcium sulphate...Once metal sulphates get formed then, add Lime to do flocculation and filter out precipitated sulphate salts..

7. Lime treatment is undoubtedly the cheapest. It depends on the budget allocated for its massive removal. Is UV advisable in this case...?!

8. For base metals like zinc, nickel, copper, all you need is lime - raise the pH and they all precipitate easily.  The precipitate can be hard to settle/filter, in which case, just search for a technology called HDS (high density sludge); that should be what you need.

9. You can use aluminum sulfate to perform the coagulation of the metals present in the effluent, verifying the best pH in the Jar test. Then an adsorption treatment can be used, always verifying the final destination of the produced effluents, if they are in accordance with the local environmental legislation.

10. If you want to use sulfate ions (not radicals) use the cheapest , probably sodium sulfate. Sulfuric acid would also lower the pH which you might have to adjust. You might do better with lime treatment. Standard coagulation, perhaps enhanced,  might work fine.

    1 Comment

    1. The waste stream is from plating baths containing sequestering agents such as EDTA, pyrophosphate or citric acid. I am forming sulfate radicals with the process I am working with. Something along the lines of hydroxyl radials formed with Fenton's reaction. 

11. None of the above! Sulfate ions will bond best to Calcium, Strontium, Barium, lead, some mercury, If we are dealing with free, not complexed ions, small amounts of sodium sulfide should remove them if the pH is high.. Some sulfonated ion exchange resins will also remove them  or EDTA- but these are expensive. Lignins & humus will also remove most things from water. A lot depends on the final destination of the cleaner water!

    1 Comment

    1. These are plating baths, which contain sequestring agents such as  EDTA, pyrophosphate, or citric and often have 1000mg/l or more of the metals.