Chromium 6 Removal?
Regarding the weak-base anion exchange for Chromium VI removal, I found a guide that you may find interesting from the City of Glendale, CA here:
The link above covers Glendale's operations and maintenance, so that you may get an idea of what they do specifically.
Attached is a link to an environmentally friendly option that uses a self-contained skid unit to process hexavalent chromium. It basically involves 3 phases:
- Regulation of pH levels
- Reduction of chromium VI to chromium III via an ascorbic-acid solution.
- Filtration/adsorption of chromium III
The tried-and-true method for chromium-6 removal is still the following:
Reduction of chromium 6 to 3 using sodium bisulfite in acid conditions (pH < 2.5) with ORP monitoring. Contact time: 15 to 30 min.
Then standard coagulation / flocculation
I would be surprised if anion exchange resin were to work unless you’re talking about chromate (CrO4-2) and not Chromium (Cr 6+ or Cr 3+)
The whole principle of the anion exchange resin is that it is positively charged to capture anions...
There's two basic answers here:
1) activated carbon or
2) the environ-clean process from Lewis Environmental Services... which uses activated carbon. The difference is that when you use LES treatments, you're getting rid of several other heavy metals without the slugs that can pass through your system when you just use the carbon by itself.
Chromium 6 has been discussed heavily in California, where they are working very hard to get the Chromium 6 removed from the water systems not because the quality of water has declined, but California state standards have become much more stringent.
It is interesting to note that Chromium 6 has only been proven to cause cancer when inhaled, studies have not yet confirmed that orally injesting it can cause cancer as well.
Here is an informative article from The Californian about the topic:
for chromium 6 wastewater, there are several kinds of methods, such as Flocculation,electrolysis, ion exchange and so on, but only ion exchange could realize the resource recovery.
Generally, weak base anion exchange resin could be used to treatment chromium 6, firstly the solution including chromium 6 could be adjusted into pH about 5, then through the ion exchange column, after saturated by chromium 6, the resin will be arranged to regeneration for reuse. it is an effective method to resource chromium 6.
you can ask Sunresin for your solution.
shirley, xrui@sunresin .com