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  for Metal Finishing since 1989
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TRI Reporting of Zinc & zinc compounds

TRI reporting. How Is zinc compounds figured? Are they also manufactured in waste treatment?

David R. Sollenberger
plating shop - Wrightsville, Pennsylvania
2000

Seems like a lot of questions surfacing lately regarding TRI or Form R's. Must be the fact that they were due July 1. Due to the complex nature of some of the regulations I would recommend that anyone with TRI questions contact the EPA hotline, 1-800-424-9346. The private consulting firm that staffs this hotline is very helpful in provide answers. They are also very current. There have been a number of changes in the last couple weeks regarding the nitrate issue which has been discussed to various degrees here. At least in this case EPA has somewhat come around at least regarding the degree that "offenders" will be punished.

Paul Schultz
- Grand Rapids, Michigan USA
2000

The answer to the zinc compound question is yes, one zinc compound can be converted into another in waste water treatment. The EPA's current stance is "count it as a compound" (be sure you count 100% of the mol weight of the compound molecule, and not just the zinc part!).

Now the real question is do you also count the water of hydration for a zinc hydroxide sludge as part of the "compound", personally I think the EPA made a mistake listing ALL zinc compounds, Especially considering that most of us supplement our diets with mineral vitamins that include Zinc, not to mention new cough formulas that tout their zinc content, and zinc that leaches from galvanized pipe into the drinking water ( we actually tested it 10 years ago when our discharge limit was 5% of the incoming water from the city). In other words the incoming zinc in the drinking water was 20 times the discharge limit ( we were using a dilution flow calculation to calculate permit limit at sample point that was diluted with non-process water at the time) .

For now the only safe thing to do is report it, and push the political / lobby buttons to get it changed.

Mike McGinness
- So. Houston, Texas
2000

Since zinc sulphate being used as fungicide agent could zinc sulphate act as antibacterial agent?

Kavitha
- Malaysia
2001

Yes Zinc sulphate can act as an antibacterial agent in high enough concentrations. In low concentrations (under 1 mg/l) it is a necessary micronutrient to bacteria and biological processes.

Mike McGinneess
- Houston, Texas, USA
2002