Detection of Copper in Wastewater

Seth Holm Chem4101 December 2009

HypothesisThere are harmful levels of copper in certain industrial wastewaters. Many expensive filtration devices are available but not widely used. The efficiency and cost effectiveness of peat filters needs to be determined.

Problem

o Wastewater from mines and landfills have harmful levels of copper pollution.

Rainwater carries the pollution into our water supplies.

o Ingesting water with high copper levels can cause health issues ranging anywhere from stomach distress to brain damage.

Overview

The EPA5 limits copper levels in drinking water to 1.3 ppm.

Current methods of filtration are not efficient and have high costs.

Copper is a useful and important raw material.

Ion exchange mechanisms allow for filtration and recycling copper.

Methods of Detection4

Accurate Simple and Fast Reproducible Chelating reagent

required Higher limit of

detection More sample

preparation

Chelating reagent required

pH dependent (because of chelate)

More sample preparation required

Multiple samples simultaneously analyzed

IR Spectroscopy Spectrofluorometry

ICP-AES For Copper Analysis6

Few interferences (Ti, Mo)

Low Limit of Detection

Easy Operation Simple sample

preparation Common

analytical instrument

Perkin-Elmer Optima 5300 DV3,5

Cost $50,000 with auto sampler

LOD 5 ppb LOQ 17 ppb Dynamic range of 4-5

orders of magnitude High resolution Easy to use Simple sample

preparation Computer controlled Multi-element analysis

Experiment1

Preserve >50ml of sample to a pH<2 with nitric acid, dilute to 100ml.

Pump 1L of the remaining sample through an APTsorb (modified peat) filled column. Then preserve sample. o Filter samples through a 0.45μm

screen.o Run each sample in triplicates through the instrument for QC .o Use controls of known copper concentration to calibrate the instrument and data.o Determine initial and final copper concentrations from the obtained data.

APTsorb1

Data Analysis1

To analyze the data obtained a calibration curve would be produced from the controls. The initial and final copper concentrations of the wastewater would then be determined from their ICP-AES data.

Past Experiments A study was conducted in 2009 by American Peat Technologies on

Sudan mine wastewater. They concluded that it would cost approximately $20,000 to treat all of the mines wastewater per year using their APTsorb product.

Copper levels were successfully reduced to below 5 ppb. This is well below the EPA’s safe drinking standards.

This filtration process has significantly lower costs then other comparable filtration methods (ranging from $100,000 to $300,000 per year).

Copper adsorbed onto the APTsorb product can be stripped off using an acid wash and recycled.

Conclusion

ICP-AES is an accurate and precise instrument for the analysis of copper containing solutions.

The APTsorb product produced by American Peat Technology is a cost effective way to treat wastewater.

Installing similar ion-exchange filtration systems at productive copper mines will significantly reduced their water pollution.

By stripping the copper from the APTsorb the copper mines can become more productive as well as more environmentally friendly.

References

1. Paul Eger, The Use of Peat Pellets to Remove Trace metals from Mine Drainage (2009)

2. T.D. Martin, C.A. Brockhoff, J.T. Creed, EPA DETERMINATION OF METALS AND TRACE ELEMENTS IN WATER AND WASTES BY INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROMETRY (1994)

3. http://www.personal.psu.edu/hxg3/MCL/icpaes.htm, accessed 12/1/09

4. Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis, 6th ed.

5. http://www.epa.gov/ogwdw000/lcrmr/index.html, accessed 12/1/09

6. http://www.oil-analysis.org/icp_aes.html, accessed 12/1/09