Intel/TRIF Electrocoagualtion Project

Space Grant Mentor: Profs. James C. Baygents & James Farrell

Research Intern & Presenter: Jake Davis

Project Purpose & Motivation

Purpose: Assess electrocoagulation (EC) as a technology for municipal and industrial water purification.—measure removal of: As, Si, Ca, Mg & dissolved organics

Motivation• EC can be used to remove a broad spectrum of contaminants

and reduce TSS• EC can be inexpensive and straightforward to implement • Anions associated with chemical coagulants (e.g. Cl and SO4

2) are avoided with EC—so, EC is salt-free and pH neutral

EC Flow Through Cell

Water In

Water Out

EC Flow Through Cell

Reaching Steady State: Al electrode

0 5 10 15 20 25 30 350

1

2

3

4

5

6Al Dose (mM) Vs Time (min)

Time (min after start)

Dose

Al (

mM

)

Faraday’s law

Reaching Steady State: Fe electrode

0 5 10 15 20 25 30 350

0.5

1

1.5

2

Dose Fe (mM) vs. Time (min)

Time (min after start)

Dose

Fe

(mM

)

Faraday’s Law

Contaminant removal: Fe electrode

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.500.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

% Species Removed vs. Dose Fe (mM) at pH 7

% Si removed % Ca removed % Mg removed

Fe Dose (mM)

% S

peci

es re

mov

ed

Feed Water: silica (50 ppm), calcium (45 ppm), and magnesium (12 ppm)

Contaminant removal: Fe electrode

Water Composition: arsenic (135 ppm), calcium (45 ppm), and magnesium (12 ppm)

Contaminant Removal: Fe electrode

0 0.5 1 1.5 2 2.50.00

10.0020.0030.0040.0050.0060.0070.0080.0090.00

100.00

% Species Removed vs. Dose Fe (mM) at pH 7

As Si Ca Mg

Fe Dose [mM]

% re

mov

ed

Feed Water: arsenic (135 ppm), silica (50 ppm), calcium (45 ppm), and magnesium (12 ppm)

Summary• The time required for an EC unit to reach steady state

is significant

• Fe dissolution is approximated by Faraday’s law

• Al dissolution is greater than Faraday’s law predicts

• EC simply and effectively reduces the arsenic and silica content of municipal and industrial water

• The removal of calcium and magnesium from water via EC is positively affected by the presence of arsenic