Table 3 Site energy distribution parameters of Pb2+ adsorption onto PSMPs at pH 6.0.

From: Effects of humic acid on Pb2+ adsorption onto polystyrene microplastics from spectroscopic analysis and site energy distribution analysis

CHA

(mg·C/L)

Ionic strength

(mmol/L)

Em*

(KJ/mol)

F(Em*)

(mg·mol/(g·KJ))

μ(E*)

(KJ/mol)

σe*(KJ/mol)

0.00

0.100a

30.7

0.0444

30.7

4.193

1.00a

30.3

0.0420

30.3

4.188

10.0a

29.9

0.0382

29.9

4.183

0.0300b

30.2

0.0407

30.2

4.189

0.330b

29.8

0.0365

29.8

4.186

3.33b

29.2

0.0361

29.2

4.184

1.00

0.100a

32.2

0.123

32.2

4.300

1.00a

32.1

0.106

32.1

4.292

10.0a

31.1

0.0967

31.1

4.271

0.0300b

32.1

0.113

32.1

4.293

0.330b

31.7

0.0999

31.7

4.279

3.33b

31.1

0.0897

31.1

4.257

2.50

0.100a

32.5

0.185

32.5

4.457

1.00a

32.2

0.163

32.2

4.403

10.0a

31.2

0.148

31.2

4.386

0.0300b

32.2

0.175

32.2

4.422

0.330b

32.1

0.151

32.1

4.401

3.33b

31.2

0.135

31.2

3.386

5.00

0.100a

33.1

0.213

33.1

4.662

1.00a

33.0

0.182

33.0

4.631

10.0a

32.9

0.157

32.9

4.596

0.0300b

33.0

0.197

33.0

4.654

0.330b

33.0

0.166

33.0

4.622

3.33b

32.8

0.142

32.8

4.589

  1. aNaNO3.
  2. bCa(NO3)2.