A Comparative Performance Evaluation of Some Novel “Green” and Traditional Antiscalants in Calcium Sulfate Scaling

Table 4

DLS calcium sulfate particles characterization in an aqueous phase at 25°C directly after cooling of a supersaturated gypsum solution.

Scale inhibitor	Blank	PBTC	MA-AA	PASP	ATMP	HEDP
Inhibitor dosage, mg·dm^−3	0	0.5	0.5	0.5	0.5	0.5
pH	6.20	6.02	6.39	6.30	5.95	5.88
Ionic strength, mol·dm^−3	0.2	0.2	0.2	0.2	0.2	0.2
Scale inhibition, %	0	41	100	81	100	40
Number of fractions (by volume)	1	2	1	1	2	3
Mean hydrodynamic diameter (by volume), nm	150 (50)	50 (20); 400 (100)	500 (90)	330 (70)	60 (20); 300 (80)	50 (20); 730 (100); 5000 (1000)
ζ-Potential, mV	−2.4 (0.1)	−3.9 (0.1)	−1.5 (0.1)	−7.0 (0.8)	−0.6 (0.1)	−1.0 (0.2)

Data in parentheses represent standard deviation for three replicate runs.
Monotonous colloidal particles growth takes place.