Anions in wastewaters - Determination of Anions in Natural and Treated Waters - page 564

Fig. 8.5 Titration curve of 20ml, 10 −3 M SO 4 3− ions with 5×10 −3 M BaCl 2

Source: Reproduced with permission from Elsevier Science [99]

gravimetry in the presence of high concentrations of aluminium(III) and iron(III).

8.20.4 Ion chromatography
Cao and Luo [101] reported a relative standard deviation of <3% and a detection limit ≥
40µg L −1 for the determination of sulphate in wastewater by ion chromatography. They
also determined fluoride, chloride, bromide, nitrite and phosphate by this method.
The application of this technique is discussed under multianion analysis in sections
8.26.2, 12.7.1 and 12.7.2.

8.20.5 Column chromatography
This technique has been used [102] to determine sulphate in waste water. A post-column
solid phase reaction detector was employed in conjunction with an anion exchange
separation column to determine 5 to 40mg L −1 sulphate.

8.21 Sulphide

8.21.1 Spectrophotometric method
Kuban et al. [103] used nitroprusside and methylene blue spectrophotometric methods for
a silicone membrane differential flow injection determination of sulphide in waste waters.
In this method the hydrogen sulphide evolved from an acidified sample was collected in
alkali prior to spectrophotometric evaluation. A detection limit of 2µg L −1 was achieved

by the nitroprusside procedure.
Reaction with p-amino dimethylaniline to form a complex with an absorption
maximum at 660nm is the basis of a further spectrophotometric procedure capable of
determining down to 0.1 mg L −1 sulphide in wastewaters [104,105]. Broderius and Smith
[106] have developed a procedure for the determination of traces of hydrogen sulphide in