Arsenic Transfer from As-Rich Sediments to River Water in the Presence of Biofilms

Table 4

Speciation of As mobilized by the different extractants in samples C and B.

Extractant	Sample	As	As	MMA	DMA	AsB	As sp.	% recovery
As-WS (µg kg^−1)	C	36.8	n.d.	n.d.	2.4	1.1	40.3	80
	B	35.1	1.9	n.d.	2.0	0.2	39.2	87
As-Ex (µg kg^−1)	C	193.4	4.9	n.d.	4.7	n.d.	203.0	104
	B	121.6	n.d.	n.d.	12.4	n.d.	134.0	89
As-SS (µg kg^−1)	C	1400.9	20.7	5.5	8.9	3.4	1439.4	104
	B	2163.1	20.0	8.4	1.9	n.d.	2193.4	86
As-TCLP (µg kg^−1)	C	276.1	50.5	15.3	4.4	n.d.	346.3	118
	B	125.9	4.6	n.d.	3.4	0.9	134.8	109

n.d.: not detectable. Detection limits: 4.1, 2.9, 4.6, and 2.5 ng L⁻¹ for As, MMA, DMA, and AsB, respectively.