Table 1.

Geochemical parameters of groundwater samples collected from the study site in Kanpur, India.

Parameter	Units	As-polluted groundwater	As-unpolluted groundwater
(i) General water quality parameters
pH	—	7.11	7.32
Measured redox potential (EHm)	mV	248	269
Calculated redox potential (EHc)	mV	112	n.a.
Temperature	°C	25.9	28.2
Conductivity	μS cm−1	4021	1023
Alkalinity	mg L−1 as CaCO3	600	550
Estimated depth of the aquifer	m	12.2	30
Total organic carbon	mg L−1 as C	40	11
Dissolved inorganic carbon	mg L−1 as C	1296	186
(ii) Elemental concentrations
Total arsenic (AsT)	μg L−1	70	2
As(V)		43	bdl
As(III)		22	bdl
Mn		1671	16
U		27	22
Al		2	bdl
Cr		6	bdl
Fe		106	838
Ni		3	10
Cu		9	2
Zn		23	259
Ba		569	83
V		bdl	bdl
Co		1	bdl
Se		10	bdl
Mo		92	bdl
Ca	mg L−1	101.5	69
Na		638.2	206
Mg		88.9	48
K		604.7	16
P		4.7	bdl

bdl: below detection limit. n.a.: not applicable.