One river, two streams: chemical and chromium isotopic features of the Neglinka River (Karelia, northwest Russia)

Figures & data

Figure 1. Schematic location map of the sampling sites: 1 is the upstream (university) site, and 2 is the downstream (city) site. Inset: Location of the sampling area (star) in the border area between Russia and Finland.

Table 1. Characteristics of run-off water samples from the Neglinka catchment. Sample locations, US: upstream; DS: downstream. B: Bezymjanny. EC: electrical conductivity; Hard.: hardness; Turb.: turbidity; SD: standard deviation.

Sampling	Sample	pH	EC	Hard.	Na	K	Mg	Ca	Cl	SO4	N-NH4	Turb.	Pmin	Ptot	Mn	Fedis	Fetot	Cu	Cr	δ^53Cr	SD (2σ)
date	location		(μS cm^−1)	(mmol L^−1)	(mg L^−1-)	(mg L^−1)	(mg L^−1)	(mg L^−1)	(mg L^−1)	(mg L^−1)	(mg L^−1)	(mg L^−1)	(μg L^−1)	(μg L^−1)	(μg L^−1)	(μg L^−1)	(μg L^−1)	(μg L^−1)	(μg L^−1)	(‰)	(‰)
06.09.2017	US	4.30	35.4	n.d.	n.d.	n.d.	n.d.	n.d.
06.09.2017	DS	7.30	296	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	1.0	1.1	0.420	0.031
04.10.2017	US	4.60	30.8	0.15	1.46	0.32	0.79	1.69	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	3.0	1.0	1.596	0.058
04.10.2017	DS	6.79	206	1.50	12.4	2.37	6.85	18.8	1.27	1.03	0.04	0.58	15	38	49	980	980	0.9	1.2	n.d.
07.11.2017	US	5.41	30.5	0.22	2.04	0.60	1.12	2.47	13.3	13.7	1.0	1.74	187	251	138	1050	1240	2.2	0.9	n.d.
07.11.2017	DS	7.36	216	1.49	13.6	2.53	7.00	18.4	1.70	0.90	0,03	2.90	19	44	45	790	1010	2.9	1.5	0.402	0.038
05.12.2017	US	5.32	28.5	0.19	1.84	0.42	1.03	2.18	14.0	12.0	1.9	21.5	56	82	113	790	1830	3.6	1.0	1.730	0.065
05.12.2017	DS	7.62	244	1.50	14.0	2.23	7.20	18.0	1.50	1.50	0.06	0.58	21	38	27	849	891	0.9	1.0	n.d.
10.01.2018	US	5.23	32.5	0.21	1.67	0.48	1.11	2.45	15.8	15.0	0.37	2.90	87	119	156	1038	1350	2.3	0.7	n.d.
10.01.2018	DS	7.26	220	1.26	12.9	2.10	6.10	15.2	1.38	1.79	0.06	0.58	14	35	47	860	880	1.5	1.0	n.d.
06.02.2018	US	5.76	30.1	0.22	1.87	0.49	1.28	2.36	15.7	11.9	0.26	1.16	52	90	125	900	1060	2.1	0.7	n.d.
06.02.2018	DS	7.62	329	2.36	15.9	2.75	12.1	27.5	1.70	1.14	0.11	0.58	28	49	44	1040	1040	1.0	1,1	n.d.
01.03.2018	US	6.31	41.7	0.30	2.57	0.59	1.77	3.06	25.0	19.0	0.33	<0.58	74	98	167	810	980	1.8	0,5	n.d.
01.03.2018	DS	7.62	380	2.82	20.0	3.60	14.7	32.2	1.84	1.16	0.17	1.74	39	62	66	1280	1340	0.6	1,0	0.295	0.033
09.04.2018	US	6.02	41.7	0.27	2.97	0.97	1.53	2.78	29.5	22.5	0.34	0.58	69	92	184	740	900	1.7	0,5	0.922	0.051
09.04.2018	DS	7.49	244	1.16	19.0	3.13	4.83	15.1	2.98	3.08	0.08	<0.58	24	64	52	890	1180	1.0	0,7	n.d.
07.05.2018	US	4.59	24.8	0.08	1.01	0.37	0.41	0.87	27.5	12.6	0.86	74.0	316	544	180	720	11600	10	0,8	n.d.
07.05.2018	DS	6.83	53,4	0.37	3.20	0.75	1.75	4.50	0.62	1.81	0.01	0.58	5	26	22	390	390	0.9	0,7	n.d.
05.06.2018	US	6.44	31.3	0.23	2.80	0.49	1.32	2.38	4.86	6.05	0.05	10.4	24	76	52	420	950	2.3	0,7	n.d.
05.06.2018	DS	7.91	402	2.84	21.0	3.78	14.1	33.7	1.39	1.55	0.03	<0.58	28	61	40	680	910	1.4	1,4	n.d.
05.06.2018	B	7.52	405	3.18	16.9	3.34	15.4	38.4	29.8	23.8	0.02	11.0	34	109	85	335	1260	3.3	1,6	n.d.
04.07.2018	US	6.87	54.4	0.43	3.51	0.84	2.58	4.30	22.9	21.1	0.04	5.20	21	61	346	605	1280	1.4	0,9	n.d.
04.07.2018	DS	7.88	583	3.46	47.0	4.82	16.9	41.4	1.78	0.95	0.12	<0.58	54	107	18

Note: The AA-6800 has a minimum detection limit of 0.10 mg/L for Cr, 0.03 mg/L for Cu, 0.02 mg/L for Mn and 0.1 mg/L for Fe in the flame method, and 0.5 µg/L for Cr and 0.5 µg/L for Cu in the electro-thermal atomization method. Chromium (wavelength 357.9 nm), Cu (324.8 nm), Mn (279.5 nm) and Fe (248.3 nm) specific hollow cathode lamps were used for analyses.

The AA-6200 has a minimum detection limit of 0.1 mg/L for Na and 0.1 mg/L for K in airacetylene flame, and 1.0 mg/L for Na and 0.5 mg/L for K in airpropane flame. A minimum detection limit is 0.2 mg/L for Ca and 0.04 mg/L for Mg in airacetylene flame. Sodium (589 nm) and K (766.5 nm) were measured in the atomic emission régime, while Ca (422.7 nm) and Mg (285.2 nm) were measured in atomic adsorption mode with the use of specific hollow cathode lamps.

n.d.: no data available.

Figure 3. Variation in (a) pH, (b) electrical conductivity, and (c) water hardness values over the period of observation. For the conductivity and water hardness, values for the city samples are divided into 10 for the sake of better presentation.

Figure 2. Variation in (a) Fe, (b) Mn, (c) Cr and (d) Cu concentrations in the Neglinka River over the period of observation.