Determination of trace metals by voltamperometry in zebra mussel (Dreissena polymorpha) employed as environmental bio-indicator

Figures & data

Figure 1.  Metals in zebra mussels (Dreissena polymorpha) by voltamperometry technique in Ebro River in different times of year. 1=zinc (mg/kg), 2=cadmium (mg/kg), 3=lead (mg/kg), 4=copper (mg/kg), 5=nickel (mg/kg), 6=iron (g/kg), 7=aluminum (g/kg), 8=tin (mg/kg), 9=selenium (mg/kg), 10=mercury (mg/kg), 11=chromium (mg/kg).

Figure 2a.  Concentrations of metals in flesh samples of zebra mussels (Dreissena polymorpha) by voltamperometry technique taken from entry point of dam at Ebro River in different times of year; units=mg/kg, 1=cadmium, 2=lead, 3=copper, 4=nickel, 5=tin, 6=selenium, 7=mercury, 8=chromium.

Figure 2b.  Concentrations of metals in flesh samples of zebra mussels (Dreissena polymorpha) by voltamperometry technique taken from exit point of dam at Ebro River in different times of year; units=mg/kg, 1=cadmium, 2=lead, 3=copper, 4=nickel, 5=tin, 6=selenium, 7=mercury, 8=chromium.

Figure 3a.  Concentrations of metals in sludge samples taken from entry point of dam at Ebro River collected along zebra mussel colonies in different times of year; units=mg/kg, 1=cadmium, 2=lead, 3=copper, 4=nickel, 5=tin, 6=selenium, 7=mercury, 8=chromium.

Figure 3b.  Concentrations of metals in sludge samples taken from exit point of dam at Ebro River collected along zebra mussel colonies in different times of year; units=mg/kg, 1=cadmium, 2=lead, 3=copper, 4=nickel, 5=tin, 6=selenium, 7=mercury, 8=chromium.

Figure 4a.  Concentrations of metals in water samples taken from entry point of dam at Ebro River collected along zebra mussel colonies in different times of year; units=mg/kg, 1=cadmium, 2=lead, 3=copper, 4=nickel, 5=tin, 6=selenium, 7=mercury, 8=chromium.

Figure 4b.  Concentrations of metals in water samples taken from exit point of dam at Ebro River collected along zebra mussel colonies in different times of year; units=mg/kg, 1=cadmium, 2=lead, 3=copper, 4=nickel, 5=tin, 6=selenium, 7=mercury, 8=chromium.

Table 1. Annual range of different water parameters collected by various depth levels.

Depth (m)	T^°C	SAT% O2	CE1	pH	Chlorophyll (mg/L)
0.1	6.3–24.9	84.0–155.1	713.0–1645.0	6.4–7.5	3.6–19.5
2	6.2–24.6	70.8–152.5	708.0–1645.0	6.4–9.5	3.4–24.5
5	6.1–24.6	67.7–152.5	708.0–1640.0	6.3–7.5	3.3–20.5
10	6.2–22.2	68.4–111.1	804.0–1639.0	6.3–7.5	3.8–13.9
20	6.2–18.8	42.3–110.9	874.0–1639.0	6.3–7.5	2.7–10.9
Note: d=(S–1)/ln N (Margalef's diversity index), where S is the number of species and N is the number of individuals.

Table 2. Analytical parameters (detection limits, linear range, and percentage recovery) of voltamperometry.

Element	LODx10^−6 (mg/Kg)	Linear range (µg/Kg)	Recovery (%)
Zn	50	0.5–10.0	99.72
Cd	25	0.2–5.0	99.54
Pb	50	0.5–10.0	99.63
Cu	2500	250.0–5000.0	99.45
Ni	50	0.5–10.0	99.87
Fe	100	1.0–20.0	99.78
Al	2500	250.0–5000.0	99.62
Se	2500	250.0–5000.0	99.57
Cr	2500	250.0–5000.0	99.63
Sn	500	5.0–100.0	99.71
Hg	1000	10.0–200.0	99.87