**4.1 Soil physical properties**

Textural properties obtained from sieve analysis of the gold mine tailings sediments using classification as prescribed by [25] are presented in **Table 6**. These results reveal that fine sand (0.150–0.075 mm) and clay (0.075–0.053 mm) were the principal fractions of all sediment samples, with an average composition of 66.03% for fine sand, 23.08% clay and 10.89% silt respectively. With the larger portion of the sediments being fine sand, there is a likelihood for nutrients accumulation is high due to the higher surface-to-volume ratios [33].

of sulfuric acid [35]. Nutrient uptake by plants may be inhibited by the level of acidity as most plant nutrients are optimally available to plants within 6.5 to 7.5 pH range which also support plant root growth [36]. The low CEC values which correlates with the high proportion of sand fragment is an indication that the sediments may likely not have reliable soil sorption capacity [37]. LOI of studied soils were in the range of (5.0–5.4%)-dry weight, which could be, attributed to growing plants

*Evaluation of Trace Elemental Levels as Pollution Indicators in an Abandoned Gold Mine Dump…*

The summary of the determined heavy metal concentrations within the sediments of the study area by using ICP-OES are presented in **Table 8**. The concentration of various heavy metal varies from 860.3–862.6 mg/kg for Cr; 324.9–328.4 mg/kg for Al; 200.9–203.4 mg/kg for As; 130.1–136.2 mg/kg for Fe; 121.9–125.8 mg/kg for Pb; 27.3–30.2 mg/kg for Co; 23.8–26.8 mg/kg for Ni;

7.2–9.2 mg/kg for Ti; 7.1–9.2 mg/kg for Cd; 4.0–5.6 mg/kg for Zn and 0.1–0.6 mg/kg for Cu. Chromium (Cr) was identified as the most abundant heavy metal in the sediment samples. Mean concentration of the metals were Cr: 861.5 mg/kg; Al: 326.8 mg/kg; As: 202.2 mg/kg; Fe: 134.3 mg/kg; Pb: 123.7 mg/kg; Co: 28.8 mg/kg; Ni: 25.4 mg/kg; Ti: 8.5 mg/kg; Cd: 8.3 mg/kg; Zn: 4.5 mg/kg and Cu: 0.2 mg/kg dry weights. The average order of metal concentration is Cr > Al > As > Fe > Pb > Co >

**Station no. pH C.E (mS/cm) CEC (meq/100 g) LOI (%)** 3.86 1.30 8.5 5.1 4.34 1.50 8.8 5.4 4.28 1.80 9.0 5.0 4.30 1.90 8.3 5.1 3.92 1.40 9.1 5.3 4.34 1.60 8.8 5.1 3.89 1.40 8.5 5.4 3.87 1.40 9.1 5.1 3.86 1.40 9.0 5.2 4.27 1.80 8.8 5.2 4.28 1.80 9.4 5.4 4.28 1.80 8.5 5.1 3.88 1.40 9.3 5.2 3.86 1.40 8.7 5.2 4.30 1.60 8.3 5.4 3.87 1.40 9.1 5.1 3.86 1.40 9.0 5.1 4.31 1.50 8.5 5.2 4.27 1.90 8.8 5.1 4.28 1.80 9.3 5.2

within the tailing's sediments.

*DOI: http://dx.doi.org/10.5772/intechopen.89582*

**4.2 Metal content**

**Table 7.**

**89**

*Geochemical properties of gold mine tailings sediments.*

Geochemical properties of the sediments such as the pH, EC and carbonate content (see **Table 7**) helps in ascertaining vital information to comprehend the soils potential to withhold heavy metals [34]. The results obtained for the sediment pH measurements, showed that the study area is very strongly acidic ranging from 3.86 to 4.34. The low pH values in the study area were related with heterogeneous deposits of sulfidic residues from the mine surroundings, which resulted in low pH values that is attributed to microbial sulfide oxidation and the resultant formation


#### **Table 6.**

*Sieve analysis of the gold mine tailings sediment samples.*

*Evaluation of Trace Elemental Levels as Pollution Indicators in an Abandoned Gold Mine Dump… DOI: http://dx.doi.org/10.5772/intechopen.89582*

of sulfuric acid [35]. Nutrient uptake by plants may be inhibited by the level of acidity as most plant nutrients are optimally available to plants within 6.5 to 7.5 pH range which also support plant root growth [36]. The low CEC values which correlates with the high proportion of sand fragment is an indication that the sediments may likely not have reliable soil sorption capacity [37]. LOI of studied soils were in the range of (5.0–5.4%)-dry weight, which could be, attributed to growing plants within the tailing's sediments.
