Environmental Impacts of Phosphate Rocks on the Water Quality of Rivers

One of the important natural sediment rocks impacting aquatic environment is Phosphate Rocks (PR).

PR comprises from several chemical compositions such as heavy metals. Mining and transportation of

PR nearby or through the rivers may expose them to pollution. Some elements such as salts and heavy

metals may be leached out into the water, when PR is in contact with water due to dipping in water streams,

precipitation events, or changes in water table. In this study via experimental lab work, PR leachability was

investigated when it immersed in Nile River. The research work focused on evaluating the release of some

constituents, including phosphors, cadmium, chromium and lead of PR on the water quality of Nile by using

leaching experiments. In these experiments, the potential impact of changing conditions, such as liquid

to solid ratio (L/S) and phosphate content in PR on long-term leaching of phosphor and heavy metals.

Results revealed that phosphors and lead were released in high concentrations, while cadmium and chromium

leached out in very low concentrations. PR leachate out 32 mg/L of phosphorus into Nile water,

which it is too much more than the allowable values for natural streams, i.e. 0.5 mg/L. Therefore,

if phosphate rocks are submersed intentionally or unintentionally into Nile river water,

this will lead to environmental risks in the area of PR submersion.

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