Pollution Assessment and Mining at Jazan Coastline, Saudi Arabia

The present work aims to evaluate and document the heavy metal distribution along Jazan coastline, southwest Saudi Arabia. Moreover, a trial for mining minerals from seawater has been performed where solvent extraction of a spike solution containing copper, cobalt and nickel has been investigated to attain the optimal extraction conditions. The optimum conditions are found to be 7 M hydrochloric acid concentration, 5 M [H + ] for 3 min shaking time with Cyanex 923 solvent conc. of 0.1 M (1:1 aqueous/organic phase ratio) at temp. 25˚C. These conditions realized 92.5% copper extraction as well as 95.6% and 96.2% for cobalt and nickel extraction respectively.

El Sorogy et al. [8] studied the distribution of heavy metals along Dammam coastal area, Saudi Arabian Gulf to evaluate the human activities and compare the rate of pollution in Dammam coastline with other neighboring worldwide coasts. The most recorded pollutants were sewage effluents, landfilling due to coastal infrastructural development, oil spills, petrochemical industries and desalination plants.
On the other hand, population and industry rapid growth have increased the demand for clean water, which necessitates the presence of many seawater desalination plants. The desalination cost will fall if additional income generated from seawater mining (recovery of valuable minerals). As well as the developing countries can afford fertilizers containing plant nutrients (Mg-K-Ca-S) through seawater mining. Moreover, seawater mining is advantageous as high grade minerals on land mining are depleting leaving low grade minerals, so increase the cost. Also, land mining results in environmental problems and hazards to miners Paripurnanda et al. [9], however, the advantage of seawater mining is that seawater is homogenous and there is no mineral grades difference as on land mining. There is a great demand for using these minerals in industry, agriculture, environmental remediation and medicine (Table 1).
Generally, there are four methods often used for mining from seawater; solar evaporation, electro-dialysis ED,u membrane distillation/crystallization MD/MDC and adsorption/desorption/crystallization. The latter technique will be applied in this paper where solvent is applied to recover copper, cobalt and nickel. Shinde and Dhadke [10], studied the solvent extraction separation of copper and nickel  [12], studied the Separation of Cu from dilute Cu-Ni-Co bearing bioleach solutions using solvent extraction with Chemorex CP-150.
The present work aims to determine the heavy metals distribution along Jazan coastline, southwest Saudi Arabia. Moreover, a trial for mining minerals from seawater, solvent extraction of a spike solution containing copper, cobalt and nickel has been investigated to attain the optimum extraction conditions.

Samples
The study area, Jazan, is located along the red sea coast at southwest of Saudi

Heavy Metals Assessment at Jazan Coastline
Physical properties of seawater and sediments samples of Jazan coastline as well as heavy metal concentration of all samples are shown in Table 2.
From the resulted data, it is clear that pH ranges from 7.40 (sample no. 14) to The data summarized in Table 3, Table 4 and Figure 1, Figure      In the meantime, the average values of all heavy metals in seaweeds samples are recorded in Table 5 and Figure 3. Comparison of average values of Jazan sediments with other coasts worldwide is shown in Table 6, where the high As, Pb and Cd values may be attributed to industrial city of Jazan, desalination plants as well as fishing boats.

Solvent Extraction of Spike Seawater Solution
The extraction of copper, cobalt and nickel from spike 1 M chloride solution using Cyanex 923 as extractant diluted with kerosene was investigated. The effect of shaking time, acid concentration, extractant concentration, H + ion concentration and temperature on the extraction was studied.

Effect of Solvent Concentration
The extraction of Cu, Co and Ni from 5 M HCl solution with 0.1 M to 1 M Cyanex 923 in kerosene was investigated. The extraction increased with increasing the solvent concentration as shown in Table 9, Figure 6.

Effect of Hydrogen Ion Concentration
The

Conclusions
From the overgoing study of the heavy elements distribution along Jazan coastline, it is showed that no contamination except for arsenic, cadmium and lead that may be attributed to Jazan new industrial city, desalination plants, sewage effluent and fishing boats.