THE IMPACT OF THERMAL DESALINATION TECHNOLOGIES MED WITH TVC AND WITHOUT TVC ON THE LIBYAN COASTLINE.

Seawater desalination has become a rapidly growing industry in Mediterranean countries due to the water scarcity. This activity results in environmental problems chiefly generated by brine discharged into the sea, which alters the physico-chemical parameters of the receiving water and threatens its marine biota. This paper has examined data from the field study survey carried out in Libya to investigate the changes in physico-chemical parameters of the receiving water due to brine emitted from the Zwuarah Desalination Plant. 19 seawater samples near the outfall of ZWDP were collected and analysed. The results of the data collection are characterized by principal-component analysis (PCA) and it is indicated that the pattern is best explained in PC1, PC2, PC3, PC4 and PC5 with 67.6%, 81.4%, 88.2%, 92.4% and 94.9% of the total variance respectively. Wide variations in the physico-chemical parameters of the receiving seawater near the ZWDP outfall have been observed between total hardness, calcium and magnesium hardness, sulfate, potassium, sodium, chloride, phosphate, iron and nitrate ions, sea bed and the sea surface temperature, pH, dissolved oxygen levels and Salinity. These were scattered in ranges (- 500 to + 9,071 mgl -1 ), (- 800 to + 361 mgl -1 ), (+ 5300 to + 1370 mgl -1 ), (- 306 to - 216 mgl -1 ), (+ 37 to + 1,900 mgl -1 ), (- 1,400 to + 1,183 mgl -1 ), (- 408 to - 570 mgl -1 ), (+ 945 to + 6,550 mgl -1 ), (- 1,626 to + 2,625 mgl -1 ), (+ 0.089 mgl -1 ), (+ 0.6966 mgl -1 ), ( + 0.15 mgl -1 ), (+15.4°C to + 3°C), (- 0.14 to + 0.06) (- 4.67 to - 2.1 mgl -1 ) and (+9.2 psu) respectively. The results revealed that physico-chemical parameters at the study site were different in ambient seawater and that indicated there is a threat to the marine ecosystem.