Optimal Management of Brine from Seawater Desalination Plants in Gaza Strip: Deir AL Balah STLV Plant as Case Study

Abstract

Brine salty water that is produced from Reverse Osmosis desalination plants usually has very large quantity and contains much higher salts ratio than that found in the sea. The disposal of such brine water has risks on environment. The objective of the research is to investigate the best brine disposal option in Gaza Strip. Five options for the disposal of brine were studied: 1) disposal of brine to the sea; 2) discharge of brine to wastewater plant; 3) deep well injection; 4) evaporation pond and 5) land irrigation. The new desalination plant Short-Term Low Volume (STLV) of a capacity of 6000 m3/d was used as a case study. Initially, the cost for each option was calculated separately, where it was found that the least cost is to pump the brine to the sea without affecting the seawater and marine life. To support this decision, two methods were used to reach the optimal option for the disposal of brine: Multi-Criteria Analysis (MCA) and Analytic Hierarchy Process (AHP). In MCA the measurement includes: economic, environmental, technical, political and social aspects, depending on a group of academics and experts in that field to fill in the questionnaire, which is a part of the analysis. As a result of that, the highest percentage among other options goes to pump the brine directly to the sea. On the other hand, the second method, which is Analytic Hierarchy Process (AHP), used the method of matrices among the different options and linked it with the standards that have been selected in the first method (MCDA). AHP method indicated also the best disposal of brine by pumping the brine to the sea.