Palmachim Desalination Facility
The desalination facility in Palmachim is a VIA MARIS project for the supply of 30,000,000 m3 of desalinated water a year to the Israeli government using the BOO (Build Own Operate) method. The contract is for a period of 24 years. The parent companies of this venture are Granite Hacarmel, Tahal, Gaon Agro, Oceana, and Ocif.
GES (formerly Tambour Ecology), a subsidiary of Granite Hacarmel, carried out the process planning for the facility through the company’s Head Process Engineer, Yaacov Mansrof, and Process Engineer Hagit Oron.
The seawater desalination process consists of a series of chemical and physical processes which are designed to absorb sea-water, to prepare it for desalination using membranes in pre-treatment processes, to desalinate the seawater via a reverse osmosis process, and to prepare them for drinking and irrigation water, through complementary treatment processes.
The quality of the water product shall be in accordance with Israeli drinking water standards, plus special requirements made regarding maximum concentrations of Boron, Chloride, hardness and total dissolved salts as specified under Table No. 1.
Parameter Units Maximal Value Minimal Value
TDS mg/lit 300
Chloride mg/lit 80
Boron mg/lit 0.4
Hardness mg/lit as CaCO3 100 75
The main process systems at the facility are (Figure no. 1)
Marine assembly for supplying raw seawater to the desalination facility: The marine assembly includes an intake unit, located at a distance of about 1200 meters off-shore and at a depth of 9 meters below the ocean surface, a marine pipeline and a shore pumping station. The marine assembly integrates processes for separation of solids and disinfection.
The pre-treatment system for treating seawater includes a filtration system and systems for adding chemicals. The filtration systems are based on common coagulation, flocculation, and bi media gravitational filtration technologies which serve the entire facility. The chemical treatment systems are scattered throughout the facility, with each first-pass desalination unit having its own designated filtration systems.
First Pass (Pass 1) – desalination of sea-water treated by the pre-treatment systems, which are desalinated by reverse osmosis process. The process is carried out by using 6 parallel trains in three intermediate stages:
- Increasing feed pressure.
- Separation, by membranes, of sea-water into product and concentrate
- Distribution of the product into front and rear sections.
Return of the concentrate energy by means of Pelton turbines: Distribution of product water into two sections: a front section of good quality water, which is not treated, and a rear section with inferior quality water which undergoes supplementary treatment. This will allow the facility to achieve the goals defined for chloride and Boron levels.
Pre-treatment system for product water from the rear section of the first pass, which includes an ion-exchange conditioning system with a 6-vessels battery and auxiliary regeneration equipment: This system serves to remove hardness from the product water, and to prevent scale from accumulating in the additional reverse osmosis desalination membranes, which are carried out in an alkaline environment.
The second pass has 4 stages which achieves good Boron removal by operating in a high-pH environment with a recovery rate of 98%. The first two stages in this pass are to include brackish-water membranes, and the last two stages are to include seawater membranes.
Hardening the final product water: The mixture obtained from mixing the front section of the first pass product with the second pass product goes through gravitational calcite filters. The dissolving calcite adds hardness to the water, which improves their taste and lowers their corrosiveness.
The facility is planned for optimal operation by maintaining low overall costs when producing average daily quantities. In addition, the facility is expected to have an integral ability to increase the daily output required by the contract, up to the client's maximum absorption ability of 102,000 m3/day. Redundancy in the facility reaches 110% at peak season, and 120% in other seasons.
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