Testing economical, environmental-friendly alternatives for use of brine water from desalination plants
The decision of the Ministry of health to have only one water system of desalinated water for all domestic uses in the Kibbutzim of the Arava valley, due to health potential hazards, will extend tremendously the brine water quantities resulting from the desalination process. Currently there are two saline, brackish water systems – one, desalinated water for drinking purposes and the other, domestic, gardening and industrial water uses.
This will result with an economical and environmental problem. The brine water should be transported to a location where it will not create a negative impact on the ground water aquifers. This solution is very expensive both in investment and running costs. Currently, brine water is transported to the recycled water centers limiting its use for agriculture.
Southern Arava R&D deals for many years in salinity issues of soil, water and crops. It is proposed to test alternative uses for the brine water by irrigating salt resistant crops and reducing salt quantities by plants biomass that will be taken out of the plots. Since plants evaporate most of their water uptake, the rate of salts contamination of aquifers will dramatically slow down. It is intended to build a model for monitoring and predicting aquifer salt contamination.
Using controlled wetlands as water recycling and purification system is expanding in many countries. The use of water plants that starts a biological process that purifies water extracting heavy metals and decomposes organic matter has been proven worldwide. The use of special water plants, that will absorb salts and later be used for animal feed, is new. Reduction of salinity in the water, to be used for irrigating commercial crops, will be tested in this study.
The main objectives of this project are to study the following:
Salt resistance fodder crops
Some fodder plants are well known for their salt resistance and high biomass production:
Salicornia – A highly resistant plant, originally native from Yotvata salt marsh with seeds that have up to 30% quality edible oil, 31% protein, yielding 34T/Ha of biomass under sea water irrigation.
Sudan grass – Grown in the Arava in the past – when irrigated with saline water of 10 DS/M, yields reach about 20% less than when irrigated with sweet water.
In this research study the following parameters will be tested: Biomass production in brine water irrigation; feed quality parameters.
Industrial lumber production
Both Erected Tamarix and Eucalyptus are trees suitable for industrial use and are highly saline resistant. Both produce high rates of biomass.
It is proposed to test these trees for industrial use such as plywood, furniture and compressed wooden products. Growth rate in the Arava is 3 times faster than that in the coastal planes where the biomass yield is 10 metric ton/yr/1000 m2.