International Water & Irrigation

15 treatment facilities to treatment at a tertiary level, which includes removal of nitrogen, may bring forth improvement in this aspect too. synopses of studies presented at the water conference in Tel Hai College an embedded sensor to measure the water potential in tree trunks This study, presented by Dr. Moshe Miron form UGKC (Upper Galilee knowledge Center), the Saturas Company, Anat Halgua - Solomon and Avishai Avni from the Saturas Company. The objective was to improve the ability to assess the water potential in the tree trunk, which is considered to be a reliable indicative measurement of the water status in trees and grape vines. Until the present this measurement was taken using a manual pressure gauge which requires much work, and it is of too low a capacity for widespread use in commercial agriculture irrigation. The ideas for an embedded electronic sensor were examined already in the eighties of the previous century. This sensor is based on a membranal osmometer principle developed by the Saturas Company, in collaboration with UGKC and the Trendlines Company. It is composed of a closed chamber containing a low osmotic potential solution and a pressure gauge. With a selective membrane facing the tree tissue side. the sensor is inserted into the lignin of the tree and the potential differences between the tree tissue and the solution in the sensor causes water to pass to and from the sensor chamber, according to the daily changes in the water potential in the tree. The water entry causes an increase in the sensor pressure and water exit causes a decrease in the sensor pressure. These changes are measured by the pressure gauge, and translated to be read as the water potential of the trunk. In trials done in Israel (at Lavie and at Ramat Magshimim) and in Spain it was found that there is a 85% correlation between the sensor data and the readings from the hand held pressure gauge. To date, testing was performed for suitability of the sensor for various crops, including almond, citrus and apple trees. A new process to remove nitrates from water This study was presented by Hovav Gilan from the Weltodo Company which develops technologies to remove pollutants from water. The study was focused on developing a process to remove nitrate, a very common pollutant. This pollutant places a risk of the public’s health, but also causes the rejection of drinking water drills in agricultural areas. At the present there are various processes used for the removal of this pollutant based on ion exchange, reverse osmosis and bio treatment. For the most part, these treatment work through concentrating the nitrate into a concentrate, but then there is a need for a second treatment for this concentrate to undergo. This is a bio treatment based on bacteria converting the nitrate into a nitrogen gas. The drawback of this treatment is the direct contact between the bacteria and the water. The technology presented by the Company was of catalytic reduction The study was focused on developing a process to remove nitrate, a very common pollutant. This pollutant places a risk of the public’s health, but also causes the rejection of drinking water drills in agricultural areas Small scale prototype of the system to be placed in wastewater treatment plants Photography: Noam Yogev