Salt Water Into Fresh

One question buzzed insistently through the mind of the young Jewish chemist as he hung on the adventures of Russian Explorer Ivan Papanin: Where did he find drinking water in the arctic? After the lecture, Alexander Zarchin shouldered his way to the front of the classroom at the Leningrad Technical Institute and got a deceptively simple answer. "We melted icebergs," explained Papanin.

Ever since, Zarchin has been fascinated by the idea of getting drinking water from the frozen sea. The Bolshevik Revolution was raging when he heard the lecture, and Zarchin soon got institute support for his experiments to help the Red army. His apparatus, used in the salt marshes of Tashkent, was too expensive, but Zarchin remained certain that the project was practical. He kept it in mind when he was sentenced to five years in the Urals for slyly registering a magnesium-extracting process under the letters "LZLE" first letters of the Hebrew Phrase meaning, "For Zions sake I will not keep silent" (Isaiah 62:1).

A Great Chance. Last week, still believing in his plan and still unable to keep silent Zarchin, 59, citizen of Israel, happily checked the calculations of another test project that may prove his point. The Israeli government had given him $270,000 to build a pilot plant in the Negev the vast, parched area in southern Israel. The plant will use water pumped from the Mediterranean Sea. "We are too poor a country to reject dreams," said one official. Only men who do nothing are always right.

Even in a country that is forced to dream Zarchin had trouble peddling his plan. After arriving in Palestine in 1947, the pale little man patiently trotted from ministry to ministry, haunting anterooms and grabbing coat sleeves. Desperately he fired off letters to Premier Ben-Gurion that were answered by an evasive secretary. "No one knew me," recalls Zarchin He was referred to as a "nudnik" (pedantic fusspot). "There were lots of cranks in Israel, and everyone thought I was one too."

When Zarchin finally got through to Ben-Gurion, he found an eager supporter. After Israeli engineers had sniffed at his scheme, Zarchin herded them to a nearby ice factory, froze and melted some sea water, and passed it around. The engineers took one sip, then let loose a delighted whoop.

Chemistry Lesson. A major drawback in the past to demineralizing water by freezing has been the cost. Zarchin's apparatus tries to beat this drawback by supplementing freezing with distillation by vapor compression. Sea water is pumped into a low-pressure chamber where a part of it is turned into vapor; part is frozen; the remainder passes off as a concentrated brine. The vapor is then slightly compressed. This process turns the vapor into pure water and also generates enough heat to melt the pure ice crystals.

Zarchin estimates that he could purify up to 80% of the sea water that enters his apparatus, claims a $10 million plant could turn out 1,000 gals, of fresh water per hour for 2-c- a cubic meter, less than half the present cost of water in the Negev. Zarchin's lesson may be a major political development in the thirsty Middle East. Huddled over his books last week in a stuffy Tel Aviv hotel room, Zarchin had no doubt of the outcome. "You'll see," he said quietly. "I'm no nudnik."

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