Researchers in West Bengal have come up with what looks from a distance like an intriguing hitech/lotech hybrid tool for purifying water:

The Central Salt and Marine Chemicals Research Institute (CSMCRI), Bhavnagar, Gujarat has developed a desalination unit that is run with the help of a pair of oxen using an indigenously developed reverse osmosis membrane. ... A pair of sturdy oxen is tied to one side of a 4-metre long mechanical link. The other side of the link is coupled to the input shaft of a gearbox. The gearbox is designed to convert animal power in the form of low rpm (rotation per minute) and high torque at the inlet shaft into mechanical power of high rpm and low torque at the output shaft. The output shaft is coupled to the crankshaft of a pressure pump which discharges 20 lit/min feed water with hydraulic pressure, which is sufficient to carry out desalination of brackish water.

Providing enough clean, fresh water for everyone on the planet is one this century's daunting challenges. Is this solution, er, worth its salt? Any engineers out there want to clue the rest of us in?