Stuff of life

Research in Texas and Qatar provides water in desert climates

By: Nathan Ball

Posted: 7/29/08

Texas A&M University researchers are finding new ways to produce fresh, clean water in the middle of a desert. Professors in Qatar and in College Station partnered to develop a method for desalinating undrinkable ground water.

"There are two types of desalination," said civil engineering professor Bill Batchelor. "Desalination to remove salts from seawater, and to remove salt, minerals and metals from inland brackish water."

The project was aimed at developing an inexpensive and environmentally friendly technology for inland desalination of brackish groundwater that produces zero liquid discharge, according to a June report issued by the Qatar Science and Technology Park.

"There is very little rainfall in Qatar," said professor Mahmoud El-Halwagi. "There are only two sources of drinking water in the region: you get water from the sea, or from inland brackish water."

Most of Qatar's drinking water comes from the Persian Gulf. Salt is removed using thermal distillation, Batchelor said, and is very energy-intensive, but this has been the method of choice in a region rich in natural gas reserves and lacking fresh water resources. Aggie researchers are working to build a prototype desalination plant which they believe will save the Qatari people energy and money.

"The problem [with osmosis desalination] is that these metals, as you concentrate waste, they form solids which clog up the membranes. Cleaning these membranes is very expensive. The idea of this project is to remove these waste products that clog up the membrane filters," Batchelor said.

The process uses a progression of stages to remove solids. Adding more lyme and aluminum is the key to removing more of the metals and salts before they clog up the osmosis membranes.

The project lead in Qatar is Professor Ahmed Abdel-Wahab. He received his doctorate at A&M in College Station where he, ironically, studied under Batchelor. Batchelor said he was pleased to be working with his old student again.

"Eighty to 90 percent of the work is being done in Qatar," Batchelor said. "So far, I have been helping to identify sources for pilot plant equipment, providing analysis for precipitants and helping to model and describe them."

This new technology for purifying drinking water, according to El-Halwagi, "is not only important for the state of Qatar, it is also important for [the United States] and this [Texas]. In Texas, if you are going to grow economically, you have to be able to use lower quality sources of water [in the future.]"

The situation is more urgent in the Middle East. A 2005 Qatar Department of Agriculture and Water report indicated that nearly a third of the 1,285 registered farms have been abandoned because fresh groundwater is being depleted. This was why A&M's research could not come at a more opportune time. "They can't wait on this much longer," El-Halwagi said.

"The biggest challenge for the research team right now is the construction of the pilot plant due to the time it takes after you order the equipment until you have them in the lab," said Abdel-Wahab. "The construction of the plant is expected to be complete in about three months from now, then the experiments on the plant will start.

"If successful, we will patent the technology and then try to commercialize it. We will not build additional plants ourselves. We are building this one for the study. If the study is successful, it will be patented and the technology will be commercialized for interested companies to purchase it and build the plants."