Desert agriculture has immense potential

AMBITIOUS: PDO weighs solar desalination to treat produced-water for reuse in intensive desert farming

Prospects for the sustainable cultivation of prodigious quantities of agricultural and farm produce in vast greenhouses constructed in the arid desert regions of Oman were showcased at a key conference held in the city last week.

The most promising of these was an ambitious initiative spearheaded by majority state-owned oil and gas producer Petroleum Development Oman (PDO). It envisions the application of solar energy to treat the copious volumes of so-called ‘produced water’ — saline, oil-contaminated and potentially toxic water produced along with hydrocarbons — for reuse in agricultural farming in the oilfield regions of the Sultanate.

Outlining the initiative on behalf of PDO was Basma al Shidhani (pictured), Senior Business Planner, who underlined the immense potential that produced-water holds as a valuable resource once suitably treated through the use of solar energy.

Speaking at the 2nd Middle East Oilfield Produced Water Management (Picture for illustration only) Conference & Exhibition, which was held at the Grand Hyatt Muscat, Basma described ‘produced water’ as a “game-changer” if viewed as a potential resource rather than a waste byproduct of oilfield operations.

PDO currently generates a staggering 900,000 barrels of produced-water daily, a figure projected to rise to 1.2 million barrels per day in 10 years, soaring to 1.7 million barrels per day in 20 years. In the past, these massive volumes of oil-tainted water were disposed of in subsurface aquifers at significant expense to the operator.

Of late, however, PDO has been collaborating with German technology firm Bauer in processing an estimated 115,000 cubic metres per day of produced-water via the use of reed-beds covering an area of 360 hectares in the Nimr desert. The hugely successful initiative, which has garnered PDO and its technology partner a number of awards, is also opening the way for research in biosaline agricultural farming.

The groundbreaking concept outlined by Basma seeks to build on PDO’s successful use of reed-bed technology to generate near-potable water quality for agricultural purposes. The initiative is conceptualised around the application of solar desalination technology to treat around 60,000 cubic metres per day of producedwater after its initial treatment by reed beds at Nimr. This solardesalinated water is then proposed to be reused in the cultivation of “high-value crops” produced in “highintensity agricultural mode” in desert greenhouses, said Basma.

The concept of ‘ desert agricultural technology’, the engineering specialist said, aims to integrate renewable energy resources, fresh water recovered from produced-water, and hydroponics. Solar energy has a critical role to play in delivering a successful project because it not only keeps operational costs at a minimum, but also avoids the large carbon footprint if fossil fuels were to be used, she explained.

In addition to the substantive commercial benefits that will inevitably flow from intensive desert agriculture centring on this concept, there are

several socioeconomic spinoffs as well, according to Basma. While local Omani farmers are expected to get involved in this venture, opportunities for local content utilisation abound as well, she said. Crucially, the suitability of the desert soil for farming will have no bearing on the success of the initiative, as the project is based on hydroponics, she noted.

Nevertheless, she warned of “limitations” that would need to be addressed in order to secure the longterm success of the initiative. One such hurdle concerns the importance of removing heavy metal content from the treated water before it is used in agriculture. Public acceptability of farm produce utilised treated produced-water also needs to be gauged and addressed if the project’s output is to be widely distributed.

“What is now needed is a comprehensive feasibility study to examine the technical, environmental, economic and financial aspects of this concept supported by a pilot plant,” said Basma. “Also necessary is suitable legislation to support those who seek to explore opportunities utilising treated produced-water for re-use in the food chain,” she added.