Water shortage and humongous population growth are some of the reasons that many countries are grappling with when it comes to using water as a resource, and the idea of it being a never-ending source is bound to come to an end at some point, and the Sultanate is no different. As the world celebrates Water Day, the Times of Oman had a quick chat with Ayisha Al Hinaai, a research officer from MEDRC Water Research, and asked her to shed some light on this year’s theme, which is wastewater. Al Hinaai explained the benefits and uses of reusing wastewater, among other things.
1. What does wastewater reuse mean in practice?
Wastewater reuse can be defined as the use of recycled water for beneficial purposes. Conventional wastewater treatment consists of a combination of physical, chemical, and biological processes and operations to remove solids, organic matter and, sometimes, nutrients from wastewater. In Oman, we use the treated water for different beneficial purposes, such as agricultural, industrial process, public parks, construction activities, and wetlands, such as the Al Ansab wetland at the Haya Water Company.
2. Is it safe to reuse wastewater?
Recycled water can satisfy most water demands, as long as it is adequately treated to ensure that water quality is appropriate for use. The treatment and uses chart shows types of treatment processes and suggested uses at each level of treatment.
For use, where there is a greater chance of human exposure to the water, more treatment is required. As for any water source that is not properly treated, health problems could arise from drinking or being exposed to recycled water if it contains disease-causing organisms or other contaminants.
I can say that it is safe if we carry out the appropriate treatment (preliminary, primary, secondary, and tertiary and/or advanced wastewater treatment) for the appropriate use.
The use of recycled water for drinking, however, is less common, largely because many people are repelled by the thought of water that’s been in our toilets going to our taps.
But a few countries, such as Singapore, Australia, and Namibia, and states, such as California, Virginia, and New Mexico are already drinking recycled water, demonstrating that purified wastewater can be safe and clean, and help ease water shortages.
The term “toilet to tap,” used to drum up opposition to drinking recycled water, is misleading because recycled water that ends up in drinking water undergoes extensive and thorough purification. In addition, it is usually added to groundwater or surface water for further cleansing before being sent to a drinking water supply where it is again treated. In fact, it has been shown to have fewer contaminants than existing treated water supplies.
3. What are the main uses of purified wastewater?
Purified wastewater in Oman is mainly used for agricultural, industrial processes (e.g. as cooling water), public parks (gardens and green spaces), and for construction activities.
4. Can you reuse wastewater in industrial production?
Reusing water in industry has the potential to reduce the costs of water supply and wastewater treatment by industries and reduces pressure on water resources. A business can directly reuse wastewater that is clean enough for the purpose for which it is being reused. Processed water is produced by industrial processes, such as cooling and heating, and often contains few contaminants after use.
5. What are the benefits of wastewater reuse?
It reduces pressure on potable sources of freshwater; nutrient-rich wastewaters can increase agricultural production in water-poor areas, use of wastewater effluent for irrigation will eliminate the need for nutrient removal at the treatment plant, and the quality of wastewater as an irrigation water supply source is usually superior to that of well water. Pollution of rivers may be reduced as less wastewater is discharged to the waterways, and provides better quality water for industrial users.