Why waste wastewater?
It’s a familiar scene on board any airline. The smile on the steward’s face while serving appetising food on aluminium trays recedes while collecting the refuse. On ground, in a restaurant or hotel, the daily challenge is clearance of food waste, used PET water bottles, soft drink cans and juice cartons.
In a household, disposal of cling wrap, biscuit packets and frozen food bags is a task not as pleasant as the purchase experience in a supermarket.
In manufacturing industries, the waste pickup truck is best seen after work hours or routed through the back entrance.
There’s a reason for according second-grade status and treatment for something we have been a cause for. Like something the cat dragged in, waste has always been considered a liability.
To understand how we can turn waste into wealth, let’s take a resource that’s part of our everyday lives – water, wastewater to be precise. Since home is where the heart is, we will review a use case of waste water treatment, right here in the UAE, with a global overview as preamble.
Worldwide, about 359 billion cubic metres of wastewater is produced each year, and about 48 percent of that water is currently released untreated, according to a study published by Ultrecht University and United Nations University. The good news is, the figure is higher than the frequently cited figure of 80 percent for untreated water.
In 2018 the World Bank launched the “Wastewater: From Waste to Resource” initiative in the Latin America and Caribbean region, to address the wastewater challenge and raise awareness among decision makers about the potential of wastewater as a resource.
What can we extract from waste water? Energy, Fertilizers, Biosolids and Nutrients. Waste water, when treated right, can be reused as drinking water. In short, a shining example of a circular economy at work, and an effort that can transform sanitation from a cost-oriented activity to a self-sustaining project.
From a world view, let’s switch our focus to the UAE.
With the Nation receiving limited rainfall (around 100 mm per year), water management is a critical function for governments and municipalities. Seven Dams located across the Emirates, particularly in the Northern and Eastern part, are a freshwater source for various regions and some also supply water for agriculture purpose (the UAE grows around 20% of its agro-produce locally). The majority of potable water is derived from desalination, ie by treating sea water.
What about waste water? Local municipalities across the Emirates are responsible for its management, treatment and disposal.
In 2014, the Emirate of Abu Dhabi revealed an environmental plan to treat and re-use all of the emirate's wastewater to irrigate farms and parks within four years. The plan will soon be a reality when construction of two massive pipelines, spanning hundreds of kilometres, is completed. The pipelines will transfer nearly 400,000 cubic metres of treated wastewater to 4,100 farms in the emirate, according to a report in the Gulf News.
The official portal of the UAE Government says Dubai is planning to get a new deep tunnel sewerage system costing AED 12.5 billion in the next five years, to replace more than 121 sewerage pumping stations. Advanced sewerage treatment systems are being planned by Sharjah, Ajman, Ras Al Khaimah and other local governments.
From the understanding of UAE’s water canvas, and the fact that the Nation’s annual water demand is approximately 5 billion cubic metres, two realities emerge.
Being part of an arid region, Ground Water is in short supply and annual recharging will not take place at the desired rate due to mismatch between rain water inflow and current rate of extraction. Another source of water treatment needs to supplement desalination, to serve the growing demand for water.
Hence, a cost-effective, environment friendly and viable option is Treated Sewage Effluent (TSE) and TSE Polishing. As per Zawya.com, UAE produces 735 million cubic metres of TSE each year, yet a quarter of this resource is either lost or discharged into the sea. Experts believe that TSE must be explored further to enhance UAE’s food and water security.
In the TSE process, treated sewage / effluent is further treated to a level where the water becomes fit for reuse for selected applications. TSE Polishing is the tertiary and final effluent wastewater treatment stage before the wastewater is discharged into natural water bodies or is used in cooling towers, district cooling units, or for irrigation purpose in place of ground or sea water.
Around the world, it is being proved that waste in any form can be re-used. Technology makes it possible to extract fuel oil from plastic waste, aluminium cans and trays can be recycled, while food waste can be composted to produce fertilizer or converted into bio-fuel.
With water treatment technology and waste water restoration techniques having evolved, water treatment companies in the UAE must view wastewater as an asset and a sustainable route to resolve water scarcity. As a responsible individual or corporate citizen, the rhetorical question we must ask ourselves is: Why Waste Wastewater?
This document is prepared in the public interest by Advanced Watertek for H2O Global News