Abwasserwirtschaft in Saudi-Arabien

Nachhaltige Wiederverwendung von Abwasser

Wie naturbasierte Lösungen helfen können Saudi-Arabien zum einen grün zu machen und zum anderen zu unterstützen die ehrgeizigen Emissionsziel zu erreichen. Ein Beitrag von Dennis Kronberg Alexandersen, General Manager, BAUER Environment und Dr. Tom Headley, Wetland Specialist, BAUER Resources GmbH.

Fresh water access in a growing Kingdom

In the past 50 years, Saudi Arabia has experienced rapid population growth reaching a total of 35 Million in 2021. Almost 85% of the population reside in urban areas. As cities grow, so do urban water challenges. For many years the Saudi people have found enough water to support their daily lives through natural oases and aquifers. Located in the arid middle-east region, characterised by limited annual rainfalls and depleting non-renewable groundwater resources, there has been a gradual shift towards desalination as the main water source. The National Water Strategy 2030 sets the framework for the interrelated freshwater and wastewater infrastructure. The government intend to promote public private partnerships to ensure delivery of high-quality water services, without compromising treatment costs or energy efficiencies. Nevertheless, there is still a critical need to conserve fresh water and recycle wastewater if the oil rich Kingdom is to square the circle in their pursuit of becoming carbon neutral by 2060.

Rethinking the water cycle

Despite being one of the world’s driest countries, the average per capita water consumption in Saudi Arabia is 278 litres/day (3rd highest globally), compared to Germany, where the water usage has fallen to 124 litres/day. Through the Qatrah program, Saudi Arabia is already committed to rationalise water consumption and aims to reach a per capita water use of 150 litres/day in 2030. The biggest consumer of water is the agricultural sector accounting for more than 81%, followed by the municipal sector at 13% and industry with approximately 5%. The water used for agriculture in Saudi Arabia comes almost exclusively from fossil aquifers that are at risk of becoming depleted in a few decades.

Nature-Based Solutions: A yellow tanker discharging raw sewage and sludge into a constructed wetland designed and constructed by BAUER Resources GmbH. source: BAUER

Future agricultural developments must involve non-conventional irrigation sources, such as treated and recycled domestic wastewater and grey water (wastewater from domestic sources excluding toilets), in combination with improved irrigation efficiency.

To progress towards a sustainable interaction with water resources, a paradigm shift is required to start viewing the water cycle through a Circular Economy lens. Wastewater needs to be viewed as a valuable resource, rather than a liability, with opportunities to yield clean water, nutrients, energy and create bio-diverse ecosystems and green landscapes. By developing smart systems which enable water to circulate in closed loops, gaining multiple benefits out of every drop, Saudi Arabia can advance beyond the wastefulness of conventional linear approaches to water resource management

Wastewater treatment with the power of nature

The water and wastewater sector is said to contribute to 5% of the global greenhouse gas emissions through energy consumption and direct emissions of methane and nitrous oxide. Consequently, the sector must reduce its own emission footprint and become more resilient to climate change impacts. Decision makers, developers and operators of wastewater infrastructure must implement alternatives to the energy, chemical and maintenance hungry conventional treatment approaches, which currently dominate the local market.

In the outskirts of urban areas and in remote locations, where land is available, while the need for recycled water is high, it would be extremely beneficial to establish biological wastewater treatment using wetland technologies. These nature-based solutions are inherently carbon neutral and can effectively convert raw wastewater, as well as grey water, into clean recyclable water, plant biomass and a nutrient-rich organic soil improver, all without consuming any electricity or chemicals.

Wetland systems can handle fluctuations in water quality and quantity, while supporting the establishment of new habitat, enhancing biodiversity, climate resilience and providing cooler and more liveable cities. This is in line with the National Environment Strategy and the recently launched Saud reen Initiative, which aims at addressing desertification by developing vegetation, protecting the environment and wildlife.

Nature-based solutions can play a vital role in achieving the Kingdom’s goals of increasing the connectivity and treatment of domestic wastewater from the current 50% to more than 95% by 2030, while making recycled water available where it is needed. By using small modular wetland technologies such as the ReedBox® or medium sized wetland installations, wastewater from clusters of unsewered homes or facilities can be treated and reused at a local level, providing a flexible solution, which realises large savings in the cost of pipelines for transporting sewage long distances to central treatment plants and conveying recycled water back for irrigation of agriculture and landscaping.

Even in areas already served by a sewer network, robust nature-based solutions can be used to extract wastewater from the network and treat it to provide clean water at locations where there is a demand for irrigation water while offsetting the need to expand the central infrastructure. This approach, known as “sewer mining”, will surely become an integral part of the future smart water cities of Saudi Arabia. By rethinking the urban, industrial and agricultural water cycles in an integrated and circular way, with nature-based solutions at the core, Saudi Arabia has the opportunity to lead the world in demonstrating how to achieve increased living standards, prosperity and access to clean water in one of the planet’s driest lands, all without increasing greenhouse gas emissions.

Dieser Artikel wurde für das Wirtschaftsmagazin GSBM, Ausgabe Dezember 2021 durch BAUER zur Verfügung gestellt. Der Artikel wurde durch Dennis Kronberg Alexandersen, General Manager, BAUER Environment und Dr. Tom Headley, Wetland Specialist, BAUER Resources GmbH auf Englisch bereitgestellt und durch GESALO vom Englischen ins Deutsche übersetzt.

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