Producing clean water from wastewater, this seemingly unrealistic task is turned into reality at modern water treatment plants and the pure-play water technology company VA TECH WABAG is a pioneer in this field. Municipal and industrial wastewater can be sustainably reused for a host of purposes, which includes Namibia, where it is reused as drinking water.
Extreme heat waves and severe droughts in Europe have led to acute water shortages and have threatened harvests. Around 30% of cropland across Europe is currently threatened by drought. In northern Italy, a water emergency has been declared and drinking water is being rationed; these and other alarming reports currently dominate our media. Water is becoming increasingly scarce in Europe, but in many parts of the world, droughts and lack of water supply have become a permanent problem and countries are turning to alternative solutions. Water recycling emerges as a proven option.
Water is too precious to be used only once.
Agriculture accounts for about 60-70% of annual water withdrawals. Enormous volumes are needed for irrigation of cultivated areas. But abundantly available wastewater can be treated relatively easily to be reused for agricultural irrigation. Conventional municipal wastewater treatment plants with mechanical/biological treatment processes can be expanded with an additional treatment stage to achieve high quality of treated wastewater according to requirements. Wastewater treatment plants are reliable alternative sources of water, as they provide continuous water of consistent quality regardless of climate and droughts. In many countries, such as Tunisia, Egypt and Saudi Arabia, this practice is already established and WABAG has implemented several plants here. Water Reuse is also practiced for the irrigation of urban green areas, as service water for street cleaning or firefighting water. Two plants of WABAG in Madinaty, a new, modern satellite town near Cairo, together produce 80,000 m3/d of service water daily from municipal wastewater, which is fed directly into a special network and used for the irrigation of green areas. This effectively saves drinking water volumes that are sufficient to cater more than 600,000 people.
Water recycling for industrial operations – sustainable and cost – efficient.
Industries have recognized the potential of multiple water use and are increasingly investing in sustainable reuse systems. For example, cooling water, boiler feed water or service water can be produced and reused from wastewater streams generated in the plant with multi-stage treatment. This minimizes fresh water consumption and at the same time the volume of wastewater and consequently reduces operating costs. Industrial recycling plants are booming in many areas, for refineries, chemical industry, steel mills or power plants. Not just the large-scale industries, even small production plants are increasingly opting for water recycling.
In Romania, for example, WABAG is currently completing the project for Clean Tech International (part of the SARIA Group) to upgrade the existing effluent treatment plant to state-of-the-art ETP employing most modern membrane filtration technology, namely Membrane Bioreactor (MBR) and Reverse Osmosis (RO). A partial flow of the total capacity of 420 m3/d wastewater will be polished by RO to be reused as boiler feed water. A model for further companies that value environmental protection and sustainability.
Advanced systems even enable zero-liquid-discharge, i.e. production without any wastewater at all. For more than 20 years, WABAG has been implementing Water-Reuse plants for a wide variety of industries in several of countries, presenting tailor-made solutions as per the client requirement
The world’s first plant that produces clean drinking water from wastewater is located in Namibia.
Wherever it is particularly dry on our planet, high efficiency is required. Namibia is home to the world’s first Direct Potable Reuse (DPR) plant, which produces clean drinking water from treated municipal wastewater, be employing an advanced, 9-stage multi-barrier treatment system. This plant alone covers up to 35% of the demand of the city of Windhoek. WABAG completed the “New Goreangab Water Reclamation Plant” in 2002 and since then it has been supplying 21,000 m3 per day of drinking water to the city
Legal guidelines for water reuse – India leads the way
Water is scarce in many parts of India, and the climate crisis is visibly exacerbating the situation. In order not to endanger the drinking water supply, the water supply for industrial plants is cut off in the event of extreme water shortages. The southern Indian state of Tamil Nadu is a reuse pioneer and in 2019 issued a directive requiring industrial companies to use treated wastewater from municipal sewage treatment plants for industrial water production – and has also set an example here. For the mega-city of Chennai, WABAG has implemented a 45,000 m3/d recycling plant that treats water from the effluent of the Koyambedu wastewater treatment plant using ultrafiltration and reverse osmosis, among other technologies, to produce clean water of drinking quality that is pumped to nearby industrial centers via a distribution network. Since commissioning in 2019, WABAG has also taken over operational management for 15 years. In June 2022, the company was awarded another order for a similar recycling plant in Ghaziabad near Delhi in northern India. The 40,000 m3/d plant is scheduled to go operational in 2024.
“Water reuse, with the implementation of effective treatment technologies, is a proven method that is becoming the need of the hour along with the effects of global warming. Municipalities and industries can opt for the sustainable approach of water recycling and reuse to secure water supplies while protecting precious fresh water resources.” confirms Dr. Josef Lahnsteiner, Head of R&D and Technology at the international WABAG Group and Chairman of the Water Reuse Specialised Group of the International Water Association (IWA).