Wastewater, challenges and opportunities
As we all know, good water quality is essential to human health, economic development, and basically, life itself. However, as populations grow and natural environments become degraded, ensuring sufficient and safe water supplies for everyone is becoming increasingly challenging.
Due to population growth, accelerated urbanization and economic development, the quantity of wastewater generated and its overall pollution load are increasing globally. This challenging present and misty future require us to value wastewater for its potential, rather than discard or ignore it.
Water must be carefully managed during every part of the water cycle: from fresh water abstraction, pre-treatment, distribution, use, collection and post-treatment, to the use of treated wastewater and its ultimate return to the environment, ready to be abstracted to restart the cycle.
The availability of safe water supplies is directly linked to how wastewater is managed. Globally, 80% of wastewater flows back into the ecosystem without being treated or reused, contributing to a situation where around 1.8 billion people use a source of drinking water contaminated with faeces, putting them at risk of contracting diseases.
Even in cities where wastewater is collected and treated, the efficiency of treatment may vary according to the system used. However, water used by a municipal authority for irrigating green spaces or cleaning streets does not need to be treated to a potable standard. Treating wastewater to a water quality standard appropriate to its intended use increases the potential for cost recovery.
The growth of urban demand for water will require new approaches to wastewater collection and management. Indeed, reused wastewater may help address other challenges including food production and industrial development.
Industrial water consumption is responsible for 22% of global water use. In 2009 in Europe and North America, water consumption by industries was 50% as compared to 4-12% in developing countries. It is expected that in rapidly industrialising countries, this proportion could increase by a factor of five in the next 10-20 years. Therefore, there is a strong incentive to use wastewater in-house and locally, based on cost savings alone.
Businesses can directly use some wastewater, providing it is fit for purpose. For instance, using process water for cooling or heating, or rainwater from roof collection or concrete aprons for toilet flushing, irrigation or vehicle washing.
Images from: https://www.unwater.org/