Water recycling and how it can boost sustainability
Water scarcity will be a reality for an estimated 2 to 4 billion people worldwide by 2025. Our vital resources are becoming increasingly scarce; thus, nations cannot afford to flush them down the drain. But this is what is happening. After using water in our homes and businesses, water is washed away rather than reused, and losing valuable nutrients along the way.
Wastewater itself is rich in carbon and nutrients. Collected and appropriately treated, it can provide communities with new water, energy, and fertilizers. Several countries and large cities have already built better wastewater treatment plants that recover nutrients and thus produce ‘new water’ that is being reused.
However, not all nations can afford such elaborate wastewater treatment centers. So how can we ensure that we reuse water and recycle it to better ensure more sustainably?
What is water recycling?
Water recycling uses treated wastewater for practical purposes like landscape and agricultural irrigation, replenishing a groundwater area, industrial processes, and even toilet flushing. Water recycling offers a better use of existing resources and reduces financial costs.
Wastewater treatment is used to facilitate water recycling by ensuring the water quality requirements are adequate for its planned reuse. For example, recycled water used for landscape irrigation does not require as much treatment as recycled water used for drinking water.
What are the sources and uses for water recycling?
Water sources for potential reuse can include municipal wastewater, industrial process and cooling water, stormwater, agriculture runoff, return flows, and produced water from natural resource extraction activities.
These water sources are adequately treated to meet specifications for a particular subsequent use. For example:
- agricultural irrigation
- landscape irrigation
- water supply
- industrial operational usage for power plants, refineries, mills, and factories
- toilet flushing
- dust control or surface cleaning of roads, construction sites, and other trafficked areas
- concrete mixing and other construction processes
- supplying artificial lakes and inland or coastal aquifers
- environmental restoration
What are the benefits of water recycling?
Recycled water has several benefits, including the potential for allowing many communities to meet their water demands. It has to be adequately treated to ensure appropriate water quality, which means that more treatment is required in cases with a greater chance of human exposure to the water.
1. Water recycling can be used for non-potable and potable purposes
Most recycled water is used for non-potable (not for drinking) purposes, like agriculture, public parks, and landscapes, and industrial objectives, for example, cooling water for power plants and oil refineries, water for facilities within paper mills and carpet dyers, toilet flushing, construction activities, dust control, concrete mixing, and artificial lakes — its possibilities are endless.
The majority of water recycling projects have been developed to meet non-potable water needs. Nevertheless, some of these nonpotable projects use recycled water for potable uses, namely topping up groundwater aquifers and extending surface water reservoirs.
In groundwater recharge projects, recycled water can be spread or injected into groundwater aquifers to increase groundwater supplies and prevent saltwater intrusion in coastal areas.
2. Environmental impact of water recycling
While not only providing a dependable, locally-controlled water supply, water recycling provides enormous environmental benefits. By providing an additional water source, water recycling can help society find ways to decrease water depletion in vulnerable ecosystems.
Other benefits include decreasing wastewater discharges and reducing and preventing pollution. Recycled water can also create or enhance wetlands and riparian habitats.
3. Water recycling reduces pollution
Recycled water may contain higher nutrients, like nitrogen, than potable water. Applying recycled water for agricultural and landscape irrigation can provide an additional source of nutrients and lessen the need to use synthetic fertilizers. This approach also reduces an important source of pollution in water bodies
4. Water recycling saves energy
As societies develop and the population grows, water demand also grows, which means that more water is extracted, treated, and transported, sometimes over great distances, requiring a lot of energy.
Suppose the local source of water is groundwater. In that case, the groundwater level becomes lower as more water is removed, which increases the energy needed to pump the water back to the surface.
Recycling water onsite or locally reduces the energy required to transport water long distances or pump water from deep into an aquifer. Treating water quality to a specific water purpose also reduces the amount of energy needed to treat the wastewater. As discussed, the water quality required to use a toilet is not as stringent as the water quality standards required for drinking water.
Once again, it will require less energy.
Water recycling needs to be more effective
Big city wastewater systems are very effective. However, they are also costly to build, maintain, and use. This is because they have been constructed on existing legacy systems.
Although existing city infrastructure is still better than in poorer towns and regions, building new cities with efficient water recycling infrastructure is better and cheaper.
Water recycling is the future for new cities
An alternative solution is building new Earth cities with efficient decentralized wastewater treatment plants. Unlike traditional city wastewater treatment plants, in decentralized plants, raw wastewater is treated where it is produced instead of being confined in a sewage system.
Another positive effect of building earth cities is that each site will be adaptable to meet local climatic conditions, water availability, and intended water uses.
If adequately managed, recycling our water becomes an affordable and sustainable source of energy, nutrients, and other recoverable materials, all of which is in the end good for the environment and the community.
Resources you’ll love:
Originally published at https://www.100tm.earth on August 1, 2022.
