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What happens to the wastewater running down the drain from your sink, shower or sewer lines? In this article, I will discuss the different aspects of wastewater management. First, a few definitions to classify the different types of wastewater we generate;
- Sewage: this is wastewater and excrement conveyed in sewer lines.
- Sullage: is wastewater from sinks, showers or baths that does not include wastewater coming from toilets.
- Industrial wastewater: is wastewater produced from industrial activities like manufacturing or agriculture that might be harmful to the environment.
Wastewater management is the process of controlling, directing, and disposing of wastewater in a way that is safe and environmentally responsible. In this article, I will provide you with an understanding of the issues involved and share tips on how you can make a difference.
Waste water is any water that has been used in your home. It can come from washing, bathing and cleaning, toilet flushing and even rainwater that runs off roofs and roads into the drains. Waste water can be grey (dirty) or clear (clean).
Wastewater treatment plants treat all of these types of waste water so that it meets strict standards for public health protection.
Whether you are an individual , business, or an entire community, you can make a positive impact on the environment by learning and understanding more about sustainable wastewater practices. Let’s take a look at how you can help make a difference and ensure that our wastewater is managed responsibly.
What is Wastewater Management?
Wastewater management is the process of treating, collecting, and disposing wastewater in a sustainable way. The wastewater that is produced when we flush toilets, wash clothes, and clean dishes is called domestic wastewater, and it is a pollution source in our water systems. The contaminants can be solid, liquid or gas.
When livestock is raised in confinement, they also produce large amounts of excess wastewater as well. This type of wastewater is called industrial wastewater. Whether produced by a household or a business, these types of wastewater need to be treated before they can be safely reused or released back into the environment.
Solid contaminants can include things like food scraps, hair and lint. Liquid contaminants may include detergents, soaps, oil and chemicals that might have been poured down drains or flushed down toilets and sinks. Gas contaminants may be produced by biological activity in sewers or septic tanks (these are both underground tanks where waste water collects).
Types of Wastewater
Domestic wastewater is wastewater that is produced from household activities such as washing clothes, taking showers, flushing toilets, and cleaning the house. This wastewater can be treated at the household level or at a centralised wastewater treatment plant.
Industrial wastewater is wastewater produced from manufacturing processes, mining, and agricultural activities. Industrial wastewater is generally treated at a centralised wastewater treatment plant.
Stormwater is excess rainwater that flows from land and is discharged as surface water. Stormwater can also be treated and reused for various uses.
Agricultural wastewater is wastewater produced from agricultural activities such as growing crops or raising livestock. Agricultural wastewater is generally treated at the household level.
The Environmental Impacts of Wastewater
When wastewater is untreated and released into the environment, it can negatively impact local ecosystems. Excessive amounts of certain contaminants in wastewater can lead to harmful algal blooms and low oxygen levels. These blooms can kill marine life, create bad odours, and even toxic environments that are unsafe for humans to be around. When wastewater is treated and released back into the environment, it has minimal to no impact on local ecosystems.
How is wastewater treated?
Methods for treating wastewater are broadly classified into 4 categories:
- Physical Treatment: Physical wastewater treatment involves the use of several physical processes, such as screening and sedimentation. The water is kept moving so that any solid materials in it can be removed by skimming. Rather than using chemicals, this method relies on natural processes to clean the wastewater.
Another physical water treatment technique is aeration. Aeration involves circulating air through the wastewater to provide oxygen to it. Filtration, another physical water treatment method, passes the wastewater through a special kind of filter that separates contaminants and insoluble particles from it. The most commonly used filter is the sand filter, which removes grease from wastewater.
- Chemical Treatment: involves the use of chemicals to kill bacteria and remove contaminants. Chlorine, an oxidising agent, is used to purify water by killing the bacteria which decomposes it by adding contaminants to it. Another oxidising chemical used for water treatment is ozone. Neutralisation is a technique where an acid or base is added to bring the water back to its natural pH of 7.
- Biological Treatment: The biological treatment method utilises different biological processes to break down the organic matter in wastewater, such as soap and human waste. Microorganisms metabolise organic matter in the wastewater in biological treatment. There are method of biological wastewater treatment:
- Aerobic processes: Bacteria decomposes the organic matter and converts it into carbon dioxide that can be used by plants. Oxygen is used in this process.
- Anaerobic processes: Here, fermentation is used for fermenting the waste at a specific temperature. Oxygen is not used in anaerobic process.
- Composting: A type of aerobic process where wastewater is treated by mixing it with sawdust or other carbon sources.
- Sludge Treatment: This process involves removing as much moisture as possible from sludge residues from wastewater. The solid-liquid separation process requires the least possible residual moisture in the solid phase and the lowest possible solid particle residues in the separated liquid phase.
What happens to wastewater after treatment?
Treatment is the process of removing contaminants from wastewater. The goal is to return clean water to the environment.
There are four basic ways that treated wastewater can be discharged:
- To lakes and rivers
- Into the ocean or coastal waters
- Into ground (soil), called subsurface discharge
- Through reuse, which is also called reclaimed water
Benefits of Sustainable Wastewater Management
Some of the benefits of sustainable wastewater management include.
- Sustainable wastewater management has many benefits, including reducing the amount of pollution in local ecosystems, providing drinking water for communities, and reducing the lifespan of wastewater treatment facilities.
- Sustainable wastewater management can reduce the amount of pollution in our rivers, streams, and the oceans by reducing the amount of untreated wastewater that is released into the environment.
- It can also help provide drinking water for many communities. Many communities rely on surface water for their drinking water, and industrial wastewater treatment plants can be used to treat and re-use this water.
- Sustainable wastewater management can also help increase the lifespan of wastewater treatment facilities. By reducing the amount of contaminants in the wastewater being treated at these facilities, the facilities will be able to last for a longer period of time.
How Individuals Can Make a Difference
When it comes to wastewater management, individuals can make a big difference. Individuals can reduce their wastewater output by 25 percent by making small changes such as
- Repairing leaky pipes
- Turning off the water when brushing teeth, and
- Installing water-saving devices; Did you know that most households are using more than 30% of their total water consumption just by flushing toilets? Toilets and taps use quite a lot of water compared to other appliances like washing machines or dishwashers because they run constantly instead of just briefly turning on every now and then like other appliances may do while they do their job(s). Installing high-efficiency dual flush toilets (1L flush) can save up to 2 litres per flush compared with older models while installing aerators from taps will also help reduce flow rate by 10%.
- Have a rainwater tank; If you have a roof, why not harvest some of the rain that falls on it? A simple tank and some piping can capture and store the rainwater, so it’s available to use when necessary. This is especially useful in dry areas where rainfall is low during certain seasons or even years. Rainwater tanks significantly reduce your water usage, which means lower bills for you!
- In Agriculture, farmers can also help improve wastewater treatment by reducing overuse of fertilisers, and by not over-applying manure or pesticides. Individuals can also help improve wastewater management through advocacy.
How Businesses Can Make a Difference
Businesses can make a big difference in their wastewater management practices.
- Businesses can implement sustainable wastewater management practices by installing nutrient management plans,
- Businesses can also help by reducing the amount of contaminants in their wastewater by installing filtration systems in their manufacturing processes.
- Simple installations that can prevent stormwater runoff from entering their wastewater systems is a good way to recover water that can be reused for other processes.
Conclusion
The next time you wash your hands or take a shower, think about how important it is to have clean water.
When wastewater is treated and released back into the environment, it has minimal to no impact on local ecosystems. Wastewater management is the process of treating, collecting, and disposing wastewater in a sustainable way. By reducing the amount of pollutants and contaminants in wastewater, and by preventing stormwater runoff from entering wastewater systems, communities can improve their wastewater management practices. Wastewater management is one of the most complex systems in our society and it can be improved with the right knowledge and technology.