After oxygen, fresh, clean water is the most basic requirement for the majority of life on Earth in order to survive. However, this is a true luxury that isn’t accessible for many millions of people around the world.
The importance of properly dealing with wastewater from human endeavours is obvious, as dirty water can contain infectious diseases such as cholera, typhoid, dysentery, trachoma, and others. Today hundreds of thousands of people die every year from these types of waterborne diseases, and even though these numbers are declining there is still work to be done.
Below is a brief introduction on what sanitation is and why it’s important:
Are you interested in learning more about this topic? We’ve discovered some facts that will help to illuminate some of the terms and processes around sanitation and wastewater management, which allows authorities to provide people with access to clean, and safe, water sources.
- There are two different types of wastewater – when it has come from domestic baths, kitchens, and laundries it is called gray water, and when the wastewater contains animal, human, or food waste it is referred to as black water.
- There are generally two approaches, and two types of technologies, for disposing of these types of waste: the decentralized system and the centralized system.
- The decentralized system is where waste is simply deposited in nearby water sources (such as streams or rivers), or dumped in to a cesspit. This system is archaic and not healthy for humans or the environment.
- The centralized system, which involves the use of self-cleansing sewers, is the safer and healthier option. However it isn’t a modern idea, dating back to around 2,500 BC where a version of it was used in the small cities of the Indus Valley civilization.
- Romans are very well known for their sophisticated water supply systems, and by the third century BC they were using three hundred litres of water, per capita, per day, just to use in the baths.
- In today’s centralized systems wastewater is placed through a number of processes. The initial, or primary, treatment is where the solids and liquids are separated using screening and sedimentation (the resulting matter is called sludge).
- The next, or secondary, treatment is where bacteria are introduced to consume any organic matter that is still in the water.
- Then the water is placed through an advanced, or tertiary, treatment using processes that might include adsorption, where activated carbon removes more organic matter.
- Oxygen might then be dissolved in to the final water to make sure that the waterbodies (and environments) that receive it have adequate levels of dissolved oxygen.
- The waste products from all of these treatment stages are not wasted, in a process called wastewater reclamation. For example, the sludge from the first stage is made available as fertilizer for agricultural use.
- Sadly, at a global scale over 2 billion people are without access to improved sanitation, which includes over 1 billion who have no facilities at all.
Featured image credit: black faucet kitchen sink by kaboompics. Public Domain via Pixabay.