When was sewage treatment invented?

From around 12,000 to 6,500 years ago, humans appear to have dug permanent wells for water use during the Neolithic era, also known as the New Stone Age; however, little is known about sewage and its channels.

However, around 3000 BCE, there is evidence of a small 'cell-like' room in homes in Skara Brae (a settlement in Scotland) that may have been used as a primitive-style toilet. These rooms showed up to be linked to an indoor, tree bark lined, stone fresh and wastewater system that circulated liquids throughout the small space.

Bronze and early iron ages

During the Bronze and early Iron Ages, different parts of the world were doing few different things.

• Mesopotamia: Around 4000 BCE, the world was introduced to clay sewer pipes, which were used to capture rainwater in wells or eliminate wastewater. Around 3200 BCE, they also introduced the world to the first known examples of brick-built 'Latrines' (i.e. toilets).
• Ancient Persia:The first sanitation systems in this area were built in prehistoric Iran between 3000 and 2000 BCE. For water supply and cooling, Persian Qanats (gently sloping underground water channels) and ab anbars (traditional reservoirs) were used.
• Ancient Egypt:Copper drainage pipes were discovered in the Pyramid of Sahure (2400 BCE) and an adjoining temple complex.

Ancient East Asia

Evidence of some of the earliest human-made water wells has been discovered in Ancient China (as early as 6000 to 7000 years ago). Plumbing evidence from the Qin (221 to 206 BCE) and Han (206 BCE to 220 AD) dynasties has also been discovered.

Indus valley civilisation

The East Asian Indus Valley Civilisation has a lot of early evidence for sewage treatment. This Bronze Age civilization lasted from 3300 BCE to 1300 BCE (in its mature form from 2600 BCE to 1900 BCE), and its homes were made of mud or mud bricks, as well as clay bricks. The majority of houses had their own private toilet, and sewage was disposed of through underground drains constructed with carefully laid bricks. They had a sophisticated water management system for the time, with numerous reservoirs established and drains from homes connected to larger public drains. Water from the roof and upper storey bathrooms was carried through enclosed terracotta pipes or open chutes that emptied into street drains in practise.

Ancient Mediterranean

• Ancient Greece:The Minoan civilisation of Crete, known as the ancient Greek civilisation of Crete, were the first to use underground clay pipes for sanitation purposes. They were one of the first to use a flush toilet, around the 18th century BCE, and used stone sewers that they flushed out with clean water on a regular basis.
• Roman Empire:The Cloaca Maxima was built in Ancient Rome and is one of the world's oldest sewage systems. It conveyed sewage to the Tiber River, and public toilets were built above it. There are also Roman towns in the United Kingdom that had complex sewer systems from 46 BCE to 400 AD.

Medieval and early modern ages

• Islamic world: Bathhouses were very common throughout the Islamic world due to the stresses that Islam places on cleanliness and personal hygiene, particularly when it comes to Islamic hygienical jurisprudence (which dates back to the 7th century). Islamic toilet hygiene also requires washing with water after using the toilet for purity and to reduce germs.
• Medieval Europe:Small natural waterways were used to dump sewage in mediaeval European cities, and these waterways were eventually covered and turned into sewers. Open gutters and drains ran through the streets' centre (known as kennels in the UK and split streets in Paris). The first closed sewer built in Paris, however, was designed by HuguesAubird in 1370 on Rue Montmartre and was 300 metres long; it was built to help combat the foul odour.
• Classic and early modern Mesoamerica:It has been discovered that the Classic Maya of Palenque, which flourished around the 7th century in southern Mexico, had underground aqueducts and flush toilets.

In Bunzlau (Silesia) in 1531, Edinburgh (Scotland) in 1650, Paris (France) in 1868, Berlin (Germany) in 1876, and various parts of the United States since 1871, wastewater was used for beneficial crop production.

In the following centuries (16th and 18th centuries), "sewage farms" were increasingly seen as a solution for the disposal of large volumes of wastewater in many rapidly growing countries/cities of Europe (e.g., Germany, France) and the United States, some of which are still in operation today. Irrigation with sewage and other wastewater effluents has a long history in China and India, and in Melbourne, Australia, a large "sewage farm" was established in 1897.

The history of STPs

London was re-struck by the cholera epidemic in 1848 and 1854, killing more than 25,000 people (Burian et al., 2000). Dr. John Snow was currently the first physician to link the outbreak of cholera to a freshwater supply contaminated with a public fountain on Broad Street. This led to understanding the relationship between sewage discharge and disease outbreak.

At the beginning of the 20th century, STP mainly used sand basins (initial cleaning) to remove suspended solids from sewage before being discharged into rivers. In the early 1900s, about 1,000,000 other people in the United States were serviced by 60 such STPs.

In the early 1900s, a primary trickle filter was built in Madison, Wisconsin, to provide organic (secondary) wastewater treatment. The Imhoff tank was further developed in 1906 by German engineer Karl Imhoff for solids separation and other remedies.

The first activated sludge process was established in 1916 in San Marcos, Texas (Burian et al., 2000).

Advances in sludge digestion and gas production have also been made by researchers and utilities. From the mid-19th century to the present, more than a few biological and biochemical processes have been constructed to remove pollutants from wastewater. Prior to, the goal was primarily to reduce total suspended solids (TSS), biochemical oxygen demand (BOD), and pathogens.

Primary sustainable wastewater treatment and secondary organic treatments were considered sufficient to produce purified wastewater with appropriate requirements. During industrialization and scientific progress, chemical and toxic compounds have been detected in tributaries of municipal sewage treatment plants. This led to the need for additional treatment beyond the second-line treatment, which led to the third-line treatment. The tertiary or advanced treatment can be physical, chemical, organic, or a mixture of these processes.