The three main steps of treatment at the sewage treatment plant are Primary (physical), Secondary (biological) and tertiary treatment.

1. Different Processes for Sewage
Treatment
In an era of increasing water scarcity, responsible wastewater treatment is not just a necessity but a
crucial step towards sustainable water management and a healthier planet. Sewage needs a makeover
through effective treatment. The three main steps of treatment at the sewage treatment plant are
Primary (physical), Secondary (biological) and tertiary treatment. They have a crucial role in
transforming sewage into something less harmful for our surroundings and beneficial to overall
environment. So, let's take a peek behind the scenes of sewage treatment and explore the crucial
processes that keep our waterways clean and our environment thriving.
Primary (Physical) Treatment
In the first step, physical treatment targets the sewage's solid matter. This process is like the bouncer at
a club, stopping all the unruly particles from causing chaos downstream. Coarse and fine Screens, akin to
the club's entrance gate, trap debris, plastics, and other solid waste. Once inside, grit chambers take
over, slowing down the flow and allowing the heavier particles, like sand and gravel, to settle at the
bottom.
Then comes the sedimentation tank, the VIP section of sewage treatment. Here, the remaining
suspended solids sink to the bottom, leaving the Clear sewage at the top and transfer for further
treatment. The sludge, the unwanted residue, is pumped out like partygoers being escorted out after
closing time. Physical treatment, in a nutshell, is the sanitation support, filtering out the suspended
impurity before the real cleaning begins.
Secondary (Biological) Treatment
Now, it's the turn of the unsung heroes – the microscopic organisms in biological treatment. Sewage
works as tiny workers that tirelessly break down organic matter in the sewage. In activated sludge
treatment, these microorganisms gorge on the remaining pollutants, turning them into harmless
substances. In trickling filter treatment, the microbes cling to surfaces as the sewage trickles over them.
It's a bit like tiny cleaners stationed on rooftops, purifying the sewage as it flows beneath. The final act,
in the lagoon system, involves letting nature take its course. Algae and bacteria team up to naturally
break down the remaining contaminants. Biological treatment is the silent workforce, diligently
transforming sewage into something nature can embrace. Nowadays, tricking filter and lagoon are
replaced by aeration tank and secondary clarifier combination or Sequential Batch Reactor (SBR) in
which aeration and clarification takes place in a single tank.

2. Disinfection
Chlorine and other disinfectants step up to annihilate harmful bacteria and viruses lingering in the
treated sewage. This ensures stoppage of further growth of pathogens, bacteria, viruses for a certain
period in the treated sewage for safe discharge.
Tertiary Treatment
Sewage recycle/reuse is the necessity of the time. This can be used in irrigation, industrial processes, city
landscaping, gardening etc. This will ensure less dependability on fresh water from river/ ground water
and at the same time will avoid getting rivers or any other water body polluted due to disposal of
sewage into them.
This tertiary treatment can be customized as per the end use. For landscaping, gardening andirrigation
only disinfection with filtration may suffice the purpose. However for industrial purposes treatment can
be further purified by applying membrane filtration like UF and RO to make it suitable for cooling tower
and even for manufacturing process.
This approach will definitely reduce the burden of fresh water consumption and provide a greener
solution of sewage management.
Energy generation
This is another approach for the greener environment by using sludge generated from the sewage
treatment plant for the energy generation. Sludge generated from the plant is digested in anaerobic
digesters in which biogas is generated. This biogas is utilized in Biogas engine to produce electricity. This
electricity is used for running of the same plant and may be connected to the grid for transfer. So by this
approach waste is utilized to produce energy and reduces the load of electricity requirement from the
power grid/ power plant.
Conclusion
In conclusion, sewage treatment is a symphony of processes working in harmony to safeguard our
environment. The need for wastewater treatment is paramount in preserving environmental health.
Untreated wastewater poses a severe threat, contaminating water sources, endangering aquatic life,
and risking public health. Effective treatment through the best sewage treatment equipment mitigates
these risks, removing pollutants, pathogens, and harmful chemicals. It safeguards our waterways,
ensuring access to clean water for communities and preventing ecological damage. Each process has a
defined role in the process of sewage treatment. Physical treatment sieves out the visible
troublemakers, chemical treatment annihilates the invisible foes, and biological treatment employs
microscopic heroes to devour the remaining pollutants. These processes, though often unnoticed,
ensure that what once was a hazardous concoction becomes water fit for nature's embrace. In the world
of sewage treatment, each step plays a pivotal role in turning waste into a resource, preserving our
waterways for generations to come.