Hospitals are major consumers of water and also produce a large amount of wastewater on a daily basis. Waste produced by hospitals has hazardous pollutants, which if left untreated has adverse impacts on the environment and people. There is a need for safe disposal of biomedical waste from hospitals which require segregation and treatment.

Wastewater from hospitals is more complex in nature compared to other wastewater.
The treatment of this wastewater is also more complicated as a result.

1. Pre-treatment:

This is the most essential stage of treatment in a sewage treatment plant. Large pollutants like sticks, rags, along with other inorganic solids present in the hospital wastewater are removed in the pre-treatment stage of water treatment. This is the most important stage in water treatment as the presence of such debris could damage the treatment plant’s parts and equipment.

2. Primary treatment:

In the second stage of treatment solids and grease from wastewater is conducted. This is a physical separation. Water is allowed to flow into the primary filter or clarifier for a few hours so that solid particles settle and lighter particles float. The particles that float on top are skimmed off from the tank. The solid that settles is made up of 60% of solids. Now water has been partly treated and needs to be treated further in the next step.

3)Secondary treatment:

This stage unlike the previous one is not physical in nature, but a biological treatment process. Inorganic matter that is dissolved in wastewater is removed in the secondary stage of wastewater treatment. Bacteria are used to convert colloidal and dissolved organic matter. The wastewater that was treated in the previous step flows from a primary tank to aeration tank, and oxygen is provided here using an air blower. The wastewater then flows into a second clarifier where solids settle. Secondary sludge is formed here, part of which is recycled to activate the sludge process and the remaining is mixed with primary sludge and sent to the sludge digestion tank. 905 of inorganic solids are cleaned in this stage of treatment.

4.Tertiary treatment:

This is the last stage of treatment where suspended solids are removed along with the organic matter present in wastewater. Certain microorganisms still remain in the waste even after the stage of biological treatment. They are removed using disinfection. Disinfection agents that are used depending on the kind of water conditions are added. After water is treated with such agents, it is finally ready for reuse or safe disposal.

Owing to the benefits and need for treating wastewater, a larger number of hospitals are installing sewage treatment plants and contributing in protecting the environment from the damage of this waste.