A Sewage Treatment Plant (STP Plant) is an essential system for treating wastewater generated from residential societies, commercial complexes, hotels, hospitals, and industries. With increasing water scarcity and strict environmental norms issued by the Central Pollution Control Board, installing an STP plant has become mandatory for many projects across India.
Koshish India provides advanced and energy-efficient STP plant solutions designed to meet discharge standards and promote water reuse. If you are searching for “STP plant manufacturer in India,” “STP plant cost in India,” “commercial sewage treatment plant,” “industrial STP plant installation,” or “compact STP plant for apartments,” this guide will help you understand everything in detail.
What is an STP Plant?
An STP Plant is a wastewater treatment system that removes contaminants such as organic matter, suspended solids, oil and grease, and harmful microorganisms from sewage water. The treated water can be reused for:
Toilet flushing
Gardening and landscaping
Cooling towers
Construction use
Industrial processes
The main objective of a sewage treatment plant is to reduce BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), TSS (Total Suspended Solids), and pathogens to meet pollution control standards.
STP Plant Working Process
The STP plant working principle consists of three major treatment stages:
1. Primary Treatment
Screening removes plastic, paper, and large waste particles
Grit chamber removes sand and heavy solids
Primary settling tank separates sludge
This stage removes physical impurities from wastewater.
2. Secondary (Biological) Treatment
Aeration tank supplies oxygen
Microorganisms break down organic pollutants
Secondary clarifier separates treated water and sludge
This stage significantly reduces BOD and COD levels.
3. Tertiary Treatment
Pressure sand filtration
Activated carbon filtration
UV or chlorination disinfection
After tertiary treatment, water becom