Sewage treatment involves removing contaminants from wastewater (household, industrial, or stormwater) before releasing it into the environment. Different equipment is used at each stage of treatment.
Author: Anna
Sewage treatment involves removing contaminants from wastewater (household, industrial, or stormwater) before releasing it into the environment. Different equipment is used at each stage of treatment.
Removes large solids and debris to protect downstream equipment.
Bar Screens – Remove large objects (rags, sticks, plastics).
Grit Chambers – Separate sand, gravel, and heavy particles.
Comminutors – Grind large solids into smaller pieces.
Removes suspended solids via sedimentation.
Primary Clarifiers/Settling Tanks – Allow solids to settle as sludge.
Skimmers – Remove floating oils and grease.
Breaks down organic matter using microorganisms.
Activated Sludge Process (ASP) – Aeration tanks + bacteria.
Trickling Filters – Biofilm grows on media to digest waste.
Sequencing Batch Reactors (SBRs) – Batch-process treatment.
Membrane Bioreactors (MBRs) – Combine biological treatment + ultrafiltration.
Further purifies water for reuse or safe discharge.
Sand Filters – Remove fine particles.
UV Disinfection – Kills pathogens with ultraviolet light.
Chlorination/Dechlorination – Chemical disinfection.
Reverse Osmosis (RO) – Removes dissolved salts & contaminants.
Processes the collected sludge for disposal or reuse.
Sludge Thickeners – Reduce water content.
Anaerobic Digesters – Break down sludge, produce biogas.
Belt Filter Presses/Centrifuges – Dewater sludge.
Incineration – Burns sludge to ash (for hazardous waste).
| Equipment | Function | Application |
|---|---|---|
| Bar Screen | Removes large debris | Pre-treatment |
| Grit Chamber | Separates sand/gravel | Pre-treatment |
| Aeration Tank | Supplies oxygen for bacteria | Secondary treatment |
| Clarifier | Separates sludge & clean water | Primary/secondary |
| UV Disinfector | Kills bacteria/viruses | Tertiary treatment |
| Sludge Dewatering Press | Reduces sludge volume | Sludge handling |
Flow Rate – Must handle peak wastewater volumes.
Pollutant Load – Organic matter, chemicals, heavy metals.
Space Availability – Compact systems (MBR) vs. large lagoons.
Energy Efficiency – Aeration consumes the most power.
Regulatory Compliance – Must meet local discharge standards.
Electrocoagulation – Uses electricity to remove contaminants.
Advanced Oxidation Processes (AOPs) – Breaks down micropollutants.
Moving Bed Biofilm Reactor (MBBR) – Combines ASP + biofilm carriers.
Clogging Prevention – Regular cleaning of screens & filters.
Aeration System Checks – Ensure proper oxygen levels.
Sludge Handling – Prevent odor & overflow issues.
Sewage treatment involves multiple stages, each requiring specialized equipment. The right system depends on wastewater characteristics, regulations, and budget. Modern advancements (MBRs, AOPs) improve efficiency and water reuse potential.