Back to: MICROBIOLOGY 400 LEVEL
Welcome to class!
Hello again, champion! It’s always exciting to have you here, pushing forward in your learning journey with so much passion and commitment. Today, we’re going to look at a topic that speaks directly to sustainability and environmental care—Effluent Treatment Methods. This topic is especially relevant in Nigeria and across Africa, where industries are growing fast, and proper waste handling is becoming more important every day.
Effluent Treatment Methods
What Are Effluents?
Effluents are liquid waste or wastewater released by industries during production. In microbial industries, this wastewater often contains organic matter, microbial cells, nutrients, toxins, or chemicals that must be removed before being discharged into the environment.
Think of the dirty water from a yoghurt factory, a brewery, or a pharmaceutical plant. If it’s not treated properly, it can pollute rivers, damage farmland, or even cause diseases. That’s where effluent treatment comes in.
Why Effluent Treatment Is Important
Protects the environment – Prevents pollution of rivers, streams, and soil.
Preserves public health – Reduces the risk of waterborne diseases.
Meets legal standards – Ensures companies comply with NAFDAC, NESREA, and global environmental regulations.
Supports sustainable development – Makes industries more eco-friendly and socially responsible.
Major Effluent Treatment Methods
Effluent treatment usually happens in stages, and each stage is designed to remove specific types of pollutants.
Preliminary Treatment
Removes large solid particles like plastic, stones, or food chunks using screens or grit chambers.
This helps protect equipment in the next stages.
Primary Treatment
Settles down suspended solids using sedimentation tanks.
Sludge (settled material) is collected from the bottom, and oily materials are skimmed off the top.
Secondary (Biological) Treatment
Uses microorganisms to break down organic waste.
Examples:
Activated sludge process – air is pumped into tanks to help bacteria digest waste.
Trickling filters – wastewater trickles over stones or plastic surfaces covered with helpful microbes.
Tertiary (Advanced) Treatment
Removes leftover nutrients (like nitrogen and phosphorus), colour, or pathogens.
Methods include filtration, chemical treatment, or UV disinfection.
Sludge Treatment
Sludge collected from earlier stages is stabilised, dried, or used as fertiliser or biogas.
Disinfection
Before final discharge, the treated water is disinfected using chlorine, ozone, or UV light to kill remaining microbes.
Effluent Reuse and Recycling
With rising water scarcity, some industries treat and reuse their effluent for non-drinking purposes like irrigation, cleaning, or even cooling machines. This saves money and conserves resources.
A Nigerian Example
Many Nigerian breweries and food industries now use bioreactors and sedimentation systems to treat their wastewater before releasing it into the environment or municipal drainage. This helps them meet NESREA standards and avoid penalties.
Summary
- Effluents are liquid waste from industries that must be treated before discharge.
- Effluent treatment protects health, environment, and ensures regulatory compliance.
- Treatment is done in stages: preliminary, primary, secondary, tertiary, and disinfection.
- Microorganisms play a key role in breaking down organic waste.
- Treated water can be reused, making industries more sustainable.
Evaluation
- What are effluents, and why must they be treated?
- List and briefly explain two stages of effluent treatment.
- How are microorganisms involved in treating wastewater?
- Name one Nigerian agency responsible for regulating effluent discharge.
Understanding effluent treatment helps you become a microbiologist who not only produces value but also protects our beautiful environment. Keep learning and keep leading—Afrilearn is proud to be part of your journey. See you in the next class, superstar!