Wastewater treatment plays a critical role in protecting public health, preserving natural water sources, and ensuring sustainable sanitation. As communities grow and industries expand, the need for effective wastewater management becomes even more pressing. Without proper treatment, wastewater can contaminate drinking water supplies, contribute to environmental degradation, and pose serious health risks.
Understanding the basic principles of wastewater treatment is essential for anyone involved in sanitation, environmental management, or infrastructure development.
This post explores the principles of wastewater treatment, breaking down key processes, technologies, and industry standards. Whether you’re a homeowner, business owner, or developer, knowing how wastewater treatment works can help you make informed decisions about the most efficient and sustainable solutions.
At Calcamite, we specialise in cost-effective, decentralised wastewater treatment solutions designed to meet the specific needs of homes, businesses, and remote communities. Our modular systems provide reliable treatment while ensuring compliance with environmental regulations.
Now, let’s take a closer look at how wastewater is treated and why it matters.
Overview of Basic Principles of Wastewater Treatment
Wastewater treatment involves a combination of physical, biological, and chemical processes to remove contaminants before the water is safely reused or discharged.
- Physical treatment methods include screening, mixing, flocculation, sedimentation, flotation, filtration, and adsorption to separate solids and other particles.
- Biological treatment uses microorganisms to break down organic substances. This process converts contaminants into gases (released into the atmosphere) and biological cell tissue, which can be removed through settling or filtration. It also helps eliminate nitrogen and phosphorus, preventing water pollution.
- Chemical treatment involves adding chemicals to remove specific contaminants. Common processes include precipitation, gas transfer, adsorption, and disinfection to ensure wastewater meets safety standards.
At the core of these treatment processes is the mass balance principle, which states that while mass cannot be created or destroyed, its form can change (e.g., liquid to gas). This principle helps define how materials are transformed during wastewater treatment.
Read our blog on understanding wastewater treatment for a deeper dive into these processes
Key Processes in Wastewater Treatment
Wastewater treatment occurs in multiple stages to ensure thorough purification.
1. Primary Treatment
The first stage of treatment focuses on removing solid waste and allowing organic matter to settle. This is typically done in anaerobic settling tanks, such as septic tanks, where heavier solids settle at the bottom and begin to break down.
Microorganisms play a crucial role in this process by converting organic matter into carbon dioxide (CO₂), water, and biomass. Some bacteria even help with phosphorus removal, preventing nutrient pollution in natural water sources.
At Calcamite, our modular wastewater treatment systems include flow equalisation tanks to manage peak flows, ensuring a steady treatment process and preventing system overload.
2. Secondary Treatment
This stage removes dissolved and colloidal organic material through aerobic biological processes. There are two main types:
- Suspended growth systems – Microorganisms remain suspended in the wastewater, breaking down organic material through constant mixing.
- Attached growth systems – Microorganisms grow on a fixed surface (such as plastic media, rock, or gravel) and consume contaminants as the wastewater flows past.
At Calcamite, we use attached growth media with a high surface area to support robust biofilm growth. This technology is highly effective for small-scale wastewater treatment plants, ensuring reliable and low-maintenance performance.
Learn more about our wastewater treatment solutions
3. Disinfection & Tertiary Treatment
Once secondary treatment is complete, disinfection is required to eliminate any remaining pathogens. The most commonly used method is chlorination, as it is cost-effective and ensures proper microbial control.
For applications requiring higher effluent quality, additional tertiary treatment steps, such as chemical treatment and filtration, can be added.
Standards and Guidelines in Wastewater Treatment
Wastewater treatment systems in South Africa must comply with the National Water Act (1998), which sets general and special effluent limits based on environmental sensitivity and water usage.
Calcamite’s wastewater treatment plants are designed to meet or exceed these regulatory requirements, ensuring compliance for various applications.
Reliable Wastewater Solutions from Calcamite
Calcamite designs high-performance wastewater treatment plants that cater to a variety of needs, from residential and commercial properties to off-grid communities.
Our modular and scalable systems ensure effective treatment while keeping installation and maintenance simple. Whether you need a simple septic tank or an advanced sanitation solution, we offer reliable, compliant, sustainable results.
If you’re looking for a wastewater treatment system that meets regulatory standards while offering efficiency and long-term savings, explore Calcamite’s wastewater treatment solutions or get in touch with our team for expert guidance.
