Wastewater treatment is a complex topic that involves numerous processes, components and equipment that all have the singular goal to turn any liquid into water that can either be reused or returned to the water cycle. There are even a lot of wastewater treatment systems that everyone from households to industries use to meet their wastewater treatment needs. These technologies include the Nano-Bubbler, Clear Flow Systems, and Water Right Systems, among others.
In this article, we’ll try to simplify the topic’s complexity and discuss the basic processes that undergo in a typical wastewater treatment system. By understanding the basic stages of wastewater treatment, you will get a general idea about its main concept and won’t have any trouble understanding other stuff related to wastewater treatment. Let’s start.
Primary Treatment
As wastewater enters a plant for treatment, it undergoes the process of sedimentation or settling, which removes fine suspended organic solids from the wastewater. It is usually done by pouring the wastewater into big sedimentation tanks (can either be square, circular or rectangular) for the macrobiotic solid matter to settle at the bottom or at the surface of tanks. Once the solid matter settles, it turns into sludge that is removed using large scrappers and is moved to the center of the cylindrical tanks. After that, the sludge is pumped out of the tanks for further treatment (it can be used as a fertilizer), with the remaining water also being pumped out for secondary treatment.
Secondary Treatment
The secondary process of treatment is where the removal of fine and dissolved colloidal organic matter occurs, with the help of microorganisms (algae, fungi, and bacteria) that help decompose the organic matter to stable organic forms. When the effluent leaves the sedimentation tank in the primary stage, it is typically transferred to a facility that uses this treatment, and different processes (activated sludge process, aerobic digestion, anaerobic ponds, etc.) are used by different plants when removing organic matter. By the end of this treatment process, the remaining organic matter turns into large particles that settle down at the bottom of huge tanks, which makes them easy to separate from the remaining wastewater. In some cases, chlorine is used to disinfect the effluent in order to complete the secondary treatment process.
Tertiary Treatment
After the primary and secondary treatment stages, wastewater needs to undergo the tertiary treatment process to ensure that it is free of suspended and dissolved substances. Even though the effluent from the secondary stage is somewhat safe for release into the environment, undergoing the tertiary stage is necessary for the following reasons: (1) it has the ability to remove up to 99% of the wastewater’s impurities; (2) it produces effluent water that is close to drinking water quality; (3) to meet standard requirements in developed countries; (4) for the removal of hazardous nitrogen and phosphorus compounds.
Conclusion
In general, wastewater treatment plants follow the same step-by-step process when treating wastewater. But since we only focused on the basic and most important steps, there are also other processes that were not mentioned in this article. If you need help with your wastewater treatment system, ECE can help design, develop and implement an industrial treatment system that suits your needs and goals. Our more than 20 years of experience in individual wastewater means that you are in good hands.