Biological wastewater treatment(also called secondary treatment) has come from the remote past. This process relies upon microorganisms to break down organic waste and remove the pollutants from wastewater. There are various secondary wastewater treatments, but they are generally categorized into two parts—aerobic and anaerobic. The popular methods are aerobic cesspits, aerobic bioreactors, activated sludge(the conventional one), technically advanced solutions such as MABR, UASBs, etc. All these methods are used to remove harmful pollutants that are biodegradable, soluble, organic, and colloids from wastewater. 

This method is a complete intersection of biology and chemistry called biochemistry. This process relies on bacteria, protozoa, and nematodes to break down organic wastes using both traditional and advanced cellular processes. The whole process aims at cleaning wastewater and making it usable for irrigation and other uses.

In this blog, you will learn about the types of biological wastewater treatments and the processes involved.

How does a biological wastewater treatment take place?

There can be several different processes involved in removing organic waste from wastewater. Also, the removal depends upon the type of microorganisms contained in the process. They could be two types of operational procedures such as aerobic and anaerobic. As microorganisms will help remove the organic waste, you need to maximize bacterial growth to speed up the treatment. In aerobic treatments, you have to maintain a consistent level of dissolved oxygen to shoot the bacterial growth and make them take action accordingly. To properly execute this process, you need to monitor and adjust aeration levels regularly. While in the anaerobic process, anaerobic digesters are used that play their part in the absence of oxygen and pull out the desired result.

As said earlier, biological treatment is divided into aerobic and anaerobic processes. The aerobic process refers to using oxygen to break down waste. On the other hand, anaerobic describes a biological process in the absence of oxygen. Let’s read the biological wastewater treatment systems including their overall functioning within industrial wastewater regimen. These processes will also help you understand the types of technologies and systems that are highly in use today.

Aerobic Wastewater Treatments

Activated Sludge

This wastewater treatment is the oldest method since it was first introduced in England in the 18th century. This conventional process is widely used in both municipal and industrial applications because of its relatively low maintenance and low operational costs. 

Organic breakdown due to the activated sludge process occurs in larger spaces as they produce a larger amount of sludges. Under this process, wastewater is put into an aeration tank to aerate in the presence of freely floating aerobic microbes. 

The biological process is actually the secondary process. The physical process where debris is removed physically is considered the primary treatment phase. Also, the primary treatment phase is responsible for removing oil via the sedimentation process. The secondary phase enables the breakdown of organic waste with the effective use of microorganisms and turned them into biological solids. These solids together are called flocs that need to be removed with the help of the sedimentation process. The freely floating flocs are put into the settling tank, where these flocs are removed with the help of the sedimentation process. Recycling of settled solids to the aeration tank controls levels of freely floating solids, while excess solids are wasted as sludge.

MABR Treatment

With the advent of technology, Biological Wastewater Treatment has become more advanced and energy-efficient. The Membrane Aerated Biofilm Reactor, MABR, process uses 90% less energy for aeration as compared to the conventional methods used for the treatment. Under this process, air at atmospheric pressure is gently blown into a spirally bound membrane in a tank. It has air on one side of the membrane and fluid on the other side in that tank. A biofilm is formed on the membrane that helps in pulling off nitrification-denitrification. Resultantly, effluent is released into the environment. 

Several other aerobic methods are also available, such as Fixed Bed Bioreactors and Moving Bed Bioreactors, etc. You can visit our website to know more about them in detail.

Anaerobic Treatment

Upflow anaerobic sludge blankets(UASBs)

This process takes help from bacteria to remove organic waste in an oxygen-free environment. The best-known anaerobic treatment is anaerobic digestion, which is used for treating effluent from agricultural, commercial, and industrial waste. Under this process, the UASB reactor is used, which is the methane-producing digester. It forms a blanket of granular sludge and is processed by anaerobic microorganisms. The biogas (methane and carbon dioxide) is either flared or used to generate steam or electricity for use in other processes at the facility. 

This process creates less sludge than aerobic processes, requiring less cleaning. But this process does require a professionalist to skillfully maintain optimal hydraulic and anaerobic conditions. To know more about biological wastewater treatments, give a visit to our website https://www.aquatech.com/ or connect with our highly professional team.