Pharmaceuticals Removal in Activated Sludge: Factors Affecting Efficiency and Strategies for Enhancement

Xiang Li^*
*Correspondence: Xiang Li, Department of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, China, Email:

Keywords

Activated sludge • System mathematical • Model operational parameters • Hydraulic Retention Time (HRT) • Pharmaceuticals

Introduction

The concentration of pharmaceuticals in the wastewater can also affect their removal in activated sludge. High concentrations of pharmaceuticals can overwhelm the microorganisms in the activated sludge, leading to a decrease in removal efficiency. Therefore, it is important to maintain low concentrations of pharmaceuticals in the wastewater to ensure optimal removal.

The Hydraulic Retention Time (HRT) is the amount of time that wastewater spends in the activated sludge system. A longer HRT allows more time for the microorganisms to break down the pharmaceuticals, leading to higher removal efficiencies. However, a longer HRT also increases the cost of the treatment process, as more infrastructures are required to maintain the system. The temperature of the wastewater can also affect the removal of pharmaceuticals in activated sludge. Generally, higher temperatures lead to higher removal efficiencies, as the microorganisms are more active at higher temperatures. However, the optimal temperature for pharmaceutical removal in activated sludge depends on the specific microorganisms present in the system.

The presence of other organic matter in the wastewater can also affect the removal of pharmaceuticals in activated sludge. Compounds such as Fats, Oils, and Greases (FOG) can compete with pharmaceuticals for the microorganisms attention, leading to lower removal efficiencies.

The removal of pharmaceuticals in activated sludge involves several mechanisms, including adsorption, biodegradation, and transformation.

Adsorption is the process by which pharmaceuticals are attached to the surfaces of the activated sludge floc. This mechanism is particularly important for hydrophobic compounds that are poorly soluble in water. The adsorption process is reversible, and pharmaceuticals that are adsorbed to the floc surface can be released back into the wastewater if conditions change.

Description

Biodegradation is the process by which microorganisms break down the pharmaceuticals into simpler compounds, such as carbon dioxide and water. This mechanism is the most important for removing pharmaceuticals in activated sludge, and it is dependent on the microorganisms present in the system. Different microorganisms have different abilities to break down different pharmaceuticals 2/2.

Activated sludge is a biological treatment process used to treat wastewater that contains high levels of organic matter. It involves the use of a mixed population of microorganisms to break down organic matter in the wastewater into carbon dioxide, water, and other compounds. The activated sludge process is widely used in wastewater treatment plants, and it has proven to be effective in removing a wide range of contaminants, including pharmaceuticals.

Pharmaceuticals are compounds that are used to treat various health conditions. They are designed to be biologically active and can have unintended effects on the environment when they are discharged into wastewater. Pharmaceuticals can enter wastewater through various sources, including human excretion, livestock farming, and hospital effluent.

The presence of pharmaceuticals in wastewater can be harmful to the environment and human health. For example, some pharmaceuticals have been found to disrupt the endocrine system in fish and other aquatic organisms, leading to reproductive problems. They can also enter the food chain through fish and other aquatic organisms, leading to potential health risks for humans.

The removal of pharmaceuticals from wastewater is, therefore, important for protecting the environment and human health. The activated sludge process is an effective method for removing pharmaceuticals from wastewater, but the removal efficiency depends on various factors.

One of the critical factors that affect the removal of pharmaceuticals in activated sludge is the physical and chemical properties of the pharmaceuticals. The physical and chemical properties of pharmaceuticals, such as solubility, stability, and molecular weight, can influence their removal efficiency in the activated sludge process. For example, pharmaceuticals that are highly soluble in water and have low molecular weight are generally more easily removed than those that are less soluble and have a higher molecular weight.

Another factor that affects the removal of pharmaceuticals in activated sludge is the microbial population in the system. The microbial population in the activated sludge process plays a crucial role in the biodegradation of organic matter, including pharmaceuticals. The presence of specific microorganisms that are capable of degrading pharmaceuticals can enhance the removal efficiency of the process.

The operating conditions of the activated sludge process also play a crucial role in the removal of pharmaceuticals. Factors such as hydraulic retention time, sludge age, and temperature can influence the growth and activity of the microbial population, which in turn affects the removal efficiency of pharmaceuticals. For example, a longer hydraulic retention time can allow for more contact between the wastewater and the microbial population, which can enhance the removal of pharmaceuticals.

The activated sludge process is also affected by the presence of other contaminants in the wastewater. The presence of other contaminants, such as heavy metals and organic compounds, can inhibit the activity of the microbial population, which can reduce the removal efficiency of pharmaceuticals. Therefore, it is essential to consider the presence of other contaminants in the wastewater when designing and operating the activated sludge process.

Conclusion

There are various strategies that can be employed to enhance the removal of pharmaceuticals in the activated sludge process. One of the most effective strategies is the use of advanced treatment processes, such as zonation and activated carbon adsorption. Ozonation involves the use of ozone to oxidize pharmaceuticals and other organic compounds, while activated carbon adsorption involves the use of activated carbon to adsorb pharmaceuticals and other contaminants.

The use of bio augmentation is another strategy that can be employed to enhance the removal of pharmaceuticals in the activated sludge process. Bio-augmentation involves the addition of specific microorganisms to the activated sludge process to enhance the biodegradation of pharmaceuticals. The added microorganisms can be selected based on their ability to degrade specific pharmaceuticals or other contaminants.