Which is correct for this trickling filter?

a)Due to the low BOD loading rate the biomass growth will be too little. Methanol needs to be dosed to keep the biomass alive.

b)Due to the high BOD loading rate the filter might clog. This can be prevented by effluent recycling in order to increase the shear stress on the biofilm.

c)Due to the high BOD loading rate the filter might clog. Because the hydraulic loading is also high, one should build an additional trickling filter to increase the filter volume.

d)Due to the high hydraulic loading, the biomass will shear off and problems with the conversion processes and effluent quality will occur. This can only be prevented by building an additional filter.

Please help it's urgent!!!!!

To determine which option is correct for this trickling filter, we need to understand the basic principles of how trickling filters work and how they can be optimized.

A trickling filter is a type of wastewater treatment system that uses a bed of media, such as rocks or plastic, for the growth of a biomass (biofilm) that can remove organic matter from wastewater through aerobic biological processes. The filter bed provides a large surface area for the biofilm to attach and perform the treatment.

In this context, let's analyze each option one by one:

a) Due to the low BOD loading rate, the biomass growth will be too little. Methanol needs to be dosed to keep the biomass alive.
This option suggests that the BOD (biochemical oxygen demand) loading rate is low, which means the organic matter content in the incoming wastewater is relatively low. As a result, the biofilm growth on the filter media might be insufficient. The introduction of methanol, which is a carbon source, can help supplement the biomass and keep it alive. However, this option does not mention anything about any potential issues with the filter itself.

b) Due to the high BOD loading rate, the filter might clog. This can be prevented by effluent recycling to increase the shear stress on the biofilm.
This option states that the BOD loading rate is high, indicating a high organic matter content in the incoming wastewater. As a result, there could be a risk of the filter bed becoming clogged due to the excessive organic material. To prevent this, effluent recycling can be implemented. Effluent recycling involves diverting a portion of the treated wastewater back to the influent side of the filter. This increases the flow and shear stress on the biofilm, helping to minimize clogging issues.

c) Due to the high BOD loading rate, the filter might clog. Because the hydraulic loading is also high, one should build an additional trickling filter to increase the filter volume.
Similar to option b, this option also mentions a high BOD loading rate, implying a significant organic matter content. Additionally, it suggests that the hydraulic loading rate is high, meaning the volume of wastewater flowing through the filter is substantial. In such cases, if the filter volume is not sufficient to handle the incoming flow, there could be a risk of clogging. To address this issue, building an additional trickling filter can increase the overall filter volume, reducing the risk of clogging.

d) Due to the high hydraulic loading, the biomass will shear off, and problems with the conversion processes and effluent quality will occur. This can only be prevented by building an additional filter.
This option focuses on the hydraulic loading, which refers to the quantity of wastewater flowing through the filter. It states that if the hydraulic loading is high, there is a risk of the biofilm shearing off due to excessive flow, resulting in issues with conversion processes and effluent quality. According to this option, the only way to address this problem is by constructing an additional filter.

Based on the explanations above, option b seems to be the most appropriate choice. It highlights the potential issue of filter clogging due to a high BOD loading rate and suggests an effective approach to prevent clogging by implementing effluent recycling. Options c and d also mention high BOD loading or hydraulic loading rates, respectively, but they propose different solutions that involve building an additional filter.

However, it's essential to note that the correct answer can vary depending on specific conditions and context. It is always advisable to consult with wastewater treatment experts, engineers, or relevant literature for accurate solutions in practical situations.