Wastewater Treatment: Trickling Filters & ASP

Trickling Filters

• Low Rate Filters: Designed for lower organic loads with a longer retention time and larger filter media.
• High Rate Filters: Designed for higher organic loads with a shorter retention time and smaller filter media.
• Construction Details: Made from materials like stone, plastic, or ceramic, with a specific surface area to enhance microbial growth.
• Recirculation Modification: Increases the flow rate through the filter, effectively enhancing the treatment efficiency.

Activated Sludge Process (ASP)

• Process Description: Uses aerobic bacteria to break down organic waste in wastewater.
• Methods of Aeration: Aerates the wastewater using diffused air or mechanical aeration to promote microbial growth.
• Loading Rates, MLSS, SVI: Loading rate refers to the amount of organic matter entering the system. MLSS (Mixed Liquor Suspended Solids) measures the amount of solids in the aeration tank. SVI (Sludge Volume Index) measures the settling characteristics of the sludge.
• F/M Ratio: Indicates the ratio of organic matter (food) to microorganisms in the aeration tank.

Oxidation Ponds and Aerated Lagoons

• Description and Function: Natural ecosystems designed for wastewater treatment with minimal infrastructure. They rely on sunlight, algae, and bacteria.
• Aerated Lagoons: Provide additional oxygen, enhancing treatment efficiency.

Treatment and Disposal of Sludge

• Digestion of Sludge: Anaerobic digestion breaks down organic matter in sludge, reducing volume and pathogens.
• Sludge Disposal: Options include land application, incineration, landfill disposal, or production of biosolids for beneficial reuse.

Septic Tank

• Working and Design: Uses a settling tank to separate solids from wastewater, followed by anaerobic digestion.
• Design Considerations: Tank size, drainage field size, and soil permeability are essential for efficient septic system function.

Disposal of Septic Tank Effluent

• On Land: Treated effluent can be discharged into a drainage field, spreading the water slowly and allowing for purification.
• In Stream: Regulations vary, but direct discharge to streams may be prohibited due to potential water quality issues.

Effluent Standards

• Discharges to Land, Streams, Sewers: Effluent standards encompass acceptable limits for contaminants like bacteria, BOD, and TSS.

MINAS

• Management of Industrial Waste and Standards: MINAS focuses on managing industrial wastewater, including treatment and disposal, to ensure safe and environmentally responsible practices.

Self-Purification Capacity of Streams

• Natural Processes: Streams naturally cleanse themselves through various processes, including dilution, sedimentation, sunlight, and microbial action.

This quiz covers key concepts in wastewater treatment processes, specifically focusing on trickling filters and the activated sludge process (ASP). You'll explore different types of filters, construction details, aeration methods, and critical metrics like loading rates and MLSS. Test your knowledge and enhance your understanding of these essential environmental engineering topics.