GROUP-6_ESE-REPORT-3

Environmental Science and Engineering

• Sludge Treatment and Disposal

• Nonpoint Source Water Pollution

• Presented by: Asis, Shaira O., Coldas, Keith Brian T., Mesa, Sunshe Marie S., Nariz, Frenz Edmond M.

Sludge Treatment and Disposal

Sludge

• Thick, gooey material removed during wastewater treatment.

• Formed after wastewater passes through screens and grit chambers.

• Settles at the bottom of the primary sedimentation basin.

• Contains 3% to 7% solids, primarily organic material (60% - 80%).

• Characterized by an unpleasant odor.

Types of Sludge

• Primary Sludge:

  • Generated during the preliminary stages of treatment.

  • Contains organic materials removed through microorganisms (bacteria, protozoa) that decompose the organic matter.

• Secondary Sludge:

  • Forms during biological treatment processes, resulting in more manageable biological solids.

• Chemical Sludge:

  • Arises from adding coagulants (e.g., ferric chloride, aluminum sulfate).

  • Denser and may pose disposal challenges due to hazardous substances.

Three Laws of Sludge Variability

• Law 1: No two wastewater sludges are identical.

• Law 2: Sludge characteristics change over time.

• Law 3: There is no such thing as an 'average sludge'.

Thickening

• First step of sludge treatment; reduces total volume.

• Accomplished in a gravity thickener tank, can cut volume to less than half.

Sludge Digestion

• Biological process decomposing organic solids into stable materials.

• Reduces mass, destroys pathogens, facilitates dewatering.

• Methods of Digestion:

  • Anaerobic Digestion: Microorganisms break down organic material without oxygen.

  • Aerobic Digestion: Microorganisms require oxygen in the process.

  • Lime Stabilization: Involves adding lime to increase pH and inhibit microbial activity for land application.

Dewatering

• Dewatered sludge retains moisture but behaves as a solid.

• Thermal Treatment: Involves heat application for drying or incineration, significantly reducing volume.

Final Disposal

• Treated sludge's final disposal must be safe and environmentally sustainable.

Equipment

• Anaerobic Sludge Digester: Specialized system treating organic wastes in the absence of oxygen.

  • Three stages: hydrolysis, acid production, gasification (methane and carbon dioxide).

• Gravity Thickener: Separates liquids from solids using scraper blades to remove settled solids.

• Floatation Thickener: Uses dissolved air flotation to raise solids to the surface for removal.

• Pressure Filters: Advanced filtration using multiple layers for improved sediment interception.

• Belt Filter: Machine that uses vacuum for efficient liquid removal from sludge.

• Buchner Funnel: Laboratory equipment for vacuum-assisted filtration.

• Capillary Suction Time Apparatus: Assesses sludge dewaterability, optimizing dewatering processes.

Ultimate Disposal

• Final disposal involves managing treated waste sludge to ensure environmental protection.

Importance of Sludge Treatment and Disposal

• Reduces sludge volume, pathogen presence, and environmental health risks.

• Stabilized sludge can be safely handled, lighter, less odorous, and easier to store.

• Cost-effective solutions for pumping and storage.

Benefits

• Potential for water reuse and agricultural fertilizer production.

• Reduced health risks, diminished sludge disposal costs, environmental protection benefits.

Problems

• Toxic chemicals in sludge that may harm health if infiltrated into water or food sources.

• Foam accumulation can lead to safety and regulatory issues.

• Physical health risks from hazardous materials.

Environmental Destruction

• Pollutants in sludge risk contaminating ecosystems and resources, causing pipeline disruptions.

Nonpoint Source Water Pollution

• Pollution from rainwater carrying various contaminants into waterways.

• Negative impacts on living organisms and the environment.

Effects of Nonpoint Source Pollution

• Health issues: leptospirosis, rashes, hepatitis.

Sources of Nonpoint Source Pollution

• Oil and industrial waste from roads, human waste, chemicals, and overuse of fertilizers.

Sediment Erosion

• Transport of soil/rock affecting river flow; leads to degraded land and ecosystems.

Classification of Erosion

• Water Erosion: Occurs through rainfall, runoff.

• Wind Erosion: Movement of fine particles in dry areas.

• Glacial Erosion: Ice movement affecting soil/rock.

• Coastal Erosion: Shoreline degradation from wave action.

  • By Human Influence: Natural vs. accelerated erosion from activities like deforestation.

Pollutant Transport

• Air pollution arises from both primary and secondary pollutants, requiring international cooperation for solutions.

Preservation of Nonpoint Source Pollution

• Limit pesticide/fertilizer use; introduce natural predators; prevent erosion; participate in cleanups; preserve vegetation along bodies of water.

Mitigation Strategies

• Setup rain gardens to absorb runoff.

• Reduce chemical use; practice proper waste disposal.

Effects of Nonpoint Source Pollution

• Causes waterborne diseases, chemical exposure, breathing problems, and compromised food safety.

  • Degrades water quality and reduces biodiversity.

Reminders

• Ensure safe water and proper waste disposal; educate others about these issues.

Legislative Acts

• Republic Act No. 9275 (Clean Water Act)

• Republic Act No. 9003 (Ecological Solid Waste Management Act)

Conclusion

• Thank you for attention!