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!