13. Sanitation /asenization/ of settlements. Hygienic characteristics of the methods for treatment and disposal of liquid and solid domestic and industrial waste. Landfilling.

Sanitation /asenization/ of settlements. Hygienic characteristics of the methods for treatment and disposal of liquid and solid domestic and industrial waste. Landfilling.

Definition: Organized collection, treatment, and safe disposal of liquid and solid domestic and industrial waste to protect public health and the environment.

Goal: Prevent contamination of water, soil, and air; reduce spread of infectious diseases, parasites, and chemical hazards.

1. Liquid Waste (Sewage) Treatment

Goal: Remove solids, organic matter, pathogens, and toxic substances to make effluent safe for discharge.

Stages of Treatment:

1. 1. Primary Treatment:

• Physical separation of solids (screening, sedimentation).
• Reduces suspended solids.

1. 2. Secondary Treatment:

• Biological degradation (aerobic or anaerobic).
• Removes dissolved organic matter and reduces pathogens.

1. 3. Tertiary Treatment:

• Advanced chemical or physical processes (chlorination, UV, nutrient removal).
• Eliminates remaining pathogens, toxic substances, and nutrients.

Industrial Liquid Waste: Requires specialized treatment for heavy metals, dyes, oils, and chemicals.

Hygienic Significance:

• Prevents waterborne diseases (cholera, typhoid, hepatitis).
• Reduces odors and protects rivers, lakes, and groundwater.

2. Solid Waste Treatment

Goal: Reduce volume, eliminate pathogens, recover resources, and prevent environmental contamination.

Methods:

1. 1. Collection & Sorting:

• Separate biodegradable, recyclable, and hazardous waste.

1. 2. Composting:

• Biodegradable waste decomposes aerobically into humus.
• High temperature (~65–70°C) destroys pathogens and helminth eggs.
• Produces safe, nutrient-rich fertilizer.

1. 3. Incineration:

• Burns waste completely, reducing volume and eliminating pathogens.
• Requires dry waste and controlled temperature (1000–1350°C).
• Suitable for hospitals, large cities, and hazardous waste.

1. 4. Recycling:

• Recovery of metals, glass, plastics, and paper.
• Reduces landfill burden and conserves resources.

1. 5. Sanitary Landfills:

• Engineered disposal sites with layered waste and daily soil cover.
• Equipped with leachate collection and gas management (methane capture).
• Minimizes disease transmission, odors, soil, and groundwater contamination.

Industrial Solid Waste: Must be carefully handled to avoid chemical and microbial hazards.