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Municipal Wastewater Treatment: How It Works Step by Step

Municipal Wastewater Treatment: Process & Technologies

How modern treatment plants transform wastewater into reusable resources while meeting environmental standards

Contemporary wastewater treatment employs a three-stage purification process—primary (physical), secondary (biological), and tertiary (advanced) treatment—to remove up to 99% of contaminants. This systematic approach ensures discharged water meets regulatory requirements while enabling sustainable reuse.

Municipal Wastewater Treatment Municipal Wastewater Treatment

1
Primary Treatment: Physical Separation

Removes 30-50% of suspended solids through mechanical processes

Bar Screens

Remove large debris (>6mm) to protect downstream equipment

Grit Chambers

Settle sand and gravel at controlled flow velocities (0.3 m/s)

Primary Clarifiers

Separate floatable oils and settleable solids (1-2 hr detention)

2
Secondary Treatment: Biological Processing

Degrades 85-95% of organic matter using microbial communities

Biological Reactor Systems

Activated Sludge
MBBR
SBR

Key Components

  • Aeration Tanks: Maintain 2 mg/L DO for aerobic digestion
  • Secondary Clarifiers: Separate biomass (MLSS 2,000-4,000 mg/L)
  • Sludge Return: 25-50% return rate to sustain biomass

3
Tertiary Treatment: Advanced Polishing

Removes residual nutrients, pathogens, and micro-pollutants

Filtration

Sand filters or membrane systems (MF/UF)

Disinfection

UV irradiation or chlorine contact (CT ≥15 mg·min/L)

Nutrient Removal

Biological nitrogen removal, chemical phosphorus precipitation

Treated Water Reuse Applications

Landscape Irrigation

Industrial Cooling

Groundwater Recharge

Municipal Non-Potable

The Critical Role of Wastewater Treatment

Public Health Protection

Eliminates waterborne pathogens and contaminants

Environmental Compliance

Meets stringent discharge regulations (BOD <20 mg/L, TSS <30 mg/L)

Resource Recovery

Enables water, energy, and nutrient recycling

Wastewater Treatment Expertise

Our engineering team provides comprehensive solutions for municipal and industrial wastewater treatment projects.

Technical support available Monday-Friday, 9:00-18:00 GMT+8


Post time: May-08-2025