Sewage Treatment Equipment Plant Factory

Sewage Treatment Equipment Plant

Comprehensive Solutions for Municipal and Large-Scale Wastewater Management

Managing wastewater from municipalities, large residential complexes, industrial parks, or sizable commercial developments requires robust and efficient treatment infrastructure. Centralized Sewage Treatment Plants (STPs) are essential for protecting public health and the environment by removing pollutants before discharge or reuse. Hebei Huayu Environmental Engineering Co. Ltd. designs, supplies, and installs comprehensive Sewage Treatment Equipment Plants, offering integrated solutions that encompass the entire treatment process from raw sewage inflow to compliant effluent discharge.

Integrated Components and Processes within a Sewage Treatment Plant

A full-scale STP integrates multiple unit processes into a cohesive system:

1. Inlet Works & Preliminary Treatment:

• Screening: Coarse screens (bar racks) remove large debris (rags, plastics, wood). Fine screens (drum, step, or band screens) capture smaller solids.

• Grit Removal: Grit chambers (aerated, vortex, detritus tanks) separate heavy inorganic materials (sand, gravel, eggshells) that could damage pumps and settle in tanks.

• Flow Measurement & Equalization (Optional but Beneficial): Monitors incoming flow. Equalization tanks dampen flow and load fluctuations, providing a consistent feed to biological stages.

2. Primary Treatment:

• Primary Sedimentation Tanks (Clarifiers): Wastewater flows slowly, allowing settleable organic solids to sink as primary sludge and lighter materials (fats, oils, grease - FOG) to float as scum. Scrapers collect sludge; skimmers remove scum. This stage removes 50-70% of TSS and 25-40% of BOD.

3. Secondary (Biological) Treatment - Core Process: Removes dissolved and colloidal organic matter (BOD) and nutrients.

• Biological Nutrient Removal (BNR): Uses anaerobic/anoxic/aerobic zones for nitrogen (nitrification/denitrification) and phosphorus (EBPR) removal.

• Simultaneous Nitrification-Denitrification (SND): Can occur in specific aeration control regimes.

• Conventional Activated Sludge (CAS): Aeration followed by settling.

• Extended Aeration: Longer retention times, lower sludge yields, often used in smaller packaged plants.

• Sequencing Batch Reactors (SBR): Fill, react, settle, decant phases in a single tank.

• Oxidation Ditches: Race-track shaped channels with horizontal aerators.

• Moving Bed Biofilm Reactor (MBBR): Plastic carriers in aerated tanks provide surface for biofilm growth; no sludge recycling needed.

• Membrane Bioreactor (MBR): Combines biological treatment with ultrafiltration membranes, replacing secondary clarifiers. Produces high-quality effluent.

• Fine Bubble Diffusers: Efficiently transfer oxygen using membrane discs/tubes.

• Surface Aerators: Mechanical devices agitating the surface to entrain oxygen.

• Aeration Tanks: The heart of most plants. Microorganisms (activated sludge) consume organic pollutants. Requires oxygen supply via:

• Biological Reactor Types:

• Nutrient Removal: Integrated processes like:

4. Secondary Clarification: Activated sludge mixed liquor from aeration flows to large circular or rectangular clarifiers. Biomass (activated sludge) settles, forming a return sludge stream (pumped back to the aeration tank) and waste activated sludge (WAS). Clear supernatant (treated effluent) flows over weirs.

5. Tertiary Treatment (Advanced Polishing):

• Ultraviolet (UV) Radiation: Effective, chemical-free.

• Chlorination: Dosing chlorine (gas, hypochlorite) followed by Dechlorination (e.g., sulfur dioxide) if needed before discharge.

• Ozonation: Powerful oxidant/disinfectant.

• Filtration: Sand filters, cloth media filters, or membrane filters (MF/UF) remove residual suspended solids.

• *Nutrient Removal (Chemical): Chemical precipitation (using Alum, Ferric Chloride, Lime) for phosphorus removal if BNR is insufficient.

• Disinfection: Essential for pathogen kill:

6. Sludge Treatment & Handling: A major part of the plant:

• Anaerobic Digestion: Produces biogas (methane) for energy recovery. Common in large plants.

• Aerobic Digestion: Uses oxygen; simpler but no energy recovery.

• Lime Stabilization: Chemical treatment.

• Sludge Thickening: Gravity thickeners, Dissolved Air Flotation (DAF), or centrifuges concentrate sludge volume.

• Sludge Stabilization: Reduces pathogens and volatile solids, making sludge safer for disposal. Methods:

• Sludge Dewatering: Centrifuges, Belt Filter Presses, Screw Presses, or Filter Presses remove water, producing a semi-solid "cake" (20-35% solids).

• Sludge Disposal/Utilization: Cake is landfilled, incinerated, or beneficially used (e.g., agricultural land application as biosolids, subject to strict regulations and quality criteria).

7. Control & Monitoring: Centralized SCADA systems monitor flows, levels, dissolved oxygen (DO), pH, turbidity, and control pumps, blowers, chemical dosing, and alarms. Critical for optimizing performance and meeting permit requirements.

Advantages of a Comprehensive Sewage Treatment Equipment Plant

• High Treatment Capacity: Designed for large populations or industrial flows.

• Pollutant Removal Efficiency: Achieves high removal rates for BOD, COD, TSS, pathogens, and nutrients (N, P) to meet stringent discharge standards.

• Process Flexibility & Robustness: Can handle variations in flow and load; multiple process options allow tailoring to specific needs.

• Resource Recovery Potential: Biogas from anaerobic digestion can generate heat/power. Treated effluent can be reused (irrigation, industrial). Biosolids can be used as fertilizer/soil conditioner.

• Environmental Compliance: Engineered to consistently meet national and local effluent quality regulations.

• Water Reuse Enablement: Tertiary treatment produces effluent suitable for non-potable reuse applications.

• Long-Term Infrastructure: Provides a permanent, reliable solution for community wastewater management.

• Integrated Design: Optimized interaction between all unit processes for overall efficiency.

• Operator Support: Designed with maintenance and operation in mind, supported by control systems.

Hebei Huayu Environmental Engineering Co. Ltd.'s Sewage Treatment Equipment Plants represent the backbone of modern wastewater infrastructure, delivering essential public health protection and environmental conservation for communities and industries.