Innovative Approaches to Tackle Low-Concentration Wastewater Challenges

1. Introduction: The Crisis of "Water Competition" in Wastewater Plants

Recent reports from Chinese media highlight a critical issue: Sewage Plants are struggling with insufficient influent volume and low pollutant concentrations. As one plant manager stated, *"Our 2,000-ton/day facility processes less than 100 tons daily, crippling operational efficiency."* This mirrors a systemic problem – outdated infrastructure, flawed payment models, and "over-designed" facilities.

2. Root Causes of Low-Concentration Wastewater

2.1 Incomplete Sewer Networks & Rainwater Infiltration

Inadequate funding leads to fragmented pipe networks. Rainwater dilution reduces COD/BOD levels, increasing treatment complexity.

2.2 Overbuilt Treatment Capacities

Facilities designed for future expansion often operate at <50% capacity (e.g., 18 plants processing 15,000 tons vs. 47,000-ton design).

2.3 Flawed "Pay-by-Volume" Model

Revenue tied to water volume incentivizes diluted influent, discouraging concentration improvement.

3. Cutting-Edge Solutions for Low-Concentration Wastewater

3.1 Smart Carbon Source Optimization

• Strategy: Dynamic dosing points (e.g., shifting methanol injection from anaerobic to anoxic zones)

• Impact: 30% reduction in carbon consumption while maintaining TN/TP removal rates.

3.2 Process Modifications: AAO+ Systems

Integrating low-oxygen aeration zones reduces energy use by 25% and enhances COD/TN removal.

3.3 Hydrolytic Acidification Pretreatment

Adding anaerobic hydrolysis tanks converts complex organics into bioavailable carbon, boosting denitrification efficiency by 40%.

3.4 Critical Adjustments to Primary Sedimentation

3.5 External Carbon Source Selection

Acetate-based sources achieve 2× faster denitrification vs. glucose. Pilot testing is essential for cost efficiency.

3.6 Advanced Technologies: CANON & Short-Cut Nitrification

• CANON: Saves 100% external carbon and 66% aeration energy.

• Short-Cut Nitrification: Reduces carbon demand by 40%.

4. Integrated Plant-Pipe-River Management: The Future

China’s 2025 policy mandates "plant-pipe-river" integration. Key steps include:

• Real-time monitoring sensors in networks

• AI-driven load forecasting

• Performance-based contracts

5. Case Study: JUNTAI’s MBBR & Bio-Block Applications

A Jiangsu plant using JUNTAI’s Mbbr Media + Bio-Blocks achieved:

• 25% lower aeration energy (via fine-bubble diffusers)

• 15% higher nitrification in low-C/N conditions

• 20% reduced sludge volume (linked to dewatering systems)