Leachate treatment system of Bac Ninh waste power plant

Date public: 28-05-2024||View: 1816

With a total investment of USD 58 million, the Bac Ninh Waste-to-Energy (WTE) Plant is one of three key facilities outlined in Bac Ninh Province’s Master Plan for Environmental Protection. In 2024, Dai Nam Environment Co., Ltd. successfully completed the design, construction, and commissioning of a state-of-the-art Leachate Wastewater Treatment System (STP) with a treatment capacity of 480 m³/day-night.

1. Project Information

Project Name: Leachate Wastewater Treatment System (STP) – Bac Ninh WTE Plant
Project Owner: Dai Nam Environment Co., Ltd.
Location: Bac Ninh WTE Plant, Bac Ninh Province, Vietnam
Treatment Capacity: 480 m³/day-night
Effluent Standard: National Technical Regulation on Industrial Wastewater QCVN 40:2011/BTNMT – Column A

2. Technology Process Diagram

Dai Nam applies a standardized leachate treatment technology compliant with national environmental regulations (Column A). The wastewater treatment process includes the following stages:

Collection Pit: Wastewater passes through a screening unit to remove large solids, preventing clogging in pumps and pipelines.
Equalization Tank: Designed with sufficient retention time to balance flow rate and pollutant concentrations.
Primary Physico-Chemical Settling Tank (Coagulation & Flocculation): Removes suspended solids (TSS) and directs sludge to a sludge storage tank. Partially treated water flows into Intermediate Tank 1.
Intermediate Tank 1/2: Divided into reaction and pumping chambers. pH sensors and mixers ensure optimal conditions before wastewater enters the UASB tank.
UASB (Upflow Anaerobic Sludge Blanket) Reactor: Anaerobic digestion occurs as wastewater is distributed upward through anaerobic sludge.
Anoxic Tank: Denitrification occurs here. Nitrate-rich water is recirculated from the downstream aerobic tank, and activated sludge is returned from the secondary clarifier to maintain biological activity.
Aerobic Tank: Ammonium is oxidized to nitrate. Sludge return from the clarifier to the anoxic tank ensures continuous biological processing. Effluent flows to the biological settling tank.
Biological Clarifier: Separates treated water from microbial sludge using gravity. Structured into clear water, sedimentation, and sludge compartments.
Fenton Reactors 1, 2, 3: Advanced oxidation processes ensure complete removal of residual pollutants and maintain consistent effluent quality.
Coagulation/Flocculation Tank 2: Enhances floc formation using PAC and polymer coagulants, improving the performance of the subsequent settling tank.
Secondary Physico-Chemical Settling Tank: Further reduces TSS. Sludge is pumped to the sludge tank, and clarified water is directed to disinfection.
Disinfection Tank: Chlorine compounds are used to eliminate pathogens. Final effluent complies with QCVN 40:2011/BTNMT – Column A (Kf = 1.1; Kq = 0.9) and is safely discharged into the environment.
Sludge Storage Tank: Collects excess sludge from UASB, primary/secondary settling tanks, and the biological clarifier for further stabilization.

Control Cabinet of the Wastewater Treatment System

The air blower provides oxygen to the equalization tank and aeration tank (aerotank)

The chemical dosing pump transfers chemicals to the treatmen units and disinfection system

3. Key Advantages of Dai Nam's Leachate Wastewater Treatment System

3.1. Technological Strengths

Widely Adopted and Easy-to-Operate Technology: The system uses proven, commonly applied treatment technologies that are easy to manage and ensure consistent effluent quality.
Enhanced Physico-Chemical Treatment: Coagulants are applied to improve the removal of BOD, COD, nitrogen, TSS, and certain heavy metals in the leachate.
Integrated Biological Treatment: A combination of anaerobic, aerobic, and anoxic biological processes thoroughly degrades organic compounds and removes phosphorus via excess sludge.
Optimized Sludge Storage: Sludge tanks are designed with sufficient retention time to reduce solid content effectively.
Belt Press Dewatering: Unlike traditional sludge drying beds, belt press machines operate independently of weather conditions, minimize footprint, and significantly reduce odor emissions.
Flexible Operation Modes: The system supports automatic, semi-automatic, and manual control modes to suit different operational needs.

3.2. Design Highlights

Efficient Tank Layout: Treatment tanks are strategically arranged to align with the site’s layout and allow for future capacity expansion.
Cost-Effective Infrastructure: The main processing tanks are optimally positioned to minimize construction and piping costs.
Smart Chemical Dosing: pH probes are integrated to regulate chemical dosing automatically, reducing chemical usage and overall operating costs.
Gravity-Driven Flow Optimization: By leveraging natural differences in hydrostatic pressure, the system minimizes the need for pumps and lowers electricity consumption.
Automated System Control: Low staffing requirements reduce operational labor costs and mitigate the risk of system failure due to human error.

At Dai Nam Environmental Solutions Co., Ltd., we always tailor our wastewater treatment solutions to the specific characteristics of each project. This ensures that every system is designed with optimal resource utilization and cost-efficiency, while fully meeting all technical and environmental standards.