DL/T 5724-2015 in English

Analysis of the core content of the standard

This standard proposes the gradual treatment principle for the treatment of wastewater from the sand and gravel system of hydropower projects, and clearly requires that the SS concentration after treatment is ≤70mg/L, and focuses on standardizing the following technical links:

Key technical points

1. Process selection logic

Differential treatment schemes are adopted according to the suspended matter concentration gradient:

• 20000-50000g/m³: Cyclone purification process is recommended
• 70000-80000g/m³: Polyacrylamide coagulant must be added
• Limited site: Pretreatment + coagulation and sedimentation combined process is adopted

2. Equipment selection specifications

Implementation suggestions

1. Key points of operation and maintenance

1. The trial run must complete a 72-hour full load continuous test
2. The SS concentration of the effluent water must be tested every shift, and the dosage must be adjusted immediately if abnormal
3. Heating and insulation measures must be taken for the pipeline in winter

2. Response to common problems

In response to the blockage of the mud discharge pipe, the standard has mandatory requirements:

• Diameter of the mud discharge pipe ≥ 250mm
• High-pressure water backwashing system
• Pipeline turning radius ≥ 6 times the pipe diameter