Machining wastewater, generated from cutting fluid, cleaning agent and grinding fluid production, features "Three Highs and One Difficulty": high COD from refractory emulsified oil, high suspended solids with metal powder, high toxicity containing heavy metal ions (Cr, Ni), and extreme water quality fluctuation. The key challenges are difficult demulsification, toxin removal and standard compliance—stable colloid from emulsified oil paralyzes biochemical systems, and heavy metal-organic complexes cannot be removed by conventional precipitation.

HENGFENG POLYMER have successfully solved these industry pain points through scientific lab small-scale tests and targeted on-site commissioning, realizing efficient and stable treatment of machining wastewater with remarkable decolorization and pollutant removal effects.

The core process adopts physical-chemical combined technology for step-by-step pollutant removal:

Oil Separation → Chemical Enhanced Air Flotation → Aerobic Biodegradation → Secondary Sedimentation → Effluent Discharge

The air flotation tank stage is the key pre-treatment step. Chemical agents are dosed in sequence to achieve efficient purification:

• Caustic soda flakes: Adjust pH value to neutralize acidity
• Decolorant: Destroy organic molecular structures and remove chroma
• PAM flocculant: Agglomerate micro flocs into large particles for solid-liquid separation

This chemical enhancement effectively removes emulsified oil, colloid, chroma and partial heavy metal ions, creating favorable conditions for subsequent biochemical treatment and avoiding system poisoning.

• Add composite decolorant: 250g/ton
• Dose caustic soda flakes: Adjust pH to 7-8, 80g/ton
• Flocculation with anionic PAM: 1g/ton

• Effluent becomes clear and transparent with significant floating sludge formation
• Chroma reduced sharply from 94 to 13 degrees (outstanding decolorization effect)
• COD remains stable at a low level (no obvious change due to low raw water base)
• Emulsified oil and colloid are effectively removed, meeting biochemical treatment inlet requirements

Direct application of the lab scheme to the production line led to poor floc formation and solid-liquid separation due to raw water concentration fluctuation and complex on-site water quality.

We made two targeted optimizations for actual production:

1. Decolorant Dosage Optimization
2. Flocculant Type Replacement

Adjust composite decolorant dosage to 0.2% (2kg/ton)—effectively adapt to water volume fluctuation and water quality complexity in mass production, and strengthen the removal of refractory organic matter and chroma pollutants.

Replace anionic PAM with cationic PAM—aim at negatively charged colloid and fine suspended solids in production wastewater, enhance flocculation efficiency through electric neutralization, and significantly promote sludge aggregation and solid-liquid separation.

• Effluent Quality: Clear and transparent, chroma stably up to standard, no emulsification phenomenon
• Sludge Property: Good settleability and floatability, easy for subsequent treatment and disposal
• COD Stability: Remains at a low level stably, ensuring safe operation of the subsequent biochemical system
• System Adaptability: Strong anti-shock load capacity, adapt to real-time water quality/volume fluctuation in machining production
• Cost Control: Optimized agent ratio, no excessive dosing, realizing economical and efficient treatment

• Targeted Process Design: Take chemical enhanced air flotation as the core, accurately solve the key problem of demulsification and pollutant removal for machining wastewater
• Lab-Field Integration: Based on lab test data, optimize the scheme according to actual production conditions to avoid disconnection between test and application
• Efficient Agent Matching: Adjust agent type/dosage according to pollutant charge property, realize efficient flocculation through electric neutralization
• Stable Operation Guarantee: The optimized process has strong adaptability, ensuring long-term up-to-standard discharge and reducing enterprise environmental risk

HENGFENG POLYMER focus on industrial wastewater treatment with rich experience in machining, metal processing and mechanical manufacturing industries. Our one-stop service covers:

• Free Lab Testing: Accurate analysis of your wastewater quality index
• Custom Process Design: Formulate targeted treatment scheme according to production scale
• On-Site Commissioning & Optimization: Adjust the scheme in real time to ensure treatment effect
• Long-Term Operation Maintenance: Professional after-sales service for stable system operation

Official website: www.pampolyacrylamide.com

LinkedIn:www.linkedin.com/company/jiangsu-hengfeng-fine-chemical-co-ltd

HENGFENG POLYMER customize exclusive and economical machining wastewater treatment solutions for your enterprise, helping you achieve green production and meet international environmental standards!