Supercritical fluid technology is a promising approach for the treatment of wastewater. This article explores the use of supercritical CO2 fluid and supercritical water oxidation (SCOW) for the efficient removal of organic pollutants. The effectiveness of these methods is demonstrated through experimental results and case studies.
Experimental Results – Supercritical CO2 Extraction
| Wastewater Type | Temperature (°C) | Pressure (MPa) | Extraction Time (min) | Pollutant Removal Rate (%) |
|---|---|---|---|---|
| Dichlorvos Wastewater | 60 | 25 | – | 100 |
| Cyanide-containing Wastewater | 30-50 | 10-15 | 20-30 | ~70 |
| Acrylonitrile Wastewater | 500 | 25-28 | – | 98.8 – 99.9 |
Supercritical CO2 fluid technology offers efficient removal of organic pollutants at lower temperatures. It enables the enrichment and removal of organic matter in wastewater through adsorption and subsequent extraction with supercritical CO2 fluid.
Case Studies – Supercritical Water Oxidation
| Wastewater Type | Temperature (°C) | Pressure (MPa) | Reaction Time (s) | Pollutant Removal Rate (%) |
|---|---|---|---|---|
| Sulfur-containing | 723.2 | 26 | 17 | Complete oxidation |
| Acrylonitrile | 500 | 25-28 | – | 98.8 – 99.9 |
| Oily wastewater | Suitable range | Suitable range | Suitable range | 99.9 |
Supercritical water oxidation (SCOW) is an effective method for treating various wastewater types. It achieves rapid oxidation of organic matter in supercritical water conditions, ensuring thorough degradation without toxic by-products.
Supercritical fluid technology, encompassing both supercritical CO2 extraction and supercritical water oxidation, has shown high treatment efficiency in the removal of refractory organic pollutants. It has been successfully applied to high-concentration pesticide wastewater, cyanide-containing wastewater, and oily wastewater, among others.
Summary
Supercritical fluid technology, including both supercritical CO2 extraction and supercritical water oxidation, holds great promise for the treatment of wastewater. It offers efficient removal of organic pollutants, achieving high removal rates in various wastewater types. With its high treatment efficiency, low processing cost, and broad development prospects, supercritical fluid technology represents a significant advancement in the field of wastewater treatment.