I would like to ask how to treat wastewater with high concentrations of suspended solids
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There is a project at present where the wastewater contains high concentrations of suspended solids, mainly coal dust particles, with values reaching around 15,000. Other pollutants include COD at approximately 30,000, BOD5 at around 10,000, oils and fats below 200, and a pH of slightly acidic, around 6. Has anyone experienced dealing with such wastewater? I’m seeking advice. Please feel free to share your insights; thank you!
Coal dust particles suspended in water will settle rapidly through natural sedimentation if there is no special suspending agent present in the water. If the COD value is high, it is necessary to choose biochemical and physical or chemical treatment methods based on the components contributing to the COD. While treating COD, most of the oils and fats are likely to be degraded as well. The specific process needs to be developed by professional water treatment process design firms and engineering companies; individuals are unable to handle such tasks.
It is recommended to use an aeration grit chamber and increase the retention time, which can remove most of the suspended solids； Thereafter, coagulation sedimentation or air flotation is used (to remove not only suspended particles but also oils) ； The treated water enters the biological treatment unit.
Based on the materials provided by the poster, the analysis is as follows: ① It is recommended to analyze the components that contribute to COD; COD levels are measured by testing the water sample after natural precipitation as well as after adding chemicals to induce precipitation, in order to determine the removal rate； ②Given the high concentration of coal slurry particles, it is possible to remove them by adjusting the pH, adding coagulants, and using centrifugal dehydration devices. ③ After physical and chemical treatment, the COD concentration is measured, and based on this, it is determined whether further treatment via biological methods or physical and chemical methods is necessary. Personal opinion, for reference only.
It is necessary to analyze the water quality. Generally, coagulation and sedimentation alone will not solve the problem; biochemical treatment is certainly not sufficient in such cases. Aeration seems to be of limited use as well. Ozone oxidation or electro-oxidation is required. The specific approach depends on an analysis of the water quality, after which a suitable treatment process can be devised. If needed, I can help you contact a reliable company, but I won’t be involved in the process – you’ll need to handle the negotiations yourselves
What kind of wastewater is this from a factory? The data is incorrect; we have dealt with over 20 cases of coal chemical wastewater. Is the COD this high?