Treatment of phenol-containing wastewater
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This post was last edited by cdpulin on 2011-3-1 13:41. Wastewater 1: Flow rate of 11 m3/h, pH = 6–9, COD = 40 mg/L, phenol concentration = 9.5 mg/L, Na+ = 1000 mg/L. Requirement: Phenol concentration in the effluent must be less than 1 mg/L； Wastewater 2: Flow rate of 11 m3/h, pH = 13, COD = 2500 mg/L, phenol concentration = 120 mg/L, Na+ = 5500 mg/L; the COD originates mainly from propylene and a small amount of polymers. Requirement: The phenol concentration in the effluent must be less than 1 mg/L, and the COD must be less than 500 mg/L ； Wastewater 3: Flow rate of 11 m3/h, pH = 8–10, COD = 15,000 mg/L, phenol concentration = 750 mg/L, Na+ = 5,500 mg/L; the COD originates mainly from propylene and a small amount of polymers. Requirements: The phenol concentration in the effluent must be less than 1 mg/L, and the COD must be less than 500 mg/L. The treatment takes place within the workshop, requiring little space, and the water is reused. Do you all have any good suggestions?
This post was last edited by cdpulin on 2011-3-1 13:45. There are very few people who care about it here! Another forum is buzzing with intense discussions. Solvent extraction for phenol removal should be a good option, but the user rejected it due to special reasons related to water reuse. Since the processing is carried out in a workshop, requiring little space and a short residence time, the biochemical method is also ruled out. Due to water reuse, traditional treatment methods such as chemical dosing, oxidation, and sedimentation are also excluded. Stripping causes secondary pollution, but users don’t take this into account. Distillation, stripping, etc., have too high energy consumption; phenol is not considered due to the formation of low-concentration azeotropes with water. We’re pretty much cornered. Our approach: Use improved pervaporation to remove and concentrate propylene, and then employ membrane-based chemical absorption to remove, recover, and purify phenol. However, if conventional membrane-based chemical absorption processes are used, the investment cost for the membrane modules will be very high. If the wastewater contains 2-chlorophenol, 2,4-dichlorophenol, 2-nitrophenol, or 2,4-dinitrophenol instead of phenol, the investment cost for the membrane modules can be reduced by 3 to 5 times. This is because the volatility of these substituted phenols in low-concentration aqueous solutions is 3-10 times higher than that of phenol. To this end, we allowed the wastewater and hydrogen other than propylene to undergo mass exchange in a membrane contactor before entering the membrane-permeable chemical absorption membrane module. In this way, to achieve the same phenol removal effect, the investment in membrane modules is reduced by more than half. The reason for this is that the diffusion coefficient of phenol in hydrogen is 2-3 times that in air.
Reply to 3# yjqin1: “Using improved pervaporation to remove, recover, and concentrate propylene” is simply fantasy. First, are there any pervaporation membranes that can withstand the effects of propylene glycol at present? Second, the pervaporation membranes currently used in industrial applications in China are employed for the dehydration of organic solvents. Why doesn’t extraction work?
This post was last edited by qazxsw119 on 2012-11-3 09:27. I wonder if the project has progressed any further. Wastewater 1 can be treated by using macroporous adsorption resins to remove phenol, and its reuse is feasible ； For wastewater 2 and 3, using resin adsorption will ensure that the phenol levels meet the standards, but it is difficult to achieve the required COD levels. If biochemical treatment is not employed for this wastewater, the costs will be very high. I don’t understand how a company of such scale can limit such a large volume of water to be treated only within its workshop! ! !
To understand the water quality conditions of the poster, as well as their specific requirements for the treated water. If there are no other substances present in the wastewater, it is relatively easy to meet those requirements; you can contact qq1147514362
Saw this ancient post； Wastewater 3 should be wastewater from a phenol production facility. The project we are working on involves photochemical oxidation pre-treatment; the initial COD level is around 15,000. Through photochemical oxidation, phenol and other aromatic compounds are completely broken down to such an extent that they can no longer be detected. As a result, the COD level decreases by 30%, reaching 10,000, with a B/C ratio greater than 50% ； The TDS of this water is around 20,000; when mixed with other low-concentration wastewater, the TDS is kept at 5,000 ； Finally, the COD of the aerobic effluent is below 300.
Oxidation precipitation plus adsorption can achieve 0.02