Method for treating waste water in production of para-hydroxyphenyl hydantoin

Abstract

The invention discloses a disposing method of waste water in the p-hydroxybenzene hydantoin manufacturing course, which comprises the following steps: salting waste water with phenol mother liquid through soluble salt; stewing to divide water-phase; blending salted water phase and waste water according to 1:1-8; adsorbing the composite liquid in the resin adsorbing column under normal temperature at 0.1-2 BV per h flow; desorbing the adsorbed saturated resin; preparing for next adsorbing disposal. The invention removes p-phenolsulfonate by over 99 percent, which doesn't pollute environment.

Description

Technical field [0001] The invention relates to a wastewater treatment method, in particular to a wastewater treatment method in the production of p-hydroxyphenylhydantoin. Background technique [0002] P-Hydroxyphenylhydantoin is an important chemical raw material and pharmaceutical intermediate, mainly used in the biological preparation of D-p-hydroxyphenylglycine. Using glyoxylic acid, urea, and phenol as raw materials, synthesis of p-hydroxyphenyl hydantoin in a certain amount of acidic medium will produce high-concentration phenol-containing wastewater. If it is directly discharged without effective treatment, it will inevitably cause long-term serious pollution to the environment . [0003] At present, only the following methods have been reported in the domestic treatment methods of this production wastewater: distillation-extraction-adsorption process. [0004] The method is to firstly distill the mother liquor wastewater under reduced pressure, combine the distillate and...

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Problems solved by technology

[0005] It can be seen that the above-mentioned treatment method has lengthy process, cumbersome process and high cost. Specifically, it has the following disadvantages: ① vacuum distillation has high energy consumption and high requirements for equipment, and professional training must be carried out to operators, which will undoubtedly increase Treatment cost; ②Extraction is indeed a technology for treating phenol-containing wastewater, but there are strict requirements for the selection of extractant, that is, it must meet the requirements of non-toxicity, good chemical stability, easy recovery, and low price. The treatment effect of low-concentration phenol-containing wastewater is better, and it can only be used as a pretreatment method for high-concentration phenol-containing wastewater. The above extraction uses two-stage extraction to achieve a certain pretreatment effect. The process is complicated and increases the treatment cost. The back-extraction of the post-organic phase also has to be considered, so the above method seems to have no advantage in terms of process or cost

③ The adsorption resin is XD-303, which is a macroporous adsorption resin without any functional group modification. The adsorption of phenol molecules is only achieved by the van der Waals force, which must be consumed under the premise of ensuring the same treatment effect. A larger amount of resin, that is, the three-column series process is adopted; ④The desorption liquid is recovered by vacuum distillation, cooling, crystallization, suction filtration, etc. Although the recovery rate of phenol is close to 100%, the process is cumbersome and the treatment cost On the high side, unacceptable for most SMEs

[0006] Therefore, the above method is complicated to operate, the cost is high, and it is difficult to popularize and apply. Therefore, it is urgent to develop a wastewater treatment method with simple process, low cost, which can realize waste recycling and good effect in order to achieve better environmental and economic benefits.