Study On Membrane Extraction Of H Acid From Wastewater

Membrane extraction is a kind of new separation pattern with membrane process and liquid-liquid extraction. In contrast with traditional ones, it has many advantages, such as high efficiency, extraction process only happens on the surface of extraction phase and being extracted phase without difficult separation for emulsification between two phases. In recent years, many researches on process techniques, the characteristics of transfer, the design and the application of hollow fiber membrane has been carried out successfully and great progress has been made.In this paper, trialkylamine (7301) was used as reacting agent with n-octanol, kerosene as modifier and diluents respectively. Particular experiments and analysis had been given for extraction characteristics and efficiency. The effect of concentration, temperature, pH, flow rates between organic and water phase on extraction efficiency has been analyzed. In the end, an elaborate design for membrane extraction of H acid was made, which was a good start for its industrialization.It is the first time that H acid from wastewater was treated with membrane extraction. It is proved that the transfer resistance was centralized on the liquid side. The anti-extraction efficiency with NaOH is above 90%, which is good. The results of this research provide theoretical foundation for the design and industrialization of H acid wastewater treatment. Efficiency is greatly improved with the increase of liquid temperature.The highest extraction rate was achieved in one step membrane extraction when the volume flow rate ratio of aqueous to organic phase was 2: 1, water flow rate 0.28ml·min^-1. The measured total mass transfer coefficient (Kw) was 5.55E-07 m·s^-1 In case of high flow rate ratio of organic phase to water phase, the content of H acid can be decreased from 2233 mg·L^-1-2871mg·L^-1- in the initial solution to 43-111 mg·L^-1- using two membrane extraction modules continuously. It indicates that membrane extraction is a feasible and highly efficient process for the removal of H acid from wastewater.