Pilot Investigation of Coal Chemical Wastewater Containing Phenol by Pervaporation Process

Coal chemical wastewater contains a large number of industrial raw materials, such as phenol, resulting in difficulty as target to be treated and the resource waste as industrial raw materials. A pilot pervaporation process is investigated to separate and recycle phenols from coal chemical wastewater to reduce the follow-up biochemical processing load. Operation parameters which affect removing and recovering efficiency are studied, such as temperature, flow rate and downstream pressure. Phenol removal efficiency could reach 50% under the conditions of 70o C, 210 L/h and 3000 Pa. The system could continuously run for 20 cycles. Furthermore, the pervaporation procedure could be enhanced when pumped with gas which made the removal efficiency up to 66%

Operating Conditions of Hollow Fiber Supported Liquid Membrane for Phenol Extraction from Coal Gasification Wastewater

The extraction and recycling of phenol from high concentration coal gasification wastewater has been studied using polypropylene (PP) hollow fiber membrane and polyvinylidene fluoride (PVDF) hollow fiber membrane as liquid membrane support, the mixture of tributyl phosphate (TBP) and kerosene as liquid membrane phase, and sodium hydroxide as stripping agent in the process of extraction. The experiments investigated the effect of the operating conditions of the hollow fiber supported liquid membrane, such as aqueous phase temperature and the connection forms of membrane modules, on the extraction efficiency of phenol from high concentration coal gasification wastewater. The conclusions obtained from lab scale experiments provided guidance for scale-up experiments. So, in the scale-up experiments, three membrane modules connected in parallel, then three membrane modules connected in series were used to increase the treatment capacity and improve the treatment effect, under the operating conditions of wastewater temperature 20 ˚C, PH 7.5~8.1, flow rate 100 L/h and the concentration of stripping phase 0.1 mol/L, stripping phase flow rate 50 L/h, the extraction efficiency of the PP-TBP supported liquid membrane system was 87.02% and the phenol concentration of effluent was 218.14mg/L. And the phenol concentration of effluent met the requirements of further biodegradation treatment

The Effect of Supported Liquid Membrane and Liquid Membrane Phase on the Extraction Efficiency of Coal Gasification Wastewater

The extraction and recovery of phenol from high concentration coal gasification wastewater has been investigated using polypropylene (PP) hollow fiber membranes and polyvinylidene fluoride (PVDF) hollow fiber membranes as supported liquid membrane and the mixture of extraction agent and paraffin as liquid membrane phase, with sodium hydroxide as stripping agent. The effect of the composition of the liquid membrane phase made of N-503-kerosene, tributyl phosphate (TBP)-kerosene or trialkyl phosphine oxide (TRPO)-kerosene on extraction efficiency has been studied. The supported liquid membrane give novel extraction result for the extraction of phenol from high concentration coal gasification wastewater when proper liquid membrane phases and liquid membrane support body materials are used in supported liquid membrane system. Under the operating conditions of waste water temperature at 20 ˚C pH at 8.4, waste water and stripping phase flow rate at 5 L/h, the supported liquid membrane using PP as supported liquid membrane and the extraction agent of TBP with volume proportion of 20% could operate continuously and stablely more than 24 hours and the extraction efficiency be 4% higher than that of PVDF-TBP supported liquid membrane systems

Pervaporation Process with PDMS/PVDF Hollow Fiber Composite Membrane to Recycle Phenol from Coal Chemical Wastewater

To treat coal gasification wastewater containing phenol, polydimethylsiloxane (PDMS)/polyvinylidene fluoride (PVDF) hollow fiber composite membrane was made by dynamic negative pressure coating method, using PVDF hollow fiber membrane as base membrane, PDMS as modifying membrane material, to improve pervaporation performance of PDMS by the cross-linking modification. The influence of cross-linking agent, PDMS concentration, coating time on pervaporation performance of the composite membrane was investigated. Actual coal chemical wastewater with phenol concentration 1600-1800 mg/L, COD 13000-15000 mg/L was treated by the obtained PDMS/PVDF composite membrane, and at temperature 70℃, the flow rate of 10 L/h, pressure under membrane 3KPa, phenol flux 16.81 g/(m2·h), separation factor reaches 8.103

Pilot Scale Hollow Fiber Pervaporation System for Phenol Recycling from Coal to Chemical Wastewater

Polydimethylsiloxane (PDMS)/Polyvinylidene fluoride (PVDF) hollow fiber composite membrane was prepared by dynamic negative pressure method to treat coal to chemical wastewater containing high concentration of phenol, in which PVDF hollow fiber membrane acts as base membrane and PDMS as modified membrane. In the pilot scale experiment, the influence of aeration rate, temperature, flow rate, pressure under membrane on phenol removal efficiency were investigated and operating parameter optimized. At temperature 70℃, flow rate of 150 L/h, pressure under membrane 5 KPa, gas-water ratio 0.3, 75 L coal to chemical wastewater containing phenol fluctuated between 1600 and 1800 mg/L was treated for 6h, and phenol removal efficiency reached 72%. The system ran stably for 120 h and performed well, phenol removal efficiency being kept more than 60%