How to use the solvent extraction technology of high concentration phenol wastewater treatment
abstract: the new highly effective extractant - HLE salicylic acid industrial wastewater treatment, extraction rate > 99. 5% of extraction rate > 99%, the distribution ratio of more than 100.
and sources of wastewater containing phenol toxicity is big, serious damage to the ecological environment, this kind of treatment of wastewater has become a people attaches great importance to environmental protection.
according to the current recycling and treatment technology of wastewater containing phenol and economic calculation results, the concentration is higher than 1, 000 mg/L high concentrations of phenol wastewater, adopts the solution extraction process, can yet be regarded as an economic and efficient processing method. Using the self-developed new extractant - H LE processing in the production of salicylic acid phenol content as high as 6, 000 a 12 OOOmg/L centrifugal wastewater, recovery of phenol sodium for salicylic acid production process, the extracting agent H LE recycled, has obtained the good effect. This study discusses the extraction agent H LE under various conditions on the distribution ratio, extraction rate, extraction rate.
experimental section 1.
1 sample and reagent acid waste water samples taken from a chemical plant in jiangsu industrial wastewater, phenol content of 7 732 mg/L, pH = 1. 51, Na2SO4 content is 13. 4%, the appearance is reddish brown.
extraction agent for H LE, diluent for aviation kerosene, determination of phenol content are analytically pure reagents used.
2 extraction test at room temperature to take a certain amount of extraction solvent and aviation kerosene ( H LE: kerosene = 1:2) And 100 ml water add 250 ml separatory funnel, the oscillator, continuous oscillation after a certain period of time to place stratification, take the lower aqueous phenol content.
1。 3 extraction experiments take a certain amount of NaOH aqueous solution (
The mass fraction of 20%) And add to the extraction agent, placed on oscillator, the oscillation after a certain period of time to place stratification, cool to room temperature, extraction liquid phenol content measurement.
4 analysis method using phenol content olfactory titration, pH value using the glass electrode method.
2 2 test results and discussion. Compared to 1 on the extraction rate and the influence of the distribution ratio
test conditions: phenol content of 7 732 mg/L, a 1 pH. 51, the temperature is 25 ℃, the stratification time 3 min.
by table 1 shows that with the decrease of the compared, extraction rate and the distribution ratio of a downward trend. From the perspective of the relationship of compared with the effect of wastewater treatment, compared the effect of wastewater treatment, the better, is good for layering. Of course, along with the waste water containing phenol concentration, the change of concentration of extractant, and other related conditions, compared to do corresponding adjustments.
2。 2 the influence of temperature on the extraction rate and the distribution ratio
in the amount of waste water containing phenol 7 732 mg/L, pH of 1. 51, compared to 1:1, layered time 3 min experimental conditions, determine the extraction efficiency of removing phenol at different temperatures. Experimental results show that temperature, extraction rate fell slightly, but little change. In practical industrial production when water temperature in the 20 ~ 40 ℃ for extraction can be directly.
2。 3 the influence of extraction time on extraction rate
test conditions: phenol content in 7 732 mg/L, pH of 1. Compared to 51, the temperature is 25 ℃, 1:1. Test results as shown in figure 1
figure 1 illustrates the: H LE a kerosene system fast extraction phenol of balance, and thus in a certain stratification time extraction time of phenol extraction rate has no obvious influence. This test to choose extraction time for 3 min.
2。 4 effect on the extraction rate of phenol concentration
test conditions: time is 3 min, compared to 1:1, NaOH dosage 20 ml ( 20%) 。 Test results are shown in table 2
by table 2 shows that with the increase of the concentration of the organic phase containing phenol back extraction rate declined, but extractant recycling, no accumulation of organic phase of phenol content. 2. 5 reverse extraction time on the extraction rate of layered
test conditions: oil alkali than 1 & # 39; 1, reverse extraction dosage of N aOH 10 ml ( 20%) Original concentration of phenol, organic phase 8 446 mg/L. Test results are shown in table 3
from table shows that extraction rate were affected by the time, as long as the blender, reverse extraction equilibrium time is short, reverse extraction stratification is complete, the extraction rate of > 99%.
table 3 extraction time on the extraction rate of layered
2. 6 add alkaline effects on the extraction rate of
test conditions: layering time is 3 min, original phenol concentration in organic phase 8 446 mg/L, reverse extraction with N aOH concentration was 20%. Test results are shown in table 4.
by table 4 shows that with the increase of amount of alkaline, the extraction rate were increased rapidly, the actual amount of alkaline alkaline is theory of 1. When five times to reach a turning point, l 0mL) Gradually improve the extraction rate.
2。 7 oil alkali ratio on the extraction rate of
the influence of test conditions: time is 3 min � � organic phase 8 446 mg/L, original phenol concentration NaOH dosage of 10 ml ( 20%) 。 Test results are shown in table 5.
the table 5 shows that with the increase of alkali than oil, the extraction rate were reduced. Increase oil alkali than can improve the extraction solution of phenol concentration, sodium phenolate recycle, but must make the pledge that we shall have certain free alkali content in the extraction liquid. Conclusion
3 data analysis by above knowable, extracting agent H LE agent has good performance, fast extraction, extraction equilibrium, extraction rate reached 99. More than 5%, the extraction rate of more than 99%, distribution ratio of more than 100, and solubility is small, small consumption, hierarchical fast. H LE has been several salicylic acid production enterprise applications, the user response is good. Practice shows that extraction agent H LE is a kind of excellent extraction agent, have broad application prospects.
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