Hydrolytic acidification can be pretreatment of high-concentration lincomycinproduction wastewater.
The experiment control reactor pH of 6, 7.5 and 9. Resultsshow that the stable operation period,
combined with the actual engineeringapplication, the best removal efficiency of lincomycin
wastewater hydrolyticacidification can be obtained when pH = 7.5, pH = 9 times, pH = 6 is the worst.
Theaverage COD removal rate is 11.5%, and the highest is 11.65%, under the conditionof optimum
pH(pH=7.5 )。 The volatile acid(VFA )concentration of effluent and theacidification
degree(AD )respectively stable tendency in 148.3~148.3 mmol/L and148.3~12.6%, ORP stability
around -200 mV, the B/C of the wastewater increasedfrom 0.34 to 0.6. The COD removal efficiency of
the subsequent biochemicaltreatment after hydrolysis acidification under the conditions of pH = 7.5
and 9 isbetter than pH = 6. However, because the quantity of adjusting pH is big when theeffluent of
pH = 9 hydrolytic acidification into the subsequent biochemical treatment.
And the reagent consumption increases, higher cost, so comprehensive consideration,selecting the best
pH = 7.5 in engineering application. And the best biochemicaltreatment process after hydrolysis
acidification pretreatment for the lincomycinwastewater is anaerobic + aerobic stage, The total
removal rate of COD is 83.63%.
The COD removal efficiency of different influent COD concentration andreaction time on the
hydrolysis acidification are studied. Results show that under thecondition of optimum pH(7.5 ),
early reactor operation, with the increase of influentCOD concentration
increase(17000~20748.8~24681.2mg/L ), COD removal rateshow a trend of falling after rising
first (13~33.6~29.3% )。 But because of theaccumulation of pharmaceutical wastewater toxicity, as
well as the operation of thehigh concentration(23000mg/L above ), COD removal rate decreased.
Eventually theCOD removal rate steady at around 11% when the microbes is balanced with
theaccumulation of toxic material in the reactor. With the increase of reaction time,because of the
early adsorption effect, the COD removal rate increased rapidly in thereaction of the first 4 h, then
increase slowly. The maximum COD removal rate is14.9% when the hydraulic reaction time is 24 h.
Therefore, optimal reaction time is24 h.
Zero-valent iron (ZVI )and biological fillers were added to strengthen the resultof hydrolysis
acidification of lincomycin wastewater treatment. The experiments arecarried out in three reactors
parallel in parallel: adding the zero-valent iron in thereactor (R1 ), adding the filler of bioreactors
(R2 ), and a ordinary reactor (R0 )。
According to the results of ZVI and biological fillers were added, which can improvethe ability of the
reactor anti water shock loading, and can significantly improve theprocessing effect of hydrolysis
acidification reactor. During the period of stableoperation, the COD removal rate, AD and the B/C of
effluent of the reactor R1 andR2 are significantly higher than that of R0, ORP below R0. The B/C
increase rate ofR1 and R2 effluent is 68.38% and 57.83%, respectively, were significantly higherthan
that of R0 (48.38% )。 The COD removal efficiency of the subsequentbiochemical treatment after
R1 and R2 stage are better than that of R0. And the bestbiochemical treatment process after hydrolysis
acidification pretreatment for thelincomycin wastewater is anaerobic + aerobic stage, The total
removal rate of COD is:
R1, 98.69%; R2, 93.37%. Therefore, the ZVI and biological packing enhancedhydrolysis acidification,
respectively, improved the wastewater biodegradability, toprovide good conditions for the subsequent
biochemical treatment, and improve thesubsequent processing effect obviously.
Key words: lincomycin production wastewater; hydrolysis acidification;zero-valent iron; biological
packing
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Abstract