ABSTRACT
A test was conducted to examine the effect of several electron donors such as glucose, sodium acetate, Fe0, Fe0+glucose and Fe0+sodium acetate on reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) through inoculating the unacclimated anaerobic mixed bacteria. The optimum condition and sus-tainability of Fe0 as electron donor was also been discussed. The results showed that, Fe0+glucose enhanced the dechlorination of contaminant effectively compared to glucose. Sodium acetate, Fe0 and Fe0+sodium acetate were all effective electron donors and Fe0 was the optimum, the optimum initial pH was 8.0 and quantity of added Fe0 was 2.0 g/L. 4-CP was the mainly intermediate product for 2,4-DCP dechlorination. Fe0 could support the electron for reductive dechlorination of 2,4-DCP continuously. In contrast, when so-dium acetate as electron donor, the effect of dechlorination was inferior to Fe0 with the consumption of sodium acetate.
ABSTRACT
The degradation of nitrobenzene(NB) using a combination of Fe0 and anaerobic microorganism was studied. Nitrobenzene could be degraded effectively and the synergistic effect between Fe0 and anaerobic microorganism was apparent,and the nitrobenzene removal efficiency increased with the increasing of Fe0;the optimum pH was 5.0～6.0;as cometabolizing substrate,glucose could promote the degradation of nitrobenzene;In case of high concentration of Fe2+ and Fe3+,the anaerobic biodegradation activity of nitrobenzene were inhibited in a certain degree;0.5 mg/L Fe2+ and Fe3+ were the optimum to accelerate biodegradation rate of nitrobenzene; the degradation kinetics of nitrobenzene were followed by first-order reaction, reaction rate constant reduced along with the concentration of nitrobenzene increased.
ABSTRACT
A batch laboratory test was conducted to examine the effect of biological reductive dechlorination of 2,4-Dichlorophenol(2,4-DCP) by the addition of zero-valent iron(Fe0) in the anaerobic system, through inoculating the anaerobic mixed microorganism acclimated for two months. Meanwhile, several factors that affected "Fe0+ microbe" system were also being discussed. The results showed that, "Fe0+ microbe" system accelerated the biological dechlorination of 2,4-DCP effectively compared to the individual use. The opti-mum quantity of added Fe0 and inoculation was 0.5 g/L and 376.2 mgVSS/L in the combined system respec-tively. It showed the most effective transformation efficiency for 2,4-DCP when initial pH=8.0, whereas it become weaker when initial pH are keeping in acid condition. There existed a proportion between quantity of added Fe0 and inoculation. It enhanced degradable effect of 2,4-dichlorophenol when increased the quan-tity of inoculation at suitable ranges, which generated more enzyme or enzymatic series degraded pollutant.
ABSTRACT
Acidolysis kinetics on the process of the hydrolysis acidification by using glucose as the only energy sources was researched.It was concluded that the acidolysis kinetics constants are V_(max)=8.45d~(-1) and K_s=1089mg/L,under the circumstances of a temperature 37℃?0.5℃and the influent pH value 6.5.The results show that the rate of anaerobic acidification process is greater than that of completed an- aerobic or anoxic process.