| With industrial development, the nonbiodegradable organics became more and more to accumulate in the environment. They caused great harm to the ecological environment and human health because of its high toxicity and chemical stability. Currently, there were many treatment methods about the refractory organic wastewater, mainly include physic-chemical and biological methods, and biological methods were always the first choice among these methods because its advantages such as esay opration, high economy, low cost, etc.However, the refractory organic wastewater has complex composition of organic matter, high concentrations of pollutants, toxic, inhibition and toxin to microorganisms, these characteristics made common physicochemical and biological treatment process is difficult to achieve the desired effect. Therefore, strengthening the biological treatment process, improving the biochemical processing efficiency to refractory organic matter is an effective way to solve this problem. And by adding a carrier or other material to react with microorganisms and strengthen the role of generating capacity to increase the degradation make it become a hot and difficult research in recent years. Adding materials such as magnetic powder, powdered activated carbon, zeolite powder, sponge iron, etc. could effectively strengthen the biological treatment effect. This paper used electrolysis and biological method combined, forming an Electrolysis-bioferric method, to deal with refractory organic wastewater, give full play to the advantages of electrolysis and biological method, achieve the traditional biological methods strengthen. The issue of ordinary SBR reactor as control were studied to establish Electrolysis-bioferric method from the following aspects, first by adding inert electrode applied electric field in the SBR reactor, Investigate SBR activated sludge qualities and the degradation of aniline wastewater; secondly, using the iron anode electrolysis study the effects of different factors to the amount of dissolved iron and Fenton-effects on biological iron electrolysis method; Finally, investigated the degradation of actual aniline waste water under optimum reaction conditions( electrolysis time, lower biomass) by sequencing batch reactor, the following conclusions:(1) Comprising with ordinary SBR reactor, the electric field strength of 3 V/cm, 4.5 V/cm, the activated sludge system for both promote and better 4.5 V/cm effect; but the electric field strength is too small was 1.5 V/cm, the effect of promoting SV, MLSS SOUR and no more than two distinct values, while the electric field strength is too large, could make opposite effect to these three natures instead, affect the biological activity of the system; the change of electric field intensity had no effect to the value of MLVSS, moderate field strength of SVI no significant changes in the system, low electric field strength can be slightly on the SVI role in promoting, but higher voltage enables a significant increase in SVI, increasing the odds of sludge expansion.(2) No significant impact on the applied electric field in the system of COD concentration, but the process of degradation of the aniline, the smaller electric field strength had no effect, while at 3 V/cm, 4.5 V/cm electric field intensity, the degradation effect of aniline is much higher than ordinary SBR reactor, under a high electric field conditions will affect the degradation system, both of aniline and TN effluent concentrations illustrate this point, aniline decomposition can produce NH3, NH3-N concentration in the effluent also confirmed this statement from the other side, TP also like this.(3) In the Electrolysis-bioferric reaction system, the effect of different factors on the dissolution of iron ions within the system is different, the optimal conditions of iron leaching are: electrolysis/biological systems, electrolysis time of 30 min, voltage 6 V, and the concentration of activated sludge was 2 g/L. There are H2O2 produced under different biomass in the system, but the amount of hydroxyl radicals is smaller, cannot fully explain class Fenton whether the effects play a role.(4) Investigating the effect of Electrolysis-bioferric treatment on the actual aniline wastewater by using the sequencing batch reactor. Electrolysis apparatus into the reactor, with the voltage increases, the concentration of Fe(?), Fe(?) and TFe in the system were increased, significant improvement of COD removal cannot be seen, from the concentration of ammonia in the effluent,the 5#(6V) reactor was the highest, so was the degradation of aniline. 2 #(bio) reactor has the lowest concentration of ammonia and the most obvious nitrification, the average removal rate of TN were low, denitrification was poor; because of the large amount of iron ions in the system, the synergistic effect with biology could make TP removal better than 2# reactor.Biological research on Electrolysis-bioferric treatment showed that, the appropriate voltage range can promote microbial activity in biological systems, microorganisms may also increase mass transfer efficiency of electrolysis reaction, both methods can play a role in promoting good synergy with each other; when voltage is outside this range, it will play an adverse role to inhibit the effect of biological method, reduce the effect of strengthening treatment. |
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