芬顿铁泥组分解析及其对造纸废水厌氧处理的影响

Analysis of Fenton sludge fraction and its effect on anaerobic treatment of papermaking wastewater

芬顿技术深度处理造纸废水过程中会产生大量铁泥,处理处置困难,但芬顿铁泥中含有大量三价铁,具有很高的利用价值。为此,对芬顿铁泥的元素组成、物相结构及电化学特性进行了解析。结果表明,芬顿铁泥中铁元素含量达到38.18%,主要以无定形的FeOOH形式存在,且具有氧化还原特性和一定的电子转移能力,芬顿铁泥的电子接受能力和电子供给能力分别为62.45μmol·g^(-1)和4.59μmol·g^(-1)。将芬顿铁泥投加至厌氧序批式反应器中,考察其对造纸废水厌氧处理的影响。结果表明,当芬顿铁泥投加量为5、10和20 g·L^(-1)时,造纸废水厌氧消化过程中溶解性COD的去除率由59.88%(对照组)分别提高至63.92%、68.40%和70.34%。芬顿铁泥投加使甲烷产量分别提高了7.96%、15.81%和19.77%,同时显著降低沼气中二氧化碳与氢气的含量,提高甲烷的占比。投加芬顿铁泥的反应器出水均检测到较高的二价铁离子浓度,说明反应器中发生了异化铁还原作用,从而提升了造纸废水厌氧消化效果。

A large amount of iron sludge was produced during the advanced treatment of papermaking wastewater by Fenton technology,and it is difficult to dispose properly.However,Fenton sludge contains a large amount of ferric iron,which has a high utilization value.In this study,the elemental composition,phase structure and electrochemical characteristics of Fenton sludge were analyzed.The results showed that the iron content in Fenton sludge reached 38.18% and mainly existed in the form of amorphous FeOOH.Fenton sludge had redox characteristics and a certain electron transfer ability.The electron accepting capacity and electron donating capacity of Fenton sludge were 62.45μmol·g^(-1)and 4.59μmol·g^(-1),respectively.The effect of Fenton sludge on anaerobic treatment of papermaking wastewater was studied by batch experiments.The results showed that the removal efficiencies of soluble chemical oxygen demand increased from 59.88%(control group)to 63.92%,68.40%and 70.34%,respectively,at the dosages of Fenton sludge of 5,10 and 20 g·L^(-1).The methane yield of the reactors increased by 7.96%、15.81%and 19.77%,respectively.Moreover,the proportion of carbon dioxide and hydrogen in the biogas decreased,and the proportion of methane increased.The higher Fe2+concentration was detected in the effluent of experimental group than that in control group.This indicated that Fenton sludge in the reactor induced the dissimilatory Fe(Ⅲ) reduction,thus promoting the anaerobic digestion of papermaking wastewater.