污泥炭基微电解填料的制备、表征和实验研究

Preparation, Characterization and Experimental Study of Sludge Carbon-based micro-electrolysis filler

污泥通过水热碳化和热解炭化方法制备得到污泥炭,其含碳量为38.46%、碘吸附值为224mg/g、比表面积为214m^(2)/g,表明污泥炭有较高的含碳量和比表面积,还包含Al_(2)O_(3)、SiO_(2)等矿物成分。以污泥炭为原料,与铁粉、合金粉、粘土等原料按照一定配比混合、造粒、烘干,在氮气保护气氛下烧结得到污泥炭基微电解填料。在印染废水pH为3.5左右,固液比为1:2,曝气2h,自制的TG1和TG5填料对印染废水COD去除率分别达到50.40%和57.07%。进一步通过连续流实验比较了自制的填料和市售填料的微电解效果,自制的TG5填料对印染废水COD的平均去除率最高,去除率为26.18%,微电解后pH也最高。TG1和TG5填料的表征分析表明,填料内部有较多空隙,均匀分布的单质铁、碳和合金元素在填料内部可形成大量的微原电池,用于印染废水微电解反应时可破坏发色基团,提高电化学反应速率。

The sludge carbon was prepared by hydrothermal carbonization and pyrolysis carbonization.Its carbon content was 38.46%,iodine adsorption value was 224 mg/g,specific surface area was 214 m^(2)/g,which indicated that the sludge carbon had high carbon content and specific surface area.In addition,the sludge carbon also contained Al_(2)O_(3),SiO_(2) and other mineral components.Sludge carbon was used as raw material,mixed with iron powder,alloy powder,clay and other raw materials according to a certain proportion,then the mixture was granulated,dried,and sintered under nitrogen atmosphere in order to obtain sludge carbon-based micro-electrolysis filler.When the pH value of printing and dyeing wastewater is about 3.5,the solid-liquid ratio is 1:2,and the aeration is 2 h,the removal rate of COD of printing and dyeing wastewater by TG1 and TG 5 fillers is 50.40% and 57.07%,respectively.Furthermore,the micro-electrolysis effect of self-made filler and commercial filler was compared by continuous flow test.The TG 5 packing had the highest average removal rate of COD in the printing and dyeing wastewater,the removal rate is 26.18%,and the pH value is also the highest after micro-electrolysis.The characterization of TG1 and TG5 fillers showed that there were many micropores in the fillers,and a large number of micro primary batteries could be formed in the fillers with homogeneous distribution of elemental iron,carbon and alloy elements,which could destroy the chromophore group and improve the electrochemical reaction rate when used in the micro-electrolysis reaction of printing and dyeing wastewater.