赤铁矿抑制硫酸盐废水厌氧消化产甲烷过程中硫化氢形成与机制

Effect of Hematite on the Inhibition of Hydrogen Sulfide Formation and Its Mechanism During Anaerobic Digestion and Methanogenesis of Sulfate Wastewater

为了实现高浓度硫酸盐废水厌氧消化过程中甲烷的高值化产出,本文探究了赤铁矿添加对硫酸盐废水厌氧消化系统中硫化氢形成的抑制效果与作用机制.以人工配制的硫酸盐废水为研究对象,考察不同赤铁矿投加量下高浓度硫酸盐废水的厌氧消化性能,并分析反应体系中硫元素的迁移转化途径.结果表明,未添加赤铁矿的反应器的厌氧消化启动时间及硫化氢浓度分别是0. 5 g·(30 mL)^(-1)赤铁矿添加组的1. 64倍及180倍.这说明添加赤铁矿不仅能够缩短厌氧消化的延迟时间,而且有效降低反应器中硫化氢的浓度.硫元素的动态平衡分析结果显示,添加0. 5 g·(30 mL)^(-1)赤铁矿反应器中固体硫含量占总硫的96. 9%. XPS结果进一步表明,赤铁矿添加主要是促废水中的S_(2-)以Fe S_2的形式固定.因此,赤铁矿的添加能够有效加速硫酸盐废水厌氧消化过程,同时降低反应器中硫化氢的浓度.

In order to achieve the high value production of methane, this paper investigated the effect and mechanism of hematite on the inhibitation of the formation of hydrogen sulfide during the anaerobic digestion of high-concentration sulfate wastewater. Different dosages of hematite were added to artificially prepared sulfate wastewater to analyze the migration and transformation pathways of sulfur in the reaction system. The results showed that the delay time of the anaerobic digestion process and the hydrogen sulfide concentration in the control reactor were 1.64 times and 180 times those in the reactor with the optimal hematite dosage of 0.5 g·(30 mL)^-1, respectively. Thus, the addition of hematite effectively shortened the delay time and reduced the concentration of hydrogen sulfide. Dynamic equilibrium analysis of sulfur in different anaerobic digestion reactors showed that the solid sulfur content in the reactor accounted for 96.9% of the total sulfur. XPS results further demonstrated that hematite mainly enhanced the fixation of S^2- in the form of FeS2. Therefore, the addition of hematite can effectively accelerate the anaerobic digestion of sulfate wastewater while reducing the concentration of hydrogen sulfide in the reactor.