嗜酸性氧化亚铁硫杆菌对市政污泥脱水性能的影响

Effect of Acidithiobacillus ferrooxidans on the dewatering performance of municipal sludge

嗜酸性氧化亚铁硫杆菌具有氧化亚铁离子及产酸的特性,可改变污泥颗粒表面电化学性质,从而改善污泥的脱水性能.本文研究了一株嗜酸性氧化亚铁硫杆菌生物酸化铁氧化效果,从pH、Fe(Ⅱ)含量及污泥比阻等方面探究其改善污泥脱水性的可行性及效果,并探究菌群不同接种量对污泥脱水效果的影响.实验结果表明,Fe2+可通过促进嗜酸性氧化亚铁硫杆菌进行生物酸化铁氧化生化过程,最终反应体系pH降为2.6左右,Fe2+含量基本为0,比阻降为0.57×1012 m·kg-1,从而使污泥更易脱水.不同接种量会影响污泥的脱水性能.接种量越大,菌体氧化Fe(Ⅱ)能力越强且时间也越短,平衡时pH越低;当接种量大于50%时,最终pH可降至2.8;污泥的脱水性能得到明显改善.

The Acidithiobacillus ferrooxidans has the characteristics of ferrous oxide ion and acid production,which can change the electrochemical properties of the surface of the sludge particles,thereby improving the dewatering performance of the sludge.This paper studied the effect of the Acidithiobacillus ferrooxidanson bio-acidification and ferrous oxidation.It investigated the feasibility and effect of improving sludge dewatering with the varieties of pH,Fe(Ⅱ)content and SRF and the effect of different inoculum levels on the dewatering performance of the sludge.The experimental results show that Fe2+can promote biochemical process of bio-acidification and ferrous oxidation by promoting Acidithiobacillus ferrooxidans.At last,pH decreased at 2.6,the Fe(Ⅱ)content was basically at 0,and the SRF was 0.57×1012 mokg-1,which made the sludge easier to dewater.Different inoculum levels will affect the dewatering performance of the sludge.The inoculum was larger,the ability of the bacteria to oxidize Fe(Ⅱ)was stronger and the time was shorter.The pH at equilibrium was lower.The pH can reduce to 2.8 when the inoculum is greater than 50%;the dewatering performance of the sludge is significantly improved.