不锈钢缩放管中典型致垢微生物致垢能力

以电厂循环冷却塔塔底黏泥中分离纯化出的3种致垢微生物铁细菌（IB）、硫酸盐还原菌（SRB）、黏液形成菌（HB）为实验菌种，利用污垢热阻动态模拟实验台，在恒定工况下（水温30 ℃，流速0.4 m/s），动态模拟了3种致垢菌及其混合菌的微生物污垢形成过程。实验测得了3种致垢菌和混合菌的污垢热阻，并对垢样成分进行了ICP-MS和阴离子分析。结果表明：污垢诱导期分别为28 h、45 h、70 h和18 h；污垢热阻渐近值为2 10?4 m2?K/W、1.75 10?4 m2?K/W、1.45 10?4 m2?K/W和4.9 10?4 m2?K/W。由此表明致垢菌的致垢能力大小为：混合菌＞IB＞SRB＞HB。垢样成分分析结果表明：IB垢样成分分析中Fe、C和NO3?含量较多，而重金属离子及Cl?含量较少，说明其具有较强的致垢能力而腐蚀能力较弱；SRB垢样分析显示，S、Fe及Cl?相对较高，且重金属Ni、Cr含量较多，说明其致垢的同时具有较强的腐蚀特性；HB形成的污垢主要以C、N及NO3?为主，且含有一定量的Cl?，表明此菌也具有一定的腐蚀性质。

Study on fouling ability of typical fouling microorganisms in the stainless steel zoom pipe

This study simulated dynamical fouling process of three fouling microorganisms, i.e. iron bacteria (IB)，sulfate-reducing bacteria (SRB)，and slime forming bacteria (HB)，and their mixtures isolated from the slime in the bottom of circulating cooling tower. Experimental conditions were kept constant at 30 ℃ water temperature and 0.4 m/s flow rate. The fouling resistances for IB，SRB，HB and their mixture were by ICP-MS and anion analysis of fouling samples was investigated. The results showed that the induction time of fouling for the four groups were 28 h，45 h，70 h and 18 h，respectively. The fouling resistance asymptotic values were 2×10?4 m2?K/W，1.75×10?4 m2?K/W，1.45×10?4 m2?K/W and 4.9×10?4 m2?K/W，respectively. The fouling abilities of the four groups were in the order of mixture＞IB＞SRB＞HB. The composition analysis of fouling samples showed that IB contained relatively high concentrations of Fe，C and NO3? ，and low contents of heavy metal ions and Cl?， indicating abilities of strong fouling and weak corrosion. The SRB sample contained mainly S，Fe，Cl?，Ni and Cr，indicating strong corrosion abilities. The HB sample mainly contained C，N，NO3? and certain amount of Cl?，showing its ability of corrosion.