Abstract：
The OH production by adding magnetite (MGT) alone has been reported in composting. However, the potential of nitrilotriacetic acid (NTA) addition for magnetite-amended sludge composting remained unclear. Three treatments with different addition [control check (CK); T1: 5 % MGT; T2: 5 % MGT + 5 % NTA] were investigated to characterize hydroxyl radical, humification and bacterial community response. The NTA addition manifested the best performance, with the peak OH content increase by 52 % through facilitating the cycle of Fe(Ⅱ)/Fe(Ⅲ). It led to the highest organic matters degradation (22.3 %) and humic acids content (36.1 g/kg). Furthermore, NTA addition altered bacterial community response, promoting relative abundances of iron-redox related genera, and amino acid metabolism but decreasing carbohydrate metabolism. Structural equation model indicated that temperature and Streptomyces were the primary factors affecting OH content. The study suggests that utilizing chelators is a promising strategy to strengthen humification in sewage sludge composting with adding iron-containing minerals.
摘要：
据报道，堆肥中单独添加磁铁矿（MGT）会产生OH。然而,添加次氮基三乙酸（NTA）用于磁铁矿改良污泥堆肥的潜力尚不清楚。研究了三种不同添加量的处理[对照检查（CK）;T1：5％MGT;T2：5％MGT+5％NTA]以表征羟基自由基，腐殖质和细菌群落反应。NTA添加表现出最佳性能，通过促进Fe（Ⅱ）/Fe（Ⅲ）的循环，OH含量增加了52％。导致最高的有机物降解（22.3％）和腐殖酸含量（36.1g/kg）。此外，NTA添加改变了细菌群落反应，促进铁-氧化还原相关属的相对丰度，和氨基酸代谢，但减少碳水化合物代谢。结构方程模型表明，温度和链霉菌是影响OH含量的主要因素。研究表明，利用螯合剂是一种有前途的策略，可以通过添加含铁矿物来加强污水污泥堆肥中的腐殖化。
