College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
Everbright Water Technology Development (Nanjing) Co., Ltd, Nanjing, Jiangsu 211106, PR China.
Chemosphere. 2019 Aug;228:264-270. doi: 10.1016/j.chemosphere.2019.04.143. Epub 2019 Apr 22.
Biochars derived from wetland biomass have been extensively applied in water and wastewater treatments. This study investigated the quantity and chemical quality of dissolved organic matter (DOM) released from the biochar prepared from the typical wetland plant (Typha orientalis) at different pyrolysis temperatures (300-700 °C) by using fluorescence excitation-emission (EEM) spectrophotometry with parallel factor analysis (PARAFAC) and UV-Visible spectroscopy. The results showed that the content of DOM released from biochars at low pyrolysis temperatures (300-500 °C) was higher than that observed at high pyrolysis temperatures (600-700 °C). The distribution of DOM components (mainly including three humic acid-like substances, one fulvic acid-like substance and one tyrosine-like substance) varied significantly due to the increase of pyrolysis temperatures. The fulvic acid-like material was the key DOM component at the low pyrolysis temperature while the humic acid-like material became dominant at the high temperature. DOM quality indices also indicated that the percentage of the low molecular-weight DOM increased with the decreasing DOC concentration due to the higher temperatures. The results obtained in this study would be beneficial to guide the rational application of biochars in waste treatments.
由湿地生物质制成的生物炭已广泛应用于水和废水处理。本研究通过荧光激发-发射光谱法（EEM）与平行因子分析（PARAFAC）和紫外可见光谱法联用，研究了在不同热解温度（300-700°C）下由典型湿地植物（香蒲）制备的生物炭释放的溶解有机物质（DOM）的数量和化学质量。结果表明，低热解温度（300-500°C）下生物炭释放的 DOM 含量高于高热解温度（600-700°C）下的含量。由于热解温度的升高，DOM 组分（主要包括三种类腐殖酸物质、一种类富里酸物质和一种类酪氨酸物质）的分布发生了显著变化。在低温热解时，类富里酸物质是关键的 DOM 组分，而在高温时，类腐殖酸物质成为主要组分。DOM 质量指数也表明，由于温度较高，低分子量 DOM 的比例随着 DOC 浓度的降低而增加。本研究的结果将有助于指导生物炭在废物处理中的合理应用。
