Guangdong Provincial Engineering Technology Research Center for Life and Health of River&Lake, Pearl River Water Resources Research Institute, Pearl River Water Resources Commission of the Ministry of Water Resources, Guangzhou 510611, China; Guangdong Industrial Contaminated Site Remediation Technology and Equipment Engineering Research Center, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Guangdong Provincial Engineering Technology Research Center for Life and Health of River&Lake, Pearl River Water Resources Research Institute, Pearl River Water Resources Commission of the Ministry of Water Resources, Guangzhou 510611, China.
Sci Total Environ. 2021 Apr 20;766:142618. doi: 10.1016/j.scitotenv.2020.142618. Epub 2020 Oct 1.
The affinity of biochar (BC) adsorbing phosphate was weak, while generation of magnesium oxide (MgO)-BC nanocomposites that transformed the crystal structures of BC would change the adsorption processes in improving the phosphate adsorption. Hereon, four different crystal structure of absorbents were selected to illustrate why the crystal structures and surface properties of absorbents were of great importance for the phosphate adsorption. The results showed that MgO/KBC with higher combination degree between MgO and KBC could change the normal crystal structure (MgO/KBC1, MgO phase (dominant)) to C-Mg-O phase (dominant). Therefore, MgO/KBC could achieve highest adsorption rate (k, 8.059 g mg min) and q (maximal adsorption capacity, 121.950 mg g) for phosphate adsorption among absorbents, and even it had high anti-interference capacity for anions and natural organic matter (NOM). The mechanisms of MgO/KBC for phosphate adsorption were hydrogen-bond interaction, inner-sphere complexation and surface chemical adsorption; adsorption of phosphate on MgO/KBC1 was mainly controlled by inner-sphere complexation (Mg-O-POH, Mg-O-POH species). In addition, the adsorbability of MgO/KBC for phosphate could be restored after recalcination, which further proved that an efficient nanocomposite, calcinated from waste biomass (fallen leaves), was proposed to control eutrophication.
生物炭 (BC) 对磷酸盐的亲和力较弱，而生成氧化镁 (MgO)-BC 纳米复合材料则会改变 BC 的晶体结构，从而改变吸附过程，提高对磷酸盐的吸附性能。在此，选择了四种不同晶体结构的吸附剂来阐明为什么吸附剂的晶体结构和表面特性对磷酸盐的吸附非常重要。结果表明，MgO/KBC 中 MgO 和 KBC 的结合程度较高，可将正常晶体结构（MgO/KBC1，MgO 相（主要））转变为 C-Mg-O 相（主要）。因此，MgO/KBC 对磷酸盐的吸附具有最高的吸附速率 (k，8.059 g mg min) 和 q（最大吸附容量，121.950 mg g），并且对阴离子和天然有机物 (NOM) 具有较高的抗干扰能力。MgO/KBC 对磷酸盐的吸附机制是氢键相互作用、内配位络合和表面化学吸附；MgO/KBC1 上的磷酸盐吸附主要受内配位络合 (Mg-O-POH、Mg-O-POH 物种) 控制。此外，MgO/KBC 对磷酸盐的吸附能力在煅烧后可以恢复，这进一步证明了一种从废生物质（落叶）煅烧而成的高效纳米复合材料可用于控制富营养化。
