Department of Environmental Science and Engineering, School of Energy and Environment, Wuxi Engineering Research Center of Taihu Lake Water Environment, Southeast University, Nanjing 210096, China.
Department of Water Supply and Drainage Science and Engineering, College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China.
Int J Environ Res Public Health. 2022 Mar 28;19(7):4016. doi: 10.3390/ijerph19074016.
The excessive nitrogen and phosphorus discharged into the water environment will cause water eutrophication and thus disrupt the water ecosystem and even exert biological toxicities. In this study, the absorption removal of nitrogen and phosphorus from the anaerobic tank in an anaerobic−anoxic/nitrifying system using four different kinds of biowaste-reclaimed biochars were investigated and compared. The effects of temperature and pH on nutrient adsorption removal were further investigated. The four kinds of biochar were successfully prepared and well characterized using a scanning electron microscope, fourier transform infrared spectroscopy, X-ray diffraction and Brunner−Emmet−Teller methods. Generally, there was no significant change in chemical oxygen demand (COD) and NH4+-N removal efficiencies when treated by the different biochars, while the activated sludge biochar (ASB) displayed the highest total phosphorus (TP) removal efficiency. The initial TP concentrations (<40 mg/L) displayed no remarkable effects on the TP adsorption removal, while the increase of temperature generally enhanced TP and NH4+-N adsorptions on the ASB. Besides, the increase of pH significantly promoted NH4+-N removal but depressed TP removal. Moreover, the adsorption process of TP by the ASB complies with the secondary kinetic model, suggesting the chemical precipitation and physical electrostatic interaction mechanisms of TP adsorption removal. However, the adsorption of NH4+-N conformed to the inner-particle diffusion model, indicating that the NH4+-N adsorption was mainly involved with pore diffusions in the particles.
过量的氮和磷排入水环境会导致水体富营养化，从而破坏水生态系统，甚至产生生物毒性。在这项研究中，使用四种不同的生物废弃物回收生物炭，考察了厌氧-缺氧/硝化系统中厌氧池对氮和磷的吸收去除。进一步研究了温度和 pH 值对养分吸附去除的影响。利用扫描电子显微镜、傅里叶变换红外光谱、X 射线衍射和 Brunner-Emmet-Teller 方法成功制备并对四种生物炭进行了很好的表征。一般来说，用不同的生物炭处理时，化学需氧量（COD）和 NH4+-N 去除效率没有明显变化，而活性污泥生物炭（ASB）显示出最高的总磷（TP）去除效率。初始 TP 浓度（<40mg/L）对 TP 吸附去除没有明显影响，而温度的升高一般会增强 ASB 对 TP 和 NH4+-N 的吸附。此外，pH 值的升高显著促进了 NH4+-N 的去除，但抑制了 TP 的去除。此外，ASB 对 TP 的吸附过程符合二级动力学模型，表明 TP 吸附去除的化学沉淀和物理静电相互作用机制。然而，NH4+-N 的吸附符合内扩散模型，表明 NH4+-N 的吸附主要涉及颗粒内的孔扩散。
