摘要
Abstract
In order to systematically screen efficient substrates for ammonia nitrogen and phosphorus removal in constructed wetlands,magnetite,furnace slag,biochar,ceramsite,zeolite,iron-carbon,and volcanic rock were selected to study their adsorption characteristics.Through isothermal adsorption experiments and kinetic adsorption experiments,combined with X-ray diffraction(XRD)analysis of the mineral phases of the substrates,the study systematically investigated their adsorption characteristics and mechanisms for ammonia nitrogen and total phosphorus.The results indicate that the adsorption performance of substrates is closely related to their physical properties and phase compositions.Zeolite exhibited the fastest adsorption rate and highest capacity for ammonium nitrogen due to its unique aluminosilicate framework and strong cation exchange capability.Iron-carbon substrate enhances its chemical adsorption process through internal micro-electrolysis effects,exhibiting the highest theoretical saturated adsorption capacity for phosphorus and demonstrating good potential for ammonia nitrogen.Volcanic rocks and furnace slag efficiently remove phosphorus through precipitation due to their rich Ca and Mg elements,while biochar exhibits desorption during phosphorus adsorption owing to the lack of metal active sites.From a comprehensive perspective,zeolite and iron-carbon exhibited the best overall performance in ammonia nitrogen and phosphorus removal,while volcanic rock showed outstanding phosphorus removal capability.Zeolite,iron-carbon and volcanic rock are suitable as efficient substrates for constructed wetlands.In practical applications,these materials can be used individually or in combination according to target pollutants to achieve synergistic purification effects.关键词
人工湿地/填料/氨氮/磷/等温吸附/动力学吸附Key words
constructed wetland/substrates/ammonia nitrogen/phosphorus/isothermal adsorption/kinetic adsorption分类
资源环境
