生物炭多孔滤料的制备及其除磷性能研究

Preparation of biochar porous filter media and its performance in phosphorus removal

关键词:  生物炭  粉煤灰  滤料制备  吸附除磷

Key words:  biochar  fly ash  filter media preparation  phosphorus removal by adsorption

摘要:

以生物炭、粉煤灰为主要原材料，采用免烧结工艺制备生物炭多孔除磷滤料（BPP）。通过Box-Behnken试验设计法得出最佳滤料配比:粉煤灰和石灰40 g，胶凝材料15 g，生物炭25 g，水添加量为60g，发泡剂添加量0.8g，在该配比下，BPP在动态水中的散失率为7%。采用扫描电子显微镜（SEM）、红外光谱（FT-IR）、比表面积测定仪（BET）等表征手段分析其微观形貌、元素变化及晶体结构，考察了滤料投加量、溶液初始磷浓度、溶液pH和溶液中的共存离子对吸附磷酸盐的影响，探讨了动力学吸附机制。结果表明:在磷浓度10 mg/L，投加量5 g/L的条件下BPP对TP的去除率达95%以上，吸附量为1.90 mg/g；该滤料适合处理低浓度的含P废水，在pH为2、12的环境下对磷的吸附效果较好且抗离子干扰能力较强，在实际应用中有较强的适用性；其吸附过程符合准二级动力学模型，主要是受到化学吸附的影响。

Abstract:

s: The optimal ratio of filter media was obtained by Box-Behnken design of experiments method: 40 g of fly ash and lime, 15 g of gelling material, 25 g of biochar, 65 g of water addition, and 0.8 g of the mass for blowing agent addition, in which the dissipation rate of BPP in dynamic water was about 7%. Scanning electron microscope (SEM), infrared spectroscopy (FT-IR), specific surface area tester (BET) and other characterization means were used to analyze its micro-morphology, elemental changes and crystal structure, and the effects of filter media addition, initial phosphorus concentration of the solution, solution pH and coexisting ions in the solution on the adsorption of phosphate were investigated, and the kinetic adsorption mechanism was explored. The results showed that the removal rate of phosphorus by BPP under the condition of phosphorus concentration of 10mg/L and dosage of 5 g/L was more than 95%, and the adsorption amount was 1.90 mg/g. The filter media is suitable for the treatment of low concentration of P-containing wastewater, the adsorption effect of phosphorus is better and the resistance to ionic interference is stronger under the environment of pH 2, 12, which is more applicable in practical applications; the adsorption process conforms to the quasi-two-stage kinetic model, which is mainly affected by the chemical adsorption.