铁改性生物炭用于农村生活污水磷的高效去除  

Efficient Phosphorus Removal from Rural Domestic Wastewater by Iron-Modified Biochar

作　　者：纳云 马巍 李娜 刘陆 陈荣志 NA Yun;MA Wei;LI Na;LIU Lu;CHEN Rongzhi(Qinghai Ecological Planning and Environmental Protection Technology Center,Xining 810007,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]青海省生态环境规划和环保技术中心,青海西宁810007 [2]中国科学院大学资源与环境学院,北京101400

出　　处：《水处理技术》2024年第11期31-38,共8页Technology of Water Treatment

基　　金：青海省农村分散式生活污水治理关键技术应用推广项目第二次(2023000107)。

摘　　要：以玉米秸秆为原料制备生物炭,通过与铁盐混合共热解制得铁改性生物炭(BC-Fe)。通过SEM、XRD、XPS和比表面积分析(BET)等表征手段探究了改性生物炭的形貌和结构特性。同时,吸附实验研究了该改性生物炭对磷的吸附特性与影响因素。结果表明,经铁改性的BC-Fe21具有最优异的磷酸盐吸附能力,在pH为5~11的范围内均展现出较好的除磷效果,说明BC-Fe21具有广泛的pH适应性。吸附动力学模型和等温吸附模型拟合结果显示,其吸附过程符合准二级动力学模型(R^(2)=0.97)和Langmuir等温吸附模型(R^(2)=0.98),说明BC-Fe21的对磷的吸附过程主要是单层化学吸附,且其最大理论吸附量为45.57 mg/g;共存阴离子实验表明SO_(4)^(2-)、NO_(3)^(-)对BC-Fe21的吸附性能影响较小,而HCO_(3)^(-)的影响明显。XPS与Fe浸出实验表明BC-Fe21表面稳定存在的Fe^(Ⅱ)/Fe^(Ⅲ)物种是水体磷酸盐去除的主要贡献者,其主要通过与磷酸盐的直接配位作用去除水体中的磷。本研究为农村水环境污染的削减和废弃物的再利用提供了一条可行途径。Phosphorus pollution in water is serious in China's rural areas.The efficient removal of phosphorus from rural domestic sewage has become the focus of attention.In this study,biochar was prepared in batches using corn stover as the raw materials.An iron-modified biochar(BC-Fe)was further synthesized by co-pyrolysis of biochar and iron salt for phosphate adsorption.Some characterizations including Scanning Electron Microscopy(SEM),X-ray Diffractometry(XRD),X-ray Photoelectron Spectroscopy(XPS),and physical adsorption analysis were applied to determine the surface morphology and physical/chemical properties of the modified biochar.In addition,the adsorption experiments were conducted to reveal the adsorption behavior and influencing factors of the absorbents.The results showed that the iron-modified BC-Fe21 had the most excellent phosphate adsorption capacity(77.0%within 4 h).The exceptional phosphate removal performance in a wide pH range of 5~11 was exhibited,demonstrating the superior pH adaptability of the adsorbent.Adsorption kinetics fitting showed that phosphate adsorption by BC-Fe21 was more consistent with pseudo-secondary kinetics(R^(2)=0.97),indicating a chemosorption towards phosphorus.The adsorption thermodynamic results showed a better fit to the Langmuir isothermal adsorption model(R^(2)=0.98),suggesting the adsorption of phosphate is monolayer adsorption with a maximum adsorption of 45.57 mg/g.Anion interference experiments showed that SO_(4)^(2-)and NO_(3)^(-)interfered almost negligibly with phosphate adsorption by BC-Fe21,whereas HCO_(3)^(-)exhibited a significant inhibition,which may originate from the competition for adsorption sites.XPS and Fe leaching tests showed that the stable FeII/FeIII species on the surface of BC-Fe21 played the dominant role in phosphate removal from the water through a direct coordination process with PO43-.This study provides a feasible route for pollution reduction and rural waste reuse.

关 键 词：农村生活污水 磷吸附 生物炭 铁改性 再利用 

分 类 号：TQ424[化学工程] X799.3[环境科学与工程—环境工程]