造纸污泥生物炭对四环素的吸附特性及机理

以造纸污泥为原料,在限氧条件下,通过控制热解温度（300,500和700℃）,制备生物炭（SBC300、SBC500和SBC700）,比较了3种生物炭的基本理化性质;以四环素（TC）为目标污染物,研究了造纸污泥生物炭（SBC）对TC的吸附特性及机理.结果表明,SBC对TC的吸附以化学吸附为主,吸附平衡时,SBC300对TC的去除率最低,为38.8%,SBC700的去除率最高,为54.1%;同时Langmuir模型能更好地描述此吸附过程,且最大吸附量依次为SBC700（63.8mg/g） > SBC500（50.6mg/g） > SBC300（40.0mg/g）.热力学分析表明,SBC对TC的吸附为自发且吸热的过程.pH值影响TC的存在形态及SBC的表面带电情况,对吸附过程有较大影响.通过吸附等温线分解法定量描述了表面吸附作用及分配作用的贡献率,结合FTIR分析,表明SBC对TC的吸附可能是分配作用、静电作用、氢键作用、π-π EDA作用及离子交换作用等共同作用的结果.     

窄孔径含磷棉秆生物质炭的制备及对四环素的吸附机制

以棉秆为生物质原料,磷酸为改性剂,一步碳化制备了兼具高比表面积(1 916 m²·g^-1)和孔体积(1.398 2 mL·g^-1)的窄孔径含磷棉秆生物质炭(CSP),并研究了其对四环素(TC)的吸附行为.结果表明,磷酸改性制备的窄孔径含磷棉秆生物质炭对TC吸附量高达669mg·g^-1,是未改性棉秆炭的43.6倍;红外光谱(FTIR)、 X射线(XPS)和等温吸附研究表明,CSP对TC的高吸附量是表面络合、氢键、孔隙填充和π-π色散等多种吸附力共同作用的结果,其中磷酸改性赋予的高活性磷酸酯类基团(P—O—C)与TC分子间的化学络合作用强且贡献度高,是吸附量显著提升的最关键因素.静态等温吸附与热力学研究结果进一步证实TC在含磷棉秆炭吸附过程中化学吸附起主要作用,吸附过程属于自发的吸热过程.研究结果可为利用棉秆资源定向制备高效吸附TC的高活性磷掺杂生物质炭提供了一种潜在的简便高效途径.     

Removal of tetracycline from aqueous solution by a Fe3O4 incorporated PAN electrospun nanofiber mat

Pollution of antibiotics, a type of emerging contaminant, has become an issue of concern,due to their overuse in human and veterinary application, persistence in environment and great potential risk to human and animal health even at trace level. In this work, a novel adsorbent, Fe3O4 incorporated polyacrylonitrile nanofiber mat(Fe-NFM), was successfully fabricated via electrospinning and solvothermal method, targeting to remove tetracycline(TC), a typical class of antibiotics, from aqueous solution. Field emission scanning electron microscopy and X-ray diffraction spectroscopy were used to characterize the surface morphology and crystal structure of the Fe-NFM, and demonstrated that Fe-NFM was composed of continuous, randomly distributed uniform nanofibers with surface coating of Fe3O4 nanoparticles. A series of adsorption experiments were carried out to evaluate the removal efficiency of TC by the Fe-NFM. The pseudo-second-order kinetics model fitted better with the experimental data. The highest adsorption capacity was observed at initial solution p H 4 while relative high adsorption performance was obtained from initial solution p H 4 to 10. The adsorption of TC on Fe-NFM was a combination effect of both electrostatic interaction and complexation between TC and Fe-NFM. Freundlich isotherm model could better describe the adsorption isotherm. The maximum adsorption capacity calculated from Langmuir isotherm model was 315.31 mg/g. Compared to conventional nanoparticle adsorbents which have difficulties in downstream separation, the novel nanofiber mat can be simply installed as a modular compartment and easily separated from the aqueous medium, promising its huge potential in drinking and wastewater treatment for micro-pollutant removal.     

氢氧化铌对水溶液中磷酸根的吸附特性研究

以氢氟酸法制备的氮氧化铌作为磷酸根的吸附剂,考察了氢氧化铌用量及焙烧温度对吸附效果的影响.在25℃,磷酸根初始浓度为50 mg/L、体积200 mL的条件下,确定吸附剂的最佳用量为0.1 g,此时氢氧化铌原样对磷酸根的最大吸附量为48.2 mg/g.上述条件下,经200、300、400、500℃焙烧后的氢氧化铌对磷酸根...     

Removal of tetracycline from aqueous solution by a Fe3O4 incorporated PAN electrospun nanofiber mat

Pollution of antibiotics, a type of emerging contaminant, has become an issue of concern, due to their overuse in human and veterinary application, persistence in environment and great potential risk to human and animal health even at trace level. In this work, a novel adsorbent, Fe₃O₄ incorporated polyacrylonitrile nanofiber mat (Fe-NFM), was successfully fabricated via electrospinning and solvothermal method, targeting to remove tetracycline (TC), a typical class of antibiotics, from aqueous solution. Field emission scanning electron microscopy and X-ray diffraction spectroscopy were used to characterize the surface morphology and crystal structure of the Fe-NFM, and demonstrated that Fe-NFM was composed of continuous, randomly distributed uniform nanofibers with surface coating of Fe₃O₄ nanoparticles. A series of adsorption experiments were carried out to evaluate the removal efficiency of TC by the Fe-NFM. The pseudo-second-order kinetics model fitted better with the experimental data. The highest adsorption capacity was observed at initial solution pH 4 while relative high adsorption performance was obtained from initial solution pH 4 to 10. The adsorption of TC on Fe-NFM was a combination effect of both electrostatic interaction and complexation between TC and Fe-NFM. Freundlich isotherm model could better describe the adsorption isotherm. The maximum adsorption capacity calculated from Langmuir isotherm model was 315.31 mg/g. Compared to conventional nanoparticle adsorbents which have difficulties in downstream separation, the novel nanofiber mat can be simply installed as a modular compartment and easily separated from the aqueous medium, promising its huge potential in drinking and wastewater treatment for micro-pollutant removal.     

Removal of tetracycline from aqueous solution by a Fe3O4 incorporated PAN electrospun nanofiber mat

Pollution of antibiotics, a type of emerging contaminant, has become an issue of concern, due to their overuse in human and veterinary application, persistence in environment and great potential risk to human and animal health even at trace level. In this work, a novel adsorbent, Fe₃O₄ incorporated polyacrylonitrile nanofiber mat (Fe-NFM), was successfully fabricated via electrospinning and solvothermal method, targeting to remove tetracycline (TC), a typical class of antibiotics, from aqueous solution. Field emission scanning electron microscopy and X-ray diffraction spectroscopy were used to characterize the surface morphology and crystal structure of the Fe-NFM, and demonstrated that Fe-NFM was composed of continuous, randomly distributed uniform nanofibers with surface coating of Fe₃O₄ nanoparticles. A series of adsorption experiments were carried out to evaluate the removal efficiency of TC by the Fe-NFM. The pseudo-second-order kinetics model fitted better with the experimental data. The highest adsorption capacity was observed at initial solution pH 4 while relative high adsorption performance was obtained from initial solution pH 4 to 10. The adsorption of TC on Fe-NFM was a combination effect of both electrostatic interaction and complexation between TC and Fe-NFM. Freundlich isotherm model could better describe the adsorption isotherm. The maximum adsorption capacity calculated from Langmuir isotherm model was 315.31 mg/g. Compared to conventional nanoparticle adsorbents which have difficulties in downstream separation, the novel nanofiber mat can be simply installed as a modular compartment and easily separated from the aqueous medium, promising its huge potential in drinking and wastewater treatment for micro-pollutant removal.     

钢铁废水污泥吸附除磷特性

为处理含磷废水同时实现钢铁污泥资源化利用,将钢铁污泥用于吸附除磷,从磷吸附影响因素、动力学模型、吸附等温线等方面研究了钢铁污泥对水中磷酸盐的吸附特性,并通过扫描电子显微镜(SEM)、X射线衍射仪(XRD)等表征手段对吸附机理进行了探究.结果显示,钢铁污泥对水中磷具有优良的吸附性能,在pH = 2.00,温度为40℃时,磷的理论饱和吸附量可达8.917mg/g.实验数据符合Langmuir方程,为单分子层吸附.60min即可达吸附平衡,吸附过程符合拟二阶动力学方程,主要为化学吸附.SEM和XRD分析结果表明,吸附后污泥表面可能存在FePO₄、Ca_xFe_y(PO₄)_2x/3+y等物质,推测磷的去除可能是PO₄^3-与Fe³⁺或Ca²⁺等的化学沉淀作用,以及Fe³⁺的水解产物与PO₄^3-发生化学吸附并进行络合反应形成络合物的共同沉淀作用.研究结果表明钢铁污泥在吸附除磷方面具有潜在应用价值.     

MgO改性赤泥复合材料对废水中氮磷的同步回收

为处理高浓度氮磷废水同时实现赤泥资源化利用,通过赤泥负载氧化镁制备高效氮磷回收材料(MgO-RM),用以对废水进行氮磷同步回收.考察了废水初始pH值、废水氮磷比和MgO-RM投加量对氮磷同步回收效果的影响.采用动力学模型和等温吸附模型对回收特性进行了描述,在此基础上利用FTIR、XRD、SEM、BET测试手段对MgO-...     

Facile one-step synthesis of functionalized biochar from sustainable prolifera-green-tide source for enhanced adsorption of copper ions

The use of biochars formed by hydrothermal carbonization for the treatment of contaminated water has been greatly limited,due to their poorly developed porosity and low content of surface functional groups.Also,the most common modification routes inevitably require post-treatment processes,which are time-consuming and energy-wasting.Hence,the objective of this research was to produce a cost-effective biochar with improved performance for the treatment of heavy metal pollution through a facile one-step hydrothermal carbonization process coupled with ammonium phosphate,thiocarbamide,ammonium chloride or urea,without any posttreatment.The effects of various operational parameters,including type of modification reagent,time and temperature of hydrothermal treatment,and ratio of modification reagent to precursor during impregnation,on the copper ion adsorption were examined.The adsorption data fit the Langmuir adsorption isotherm model quite well.The maximum adsorption capacities(mg/g) of the biochars towards copper ions followed the order of 40-8 h-1.0-APBC(95.24) 140-8 h-0-BC(12.52) 140-8 h-1.0-TUBC(12.08) 140-8 h-1.0-ACBC(7.440) 140-8 h-1.0-URBC(5.277).The results indicated that biochars modified with ammonium phosphate displayed excellent adsorption performance toward copper ions,which was 7.6-fold higher than that of the pristine biochar.EDX and FT-IR analyses before and after adsorption demonstrated that the main removal mechanism involved complexation between the phosphate groups on the surface of the modified biochars and copper ions.     

活化赤泥去除猪场废水生化处理出水中的磷和重金属

以铝矿工业废渣赤泥为原材料,采用焙烧活化方法进行活化处理,并将其用于畜禽废水生化处理出水中磷和重金属的吸附去除.同时,研究考察了吸附剂除磷、除重金属的能力以及投加量、pH值和反应时间对去除效果的影响.结果表明,赤泥和活化赤泥对磷、铜、锌、砷吸附规律符合Langmuir吸附等温方程;焙烧改性后,赤泥对磷、铜、锌、砷的去除能力显著提高,900℃焙烧活化饱和吸附量可分别由46.26、18.18 、15.45、18.83 mg·g-1提高至149.00、65.17、99.20、27.51 mg·g-1;pH显著影响除磷、除重金属的效果,高pH条件有利于磷、铜、锌、砷的去除;赤泥和活化赤泥除磷、铜、锌、砷的作用机理包含金属氧化物表面的表面络合作用机理,其对砷和磷的去除机理还包括共沉淀作用.