【作者】 李杨；

【导师】 杨平； 杨雪梅；

【作者基本信息】 四川大学 ， 环境工程（专业学位）， 2022， 硕士

【摘要】 阳化河是长江上游四川段沱江水系的一级支流,共有5个饮用水取水点,为施家镇、禾丰镇、金马镇等10个乡镇的13.53万人口提供生活饮用水。随着阳化河流域城市化、工业化进程加快,以及畜禽养殖规模化发展,工业污染、畜禽养殖污染和生活性污染可能会威胁阳化河流域饮水安全。因此,本论文首先对阳化河流域典型污染物抗生素和重金属浓度进行分析,并进行风险评估;然后,合成SA@Fe（OH）₃吸附剂来应对阳化河流域可能存在的抗生素和重金属污染问题,从而保证居民饮用水安全。吸附法操作简便、效率高,不断开发低成本、高去除率、环境友好的新型吸附材料并将其运用于实际工程至关重要。海藻酸钠凝胶是一种新型吸附材料,制备简单,经济环保,本文利用铁元素对海藻酸钠改性制备气凝胶型复合吸附剂,用于吸附阳化河典型污染物NOR、TC、Cu（Ⅱ）,并对其吸附效能和吸附机理进行系统研究,以期为流域水质保护及其饮用水源重金属、抗生素污染防治提供一定的技术支持。本文根据阳化河水样检测分析结果进行了水质状况评价,利用生态风险评价模型和人体健康风险模型对地表水中重金属、抗生素进行风险评估,借助相关性分析和主成分分析对常规污染物、重金属和抗生素进行了同源性、相关性等溯源评价,从而确定了阳化河地表水中的典型污染物。针对典型污染物制备海藻酸钠型改性凝胶吸附剂,筛选最佳氢氧化物改性剂,比较海藻酸钠与改性组分配比,最终通过模板合成法制备SA@Fe（OH）₃吸附剂。利用SEM、EDS、FTIR、XPS、BET等手段对SA@Fe（OH）₃进行结构与表面形貌的表征分析并探究所制备SA@Fe（OH）₃吸附剂对水体中典型污染物NOR、TC和Cu（Ⅱ）的去除效能,考察了初始pH值、初始浓度、共存阴阳离子和天然有机质等因素对吸附性能的影响,并通过动力学、吸附等温模型拟合及材料表征,阐述SA@Fe（OH）₃吸附剂去除NOR、TC和Cu（Ⅱ）的作用机理。最后,考察了SA@Fe（OH）₃吸附剂在NOR+Cu、TC+Cu复合体系与模拟阳化河污水中对NOR、TC和Cu（Ⅱ）的吸附性能。主要研究结果如下:（1）阳化河流域地表水常规水质指标监测中,除个别采样点的水样存在部分污染物浓度超标现象,大部分河段氨氮、总磷、高锰酸盐指数、CODCr都处于较低水平,均能达到地表水Ⅲ类水质标准。（2）地表水中重金属的平均浓度排序为Cr>Cu>Zn>Cd>Ni>Pb>As,水体中七种重金属的累积浓度范围为11.23¹8.2μg/L。采用单因子污染指数法对阳化河地表水中重金属可能产生的生态风险进行评价,Cr、Cu、Zn、Pb、Cd、As、Ni对于阳化河流域水环境均不会产生生态风险,其中Cr、Cd风险系数较高,所以当该流域地表水中Cr、Cd占比较高时,可能造成生态风险。采用人体健康风险模型评价饮用阳化河地表水的风险,流域中的重金属不存在非致癌风险;致癌风险中,致癌物Cr是主要贡献者,对于人体健康可能存在较低程度的危害。（3）地表水中抗生素平均浓度排序为NOR>CIP>TC>SMX>PEN>ROX,水体中6种抗生素的累积浓度范围为33.13⁵7.79 ng/L,NOR、CIP、TC是水体中的主要抗生素类污染物。6种抗生素的RQ范围为0⁰.85,其中NOR、PEN、CIP具有一定程度的生态风险,阳化河地表水中抗生素存在叠加高生态风险（RQsum>1）。采用人体健康风险评价模型进行风险评估,饮用摄入阳化河地表水时,流域中的抗生素不存在致癌风险和非致癌风险,考虑抗生素具有积聚性,TC、NOR和CIP是人体健康风险的主要关注对象。（4）对阳化河目标污染物进行相关性分析和主成分分析,常规污染物与重金属、抗生素之间相关性较弱;Cr、Cd、As、Ni、Zn、Cu、Pb之间分别两两显著正相关,重金属单体具有同源性;NOR、PEN、ROX、TC、SMX和CIP之间相关性均较差,抗生素化合物不具有同源性;NOR、PEN、TC与6种重金属之间分别显著正相关,存在同源性和复合污染的可能。以Cu、TC、Cr、Cd、NOR等污染物为主要载荷的PC1可以解释阳化河流域简阳段44.8%的污染情况。（5）制备的SA@Fe（OH）₃对目标污染物NOR、TC有较好的去除效果,其对NOR、TC的吸附符合准二级动力学模型和Freundlich模型,最大吸附量分别为230.99 mg/g、281.39 mg/g。pH对吸附NOR和TC有较大的影响,表现为吸附量随pH增加而下降。在溶液中有Cl^-、SO₄^2-、Ca²⁺共存时,SA@Fe（OH）₃对NOR和TC的吸附表现出一定稳定性,而HA和FA的存在会不同程度地抑制SA@Fe（OH）₃的吸附能力。SA@Fe（OH）₃对NOR和TC的吸附过程为吸热过程,在高温下更加有利。SA@Fe（OH）₃对NOR和TC的吸附主要是配位结合、静电吸引和氢键共同作用的结果（6）SA@Fe（OH）₃对Cu（Ⅱ）的吸附行为更符合准二级动力学模型和Freundlich模型。由Langmuir模型计算得,SA@Fe（OH）₃对Cu（Ⅱ）的最大吸附量为53.15 mg/g。SA@Fe（OH）₃对Cu（Ⅱ）的吸附过程为吸热过程,温度越高越有利于吸附。pH对Cu（Ⅱ）的吸附影响较大,在强酸溶液中SA@Fe（OH）₃与Cu（Ⅱ）的结合作用几乎被完全抑制或掩蔽。水溶液中Ca²⁺的存在对吸附影响较为显著,Cl^-和SO₄^2-的影响较小,而HA、FA由于可以和Cu²⁺产生络合作用,会促进Cu（Ⅱ）的吸附。SA@Fe（OH）₃对Cu（Ⅱ）的吸附机理主要是配位结合和化学沉淀。（7）SA@Fe（OH）₃对NOR、TC、Cu（Ⅱ）的吸附能力总体具有稳定性,在TCCu和NOR-Cu的双组分体系中,SA@Fe（OH）₃对Cu（Ⅱ）依旧保持着良好的吸附效果,对NOR或TC的吸附效果均得到不同程度的促进。在成分复杂的模拟阳化河水体样本中,吸附效果依旧保持为去离子水中处理效果的70%以上。更多还原

【Abstract】 The Yanghua River is a first-class tributary of the Tuojiang River system in the Sichuan section of the upper reaches of the Yangtze River.There are 5 drinking water intake points,providing drinking water for 135,300 people in 10 towns including Shijia Town,Hefeng Town and Jinma Town.With the acceleration of urbanization and industrialization in the Yanghua River Basin,and the large-scale development of livestock and poultry breeding,industrial pollution,livestock and poultry pollution,and domestic pollution may threaten the drinking water safety of the Yanghua River Basin.Therefore,this paper firstly analyzed the concentration of antibiotics and heavy metals in Yanghua River,and conducted risk assessment;then,SA@Fe（OH）₃adsorbent was synthesized to deal with the possible pollution of antibiotics and heavy metals in Yanghua River,so as to ensure the safety of drinking water for residents.The adsorption method is widely used due to its advantages of simple operation,high efficiency,and recyclability.The development of new adsorption materials with low cost,high removal rate,and environmental friendliness is very important for the promotion of adsorption methods in practical engineering applications.Sodium alginate gel is a new type of adsorption material,which is simple to prepare,economical and environmentally friendly.In this paper,iron element was used to modify sodium alginate to prepare a low-cost,green and sustainable aerogel-type composite adsorbent.This adsorbent was used for the adsorption of typical pollutants NOR,TC and Cu（Ⅱ）in Yanghua River.Its adsorption efficiency and adsorption mechanism were systematically studied,in order to provide certain technical support for the protection of watershed water quality and the prevention and control of heavy metal and antibiotic pollution in drinking water sources.In this paper,standard monitoring methods were used to detect and analyze Yanghua River water samples.The water quality of Yanghua River surface water was assessed on the basis of the detected concentration.The risk assessment of heavy metals and antibiotics in surface water were carried out by using some models.With the help of correlation analysis（CA）and principal component analysis（PCA）,the pollution homology and correlation of conventional pollutants,heavy metals and antibiotics were traced.According to these results,the typical pollutants in the surface water of Yanghua River were selected.The sodium alginate（SA）modified gel adsorbent was prepared for typical pollutants.By screening the best hydroxide modifier and comparing the effect of the ratio of SA and modified components on the adsorption efficiency of antibiotics,the SA@Fe（OH）₃ adsorbent was finally prepared by template synthesis.The structure and surface morphology of SA@Fe（OH）₃ were characterized by SEM,EDS,FTIR,XPS,BET and other means.The removal efficiency of the prepared SA@Fe（OH）₃ adsorbent on typical pollutants NOR,TC and Cu（Ⅱ）in water was investigated.The effects of different factors on adsorption were also investigated,such as initial pH value,initial concentration,coexisting anions and cations and natural organic matter.The mechanism of removal of NOR,TC and Cu（Ⅱ）by SA@Fe（OH）₃ adsorbent was described by kinetics,adsorption isotherm model fitting,SEM and EDS characterization.Finally,the adsorption performance of SA@Fe（OH）₃ adsorbent for NOR,TC and Cu（Ⅱ）in NOR+Cu,TC+Cu composite system and simulated Yanghua river sewage was explored.The main findings were as follows:（1）In the routine monitoring of surface water quality indicators in the Yanghua River,the concentration of some pollutants in the water samples from individual sampling points exceeded the standard.Ammonia nitrogen,total phosphorus,permanganate index,and CODCr in most of the river sections were all at low levels,all of which can reach the surface water quality standard of Class Ⅲ.（2）The average concentrations of heavy metals in surface water were in the order of Cr>Cu>Zn>Cd>Ni>Pb>As,and the cumulative concentrations of the seven heavy metals in the water ranged from 11.23 to 18.2 μg/L.The single-factor pollution index method was used to evaluate the ecological risk of heavy metals in the surface water of Yanghua River.Cr,Cu,Zn,Pb,Cd,As,and Ni did not cause ecological risks to the water environment of Yanghua River.Among them,the risk coefficients of Cr and Cd were relatively high,so when the proportion of Cr and Cd in the surface water is relatively high,it may cause ecological risks.The human health risk model was used for the risk of drinking the surface water of the Yanghua River.There was no noncarcinogenic risk of heavy metals in the watershed.In the carcinogenic risk,the carcinogen Cr was the main contributor,which there may be a low level of hazard to human health.（3）The average concentration of antibiotics in surface water were in the order of NOR>CIP>TC>SMX>PEN>ROX,which cumulative concentration ranged from33.13 to 57.79 ng/L.NOR,CIP,and TC were the main antibiotics in the water.The RQs of the six antibiotics ranged from 0 to 0.85,among which NOR,PEN,and CIP may have certain ecological risks.Antibiotics in the surface water of Yanghua River had a superimposed high ecological risk（RQsum>1）.The human health risk assessment model was used for risk assessment.When drinking the surface water of Yanghua River,there was no carcinogenic or non-carcinogenic risk of antibiotics in the watershed.Considering the accumulation of antibiotics,TC,NOR and CIP were the main concerns for human health risks.（4）CA and PCA were carried out on the target pollutants in Yanghua River.The correlation between conventional pollutants,heavy metals and antibiotics was weak.Cr,Cd,As,Ni,Zn,Cu,Pb were significantly positively correlated in pairs,and heavy metal monomers had homology.NOR,PEN,ROX,TC,SMX,and CIP had poor correlations respectively,and had no homology.NOR,PEN,TC and 6 heavy metals were significantly positively correlated,so there was the possibility of homology and compound pollution.PC1 with Cu,TC,Cr,Cd,NOR and other pollutants as the main load can explain 44.8% of the pollution in the Yanghua River.（5）The prepared SA@Fe（OH）₃ had a good removal effect on the target pollutants NOR and TC.The adsorption of NOR and TC were in line with the pseudo-secondorder kinetic model and the Freundlich model.The maximum adsorption capacity were230.99 mg/g and 281.39 mg/g.pH had a great influence on the adsorption of NOR and TC,the adsorption capacity decreased with the increase of pH.In the presence of Cl^-,SO₄^2-,and Ca²⁺ in the solution,SA@Fe（OH）₃ showed a certain stability,while the presence of HA and FA would inhibit adsorption to varying degrees.The adsorption processes of NOR and TC on SA@Fe（OH）₃ were an endothermic process,which were more favorable at high temperature.The adsorption of NOR and TC by SA@Fe（OH）₃was mainly the result of coordination binding,electrostatic attraction and hydrogen bonding.（6）The adsorption behavior of SA@Fe（OH）₃ for Cu（Ⅱ）was more in line with the pseudo-second-order kinetic model and the Freundlich model.Calculated from the Langmuir model,the maximum adsorption capacity of Cu on SA@Fe（OH）₃ was 53.15mg/g.The adsorption process of Cu on SA@Fe（OH）₃ was an endothermic process,and the higher the temperature,the better the adsorption.The pH had a great influence on the adsorption of Cu（Ⅱ）,and the binding effect of SA@Fe（OH）₃ and Cu（Ⅱ）in strong acid solution was almost completely inhibited or masked.The presence of Ca²⁺in the aqueous solution had a more significant effect on the adsorption,Cl^-and SO₄^2-had less effect,while HA and FA can promote the adsorption of Cu（Ⅱ）due to their complexation with Cu²⁺.The adsorption mechanism of SA@Fe（OH）₃ for Cu（Ⅱ）was mainly coordination binding and chemical precipitation.（7）The adsorption capacity of SA@Fe（OH）₃ for NOR,TC,and Cu（Ⅱ）were generally stable.In the two-component system of TC-Cu or NOR-Cu,SA@Fe（OH）₃still maintained a good adsorption effect on Cu（Ⅱ）,and the adsorption effect of NOR or TC was promoted to different degrees.In the simulated Yanghua River water sample with complex composition,the adsorption effect remained above 70% of the treatment effect in deionized water.更多还原