动态法研究2,4-二氯苯酚在土壤中的吸附

用土柱模拟实验研究了土壤组成，2，4-二氯苯配件 浓度对土壤吸附量和吸队速度的影响。并对其吸附动力学进行了初步探讨。     

基于磁性荧光双探针基础上的2,4-二氯苯氧乙酸残留的快速免疫检测体系的建立(英文)

建立了一个基于磁性荧光双探针基础上的免疫快速检测体系,以实现液相中快速检测食品中2,4-二氯苯氧乙酸(2,4-D)残留.该体系将2,4-D抗体结合Fe3O4@SiO2-NH2得到的复合物作为磁性探针和固相载体,2,4-D-OVA被标记CdTe@SiO2-NH2作为荧光探针以产生荧光信号,通过荧光探针与磁性探针复合物与2,4-D抗体竞争结合实现免疫快速检测.探讨了荧光探针最佳优化条件,在p H值8.2,2,4-D-OVA加入量为500μL,偶联时间为70 min时,偶联得到的荧光信号最强,双探针检测后得到该检测体系最低检测限为3.55×10-8.得到金磁、量子点荧光双探针免疫系统,绘出标准曲线,得到最低检测限达3.55×10-8.该检测体系与传统ELISA方法相比,可以大大缩短检测时间,放大检测信号.     

农药废液中氧乐果及其中间体土壤吸附系数和降解速率的测定

针对农药厂高浓度铵磷废液中所含氧乐果及其合成中间体氧硫磷酯，测定了它们２０℃时在三种共试土壤中的吸附系数和降解速率。实验结果表明：它们在土壤中的吸附行为服从Ｆｒｅｕｎｄｌｉｃｈ等温附方程，２０℃时氧乐果和氧硫磷酯的吸附系数分别为９．６２、１１．５２、２１．３６和３３７２．６８、４３１７．８７、８１５３．７４，其吸附量随土壤有碳含量升高及分子极性的减少而增大。土壤中的降解表现上遵循一级反应动力学关系     

2,4-二氯苯氧乙酸在线免疫传感器监测技术的应用研究

针对水中存在的2,4-二氯苯氧乙酸(2,4-D),采用在线免疫传感器进行监测,实验结果表明:2,4-D在线免疫传感器对2,4-D质量浓度的响应符合Logistic曲线方程,在10~200μg/L的范围内,在线免疫传感器的信号响应符合半对数线性方程.免疫芯片存在一定的记忆效应. 48组测定比对实验表明,在线免疫传感器的测定误差小于人工测定误差,2,4-D在线免疫传感器可用于西江水的监测,运行稳定,信号可靠,为实现水环境有毒有害有机物的在线监测预警提供了一种新的技术解决方案.     

Characterization of nanoscale iron and its degradation of 2,4-dichlorophenol

Nanoscale iron was detected by TEM, X-ray diffraction and X-ray photoelectron spectroscopy. It was found that the size of the nanoscale iron particles is in the range of 30–40 nm according to TEM image, and it contains abundant Fe₃O₄ as passivating layers on the surface of the core-shell structure. To improve its performance, dilute HCl was used for the removal of the passivating layers, and the degradation of 2,4-dichlorophenol (2,4-DCP) was measured for the nanoscale iron samples treated and untreated. Experimental results demonstrated that the removal of 2,4-DCP by untreated nanoscale iron is mainly due to the adsorption of 2, 4-DCP by nanoscale iron, and there are no degradation products detected by HPLC in the process. However, excellent dechlorination of 2,4-DCP was gained by HCl-treated nanoscale iron, and 2-chlorophenol, 4-chlorophenol and phenol were detected during the process. It was concluded that dechlorination is the key reaction pathway for the degradation of 2,4-DCP by activated nanoscale iron, and phenol is found to be the main product.     

土壤石油高效降解菌的筛选、鉴定及其特性研究

从华中某油田石油污染土壤中分离筛选出了3株高效石油降解菌S-4、S-5和S-7,在30℃,200 r/min恒温摇床上震荡培养14 d后,石油烃降解率分别为41.60%、40.59%和43.53%。经16S r DNA基因序列鉴定,S-4、S-5和S-7分别属于肠杆菌属(Enterobacter)、假单胞菌属(Pseudomonas)和Kosakonia属。通过实验表明,菌株的最适降解pH为7,最佳氮源为硝酸铵(NH4NO3),最佳氮、磷比为5:1,在添加营养元素的条件下,经过48 d的降解,S-4、S-5和S-7菌株对土壤中石油烃总降解率分别为74.24%、71.66%和80.29%。     

Effective adsorption of 2,4-dichlorophenol on hydrogenated graphene: kinetics and isotherms

The effective adsorption capability of a hydrogenated graphene （H-Gr） was demonstrated. The H-Gr was firstly prepared by heating graphene （Gr） in a hydrogen flow at 1,000 ℃. The specific surface area, layer number, zeta potential, surface defects, surface compounds groups and elemental ratio of H-Gr were investigated. Taking 2,4-dichlorophenol as a target pollutant, the adsorption ability of H-Gr was evaluated. The results showed that the adsorption kinetics followed the pseudo- second-order equation well. For the adsorption isotherms, the equilibrium data of H-Gr were found to fit to Langmuir model, which was different from the Freundlich model of Gr. The adsorption capacity of H-Gr was high to 287.01 mg/g, almost three times as much as that of Gr, which was benefit from the increase of specific surface area and zeta potential. This work suggests that H-Gr may be a potential candidate for the adsorption of aromatic compounds from water and has great prospect for practical application.     

Photocatalytic degradation pathways and adsorption modes of H-acid in TiO2 suspensions

Effect of adsorption mode on photodegradation of H-acid in TiO2 suspension was studied using DFT calculation,UV-Vis spec-troscopy,FTIR,and ionic chromatography.At pH 2.5,H-acid was adsorbed on TiO2 surfaces by one dissociated sulfonic group.The adsorbed sulfonic group was attacked by surface ·OH,resulting in the production of SO42-and the cleavage of the naphtha-lene ring.At pH 5.0,H-acid was adsorbed on TiO2 surfaces by two sulfonic groups.The two adsorbed sulfonic groups were sim-ultaneously attacked by surface ·OH,leading to a faster initial production of SO42-and initial degradation rate of H-acid than those under pH 2.5.Microscopic adsorption structures may be more important than adsorption amount in controlling the photo-degradation pathways of organic pollutants.     

用IAL-CHS反应器降解2,4-DCP和处理啤酒废水的比较

利用IAL-CHS反应器分别吸附单一的微生物Achromobactersp.来降解2,4-二氯酚(2,4-DCP)和吸附复合微生物菌群来处理啤酒废水.通过比较试验表明,单一的微生物和复合微生物菌群均能很容易地在蜂窝陶瓷载体的表面上形成生物膜,并表现出较高的生物活性.在连续降解2,4-DCP时,反应器稳定运行之后,2,4-DCP的去除率达到98％.连续流处理啤酒废水时,在水力停留时间为7h条件下,随着进水的COD浓度逐渐增加,其COD去除率达到95.5％.有机物负荷也逐渐增高,达到3.52kgCOD／(m3·d).     

土壤中阿特拉津降解实验研究

通过批实验确定了阿特拉津在不同土壤样本中的降解速率，同时对各土壤特性与降解速率的相关性进行了统计分析，并比较了阿特拉津在灭菌土壤与未灭菌土壤中的降解过程．结果表明：土壤中阿特拉津降解速度缓慢，而且实验土壤对阿特拉津的吸附作用较弱，故阿特拉津的施用对当地浅层地下水和地表水资源存在较大威胁；非生物降解和生物降解所起的作用相当；实验地区阿特拉津的降解参数服从正态分布；在水平α=0．05下，降解速率与已知的几种土壤特性及吸附参数的相关性较弱，     

微塑料对土壤磷吸附的影响

微塑料是一类土壤中广泛存在的新兴污染物,其对土壤磷吸附的影响尚不明确。文中分析了0.1%～10%含量微塑料对土壤磷吸附特性的影响及机制。结果表明,微塑料会使得吸附第一阶段液膜扩散阶段速率显著提升（p<0.05）。与纯土壤（q_e=6.456 mg/g）相比,含量1%以下的微塑料显著降低了土壤磷吸附容量（p<0.05）,但5%以上的微塑料显著提升了土壤磷吸附容量（p<0.05）。同等含量下,微塑料粒径越小,微塑料-土壤体系的磷吸附量越大。微塑料可与磷竞争吸附位点,降低了微塑料-土壤体系对磷的吸附,但微塑料也可直接吸附磷,故当微塑料为5%及以上时,微塑料-土壤体系对磷的吸附量升高。因此,土壤微塑料污染可显著改变土壤对磷的吸附特性,且与微塑料的含量和粒径等因素密切相关。     

陇东油区包气带土壤对原油吸附行为

通过静态吸附实验研究了陇东油区包气带土壤对原油的吸附行为,考察了溶液pH、温度、石英砂及不司介质对原油吸附的影响.结果表明:陇东土壤对原油吸附等温线很好地符合Langmuir和线性吸附方程,其吸附系数为0.0135,0.0126L/g,且在水相中原油快速吸附到土壤颗粒上,5 h后基本达到平衡.5种介质吸附原油能力依次为石英砂＜高岭土＜黄绵土＜高压灭菌土＜硅藻土.水相pH、温度和石英砂质量分数的升高,不利于原油在土壤中的吸附,而增加盐度会加大原油的吸附量.对于土壤偏碱性,砂粒质量分数高的陇东地区,这些特性有利于原油在包气带土壤中向下运移.     

浙江天童森林退化和受损对土壤呼吸的影响

以常绿阔叶林顶级群落为参照,选择了常绿阔叶林亚顶极群落、针叶林、灌丛和灌草丛代表不同退化类型;同时,以4种人工采伐处理代表常绿阔叶林不同受损程度,分别研究了不同退化和受损程度影响下,土壤的呼吸速率及影响因素.结果表明:(1)土壤呼吸速率具有明显的季节动态;(2)土壤呼吸速率分别在常绿阔叶林顶极群落与灌草丛最高,其次分别...     

基于污染压力-退化表征的珠江河口湿地土壤退化评价

湿地土壤质量的综合评价对湿地土壤生态系统的优化管理与恢复措施的实施具有重要意义. 本文基于珠江 河口湿地污染现状和PSR(压力-状态-响应)体系,从社会和污染因素选取9个压力指标,从生物和非生物方面选取11个 状态指标,从教育、管理和科研方面选取了3个响应指标,构建了珠江河口湿地土壤退化指标评价体系. 运用数据归一化 方法计算每个采样点的退化指数(ID)和综合健康指数(ICH),然后,运用 YAAHPV3层次分析软件对研究区3个典型样 点进行退化分析,结果表明:珠江三角洲湿地的大部分地区的ICH为6.73~37.52,显示土壤普遍呈现亚健康状况;番禺 区以污染为主的退化驱动比南沙区以围垦为主的退化驱动强度更大,3个典型湿地样点土壤的退化程度由大到小依次 为11涌洪奇沥湿地(0.4818)、番禺外贸码头湿地(0.3426)、15涌沟渠湿地(0.1756). 层次分析法评价结果表明,珠江 河口湿地土壤质量状况不容乐观,珠江河口湿地保护和管理工作的重点,应当以治理土壤污染和减小滩涂围垦幅度进行 开展      

土壤中PVA降解菌的分离与筛选

以含PVA的土壤作为菌种来源,PVA为唯一碳源,在相同培养条件下,采用I2-KI及硼酸染色法进行初筛,再通过测定PV A 降解效率的方法进行复筛。初筛得到PV A 降解菌6株,复筛得到4株单一的PV A降解菌A ,C ,E ,F ,降解效率在48％～61％之间。通过对4株PV A降解单菌进行生理生化实验鉴定出A为假单胞菌属,C为球菌属,E为微球菌属,F为链球菌属。     

秸秆不同处理方式对土壤氮磷吸附特性的影响

为探讨秸秆不同处理方式对土壤氮磷吸附特性,将破碎秸秆、腐熟秸秆和秸秆炭添加到模拟施肥的土壤中,研究了秸秆还田后对土壤氮磷吸附特征的影响。结果表明,不同处理的秸秆添加土壤对铵态氮吸附速率和吸附量大小均为秸秆炭破碎秸秆腐熟秸秆;对磷酸根吸附速率和吸附量大小均为秸秆炭破碎秸秆,腐熟秸秆对磷酸根负吸附。Freundlich方程能更好的描述铵态氮和磷酸根的吸附热力学过程,吸附动力学都符合伪二阶动力学方程。