Adsorption removal of roxarsone, arsenite(Ⅲ),and arsenate(Ⅴ) using iron-modified sorghum straw biochar and its kinetics

Arsenic(As)contamination in groundwater is a major problem in many countries,which causes serious health issues.In this paper,a novel method has been developed for the simultaneous removal of ROX and As(Ⅲ/Ⅴ)using the modified sorghum straw biochar(MSSB).The MSSB was characterized by X-ray diffraction,scanning electron microscopy,Fourier Transform Infrared,and Brunauer–Emmet–Teller(BET)surface area.The removal performance of MSSB for ROX,arsenite[As(Ⅲ)],and arsenate(As(Ⅴ))was investigated using batch experiments.At pH of 5,the arsenic concentration of 1.0 mg/L,adsorbent dose of 1.0 g/L,the maximum adsorptioncapacities of ROX,As(Ⅲ),and As(Ⅴ)were 12.4,5.3,and 23.0 mg/g,respectively.The adsorption behaviors were fit well with the Langmuir and the pseudo-second-order rate model.The results showed that MSSB acted as a highly effective adsorbent to simultaneously remove the composite pollution system consisted of ROX and As(Ⅲ/Ⅴ)in aqueous solutions,providing a promising method in environmental restoration applications.

张守琳运用“温阳解毒通络”法治疗糖尿病肾脏病(Ⅳ-Ⅴ期)经验探析

糖尿病肾脏病属中医学的“肾消(消肾)”“下消”“水肿”等范畴,目前已成为终末期肾病的主要原因。张守琳教授认为“阳虚毒瘀肾络”是糖尿病肾脏病(Ⅳ-Ⅴ期)的基本病机,阳气受损为发病之本,毒瘀肾络是发病的关键环节,并确立了“温阳解毒通络”的治疗原则,有效延缓了肾功能损伤的进展和进入透析的进程。

一个遗传性凝血因子Ⅴ缺陷症家系的临床表型及分子致病机制研究

目的:探讨一个遗传性凝血因子Ⅴ缺陷症(coagulation factor V deficiency,FⅤD)家系的临床表型及分子致病机制。方法:采用一期法测定凝血因子Ⅱ、Ⅴ、Ⅶ、Ⅷ、Ⅸ、Ⅹ、Ⅺ、Ⅻ(FⅡ∶C、FⅤ∶C、FⅦ∶C、FⅧ∶C、FⅨ∶C、FⅩ∶C、FⅪ∶C、FⅫ∶C)、活化部分凝血活酶时间(activated partial thromboplastin time,APTT)及凝血酶原时间(prothrombin time,PT)进行表型鉴定;应用高通量外显子测序筛查全基因变异,Sanger测序验证F5基因可疑变异;利用Mutation-Taster、PolyPhen-2生物信息学软件预测变异致病性、ClustalX软件分析氨基酸保守性和PyMol软件模拟变异蛋白模型。结果:先证者PT、APTT明显延长,FⅤ∶C仅为5.45%,TT、FIB及其余凝血因子均无明显异常。其母亲、父亲、姐姐的PT、APTT均延长,FⅤ∶C不同程度减低。基因检测显示先证者F5第3号外显子存在c.286G>C(p.Asp96His)纯合错义变异,其父亲、母亲、姐姐均存在c.286G>C(p.Asp96His)杂合错义变异。生物信息学分析提示p.Asp96His为致病变异,相关的氨基酸位点在10个物种中高度保守。蛋白模拟显示,Asp96变异为His96后可导致原有氢键消失和距离改变,破坏了原有的氢键相互作用力,影响蛋白结构的稳定性。结论:F5第3号外显子c.286G>C(p.Asp96His)错义变异可能导致了先证者及家系成员FⅤ∶C的减低,也是引起凝血因子Ⅴ缺陷症的遗传学病因。

Effect of competing solutes on arsenic(Ⅴ) adsorption using iron and aluminum oxides

The study focused on the effect of several typical competing solutes on removal of arsenic with Fe2O3 and Al2O3. The test results indicate that chloride, nitrate and sulfate did not have detectable effects, and that selenium（Ⅳ） （Se（Ⅳ）） and vanadium（Ⅴ） （V（Ⅴ）） showed slight effects on the adsorption of As（Ⅴ） with Fe2O3. The results also showed that adsorption of As（Ⅴ） on A12O3 was not affected by chloride and nitrate anions, but slightly by Se（Ⅳ） and V（Ⅴ） ions. Unlike the adsorption of As（Ⅴ） with Fe2O3, that with Fe2O3 was affected by the presence of sulfate in water solutions. Both phosphate and silica have significant adverse effects on the adsorption of As（Ⅴ） adsorption with Fe2O3 and Al2O3. Compared to the other tested anions, phosphate anion was found to be the most prominent solute affecting the As（Ⅴ） adsorption with Fe2O3 and Al2O3. In general, Fe2O3 has a better performance than Al2O3 in removal of As（Ⅴ） within a water environment where multi competing solutes are present.

老年Ⅳ~Ⅴ级颅内动脉瘤介入栓塞术中血压管理策略对预后的影响

目的:探究介入栓塞术中不同血压管理策略对老年Ⅳ~Ⅴ级颅内动脉瘤患者的预后影响。方法:回顾性选取我院收治的老年Ⅳ~Ⅴ级颅内动脉瘤患者110例,并纳入训练集。使用随机数字表法将患者分为观察组(55例)和对照组(55例),比较训练集两组患者的临床资料;使用Kaplan-Meier法进行生存曲线的绘制,比较不同血压管理策略患者的2年预后不良发生率;Cox单因素和多因素回归分析患者术后预后不良的影响因素;构建预测患者术后预后不良的列线图模型;通过验证集患者以受试者工作特征曲线(ROC)和校准曲线对模型效能进行评价。依据模型预测个体风险评分,构建危险分层系统。结果:观察组患者的2年预后不良发生率明显低于对照组(P<0.05);高血压、手术时机为中期和晚期、平均动脉压≥65 mmHg、血压波动幅度≥16 mmHg、瘤体长径与瘤颈宽度的比值(AR)>2.0是老年Ⅳ~Ⅴ级颅内动脉瘤患者介入栓塞术预后不良的独立危险因素(P<0.05),术中血压管理策略为控制性降压是老年Ⅳ~Ⅴ级颅内动脉瘤患者介入栓塞术预后不良的保护因素(P<0.05);列线图预测模型有较好的区分度及准确度。危险分层系统将所有患者分为4个危险分组:极低风险组(总分<30分)、低风险组(30分≤总分<78分)、中风险组(78分≤总分<106分)和高风险组(总分≥106分)。该危险分层系统能区分不同术中血压管理策略患者的预后不良发生情况(P<0.05)。结论:在手术过程中应实施瑞芬太尼联合尼莫地平控制性降压的血压管理策略,可以提高患者的预后水平。

盐城坳陷带典型区域新近系盐城组第Ⅴ承压含水层特征方法研究

盐城市区地处苏北盐城坳陷带,境内的新近系盐城组孔隙含水层深达1000~1300m。前人对400m以下的第Ⅴ承压含水层划分、研究较为粗略。通过岩芯分析、物探、野外调查、水化学分析、数值模拟等多种方法的综合运用,重新划定了第Ⅴ承压含水层的赋存边界,深入研究了区域该含水层的赋存特征,同时计算了其可持续利用资源量。研究成果可为盐城坳陷带其他区域该含水层的研究提供科学的借鉴。

高效液相色谱串联电感耦合等离子体质谱(HPLC-ICP-MS)测定祛痱粉和爽身粉中As(Ⅲ)与As(Ⅴ)

为更科学地评价化妆品中含有的砷对人群的健康影响,建立了祛痱粉和爽身粉中三价砷As(Ⅲ)和五价砷As(Ⅴ)的高效液相色谱串联电感耦合等离子体质谱(HPLC-ICP-MS)检测法,并用该方法检测市售祛痱粉和爽身粉中As(Ⅲ)和As(Ⅴ)的含量。样品采用热浸提的提取方式,经HAMILTON PRP-X100色谱柱(250 mm×4.1 mm,10μm)分离,以添加2%甲醇的150 mmol/L碳酸铵溶液为流动相进行等度洗脱,用ICP-MS进行检测。在1.0~50.0 ng/mL的浓度范围内,As(Ⅲ)和As(Ⅴ)均呈较好的线性关系,相关系数r≥0.999。As(Ⅲ)和As(Ⅴ)的方法检出限(3S/N)分别为0.001 5 mg/kg和0.001 mg/kg,两种形态的平均加标回收率分别为90.2%~95.9%、103%~108%;RSD分别为2.1%~4.6%、2.7%~5.2%。方法简便、快速、灵敏度高,适用于大批量祛痱粉和爽身粉中As(Ⅲ)和As(Ⅴ)的检测分析。在采集并检测的包含20个品牌共34份样品中,检出率为67.6%,检出样品中As(Ⅲ)和As(Ⅴ)的含量分别为0.006~0.015 mg/kg、0.006~0.105 mg/kg,平均值分别为0.010 mg/kg、0.023 mg/kg,检出结果均未超出我国《化妆品安全技术规范》(2015年版)对总砷的限值2 mg/kg,但As(Ⅲ)和As(Ⅴ)的检出率较高,应当引起重视并进一步制定相关标准。

典型峡谷Ⅴ型地貌下桥址区风特性

为得到山区峡谷典型Ⅴ型地形下的桥梁抗风设计的关键风特性参数,通过“数值风洞试验”建立模型,以实桥为工程背景构建三维地形网格,基于3种典型湍流模型和流体壁面粗糙度对桥位的风场特性进行分析,选取最优湍流模型和流体壁面粗糙度对该地形桥位处的风场特性进行分析;围绕两个影响桥址区风特性的地形参数(山体高度和夹角),阐明Ⅴ型峡谷地形下风特性参数的变化规律,并与现行规范进行对比,推算桥面设计基准风速。结果表明:该Ⅴ型峡谷地形的最佳湍流模型和流体壁面粗糙度分别为RNG k-ε和20 m;随着山体高度及山体夹角两参数的变化,风速增加幅度分别为2.37%~12.56%和1.24%~6.98%;山体高度及山体夹角两变参数下,梯度风高度分别为700 m和800 m左右;实际湍流强度大于规范中四类地表规范值,在离地高度40 m范围内,湍流强度更接近于D类地表。实际Ⅴ型峡谷桥址区不能简单按规范归为C类或D类地形,在设计风参数计算时应综合考虑规范和经验公式,还可借助模拟手段来提高其准确性。

Combined Effect of Fluoride and Arsenate on Gene Expression of Osteoclast Differentiation Factor and Osteoprotegerin

Objective To study the combined effect of fluoride and arsenate on the expression of SD rat osteoblastic osteoclast differentiation factor （ODF） mRNA and osteoprotegerin （OPG） mRNA. Methods Osteoblasts were obtained by enzymatic isolation from newborn SD rats. A factorial experiment was performed. Osteoblasts were exposed to NaF （0.5 mmolF/L, 4 molF/L） and Na3AsH2 （12.5 μmolAs/L and 200 μmolAs/L） separately or F plus As and cultured for 48 h. The gene expression of osteoblastic ODF and OPG was observed by RT-PCR. Results The expression ofODF mRNA increased in F0.5, F4 groups compared with control group and two groups of F0.As200, F,As200 compared with As200 group, and decreased significantly in groups of F4As12.5, F0.5As200, and F4As200. The expression of OPG rnRNA decreased in groups of F4, As200, F4As12.5, F0.5As200, and F4As200. Conclusion The joint effect of fluoride and arsenate on the gene expression of ODF is antagonistic, while the combined effect on the gene expression of OPG is synergistic. F4, F4As12.5, and F0.5As200 promote bone resorption of rat osteoclasts, whereas F0.5As12.5 inhibits osteolytic effect of rat osteoclasts.

Fe(Ⅱ)非生物氧化-沉淀联合工艺对As(Ⅴ)去除的研究

由于现代化工业进程快速发展,大量砷污染物进入水体,引起水质恶化。提出了氧诱导Fe(Ⅱ)非生物氧化与As(Ⅴ)共沉淀,是一种节省成本、时间且高效的As(Ⅴ)去除方法。考察了pH、Fe(Ⅱ)/As(Ⅴ)摩尔比、溶解氧(DO)浓度、温度及共存离子对As(Ⅴ)去除的影响。结果表明,同步氧化Fe(Ⅱ)可显著提高亚铁除砷效率。随着pH从5.3增加到8.0,As(Ⅴ)去除能力先增大后减小,最佳pH为6.4;溶解氧质量浓度从0提高到4 mg/L,反应60 min后As(Ⅴ)的去除率提升了37.85%;反应体系中共存离子(Cu^(2+)、Ni^(2+)、Mn^(2+)、Cl-、NO_(3)^(-)、PO_(4)^(-))存在时,Mn^(2+)促进As(Ⅴ)的去除,Mn(Ⅱ)=0.5 mg/L,As(Ⅴ)的去除率提高了11%;提高温度和亚铁浓度均能增加As(Ⅴ)的去除率。SEM-EDS结果表明,氧气存在时固体颗粒由松散细小转化为轮廓清晰、簇团密实的球形团聚,颗粒粒径增大,增强了As(Ⅴ)的固定。以活性氧(ROS)为氧化剂,与Fe(Ⅱ)发生类Fenton反应是Fe(Ⅱ)氧化的机理,砷酸铁和含砷的铁(氢)氧化物是砷固定的主要形态。

Competitive and cooperative adsorption of arsenate and citrate on goethite

The fate of arsenic in natural environments is influenced by adsorption onto metal （hydr）oxides. The extent of arsenic adsorption is strongly affected by coexisting dissolved natural organic acids. Recently, some studies reported that there existed competitive adsorption between arsenate and citrate on goethite. Humic acid is known to interact strongly with arsenate by forming complexes in aqueous solution, hence it is necessary to undertake a comprehensive study of the adsorption of arsenate/citrate onto goethite in the presence of one another. The results showed that at the arsenate concentrations used in this study （0.006-0.27 mmol/L）, citrate decreased arsenate adsorption at acidic pH but no effect was observed at alkaline pH. In comparison, citrate adsorption was inhibited at acidic pH, but enhanced at alkaline pH by arsenate. This was probably due to the formation of complex between arsenate and citrate like the case of arsenate with humic acid. These results implied that the mechanism of the adsorption of arsenate and citrate onto goethite in the presence of one another involved not only competition for binding sites, but the cooperation between the two species at the watergoethite interface as well.

Phylogenetic analysis and arsenate reduction effect of the arsenic-reducing bacteria enriched from contaminated soils at an abandoned smelter site

Microbial reduction of As(V)(i.e.,arsenate)plays an important role in arsenic(As)mobilization in aqueous environment.In this study,we investigated As(V)reduction characteristics of the bacteria enriched from the arsenic-contaminated soil at an abandoned smelter site.It was found that As(V)was completely reduced to As(III)(i.e.,arsenite)in 21 h.After 3-d incubation,a yellow solid was precipitated and the concentration of As(III)decreased sharply.After 150 h incubation,ca.65%of soluble arsenic was removed fro...

Arsenic Distribution,Species,and Its Effect on Maize Growth Treated with Arsenate

A pot experiment was conducted to investigate the effect of different arsenic （As） levels on maize （Zea mays L.） growth and As accumulation and species in different parts of maize plants,as a guideline for production of maize in As-polluted areas with the objective of preventing As from entering the food chain,and improving understanding of the mechanisms of effect of As on plant.Zhengdan 958 was grown at five As levels added to soil （0,12.5,25,50,and 100 mg kg^-1 As）.As concentration in maize tissues increased in the order of grain〈stalk〈leaf〈〈root.The As concentration in maize grain exceeded the maximum permissible concentration of 0.7 mg kg^-1 in China at levels of 50 and 100 mg kg^-1.As species were presented in root,stalk,and grain,but organic As was the major As species identified in the grain.Maize plants were able to reduce arsenate to arsenite.Low As levels of 12.5 and 25 mg kg^-1 improved maize growth and grain nutrition quality,while high levels of As 50 or 100 mg kg^-1 inhibited them.Yield reduction at high As levels resulted mainly from reduced ear length,kernel number per row,and kernel weight.

Arsenate and phosphate interaction in Saccharomyces cerevisiae

In the present study, arsenate（As（V）） and phosphate（P（V）） interactions were investigated in growth, uptake and RNA content in yeast（Saccharomyces cerevisiae）. Yeast grew slowly with As（V） concentrations increasing in the medium. However, the maximal population density was almost the same among different As（V） treatments. It was in the late log phase that yeast growth was aug- mented by low As（V）, which was maybe due to the fact that methionine metabolism was stressed by vitamin B6 deprivation, so As（V） treatments did not affect maximal population density. However, with P （V） concentrations increasing, the maximal population density increased. Therefore, the maximal population density was determined by P （V） concentrations in the medium but not by As （V） concentrations in the medium. Ycflp（a tonoplast transpor） transports As（GS）3 into the vacuole, but arsenic（As） remaining in the thalli was 1.27% with As（V） exposure for 60 h, from which it can be speculated that the percentage of As transported into vacuole should be lower than 1.27%. However, the percentage of As pumped out of cell was 71.49% with As （V） exposure for 68 h. Although two pathways （extrusion and sequestration） were involved in As detoxification in yeast, the extrusion pathway played a major role in As detoxification. RNA content was the highest in the early-log phase and was reduced by As（V）.

Stabilization of ferric arsenate sludge with mechanochemically prepared FeS2/Fe composites

FeS2/Fe composites were mechanochemically prepared with iron powder and pyrite for the stabilization of ferrite arsenate sludge(FAS).The effects of preparation parameters on stabilization performance were investigated.The results show that the optimum conditions are FeS2/Fe molar ratio of 5:5,milling time of 2 h,ball-to-material mass ratio of 15:1 and milling with stainless steel ball.Then,the composites were characterized by XRD,SEM,FTIR,etc.The physicochemical properties of FeS2/Fe mixture change dramatically,which is responsible for its excellent performance.Finally,the stabilization process of FAS was optimized.When the FAS is mixed with composites at mass ratio of 4:1 and milled for 30 min,the As leaching concentration of FAS can be reduced from 639.15 to 4.74 mg/L with the stabilization ratio of 99.2%.

Sorption Kinetic of Arsenate as Water Contaminant on Zero Valent Iron

This study investigates the sorption of arsenate from water using zero-valent iron ZVI as sorbent. Batch experiments were carried out to study the sorption kinetics of arsenate under different concentrations of arsenate varies from 0.5 to 200 mg/l. A kinetic model was considered to describe the arsenates sorption on ZVI material. The kinetics of the arsenate sorption processes were described by the Langmuir kinetic model. The sorption capacity increases with high initial concentration which obtained the maximum sorption 2.1 mg/g at 200 mg/l of arsenate initial concentration. The results show that the rapid initial sorption rates of arsenate were occurred at the beginning of experiments running time, followed by a slower removal that gradually approaches an equilibrium condition. The data from laboratory batch experiments were used to verify the simulation results of the kinetic model resulting in good agreement between measured and modeled results. The results indicate that ZVI could be employed as sorbent materials to enhance the sorption processes and increase the removal rate of arsenate from water.

Oxidation Characteristics of the Reactivity Between Pyrite and Aqueous Arsenate

Natural pyrites contain high levels of adsorbed and structurally incorporated arsenic(As),which may simultaneously result in the release of As and affect the oxidation process of pyrite.However,the oxidation and electrochemical behaviors of As on the oxidation reactivity of pyrites are still not clear.In this study,pyrite was prepared by a hydrothermal method and applied to study the oxidation mechanism between pyrite and aqueous arsenate.Analyses of X-ray diffraction,X-ray photoelectron spectroscopy,and scanning electron microscopy demonstrate that the as-prepared sample is an octahedron-like pyrite with high purity and crystallinity.The interaction between As(V)and pyrite as well as the electrochemical behaviors of pyrite oxidation in the presence of aqueous arsenate were investigated under acidic conditions by an ion analysis method,cyclic voltammetry(CV),Tafel,and electrochemical impedance spectroscopy(EIS).The results of the chemical reaction indicate that electrons are transferred from S 22-to dissolved oxygen with the formation of SO 42-in the initial As(V)concentration range of 0–0.3 mmol/L.In the initial As(V)concentration range of 0.4–1.2 mmol/L,electrons are transferred from S 22-to As(V)with the formation of elemental S 0 and As(III).The CV,the Tafel plot and EIS analyses indicate that aqueous arsenate in an electrolyte promotes oxidation reactivity and passivation of the pyrite electrode.Moreover,the electron transfer rate increases with increasing aqueous arsenate concentration in the electrolyte.

Interaction mechanism between arsenate and fayalite-type copper slag at high temperatures

The interaction mechanism between sodium arsenate and fayalite-type copper slag at 1200℃was investigated through XRD,XPS,HRTEM,TCLP and other technical means and methods.The results indicated that the proportions of sodium arsenate in the slag and flue gas phases were approximately 30%and 70%,respectively.The addition of sodium arsenate depolymerized the fayalite structure and changed it from a crystalline state to an amorphous state.The fayalite structural changes indicated that the[AsO_(4)]tetrahedron in sodium arsenate combined with the[SiO_(4)]tetrahedron and[FeO_(4)]tetrahedron through bridging oxygen to form a silicate glass structure.The TCLP test results of the samples before and after the high temperature reaction of fayalite and sodium arsenate showed that after high temperature reaction,fayalite could effectively reduce the leaching toxicity of sodium arsenate,reducing the leaching concentration of arsenic from 3025.52 to 12.8 mg/L before and after reaction,respectively.

A new mixed-valent iron arsenate black crystal

Scorodite（FeAsO4·2H2O）is the most popular phase for arsenic（As）immobilization while the reductive dissolution of Fe（Ⅲ）to Fe（Ⅱ）will promote As release.In the present study,an equilibrium between Fe（Ⅲ）and Fe（Ⅱ）was achieved in scorodite preparation system by introducing certain alcohol（methanol,ethanol,isopropanol or tert-butanol）,and thus a new mixed-valent iron arsenate black crystal formulated as Fe（Ⅱ）（5.2）Fe（Ⅲ）（8.8）（HAsO4）4（AsO4）8·H2O was prepared.In comparison with scorodite,the black crystal has higher As content（36.4%,mass fraction）and lower crystal water content（0.73%,mass fraction）.Additionally,the leaching concentration of As can be lower than the threshold value（5 mg/L）regulated by identification standards for hazardous wastes of China（GB 5080.3-2007）.Therefore,this new mixed-valent iron arsenate crystal could be classified as a non-hazardous and promising As-bearing phase in environmental applications.

Synthesis and characterization of arsenate antimonic acid AAAc(1 : 1)

The AAAc(1 : 1) was synthesized in water by As2O3 and Sb2O3 with molar ratio of 1 : 1: AAAc(1 : 1)was characterized by Raman, IR, TG/DTG, DSC, XPS and XRD. The results show that there are four peaks to vsof As-OH, As-O-Sb, Sb-OH and Sb-O-Sb in Raman spectra of AAAc(1 : 1) at 100 - 1 000 cm-1. The solution of AAAc(1 : 1) was also titrated with KOH solution. The titration results show that AAAc(1 : 1) is a hexabasic acid with dissociation constants of k1 = 3.62 × 10-2 , k2 = 3.05 × 10-3 , k3 = 6. 43 × 10-6 , k4 = 9. 78 × 10-8 ,k5 = 1.32 × 10-11 , k6 =3.87 × 10-12. AAAc(1 : 1) has a good solubility and stability in water, its solid obtained by free volatilizing water from its solution under air at ambient temperature is amorphous. Chemical and thermal analyture of AsO ( OH )2-OH-Sb ( OH )4-O-Sb ( OH )4-OH-AsO ( OH )2 or As ( OH )3-O-Sb(OH)4-O-Sb(OH)4-O-As(OH)3 (isomerism) through experimental determination and geometry optimization.