微波消解-ICP-OES内标法测定废催化剂浸出液中稀土和重金属元素

以钇为内标,建立了微波消解-电感耦合等离子体发射光谱(ICP-OES)研究废催化剂浸出液中稀土和重金属元素的方法。通过优化实验条件,标准曲线线性范围为(0.01～2.00) mg·L^-1,方法检出限为(0.004～0.008)mg·L^-1,相关系数均大于0.999。废催化剂样品加标回收率为(88.9～109.2)%,测定结果相对标准偏差为(5.0～11.3)%(n=6)。实验结果表明,该方法线性范围宽,溶剂消耗少,受干扰少,准确度高,可以同时测定废催化剂浸出液中La、Ce、Ni、Co、Sb、V。     

微波消解-电感耦合等离子体质谱（ICP-MS）法测定电镀污泥中的重金属

将电镀污泥样品自然风干,以研磨的方式对电镀污泥进行处理。比较了不同消解体系和消解时间对样品消解的影响,确定采用硝酸+盐酸+氢氟酸消解体系,利用微波消解系统对电镀污泥进行消解,消解时间为25min。使用ICP-MS法对污泥中的重金属元素进行测定,测定结果表明所检测项目工作曲线线性关系好,相关系数r均大于0.999。铬、镉、镍、铅、铜、锌加标回收率分别为91.6%～97.7%、92.0%～97.0%、95.1%～98.0%、94.3%～95.2%、97.1～102%、96.3%～98.7%;各元素测定结果相对平均偏差在0.10%～3.7%,均满足相关测定要求。计算的潜在生态危害系数、潜在生态危害指数结果表明,电镀污泥中的铬、镉、铅、铜、锌为轻微生态危害,镍为强生态危害;潜在生态危害指数RI计算值为216.69,属于中等生态危害。     

微波消解-ICP-MS测定电镀污泥中的重金属

采用微波消解系统对某电镀污泥进行消解,利用ICP-MS对污泥中的重金属进行测定。称取制备后样品,置于消解罐中充分反应后,赶酸、定容后利用电感耦合等离子体质谱法进行测定。电镀污泥中的铬为18845.2mg/kg、镉为10.3mg/kg、镍为5200.0mg/kg、铅为189.7mg/kg、铜为3271.7mg/kg、锌为49632.6mg/kg。测定结果表明所检测项目工作曲线线性关系好,相关系数r均大于0.999。铬加标回收率在91.6～97.7%之间、镉加标回收率在92.0～97.0%之间、镍加标回收率在95.1～98.0%之间、铅加标回收率在94.3～95.2%之间、铜加标回收率在97.1～102%之间、锌加标回收率在96.3～98.7%之间,均满足相关测定要求。计算的潜在生态危害系数、潜在生态危害指数结果表明,电镀污泥中的铬、镉、铅、铜、锌为轻微生态危害,镍为强生态危害;潜在生态危害指数RI计算值为216.69,属于中等生态危害。     

微波消解/ICP-AES法测定污水处理厂污泥中的重金属

采用微波消解/电感耦合等离子发射光谱法(ICP-AES)测定了城市污水处理厂污泥中Cd、Cr、Cu、Mn、Mo、Ni、Pb、Zn等8种重金属元素,并优化了ICP仪器工作参数及微波消解条件.方法的检出限为0.001～0.01mg/L.相对标准偏差为2.0%～9.2%(n=7),回收率为85.3%～105.0%.     

毛细管电泳-电致化学发光联用技术检测烟草中尼古丁含量

建立了毛细管电泳-电致化学发光联用技术(CE-ECL)检测烟草浸出液中尼古丁含量的方法。考察了检测电位、检测池中Ru(bpy)32+浓度和缓冲液pH值、CE运行缓冲液浓度和pH值、进样时间和电压,以及CE分离电压等实验条件对尼古丁测定的影响。在优化的条件下,尼古丁检测的线性范围为低浓度段:1～100μg/L(r>0.999)、高浓度段:100～1500μg/L(r>0.996),检出限为0.5μg/L(S/N=3)。将本方法用于3种品牌的烟草浸出液中尼古丁含量的测量,测定值均与烟盒上尼古丁的标注值相吻合,样品的加标回收率为95%～106%。     

应用地质累积指数评价南昌市城市污泥重金属污染

应用地质累积指数对南昌市城市污泥(包括污水处理厂污泥和纸厂废水处理污泥)的重金属污染进行了分析评价。结果表明,城市污泥重金属中Pb、Cr按地质累积指数分级均为0,属无污染;As地质累积指数为0～1之间,表现为无污染～中度污染;青山湖污水处理厂污泥主要的重金属污染元素为Cd、Hg、Cu、Zn,其平均的地质累积指数为2～4,表现为中度污染～强污染。     

超声波提取-气相色谱-质谱法测定脱水污泥中的多氯联苯

采用超声波提取,气相色谱–质谱联用法检测,建立了脱水污泥中18种多氯联苯的测定方法。污泥样品以二氯甲烷-正己烷(体积比为1∶1)为提取剂,用超声波提取20 min,在优化的仪器条件下,其中18种多氯联苯的质量浓度在0.05～100μg/mL范围内与色谱峰面积均呈良好的线性关系(r≥0.999 0)。方法的检出限为0.16～0.97μg/L,加标回收率为84.0%～117.0%,测定结果的相对标准偏差小于4.5%(n=6)。该方法样品前处理简单,重现性好,检出限低,准确度高,适用于污水处理厂脱水污泥中18种多氯联苯的测定。     

微波消解-磷钼蓝分光光度法测定城市污泥中总磷浓度

建立了微波消解-磷钼蓝分光光度法测定城市污泥中总磷的方法。在微波环境中硝酸-过氧化氢能够将城市污泥中无机磷盐和含磷有机物消解为正磷酸盐,在弱酸性条件下,正磷酸盐在铋盐的催化条件下与钼酸铵-抗坏血酸生成磷钼蓝,于分光光度计波长690nm处进行测定总磷浓度。方法的相对标准偏差0.63%～0.95%,加标回收率为101%～102%,能够满足对城市污泥中总磷浓度的测定要求。     

污泥上培植的报春花、冬葵中重金属的原子吸收测定

本文研究报春花、冬葵两种植物对污泥中重金属的吸收情况,样品用(1 4)HClO4 HNO3进行了消化处理,然后在实验选定的最佳的工作条件下,用火焰原子吸收光谱法对铅、汞、铬、镉重金属元素进行了测定。结果表明:种植冬葵和报春花前后,污泥样品重金属含量明显下降。     

微波消解-电感耦合等离子体质谱法测定鲤鱼、河蚌样品中的铜、镉、铅、铬

建立微波消解–电感耦合等离子体质谱法同时测定鲤鱼、河蚌样品中铜、镉、铅、铬4种重金属元素的含量。以20.0μg/L的Rh作为内标,采用硝酸–过氧化氢消解液,用微波消解仪消解鲤鱼、河蚌等生物样品,在选定的仪器工作条件下测定。铜、镉、铅、铬4种重金属元素的质量浓度在1～100μg/L范围内与其质谱强度呈良好的线性关系,相关系数均为0.999 9,方法检出限为0.01～0.09μg/L。测定结果的相对标准偏差为1.30%～9.95%(n=6),样品加标回收率为91.0%～111%。用所建方法对黄鱼国家标准物质(GBW 08573)进行测定,测定值与标准值基本一致,相对误差均小于7%。该方法简单、快速,灵敏度高,重现性好,适用于大批量生物样品中多种重金属元素的同时测定。     

Recovery and stabilization of heavy metal sludge (Cu and Ni) from etching and electroplating plants by electrolysis and sintering

This work dealt with the recovery and stabilization of the sludge with heavy metals (Cu and Ni) produced from etching and electroplating plants. The heavy metals in the sludge were deprived of by acid leaching, followed by precipitation with 28% NH₄OH, and finally by electrolysis. In the electrolysis, the recovery percentage and purity were investigated at different electronic currency and temperature. The metal-deprived sludge was stabilized by mixing with glass powder and clay, followed by sintering at high temperature. How the ratio of glass powder to metal-deprived sludge affected final products (sludge bricks) was explored, in terms of specific gravity, absorption capacity, unconfined compressive strength, morphology, the volume shrinkage ratio and burn-up ratio. The volume shrinkage ratio and burn-up ratio of sludge bricks increased with metal-deprived sludge contents. The heavy metal remaining in sludge bricks was assessed through TCLP (toxicity characteristic leaching procedure) and by the analysis of SEM and EDX. The results from TCLP showed that the contents of leached metals were all below the regulatory criteria. This fact approved the feasibility of our method.     

生物浸出回收废弃镍-镉电池研究

在中国,只有不到1%的废弃干电池被回收,因此有必要寻找一种既经济、快速,又利于环保的处理废弃干电池方法.生物浸出是回收废弃干电池有毒金属效果最好的方法之一.本研究应用本地下水道废水经驯化培养后产生的酸性废水作浸出菌种,考察pH值、生化反应器污水停留时间(RTB)、浸取时间、生化反应液是否添加Fe粉等实验条件对废弃镍-镉电池镍、镉浸出率的影响.结果表明,在pH值1.8~2.1、RTB 5 d、浸取时间50 d、生化反应液添加Fe粉条件下,可使镍-镉电池中镍、镉浸出率分别达到87.6%和86.4%,从而为工业生产提供了科学依据.     

Enrichment and recycling of Zn from electroplating wastewater as zinc phosphate via coupled coagulation and hydrothermal route

Electroplating is a common process of converting zinc ion in electrolyte as a micro level zinc layer on electroplating pieces. After electroplating, the remaining electrolyte on the surface of the pieces is washed with water, and accordingly, Zn-containing electroplating wastewater is generated. Hazardous Zn-containing wastewater is generated during the washing of electroplating pieces and plating tank. Herein, Zn was enriched from wastewater by commercial flocculant and then recycled as highly purified zinc phosphate via coupled acid extraction and hydrothermal treatment. Firstly, 98.4% Zn was recovered as sludge from wastewater by adding 0.2 g/L of flocculant. Then, the sludge was dissolved into an acid solution to produce a leachate with 31.2/10.8/19.3 g/L of Fe/Al/Zn and then hydrothermally treated to remove Fe/Al. The Fe removal rate was only 54.2% without phosphate and glucose but was increased to 98.6% after the addition of 0.5 g of glucose with Al/Zn loss < 2%. However, when 0.5 g of glucose and 15 g/L of phosphate were used, 99.8% Fe and 96.6% Al were synchronously removed as giniite with Zn loss < 2%. After Fe/Al separation, the remaining Zn was finally recycled as Zn phosphate particles with 98.1 wt% Zn₃(PO₄)₂·2H₂O. The added phosphate predominated the synergy removal of Fe/Al and especially lowered the Gibbs value of Al hydrolysis from 39.7 kJ/mol of boehmite to ?5.96 kJ/mol of giniite, thereby reducing start-up temperature and reaction time. The proposed method showed practical application in the enrichment and recycling of valuable metals from wastewater.     

Anaerobic treatment of low-strength brewery wastewater in expanded granular sludge bed reactor

Anaerobic treatment of low-strength brewery wastewater, with influent total chemical oxygen demand (COD) (CODin) concentrations ranging from 550 to 825 mg/L, was investigated in a pilot-scale 225.5-L expanded granular sludge bed (EGSB) reactor. In an experiment in which the temperature was lowered stepwise from 30 to 12 degrees C, the COD removal efficiency decreased from 73 to 35%, at organic loading rates (OLR) of 11-16.5 g COD/L/d. The applied hydraulic retention time (HRT) and liquid upflow velocity (Vup) were 1.2 h and 5.8 m/h, respectively. Under these conditions, the acidified fraction of the CODin varied from 45 to 90%. In addition to the expected drop in reactor performance, problems with sludge retention were also observed. In a subsequent experiment set at 20 degrees C, COD removal efficiencies exceeding 80% were obtained at an OLR up to 12.6 g COD/L/d, with CODin between 630 and 715 mg/L. The values of HRT and Vup applied were 2.1-1.2 h, and 4.4-7.2 m/h, respectively. The acidified fraction of the CODin was above 90%, but sludge washout was not significant. These results indicate that the EGSB potentials can be further explored for the anaerobic treatment of low-strength brewery wastewater, even at lower temperatures.     

反相离子对高效液相色谱法分离测定钪、锡和铝

 以 1,2 二苯乙烯 4,4′ 双 (1 偶氮 ) 3,4 二羟基苯 2 ,2′ 二磺酸铵 (芪唑 )为柱前衍生试剂 ,采用反相离子对高效液相色谱法分离和测定钪、锡和铝。在C18柱上 ,用含 2 0mmol/LHAc NaAc缓冲溶液 (pH 6 0 )和 10mmol/L十二烷基磺酸钠的甲醇水溶液作流动相 ,检测波长 5 0 0nm ,同时分离测定了钪、锡和铝的络合物。钪、锡和铝的检出限分别为 0 9μg/L ,1 0 μg/L和 1 2 μg/L ,此方法用于矿石样品分析获得满意结果。     

微波消解-原子荧光法测定固体废弃物浸出液中的总汞

建立了密闭微波消解和原子荧光法测定固体废弃物浸出液中总汞的方法.对微波消解和原子荧光条件如灯电流、硼氢化钾浓度、载气流速等进行了优化.汞的浓度在0.00-5.00μg/L 范围内与荧光强度呈良好的线性,相关系数r=0.9999,方法检出限为0.032μg/L.两种浓度汞标准溶液测定结果的相对标准偏差分别为4.6%和3....     

固体添加剂对垃圾掺烧污泥焚烧飞灰高温过程中重金属挥发特性的影响

在研究垃圾与污泥掺烧后焚烧飞灰中重金属浸出特征的基础上,重点研究了飞灰在1 000 ℃条件下高温处置过程中重金属(Cu、Zn 、Pb、Cd)随不同停留时间的挥发特性及添加剂(CaO、Al₂O₃、SiO₂、高岭土、粉煤灰)对重金属转化与挥发特性的影响。研究结果表明,飞灰中重金属Zn、Pb、Mn含量较高,Ni的含量较低,而毒性较大的Cd达到29.4 mg/kg。浸出液中七种金属都满足危险废物鉴别标准(GB5085.3-1996),并且重金属的浸出浓度受浸取时间及浸取液pH值影响较大。在同样的高温处置条件下,焚烧飞灰中不同重金属的挥发特性有较大的差别。其中,Pb表现出易挥发的特性,其挥发率超过80%,而Cu挥发性较小,其挥发率小于30%。综合来看,飞灰中重金属的挥发性大小依次为Pb>Cd>Zn>Cu。飞灰中添加Al₂O₃和高岭土可以抑制Cd的挥发,添加Al₂O₃后Pb的挥发率有所减少,添加SiO₂、CaO、高岭土、粉煤灰均使Zn的挥发率降低,而对Cu的挥发率没有抑制作用,这与飞灰中高Cl含量及各痕量元素化合物对固体添加剂活性位选择性的竞争吸附有关。     

Leaching of zinc and germanium from zinc oxide dust in sulfuric acid-ozone media

A new process of leaching zinc oxide dust by ozone oxidation in a sulfuric acid system was studied. The main factors affecting the leaching rate, such as ozone time, leaching temperature, initial acidity, leaching time, and liquid/solid mass ratio, were comprehensively investigated. The results show that leaching efficiency depends on all the above factors. The optimum conditions for leaching Zn and Ge from zinc oxide dust are as follows: ozone time 10 min, leaching temperature 90 ℃, initial acidity 160 g/L, leaching time 60 min, and liquid/solid mass ratio 7:1. Under the optimum conditions, the leaching rates of Zn and Ge are 95.79% and 93.65%, respectively. The leaching rates of zinc and germanium in the ozone leaching are 4.05% and 10.49% higher than those of the atmospheric leaching, respectively. Therefore, it is determined that ozone in solution plays a key role in rapidly oxidizing sulfide and releasing encapsulated germanium. Sulfuric acid-ozone media can efficiently extract Zn and Ge from zinc oxide dust.     

消化污泥负载稳定高效非均相光Fenton催化材料的制备及性能优化(英文)

近年来,随着我国经济飞速发展和城市人口快速增长,城市污水排放量不断增加,市政污泥产生量也随之增大.市政污泥含有大量有毒有害物质,如寄生虫卵、致病菌、有机污染物和重金属等,若不进行妥善处理处置将会对环境造成严重的二次污染.传统的污泥处理处置方法如卫生填埋、露天堆放和土地利用等已经无法满足日趋严格的污泥处理处置标准,研发新的污泥资源化利用方法具有重要的环境意义和经济价值.本课题组前期以铁盐为前驱体通过简单步骤制备了以市政污泥为载体,污泥中的重金属为可见光光敏剂,铁氧化物为活性中心的稳定高效非均相光Fenton催化剂.此催化剂在制备过程中虽然已经充分利用了市政污泥中的所有成分,但是其中部分可生化的有机大分子物质在制备过程中被直接燃烧或碳化,从而造成能源流失和浪费.为了更加充分利用市政污泥中的有机物,在制备稳定高效催化剂的同时尽可能多地回收能源和资源,本文在前期研究基础上进行了如下改进和优化:(1)采用市政污泥厌氧消化后的消化污泥为载体,通过厌氧消化手段将其中可生化的有机物转化为沼气,相对于直接用市政污泥制备催化剂,减少了能量流失,更具有经济效益和环境意义;(2)通过改变焙烧温度(250,350,450,550,650和750°C)、铁盐类型((NH4)_2Fe(SO_4)_2,FeSO_4,FeCl_3和Fe(NO_3)_3)和铁盐添加量(0,0.5,1.0,1.5,2.0和3.0 mol/L)对所制得催化材料的性能进行优化.利用红外光谱、X射线衍射、扫描电子显微镜和电感耦合等离子体质谱法等手段对所制备光Fenton反应催化剂结构进行了表征.结果表明,以消化污泥为原料制备的催化材料具有多孔和较高的比表面积,保证了在反应过程中催化剂与H2O2和被降解物质充分接触.样品中Fe含量较高,主要是以α-Fe2O3或无定形铁化合物形式存在,并通过Si–O–Fe键结合在污泥载体上,从而保证了催化剂较多的活性位点和较高的稳定性,因此所制材料可用作稳定高效的光Fenton反应催化剂.以偶氮染料罗丹明B为模式污染物评价了所制催化剂对污染物的降解效果.结果表明,在焙烧温度和铁盐添加量一定时,以亚铁盐(即(NH4)_2Fe(SO_4)_2和FeSO_4)为前驱体所制催化剂性能明显优于以铁盐(FeCl_3和Fe(NO_3)_3)为前驱体的催化剂;以(NH4)_2Fe(SO_4)_2为前驱体且其添加量为1 mol/L,焙烧温度为350 oC时所制FAS-1-350催化剂具有较高的降解速率(0.308±0.016 min.1)和较低的Fe~(2+)溶出率(0.94±0.24 mg/L).在紫外光照射下FAS-1-350重复使用6次,其催化性能没有明显降低,证实该样品结构稳定,可重复利用,具有良好的应用前景.