Recovery of vanadium and tungsten from waste selective catalytic reduction catalysts by K_(2)CO_(3) roasting and water leaching followed by CaCl_(2) precipitation

Waste selective catalytic reduction(SCR)catalysts are potential environmental hazards.In this study,the recovery of vanadium and tungsten from waste SCR catalysts by K_(2)CO_(3)roasting and water leaching was investigated.The roasting and leaching conditions were optimized:the leaching efficiencies of vanadium and tungsten were 91.19%and 85.36%,respectively,when 18 equivalents of K_(2)CO_(3)were added to perform the roasting at 900℃ for 2 h,followed by leaching at 90°C for 1 h.Notably,in the described conditions,the leaching rate of silicon was only 28.55%.Titanates,including K_(2)Ti_(6)O_(13)and KTi8017,were also produced.Si removal was achieved in 85%efficiency adjusting the pH to 9.5,and the Si impurity thus isolated was composed of amorphous Si.Tungsten and vanadium were precipitated using CaCl_(2).At pH 10 and following the addition of 0.10 mol of H_(2)O_(2)and 16 equivalents of CaCl_(2),the precipitating efficiencies of tungsten and vanadium were 96.89%and 99.65%,respectively.The overall yield of tungsten and vanadium was 82.71%and 90.87%,respectively.

Electrochemical Oxidation of Chlorimuron-ethyl on Ti/SnO_2-Sb_2O_5/PbO_2 Anode for Waste Water Treatment

The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography（HPLC）, and the chemical oxygen demand（COD） was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.

Assessment of Electric Power Generation via Water Hyacinths and Agricultural Waste

The importance and the necessary of researches on renewable energy have become a hot topic in recent years due to climate change and global warming. In addition, the fossil fuel reserves is facing rapid depletion on the earth. Currently, most researches have concentrated on producing biogas for heating, lighting, drying, cooking but lack in researching on electricity production because the possibility of producing biogas at households are common at small scale. Studying on alternative energy sources to replace traditional fuel for electric power generation brings new chances and great opportunities for development. This study presents an assessment electric power generation via water hyacinths and agricultural waste. In this paper, the evaluation electric power is generated by operating internal combustion engines which use biogas fuel to replace traditional fuel （diesel, gasoline）. The results of the studies were demonstrated by experiments on the renewable energy production system at Hoa An Biotechnology Research and Experimental Center of Cantho University.

球衣菌对Pb^(2+)的吸附及其影响因素研究

采用球衣菌(Sphaerotilus natans)FQ32为生物吸附剂,研究了Pb^(2+)初始浓度、吸附剂用量、菌龄、pH值、温度和吸附时间等理化因素对球衣菌吸附硝酸铅溶液模拟废水中Pb^(2+)的影响。结果表明,球衣菌在Pb^(2+)初始质量浓度为50 mg/L、吸附剂0.6g/L用量、菌龄32 h、pH=7、温度30℃、吸附时间60min的条件下,对Pb^(2+)的吸附率为89.98%,吸附量为74.98 mg/g;该吸附过程是一个快速的过程,在吸附5 min时,吸附量已达总吸附量的94%.90 min达到吸附平衡。球衣菌对Pb^(2+)的吸附基本为细胞表面的被动吸附,吸附条件对吸附效率有较大影响。

天然及改性膨润土吸附废水中Pb^(2+)、Ni^(2+)、Cd^(2+)的试验研究

用山东潍坊涌泉某膨润土厂生产的天然钙基膨润土和改性膨润土对模拟含Pb2+、Ni2+、Cd2+的废水分别进行了试验研究。结果表明,该厂的天然钙基膨润土和改性膨润土对废水中的Pb2+、Ni2+、Cd2+有较高的去除率,可以作为重金属离子Pb2+、Ni2+、Cd2+的吸附剂使用。

生物吸附-浮选法去除水中Pb^(2+)的研究

以苦味诺卡氏菌作为Pb2+吸附剂,研究了采用生物吸附-浮选法去除废水中Pb2+的效果及其作用机理。先通过吸附条件试验确定了试验条件:当水中Pb2+浓度为200mg/L时,培养5d的苦味诺卡氏菌用量为1g/L,试验温度为25℃,搅拌吸附时间为10min,试验pH值范围为2～7。在此基础上,考察了吸附-浮选试验中不同溶液pH值与捕收剂(DA、DB、SLS与NaOL)对Pb2+去除效果的影响。结果表明,随着pH值的升高,捕收剂中DA与DB均能保持较好的捕收效果,且其所在试验组的Pb2+吸附率均较高,因此对Pb2+的去除效果较为理想。以DA为例,当其浓度为3.3×10-4mol/L,浮选时间为10min,pH=7.2时,其所在废水组的Pb2+去除率可达80%,表明采用该方法去除废水中的Pb2+是可行的。采用SEM及X射线光散射能谱(EDS)分析了苦味诺卡氏菌对Pb2+的生物吸附-浮选机理。结果表明,生物吸附-浮选过程可能与细胞壁上羧基阴离子(—COO-)和Pb2+的静电作用以及氨基(—NH2)、乙酰氨基(—NHCOCH3)中N和Pb2+的络合作用有关,同时也与离子交换过程的协同作用有关。

硅藻土与FeCl_3组配处理含Pb^(2+)废水的研究

通过试验研究了硅藻土与FeCl3组配处理含Pb2+废水。结果表明,当进水中Pb2+浓度为52.4mg/L,采用硅藻土与FeCl3配比(质量比)为6∶1,硅藻土投量为70mg/L,控制pH在7.0~8.0、搅拌转速在120~140r/min之间,沉淀80min后出水中Pb2+可达标排放。该方法操作方便,投资少,具有良好的推广应用前景。

用PDF处理含Pb^(2+)、Cu^(2+)重金属离子废水的研究

利用马铃薯提取淀粉后的废弃物—马铃薯渣制成的新型纤维(PDF)模拟处理了含重金属离子Pb2+、Cu2+的废水,研究了吸附剂用量,吸附时间,废水的pH值,温度等对Pb2+、Cu2+的吸附影响及在含有Pb2+,Cu2+,Cd2+,Cr3+,Na+金属离子的废水中PDF对多种混合金属离子的吸附.结果表明,PDF对Pb2+、Cu2+具有良好的吸附作用,且在多种金属离子混合的废水体系中可选择性地吸附Pb2+.

Boost activation of peroxymonosulfate by iron doped K_(2-x)Mn_(8)O_(16):Mechanism and properties

Among the numerous transition metal catalysts,manganese-based compounds are considered as promising peroxymonosulfate(PMS)catalysts due to their low cost and environmental friendliness,such as cryptomelane manganese oxide(K_(2-x)Mn_(8)O_(16):abbreviation KMnO).However,the limited catalytic performance of KMnO limits its practical application.In this work,iron-doped KMnO(Fe-KMnO)was prepared by one-step hydrothermal method to optimize its catalytic performance.Compared with KMnO/PMS system,Fe-KMnO/PMS system possessed more excellent removal efficiency of tetracycline(TC).Meanwhile,the Fe-KMnO/PMS system also exhibited good practical application potential and excellent stability.The mechanism of Fe-KMnO activation of PMS was further analyzed in detail.It was found that Fe participated in the redox of high-valent Mn,which promoted the activation of PMS.Moreover,The Fe site as an adsorption site enhanced the TC enrichment ability of the catalyst,reducing the mass transfer resistance and further enhancing the TC removal ability of Fe-KMnO/PMS system.This work not only provides an excellent PMS catalyst,but also offers new insights into the mechanism of PMS activation by bimetallic manganese-based catalysts.

分子印迹-TiO_(2)光电催化降解增溶PHE废水性能研究

分别以菲(PHE)、非离子表面活性剂曲拉通X-100及两者的混合物作为模板,钛酸正丁酯为功能单体,通过溶胶-凝胶法,制备得到三种分子印迹-TiO_(2)[MIP-(TX-100)TiO_(2),MIP-(PHE)TiO_(2),MIP-(TX-100+PHE)TiO_(2)],并且制备对应的薄膜电极,用于光电催化处理模拟土壤淋洗增溶废水PHE。通过XRD、氮气吸附脱附、SEM对MIP-TiO_(2)材料及其薄膜电极进行性能表征。结果表明,MIP-(TX-100)TiO_(2)中,TX-100印迹分子的引入会改变晶体结构,出现金红石晶相TiO_(2),且其比表面积达到63.533 m^(2)/g,TiO_(2)颗粒大小及分散性较为良好,团聚现象也得到了一定的改善,其对TX-100(5 g/L)增溶的PHE(30 mg/L)溶液光电催化降解率可达74.45%。MIP-(TX-100)TiO_(2)电极对增溶废水PHE的吸附过程更符合二级动力学模型,该过程主要受化学吸附所控制。推测分子印迹过程使TiO_(2)产生大量印迹空穴,在光电催化过程中印迹空穴富集TX-100后,使PHE破除胶束障碍,从而提高了PHE的降解效率。

3,5-二溴-2-吡啶重氮氨基偶氮苯的合成及与镉(Ⅱ)的显色反应研究

报道了一种新型三氮烯类偶氮染料的合成方法及其与 Cd( )的显色反应。在 Triton X- 1 0 0存在下的弱碱性介质中 ,该试剂与 Cd( )形成 4∶ 1的红色络合物 ,最大吸收波长位于 52 6nm 处 ;表观摩尔吸收系数为 2 .0 4× 1 0 5L·mol-1·cm-1,镉含量在 0～ 1 5μg/ 2 5m L范围内符合比耳定律。方法可直接用于废水中微量镉的测定。

新显色剂4-甲基-2-磺酸基苯基重氮氨基偶氮苯的合成及与镉的显色反应研究

报道了新显色剂４－甲基－２－磺酸基苯基重氮氨基偶氮苯的合成及其与Ｃｄ（Ⅱ） 的显色反应。实验表明，在非离子表面活性剂Ｔｒｉｔｏｎ Ｘ－１００存在下，于ｐＨ １０．８ 的氨水－氯化铵缓冲介质中，试剂与Ｃｄ（Ⅱ） 形成３∶１ 的红色络合物，最大吸收波长位于５２２ ｎｍ 处，Ｃｄ（Ⅱ） 含量在０～２０μｇ／２５ｍ Ｌ范围内符合比耳定律，表观摩尔吸光系数为２．０５ ×１０５ Ｌ·ｍ ｏｌ－ １·ｃｍ － １。已直接用于废水中微量镉的测定。

没食子酸强化Fenton体系对水中DEET降解的研究

针对Fenton反应过程中生成的Fe^(3+)的还原速率相对于Fe^(2+)和H_(2)O_(2)的反应速率较慢限制了其降解效率的问题,以N,N-二乙基-间甲苯酰胺(DEET)为目标污染物,比较了3种络合剂对Fenton反应的促进效应。结果表明,在DEET浓度为200μmol/L、H_(2)O_(2)/Fe^(2+)摩尔比为20∶1、初始Fe^(2+)浓度为50μmol/L、没食子酸(GA)/Fe^(2+)摩尔比为1∶1以及pH=7.0的条件下,DEET的去除效率在20 min内达到75.3%。与传统的Fenton体系相比,DEET的降解效率提高了63.8%。HO·是加速DEET降解和矿化的主要活性氧物质。GA促进了Fe^(3+)的还原和H_(2)O_(2)的分解,从而促进了额外自由基的生成,加速了Fe^(2+)/H_(2)O_(2)体系对DEET的降解。

新显色剂2,6-二溴-4-氨磺酰基苯基重氮氨基偶氮苯与镉(Ⅱ)的分光光度研究及其分析应用

本文报道了新显色剂2,6-二溴-4-氨磺酰基苯基重氮氨基偶氮苯与镉(Ⅱ)的显色反应。研究表明,在Triton X-100的存在下,于pH11.0的硼砂-氢氧化钠介质中,该试剂与镉(Ⅱ)可生成稳定的红色络合物,其最大吸收波长位于530nm处,摩尔吸光系数为2.02×10~5。镉(Ⅱ)量在0～10μg/25mL范围内符合比尔定律。方法曾用于煤矸石及工业废水中痕量镉(Ⅱ)的测定,获得满意的结果。

农业废弃物分解产生CO_2的影响因素研究

在正交预备试验得出有机废弃物分解产生CO2 适宜条件的基础上 ,逐一进行单因子试验 ,以获得利用农业废弃物分解产生的CO2 进行棚室栽培CO2 施肥的最适发酵条件 .结果表明 ,利用有机废弃物(稻草 +猪粪 )生物发酵产生CO2 的最佳条件分别为 :温度 5 0℃、含水量 70 %、初始 pH 6 0～ 7 0 .初始C/N比因发酵目的不同有较大变化 ,以堆肥为目的时为 30 / 1,而以产生CO2 为目的时 ,则以 4 0 / 1为宜 .在 4个因素中 ,初始C/N比和含水量对CO2 释放的影响较大 ,其次是温度 ,初始

长泥龄改良A^2/O工艺的短程硝化反硝化除磷

为解决传统A2/O工艺硝化与除磷泥龄(SRT)之间的矛盾,进一步提高低C/N(P)比生活污水同步脱氮除磷效率,采用一种改良A2/O工艺在长SRT条件下处理生活污水。试验结果表明,该工艺可有效筛选和强化反应器内活性污泥,并大量富集长SRT的反硝化除磷菌(DPAO)。通过亚硝酸盐氧化菌(NOB)淘洗阶段后,反应器在SRT=19.6d、A2O段污泥浓度(MLSS)=5.5 g·L-1、水力停留时间(HRT)=8.2 h、污泥回流比(R)=90%、硝化液回流比(r)=250%、溶解氧(DO)=1.5~0.3 mg·L-1,间歇曝气段HRT=4 h、曝气周期1 h曝气1 min(DO=0.3~0.5 mg·L-1)、沉淀59 min条件下长期运行,COD、NH+4-N、TP和TN的平均去除率分别为88.71%、99.2%、93.77%和89.52%,出水亚硝化率(NO-2-N/NO-x-N)可达97.2%,DPAO占聚磷菌(PAO)比为95.5%。污水中约72.96%的COD被DPAO合成PHA除磷,15.75%的COD由异养反硝化消耗,约41.96%和31.31%的N分别通过反硝化除磷和异养反硝化去除。剩余污泥主要由DPAO和反硝化菌增殖产生,分别占82.74%和17.24%,较传统脱氮除磷途径减少了58.76%的碳源消耗和44.6%的污泥排放。

高灵敏高选择性测镉新试剂——2-氯-4-硝基苯基重氮氨基偶氮苯的合成及应用

本文报道了高灵敏度高选择性测镉新试剂——2-氯-4-硝基苯基重氮氨基偶氮苯的合成、纯化及结构鉴定。研究了该试剂在不同表面活性剂存在下的酸性离解行为及其与镉(Ⅱ)的显色反应。实验结果表明,在Triton x-100存在下,于pH7.80的磷酸二氢钾-氢氧化钠缓冲介质中。镉(Ⅱ)可与该试剂形成稳定的红色配合物,其最大吸收波长位于505mm处,摩尔吸光系数为1.57×10~5L·mol^(-1)·cm^(-1)镉量在0～12μg/25mL范围内符合比尔定律。在所拟测定条件下,方法选择性甚佳,只有Ag^+、Hg^(2+)、Cu^(2+)离子产生干扰,可通过加入适当的掩蔽剂予以消除。方法可不经分离直接用于环境水样、工业废水及铝合金标样中痕量镉(Ⅱ)的测定,结果满意。

1-偶氮苯-3-(6-甲氧基-2-苯并噻唑)-三氮烯的合成及用于汞的光度测定

合成了新显色剂1-偶氮苯3-（6-甲氧基-2-苯并噻唑）-三氮烯（ABMBTT），并用元素分析和红外光谱法对其分子结构作了验证。研究了该试剂与汞的显色反应，在pH9．5～11．0的硼酸盐缓冲介质中，有Triton X-100存在下，ABMBTT与汞反应形成2：1的橙红色络合物，其最大吸收波长在520nm处，表观摩尔吸光系数为1.50×10^5L·mol^-1·cm^-1，汞的浓度在0～20μg／25mL范围内符合比耳定律。在焦磷酸钠存在下，常见离子基本不干扰。已应用于工业废水中微量汞的测定，测定结果的RSD小于3．5%，与二苯硫腙光度进行验证，结果吻合。

4-(6-溴-2-苯并噻唑偶氮)邻苯二酚-钛(Ⅳ)-丙酮体系显色反应的研究

新有机试剂4-(6-溴-2-苯并噻唑偶氮)邻苯二酚(6-Br-BTAPC)与钛(Ⅳ)在 pH3.4的40%丙酮水溶液中发生高灵敏显色反应。形成的带负电荷的配合物的组成比为2:1表观稳定常数为3.7×10~9(25℃,μ0.1),λ_(max)为570nm,对比度(Δλ)为130nm,ε_(570)高达9.21×10~4L·mol^(-1)·cm^(-1)。建议了配合物的结构。在0～13μgTi(Ⅳ)/25ml 范围内遵从比耳定律。该法用于工业水和废水中痕量钛的分光光度测定,取得了满意的结果。

新试剂3,3'-二甲基联苯重氮氨基-4-苯基-2-噻唑分光光度法测定废水中微量汞

研究了新试剂 3,3′-二甲基联苯重氮氨基 - 4 -苯基 - 2 -噻唑( DMDPDAPT)在表面活性剂 N-氨代十六烷基吡啶 ( CPC)存在下 ,与汞 ( )显色反应的适宜条件。在 p H7.2～ 9.2范围内 ,汞 ( )与 DMDPDAPT形成2∶ 2紫红色配合物 ,其最大吸收波长为 56 0 nm,配合物的表观摩尔吸光系数ε=9.0 1× 1 0 4L· mol-1· cm-1。汞 ( )浓度在 0～ 1 2μg/2 5m L范围内符合比尔定律。此法已用于废水中微量汞 ( )的测定。