煤泥对水溶液中Ca~(2+)的吸附性能研究

在静态条件下,研究了Ca2+在煤泥表面的吸附动力学.考察了不同Ca2+初始浓度的吸附实验,并对实验结果进行了动力学方程的拟合,结果表明,煤泥对Ca2+的吸附过程较好地符合准二级动力学方程.研究了初始Ca2+浓度、溶液pH值、振荡速度和煤泥质量对Ca2+吸附量的影响,实验结果表明:(1)煤泥对Ca2+吸附量随着Ca2+溶液浓度的增加而增大,Ca2+浓度大于3.828 mmol/L时,吸附鼍基本保持不变;(2)溶液pH<9时煤泥颗粒对Ca2+的吸附主要是静电吸附,pH>9时Ca2+在煤泥表面主要是沉淀吸附和一羟基吸附;(3)Ca2+在煤泥表面吸附的最佳振荡强度为150 r/min.     

煤泥对水溶液中Ca^2＋的吸附性能研究

在静态条件下,研究了Ca^2＋在煤泥表面的吸附动力学。考察了不同Ca^2＋初始浓度的吸附实验,并对实验结果进行了动力学方程的拟合,结果表明,煤泥对Ca^2＋的吸附过程较好地符合准二级动力学方程。研究了初始Ca^2＋浓度、溶液pH值、振荡速度和煤泥质量对Ca^2＋吸附量的影响,实验结果表明：（1）煤泥对Ca^2＋吸附量随着Ca^2＋溶液浓度的增加而增大Ca^2＋浓度大于3．828mmol／L时,吸附量基本保持不变;（2）溶液pH〈9时煤泥颗粒对Ca^2＋的吸附主要是静电吸附,pH〉9时Ca^2＋在煤泥表面主要是沉淀吸附和一羟基吸附;（3）Ca^2＋在煤泥表面吸附的最佳振荡强度为150r／min。     

污泥基活性炭吸附Cu2+的应用研究

以城市污水处理厂剩余污泥为原料,以ZnCl₂为活化剂制取污泥基活性炭。以此污泥基活性炭为吸附剂,对含Cu²⁺的废水进行了吸附实验研究。考察了溶液pH值、Cu²⁺的起始浓度对Cu²⁺离子吸附量的影响;利用等温吸附实验作出吸附等温线,并考察了污泥基活性炭吸附剂吸附Cu²⁺的动力学方程。实验结果表明,污泥基活性炭对Cu²⁺具有良好的吸附性能。吸附的最佳pH值为5;吸附符合Langmuir和Freundlich吸附等温方程,吸附为优惠吸附,吸附量随着吸附质溶液浓度的增加而增大;吸附平衡时间为4 h,吸附动力学符合二级动力学方程。     

沸石负载淀粉对Pb2+、Cu2+和Ni2+的吸附性能

将淀粉负载到沸石表面得到新型重金属离子复合吸附剂ZLS。分别从沸石与淀粉质量比、吸附温度、吸附时间、pH与重金属初始浓度不同方面考察了复合吸附剂ZLS吸附 Pb²⁺、Cu²⁺、Ni²⁺的影响。实验结果表明:当沸石与淀粉质量比为10:1,pH为6,吸附温度在30℃时,复合型吸附剂ZLS对Pb²⁺、Cu²⁺和Ni²⁺ 3种重金属离子的吸附效果最好;吸附动力学研究发现,ZLS对Pb²⁺、Cu²⁺和Ni²⁺的吸附行为均符合准二级动力学以及颗粒内部扩散模型;等温吸附数据符合Freundlich模型,吸附状态属于多层吸附。     

城市垃圾焚烧渗沥液中Ca2+对厌氧EGSB处理效果的影响简

研究了城市生活垃圾焚烧厂渗沥液中Ca²⁺对厌氧颗粒污泥膨胀床反应器（EGSB）处理效果的影响,并采用静态实验方法考察了Ca²⁺对厌氧颗粒污泥产甲烷活性的影响。实验结果表明,进水COD为17 000 mg/L的条件下,当Ca²⁺浓度低于6 000 mg/L时,EGSB对COD去除率达93%以上;当Ca²⁺浓度高于6 000 mg/L时,COD去除率随运行时间明显下降,并在污泥中形成大量沉淀。静态实验结果表明,废水中低浓度Ca²⁺促进了厌氧颗粒污泥的产甲烷活性,但高浓度Ca²⁺明显抑制了其产甲烷活性,这是导致高Ca²⁺浓度条件下EGSB对COD去除率降低的主要原因。研究表明,颗粒污泥产甲烷活性恢复程度随Ca²⁺浓度增加而减弱。     

满江红干体对锌离子的生物吸附

以满江红干体为生物吸附剂,研究了不同条件下对废水中Zn²⁺的净化作用。结果表明,满江红干体对Zn²⁺的吸附是一个快速的过程,前5 min的吸附量达到最大吸附量的62.9%,30 min达到吸附平衡;初始pH值对Zn²⁺的吸附有显著的影响,最适pH值为6;随着干体量的增加,吸附率逐渐提高而吸附量则降低;随着Zn²⁺初始浓度的增加,吸附率逐渐降低而吸附量则提高。满江红干体对Zn²⁺的吸附符合Langmuir吸附等温线方程,最大吸附容量达57.5 mg/g。5次吸附解吸循环实验数据表明,重复次数和再生处理对满江红干体的吸附能力没有产生显著影响。因此,满江红干体在处理含Zn²⁺废水中的重复使用是可行的。     

棘孢曲霉（Aspergillus aculeatus）对Pb2＋和Cd2＋的吸附特征

为了研究棘孢曲霉（Aspergillus aculeatus）对溶液中Pb^2＋和Cd^2＋吸附过程的特征,分别从动力学、热力学和吸附等温线三方面进行了实验,同时还研究了pH、温度、时间、重金属离子起始浓度和吸附剂用量对吸附过程的影响。等温吸附过程可以用Langmuir方程来描述。在实验设定条件下,棘孢曲霉对Pb^2＋和Cd^2＋最大吸附量分别为71.2 mg/g和59.8 mg/g;动力学实验数据很好的符合二级     

MCM-41介孔分子筛的合成及其对铜离子的吸附性能简

以微硅粉为硅源,CTAB和PEG-6000为模板剂,合成MCM-41介孔分子筛。采用XRD、N₂吸附-脱附曲线、FTIR以及TEM表征了其结构、比表面积、孔径分布及晶体形貌,并且以该样品为吸附剂,对含Cu²⁺的溶液进行了静态吸附实验。结果表明,以微硅粉为硅源成功合成了具有典型六方排列孔道结构的MCM-41,其比表面积为869.5 m²/g,孔容为0.97 cm³/g,平均孔径为3.3 nm;溶液pH为5~6时,MCM-41对Cu²⁺的去除效果最好;MCM-41对Cu²⁺的最大吸附吸附容量36.3 mg/g;MCM-41对Cu²⁺的吸附性能符合Langmuir吸附方程的特征。动力学研究表明,该过程符合准二级动力学模型。     

酸度对好氧颗粒污泥生物吸附含铅废水影响的研究

为了有效地控制铅污染,利用序批式反应器（sequencing batch reactor,SBR）培养的以醋酸钠为碳源的好氧颗粒污泥作为吸附剂,进行生物吸附含铅废水的效能和机理的研究。通过考察酸度、接触时间和Pb²⁺初始浓度等因素的影响,验证好氧颗粒污泥吸附模型,并利用不同的脱附剂,进一步解析其生物吸附的Pb²⁺。实验结果表明, 酸度是影响好氧颗粒污泥生物吸附Pb²⁺的关键因素,当初始pH为5时,好氧颗粒污泥对含铅废水生物吸附效果最好。对低浓度（0～20 mg/L）含铅废水, 10 min后可快速达到吸附平衡。好氧颗粒污泥对Pb²⁺的实测饱和吸附量为101.97±9.00 mg/g,符合朗缪尔（Langmuir）模型。好氧颗粒污泥生物吸附Pb²⁺的过程,伴随着pH值的升高和K⁺、 Ca²⁺、 Mg²⁺的释放,此现象揭示离子交换作用是好氧颗粒污泥生物吸附Pb²⁺的机理之一。此外,脱附剂HNO₃、EDTA和CaCl₂能实现Pb²⁺的回收和好氧颗粒污泥的重复利用。     

新型TCAS吸附树脂对水中Cd2+的吸附去除研究

通过静态吸附试验,研究一种由超分子受体化合物磺化硫杂杯芳烃（TCAS）与树脂结合的产物——新型TCAS吸附树脂对重金属Cd²⁺的吸附去除性能,并初步探讨了吸附机理。试验研究结果表明,TCAS吸附树脂对Cd²⁺的饱和吸附量为14.45 mg/g。当温度为20℃,0.5 g TCAS吸附树脂对10 mL浓度为5 mg/L的Cd²⁺溶液吸附60 min时, Cd²⁺的去除率可达到99%以上。pH值是影响TCAS吸附树脂吸附效果的重要因素,在pH=5～9时,Cd²⁺的去除率随着pH值的升高而增大。在试验范围内,TCAS吸附树脂对Cd²⁺吸附符合Freundlich方程。吸附在TCAS吸附树脂上的Cd²⁺可洗脱回收,TCAS吸附树脂也可再生利用。 TCAS吸附树脂对重金属Cd²⁺的吸附机理主要归因于TCAS对Cd²⁺的络合作用。     

Deltamethrin degradation and effects on soil microbial activity

Deltamethrin [(S)-cyano-3-phenoxybenzyl-cis-(1R,3R)-2,2-dimethyl) cyclo–propane carboxylate),1] labelled at gem-dimethyl groups of the cyclopropane ring was applied on two Egyptian soils at a level of 10 mg/kg soil for a laboratory incubation experiment under aerobic and anaerobic conditions. A steady decrease of soil extractable¹⁴C-residues, accompanied by a corresponding increase of non- extractable bound ¹⁴C-residues was observed over a 90-day incubation period. The percentage of evolved ¹⁴CO₂ increased with time under aerobic and anaerobic conditions in both soils. The effect of deltamethrin on soil microorganisms as well as the counter effect of microorganisms on the insecticide was also investigated. As the incubation period increased, the inhibitory effect of the insecticide on the microorganisms decreased and the evolution of carbon dioxide depended on the applied dose. The nature of soil methanol soluble residues was determined by chromatographic analysis which revealed the presence of the parent insecticide as the main product in addition to four metabolites: 3-(2′,2′-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid (II); 3-phenoxybenzaldehyde (III); 3-phenoxybenzoic acid (IV); 3-phenoxybenzyl alcohol (V).     

Influence of releases of I-129 from reprocessing plants on the marine environment of the North Adriatic Sea

Compared to the pre-nuclear era, large amounts of ¹²⁹I have been released to the marine environment, especially as liquid and gaseous discharges from two European reprocessing plants located at Sellafield and La Hague. Their liquid discharges influence Northern Europe and most research was conducted in the area of the North Atlantic Ocean and the Baltic Sea. In this article data on ¹²⁹I content and ¹²⁹I/¹²⁷I ratios observed in the North Adriatic Sea, which is a rather enclosed basin of the Mediterranean Sea, are presented. To the best of our knowledge no data on ¹²⁹I in the Mediterranean Sea have previously been reported. As this area is isolated from direct liquid discharges, the main transport pathway is probably gaseous releases from reprocessing plants. Surface sea water, the marine alga Fucus virsoides, an iodine accumulator, and the Mediterranean mussel Mytilus galloprovincialis collected in 2009 and 2010, and marine sediment collected in 2005 and 2009 were analysed. The ¹²⁹I/¹²⁷I isotopic ratios observed were in the range from 0.8 to 3.0 × 10⁻⁰⁸ for seawater, from 0.06 to 0.35 × 10⁻⁰⁸ for marine sediment, from 0.05 to 0.10 × 10⁻⁰⁸ for F. virsoides and from 0.3 to 0.9 × 10⁻⁰⁸ for M. galloprovincialis.     

Impact of repeated pesticide applications on the binding and release of methyl 14C-monocrotophos and U-ring labelled 14C-carbaryl to soil matrices under field conditions

The dissipation of (O-methyl-¹⁴C) monocrotophos and U-ring labelled ¹⁴C-carbaryl was monitored for over two years in absence and presence of other insecticides using in situ soil columns. The dissipation of ¹⁴C-monocrotophos from soil treated with methomyl and carbaryl showed a faster rate of downward movement than in a control column tagged with the labelled insecticide alone. The same trend was observed in experiments with ¹⁴C-carbaryl that dissipated more readily in soil treated with non-labelled monocrotophos and methomyl. In the presence of other insecticides the percentage of bound residues was generally lower than in control experiments. The bound residues at the top of the column are released at a low rate under conditions prevailing in the field. The overall time required for dissipation of 50% of monocrotophos and carbaryl (t₅₀) as estimated from control experiment was approximately 20 and 24 weeks, respectively. The data indicate that repeated applications of pesticides might enhance the release of ¹⁴C-bound residues.     

黑土胶体对铅的吸附动力学特征

利用虹吸法从采自于吉林省黑土中分别提取出粒级为5~10、2~5和1~2μm的3种胶体,并通过批次实验法研究不同粒级黑土胶体对Pb2+的吸附动力学。结果表明,不同粒级土壤胶体对Pb2+的吸附过程均表现为快慢2个阶段,其中,10 min内呈现快速吸附阶段,之后为慢速吸附阶段。3种粒级土壤胶体5~10、2~5和1~2μm在pH为6、温度为25℃时,对Pb2+的饱和吸附量为114.45、126.98和131.89 mmol/kg。随pH从2升到6,粒级为5~10、2~5和1~2μm的3种胶体对Pb2+的饱和吸附量分别增加了928%、153%和142%。随温度从25℃升到55℃,粒级为5~10、2~5和1~2μm的3种胶体对Pb2+的饱和吸附量分别增加了16.56%、4.9%和4.89%。不同粒级胶体对Pb2+的吸附量由大到小依次为:1~2μm2~5μm5~10μm。不同粒级胶体对Pb2+的吸附动力学均较好地符合拉格朗日准二级动力学方程,说明该吸附过程以化学吸附为主。准二级动力学吸附速率常数表明,随着吸附剂粒径增大,吸附速率降低。4种温度范围内随着温度升高,吸附速率加快。吸附过程的限速步骤为颗粒间扩散。     

液/固体系中硅藻土对Pb2+和Cd2+的吸附机制

为了提高硅藻土在重金属废水处理上的应用水平,采用静态吸附实验考察了液/固体系中硅藻土对Pb2＋、Cd2＋的吸附影响因素、吸附等温线和吸附动力学属性。结果表明,随着投加量的减少,离子初始浓度的提高,pH值的增大,吸附作用时间的延长,硅藻土对Pb2＋、Cd2＋吸附量不断上升;硅藻土对Pb2＋、Cd2＋的等温吸附都符合Langmuir模型,硅藻土对Pb2＋、Cd2＋最大吸附量分别为10.428 mg/g和7.916 mg/g,硅藻土对Pb2＋具有更好的吸附能力;Pb2＋具有较低的水合自由能,更容易脱去水膜与硅藻土孔道内的活性基团发生吸附作用;双常数扩散方程可以很好地描述硅藻土对Pb2＋、Cd2＋的吸附动力学属性,硅藻土对Cd2＋有较快的吸附速率。     

磷酸活化-微波热解改性污泥对镉的吸附性能

以城市污水处理厂剩余污泥为原料,利用磷酸活化-微波热解制取改性污泥。以此污泥作为吸附剂,对含Cd2+废水进行了吸附实验研究。考察了溶液反应时间、Cd2+浓度、pH值和吸附剂用量对镉吸附去除效果的影响;利用等温吸附实验作出吸附等温线,并考察了改性污泥吸附剂吸附Cd2+的动力学方程。实验结果表明,改性污泥对Cd2+有良好的吸附性能,吸附最佳pH值为6.0,吸附较好地符合一级动力学吸附模型和Langmuir-Freundlich等温吸附方程,吸附为物理吸附,吸附反应发生12 h后达到吸附平衡。     

微电解-Fenton深度处理制药废水影响因素与参数控制

采用铁炭微电解-Fenton联合工艺深度处理制药废水生化出水,探讨了初始pH、曝气量、反应时间等因素对微电解出水Fe2+和Fe3+变化规律、COD降解速率以及后续Fenton氧化效果的影响,为优化微电解-Fenton氧化联合工艺提出了微电解间歇加酸的理论。间歇加酸可提高微电解系统中COD降解速率和Fe2+含量,使后续Fenton氧化无需投加FeSO4·7H2O即可达到较好的COD去除效果。结果表明,当初始pH=2.5,曝气量为0.6 m3/h,间歇加酸30 min/次,微电解反应2 h,出水投加1 mL/L的H2O2进行Fenton氧化2 h,COD总去除率可达81.33%;间歇加酸30 min/次可将微电解反应2 h出水Fe2+浓度从50 mg/L提高至151 mg/L,COD降解速率从10.6 mg COD/(L·h)提高至22.2 mg COD/(L·h)。     

Metal contamination in the lichen Alectoria sarmentosa near the copper smelter of Murdochville, Québec

Lichens were used to evaluate the metal pollution in a forest ecosystem around the smelter of Murdochville, Canada. As reached values 5.8 times higher in the smelter vicinity than in the 'background' sites. This enrichment was 2 times higher for 3 metals (Cu, Cd and Pb). The highest As, Ba, Cd, Cu, and Pb concentrations in lichens were 4, 112, 1, 23, 50 and 952mg/kg respectively. Contamination declined exponentially with increasing distance from the smelter and was related to elevation and slope exposition to the smelter flux. (206)Pb/(207)Pb and (206)Pb/(204)Pb ratios were low close to the smelter (1.16 and 18), but increased with distance to constant values (1.19 and 18.7) and showed an inverse correlation with lead concentrations. Forest contamination was detectable up to 30km from the smelter.     

金属铁去除水中Cr6+的影响因素研究

研究Fe/Cr6+比值和不同浓度的NO3-、Cl-和SO42-对金属铁去除Cr6+效果的影响.结果表明,金属铁对水中Cr6+有很好的还原去除效果;当金属铁的使用量为Cr6+量的1/2000时,铁对Cr6+的去除效果较差且易失去活性,而当金属铁的使用量为Cr6+量的8 000倍时,铁对Cr6+的去除效果较好且其活性的持续...     

黄原胶辐射接枝共聚物对Cd~(2+)的吸附研究

利用60Co-γ为辐射源,在氮气保护下对黄原胶(XG)和丙烯酰胺(AM)进行共辐射,制备黄原胶/丙烯酰胺接枝共聚物(XG-g-AM)。研究了XG-g-AM对Cd2+的吸附行为,利用红外光谱(IR)、热重分析(TGA)、X射线衍射仪(XRD)对接枝共聚物及吸附产物进行表征。结果表明:XG-g-AM对Cd2+离子吸附等温线符合Freund lich等温方程,吸附Cd2+使XG-g-AM结晶结构被进一步破坏,结晶度下降。25℃下,Cd2+浓度20 mmol/L时,吸附时间100 m in,平衡吸附量为0.835mmol/g。