氧化还原—络合滴定法连续测定Fe~(3+)、Fe~(2+)、Zn~(2+)

提出一种能够连续测定溶液中Fe3+、Fe2 +、Zn2 +含量的新方法 ,试验结果表明 :此方法所需药剂、仪器较少 ,简便易行 ,且具有较高的准确性 ,可在相关生产行业中实际应用。     

膨润土对重金属离子Pb~(2+),Zn~(2+),Cr(VI),Cd~(2+)的吸附性能

试验研究了pH值、吸附时间和吸附剂用量对膨润土吸附重金属离子Pb2 ,Zn2 ,Cr(VI)和Cd2 的影响.结果表明,在本试验的pH值、吸附时间及吸附剂用量条件下,膨润土对Pb2 ,Zn2 ,Cd2 的吸附效果均优于其对Cr(VI)的吸附效果;pH值是影响上述吸附的重要因素,离子交换和表面络合是上述吸附的主要形式.     

Zn~(2+)掺杂复合钴蓝色料的工艺研究

Zn2+掺杂复合钴蓝色料属于尖晶石型色料,采用固相反应方法,用氧化钴、氧化铝、氧化锌、钾长石等原料,成功制备了蓝色色料。该色料呈色效果受氧化钴加入量、烧成气氛、烧成温度、保温时间等因素影响。最佳工艺条件为:氧化钴加入量10%左右,弱还原气氛,1 250℃烧结,保温60 min。     

硝酸盐还原菌JNS05抑制聚驱粘损的应用研究

聚合物驱油是油田三次采油的重要方式,聚合物溶液在注入管道中存在着严重的粘度损失,影响了油田的生产和开发效果,而硫酸盐还原菌的广泛存在是导致聚合物粘损的重要原因。为此,从大庆油田回注水中筛选得到一株硝酸盐还原菌Alcaligenes sp.JNS05,室内试验表明,菌株JNS05对硫酸盐还原菌具有显著的抑制效果,将菌株培养液注入聚合物注入管道中,现场检测结果显示,聚合物粘度损失可降低5%以上。     

Zn~(2+)污染土抗剪强度及电阻率特性研究

针对土中不同质量分数Zn~(2+)在快剪试验中的抗剪强度和电阻率的变化规律,分别制取了5种不同质量分数的Zn~(2+)污染土的试样进行室内试验,观测试验过程中剪应力和剪切位移、抗剪强度和Zn~(2+)所占土的质量分数、电阻率和剪切位移及抗剪强度和电阻率的变化,并收集数据进行分析;比较了50Hz和50kHz下的电阻率变化,根据电阻率和正压力的关系,提出原始电阻率和敏感度来反映污染土的性质。结果表明:Zn~(2+)污染土在剪切过程中没有明显的屈服点,剪应力随剪切位移的增加而增大;不同质量分数的Zn~(2+)污染土在直剪过程中的电阻率在50kHz下均随位移先减小、后略有增大,而50Hz下的电阻率在高浓度下变化反常,剪切过程电阻率测试频率应采用50kHz;定义了土体的原始电阻率和敏感度来反映污染土的电阻率特性,污染程度越高,原始电阻率值越小,敏感度越低。     

城市污水专用杀菌剂的复配及其在混凝土中适用性研究

基于城市污水对混凝土的微生物腐蚀作用机制,检测了7种单一杀菌剂以及复配的三合一杀菌剂对强化污水中产酸菌和硫酸盐还原菌的灭杀效果及时效性,并研究了将优选杀菌剂掺入混凝土中对其流动性及强度的影响。结果表明,单一品种杀菌剂作用效果有限,基于优选的铜酞菁、戊二醛、溴化钠及四羟甲基硫酸磷这4种杀菌剂复配的三合一杀菌剂,当其掺量为750 mg/L时杀菌率接近100%,且时效性好,掺入60 h后杀菌率仅降低了0.3%。当把杀菌剂作为功能组分掺入混凝土时,铜钛菁无论对混凝土流动性还是强度均有一定程度提高,四羟甲基硫酸磷和戊二醛的掺量不宜超过0.1%,溴化钠的掺入则会降低混凝土强度。复配的三合一杀菌剂中,铜四戊和铜戊溴应用效果最佳,不仅对混凝土的流动性和强度均无不利影响,甚至还会有所改善,非常适合作为外加剂掺入混凝土中来提高其在污水环境下的耐微生物腐蚀性。     

羟基磷灰石对金属离子Ni~(2+)的吸附性能

采用共沉淀法和水热法制备了用于吸附金属离子Ni2+的羟基磷灰石(HA),通过XRD,TEM,FTIR和BET对其物相组成和形貌结构进行了分析,并测定了其比表面积.结果表明:共沉淀法制备的HA的结晶度低、比表面积大、表面缺陷较多;共沉淀法制备的HA对Ni2+的吸附量远大于水热法制备的HA,其饱和吸附量为60.57 mg/g,且吸附之后HA与Ni2+并没有发生各种溶解沉淀和进入晶格的化学反应,脱附容易发生,因而HA有望成为建材行业回收镍金属的高效吸附剂.     

Aeromonas veronii N8活性菌体对Zn~(2+)的吸附特征

以Aeromonas veronii N8菌为对象,对菌体的性质及其吸附Zn~(2+)特征进行研究。结果表明,Aeromonas veronii菌的生长周期在66h左右,并且Zn~(2+)对该菌的最低抑菌质量浓度为150mg/L;N8菌体对Zn~(2+)的吸附随时间的增加,吸附率逐渐增大,并且在90min后达到吸附平衡。菌体的吸附率随菌体质量浓度的增加而变大,并随Zn~(2+)质量浓度的增加而变小。吸附前、后扫描电镜及能谱分析(scanning electron microscope-energy dispersive X-ray,SEM-EDX)的表征结果显示,在菌体的细胞壁表面检测到Zn元素,说明Aeromonas veronii N8菌体对Zn~(2+)具有一定的吸附作用。菌体的Zn~(2+)吸附过程可采用Toth模型进行描述。     

产酸脱硫反应器中COD/SO42-比对硫酸盐去除率的影响研究

采用两相厌氧生物处理工艺的产酸相作为硫酸盐还原单元,以食用红糖为碳源,通过连续流实验,重点研究了产酸相中COD/SO42-值(C/S)对SO42-去除率的影响.在34±1 ℃、进水碱度(ALK)300～500mg/L、pH 6.0～6.2、氧化还原电位(ORP)-250～-350mV等条件下,当进水C/S＜2.0时,SO42-去除率小于81%;当进水C/S值为2.5～2.0时,SO42-去除率为90～81%;当进水C/S值为大于2.5时,SO42-去除率为90%以上.随着C/S值的降低,SO42-的去除效果会将有所降低.     

硝基苯废水的超临界水氧化反应动力学研究

利用自行设计的一套连续式超临界水氧化实验装置,在400℃～500℃,28 MPa,H2O2过量500%的条件下,进行了硝基苯SCWO实验,得到了反应动力学方程,得出了超临界水氧化反应动力学参数：反应活化能Ea为47.328 kJ/mol;频率因子k0为1.53×103。     

氧化还原——络合滴定法连续测定Fe^3＋、Fe^2＋、Zn^2＋

提出一种能够连续测定溶液中Fe^3 ,Fe^2 ,Zn^2 含量的新方法,试验结果表明：此方法所需药剂、仪器较少、简便易行,且具有较高的准确性,可在相关生产行业中实际应用。     

Ce^(3+)和Fe^(3+)共掺杂CaAl_(2)O_(4)高近红外反射颜料的制备与表征

离子掺杂能够调谐颜料的反射性能和颜色。采用溶胶-凝胶法制备了一系列新型低毒的Fe^(3+)、Ce^(3+)共掺杂Ca_(1-x)Ce_(x)Al_(2-y)Fe_(y)O_(4)(x=0、0.15;y=0.15、0.25、0.35)高近红外反射无机颜料。采用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)、紫外/可见/近红外光谱仪及Color CIE色度分析软件对所合成复合颜料的晶体结构、微观形貌、光学性质(反射性能)和颜色等进行了表征。XRD分析表明,煅烧温度为1100℃时,所合成的样品为磷石英结构;光学性能分析表明,随着Fe^(3+)掺杂量的增加,颜料的颜色由白色逐渐变为黄色再变为深棕色。Fe^(3+)、Ce^(3+)共掺杂所制备的颜料在780~2500 nm波长范围内具有较高的近红外反射率(NIR≥61.5%)。该Ca_(1-x)Ce_(x)Al_(2-y)Fe_(y)O_(4)“冷”颜料粉体在建筑涂料等方面具有广阔的应用前景。     

Cu~(2+)对温州软粘土电阻率特性影响的试验研究

温州制革、电镀等轻工业发达,废水中Cu~(2+)含量较高,多处地下水和土壤受到污染。选取典型温州软黏土,将土样重塑,加入不同浓度的Cu~(2+)和适量水泥进行固化,通过测试不同土样电阻率来研究Cu~(2+)对土体性能的影响。电阻率测试在改装的一维压缩固结试验中进行,压缩中部分土样电阻率变化不显著,但可量测到压缩过程中电阻率的变化规律。试验结果表明:电阻率可以很好地评估加入水泥之后土体性质的改变,在实际工程中可以用来反映土体的污染程度;土体在Cu~(2+)含量和含水量很高时,不宜采用电阻率法评估土体污染压缩的过程。     

Ca~(2+)浓度对膨润土掺砂混合土渗透性能的影响

垃圾填埋场底部铺设含黏土或膨润土掺砂混合土的防渗系统,防止渗滤液流入地下污染周边环境。采用模型试验研究Ca~(2+)离子浓度和基础局部沉降对膨润土掺砂混合土渗透特性的影响。试验结果表明Ca~(2+)浓度对膨润土掺砂混合土的渗透性能有较大影响,渗透液中Ca~(2+)浓度超过一定值后混合土渗漏;Ca~(2+)离子浓度与发生渗透时间之间有很大关系,浓度越高发生渗透的时间越短;同样沉降量条件下,含Ca~(2+)离子溶液渗透的混合土均发生渗漏,而用蒸馏水作渗透液的没有出现渗漏;钠基膨润土遇Ca~(2+)离子溶液后,当Ca~(2+)离子浓度大于两倍Na+就会发生离子交换,钠基膨润土转化为钙基膨润土,混合土的防渗性能下降。因此开展Ca~(2+)离子浓度对膨润土掺砂混合土渗透特性的研究具有较好的理论和实际意义。     

Mg2+和SO42-相互影响对水泥土强度影响的试验研究

水泥土搅拌桩周围环境中的Mg2+和SO42-对水泥土及其桩体的力学性能具有很大的影响。通过模拟试验的方法探讨了在不同硫酸镁溶液环境下不同龄期的水泥土表观和抗压强度变化规律,得出了水泥土表面腐蚀程度随着腐蚀时间的增长和硫酸镁浓度的增大而增加,水泥土抗压强度随硫酸镁浓度的增大而减小;分析了硫酸镁溶液的Mg2+浓度和SO42-浓度随时间的变化关系,得出随着时间的增长Mg2+浓度呈减小趋势,而SO42-浓度则呈抛物线型。研究认为:水泥土强度改变与环境中的Mg2+浓度和SO42-浓度密切相关。在此基础上建立了水泥土环境下考虑Mg2+浓度和SO2-4浓度相互影响的水泥土强度模型,经对比预测值与实测值,证明两者比较接近,该关系具有一定的可行性,可供工程设计参考。     

Heavy metal accumulation by aquatic fungi and reduction in viability of Gammarus pulex fed Cd2+ contaminated mycelium

The addition of Pb²⁺ (1.0 and 2.5 μg ml^?1) and Cd²⁺ (2.5 and 5.0 μg ml^?1) to growth medium decreased the growth of aquatic fungi, while Zn²⁺ even at a concentration of 10 μg ml^?1 had no inhibitory effect. Low concentrations of Cd²⁺ and Zn²⁺ on the other hand stimulated mycelial growth. The fungi accumulated considerable amounts of metal from the growth medium, generally in the order Zn²⁺ > Pb²⁺ > Cd²⁺ · Cd²⁺ was also accumulated by fungi from successive changes of medium containing low concentrations of the metal. Application of Langmuir and Freundlich isotherms to the results showed that the metals were accumulated largely by adsorption to the surface of the mycelium.Three species of aquatic fungi supported the growth of the freshwater shrimp. Gammarus pulex when provided as sole food source, sustaining from 30 to 60% of shrimps fed for a period of 21 days. A marked reduction in shrimp viability occurred however, when G. pulex was fed Pythium sp. containing Cd²⁺ (150–170 μg g^?1), with none of the shrimps surviving beyond 13 days, compared with a survival rate of 60% after 21 days for shrimps fed uncontaminated mycelium. Bodies of poisoned shrimps sampled on day 13 were found to contain Cd²⁺ (22.03 μg g^?1) showing that the metal can be transferred from aquatic fungi to G. pulex, the first step in a food chain involving freshwater fish and higher organisms.     

脱水滤液中Mg2 、PO43-和NH4 浓度对鸟粪石形成的影响

以污泥脱水滤液为研究对象,考察了按照等化学计量比改变Mg2 、PO43-和NH4 的初始浓度、单独改变NH4 初始浓度和单独改变Ca2 初始浓度对鸟粪石回收效果的影响.结果表明在按照等化学计量比改变Mg2 、PO43-和NH4 初始浓度的条件下,对Mg2 、PO43-和NH4 的回收率均随其初始浓度的增大而提高;保持Mg2 和PO43-浓度均为5.00 mmol/L,当NH4 的初始浓度提高到12.00 mmol/L时,约有90%的PO43-参与了鸟粪石的生成;Ca2 不仅可与Mg2 争夺PO43-而占据鸟粪石晶体赖以继续生长的活性位,而且还能与H2PO4-争夺OH-,抑制H2PO4-向PO43-转化并参与生成鸟粪石,同时造成对NH4 的回收率降低.     

Utilisation de la clinoptilolite en potabilisation des eaux—elimination de l'ion NH4+Clinoptilolite in drinking water treatment for NH4+ removal

The objective of this study is to develop a technique to remove ammonium ion from water intended for potable purposes. An ion exchange method is used with a selective ion exchanger, a natural cation zeolite, clinoptilolite. Glass columns (Fig. 1) are used for laboratory experiments. These experiments show that the NH₄⁺ exchange capacity is very small compared to its total capacity 2.17 meq g^?1; its value depends essentially on the NH₄⁺ initial concentration and less on the Ca²⁺ concentration in the influent water. Figure 3 illustrates the practical exchange capacity relative to the initial concentration of ammonium ion for a soft water (Ca²⁺ = 35–50 mg l^?1). We were particularly interested in waters weak in ammonium ion concentration (NH₄⁺ = 1–3 mg l^?1). In this case and for ～1 and 2 mg l^?1 NH₄⁺ concentration in water, the practical capacity is only 0.06 and 0.108 meq g^?1 respectively. The leakage is smaller than the ECC limit (European Community Council) for drinking waters (NH₄⁺ ? 0.5 mg l^?1) and the treated volume of water to breakthrough, defined at 0.5 mg l^?1 of NH₄⁺, is ?720 BV (BV = bed volume) in both cases.In another way Fig. 6 shows that hard waters (due to Ca²⁺ ions) are more difficult to treat than soft waters. The practical capacity is smaller than before and the NH₄⁺-leakage is greater. To lessen NH₄⁺-leakage to less than 0.5 mg l^?1 for soft waters down-flow and up-flow, regeneration is used. Figure 7 shows that up-flow regeneration is more attractive than down-flow regeneration.Cycle reproducibility (Figs 4 and 5) shows that the regeneration conditions satisfied our requirements: in this case, the salt consumption is 180 eq of salt per eq of NH₄⁺ eliminated. This prompted us to try to reuse the regenerant (with NH₄⁺ ion). An increase of NH₄⁺-leakage is noticed in the presence of an NH₄⁺-residual in the regenerant. This increase is more significant with down-flow regeneration.After these laboratory experiments, we carried out a semi-industrial pilot-plant. Our objective was first to verify the laboratory results and secondly to study clinoptilolite behaviour relative to the time it was used. Two plexiglass columns comprise the pilot-plant shown in Fig. 9; soft water is used for these experiments. The first column is regenerated with fresh salt solution. The cycles obtained, considering their initial NH₄⁺-concentration, are reproduced in Fig. 10. For 2 mg l^?1 NH₄⁺ in the influent water, the leakage is about 0.2 mg l^?1 and the treated volume to breakthrough (0.5 mg l^?1 of NH₄⁺) is about 750 BV. The second column is regenerated with a recycled solution. The quality of the cycles decreases with the number of reuse of the regenerant as shown in Fig. 11. Nevertheless, it is interesting to note that after 3 reuses, the performance decrease is only 25% and the leakage, although it increases is smaller than 0.5 mg l^?1.Pilot results allowed us to propose a treatment of 30,000 m³ day^?1; the cost per cubic meter water treated, relative to NH₄⁺-removal, is about 0.165 FF (0.033 US $) for a plant and 0.77 FF (0.014 US $) for the same plant at the seaside. Using two serial columns decreased the cost by about 40–50%.     

Evaluation of the toxic effect of Cd2+ and Cd(CN)42− ions on the growth of mixed microbial population of activated sludges

The effect has been studied of Cd²⁺ and Cd(CN)₄^2? ions on the growth and enzymatic activity of mixed microflora from activated sludges.Both ions tested significantly inhibited the growth of microorganisms, estimated by means of the optical density, and the inhibitory effect of Cd²⁺ was significantly greater than that of Cd(CN)₄^2? at the same mass and molar concentrations.There was also inhibition of the maximum uptake rate of glucose, but in this case there were no statistically significant differences between the inhibitory effect of the corresponding mass and molar concentrations of Cd²⁺ and Cd(CN)₄^2?.     

生物滤层中Fe^2＋的作用及对除锰的影响

通过无菌滤层与生物滤层的除铁、除锰对照试验,得出了生物滤层不但可以同时去除原水中的铁与锰离子,而且Fe^2 参与了除锰菌的代谢,对维系生物滤池中生物群系的平衡起到了至关重要的作用。同时,生物滤层对Fe^3 盐的固体微细粒子也有很好的捕捉去除作用。