粉末状骨炭用于饮用水除氟的试验研究

对粉末状骨炭的除氟性能进行了多组试验研究,结果表明:粉末状骨炭的吸附容量与原水中氟离子的浓度呈线性关系,吸附等温式符合Freundlich公式。骨炭吸附容量受骨炭粒径、pH值、水温及水中其他离子的影响,骨炭粒径还会影响吸附反应的速度。骨炭采用5%的NaOH溶液再生,再生效果良好。     

蛇纹石-黏土复合颗粒除氟的动态实验研究

为研究蛇纹石-黏土复合颗粒的除氟性能,采用室内动态实验探讨了复合颗粒在不同氟离子浓度、不同吸附柱高度和不同流速下对含氟水除氟效果的影响及其吸附动力学过程.试验结果表明:吸附剂的动态吸附容量与吸附剂高度、原水氟离子浓度呈正相关,而与进水流速呈负相关;吸附剂传质区长度与进水流速、吸附剂高度及原水氟离子浓度均呈正相关.吸附动力学拟合结果显示:蛇纹石-黏土复合颗粒对水中氟的吸附动力学符合Yoon and Nelson方程,平衡吸附容量与吸附剂高度呈正相关,与进水流速呈负相关.随着初始氟离子浓度的增加,到达吸附平衡时间缩短,吸附容量逐渐增大.     

无定形氢氧化铝吸附剂的制备及其除氟性能研究

降氟措施对高氟地下水地区居民饮用水安全具有重要意义。吸附法除氟技术被广泛应用,但仍存在适宜于偏酸性环境等难点。以提高适应高氟地下水pH值的能力为目标,通过控制反应过程中pH值制备无定形氢氧化铝吸附材料,开展吸附等温线试验、吸附动力学试验、pH值适应性试验、竞争离子试验、可重复利用性能试验和吸附机理试验。试验结果表明无定形氢氧化铝对氟离子的吸附属于优惠型吸附,Langmuir最大吸附容量为166.67 mg/g。与传统Al_2O_3吸附材料相比,在pH值为7.0~9.0时,无定形氢氧化铝吸附材料可减缓除氟效果下降速率,提高了适应地下水pH值的能力。氟去除率随着溶液中HCO_3~-、CO_2-3、PO_4~(3-)等离子浓度升高而降低。在初始氟浓度为5.00 mg/L时,可重复利用5个周期。因此,改进铝型吸附材料制备过程可显著提高吸附性能和适应高氟地下水的能力,是今后研制和改进吸附材料的重要方向。     

铅锌矿尾矿吸附水溶液中碱性品绿的研究

以铅锌矿尾矿(TLZO)作为吸附剂,研究不同条件下吸附水溶液中碱性品绿(BG)的特性,并对其吸附机理进行探讨。结果表明:pH值对BG的吸附有显著影响,最佳pH值为7.0;TLZO吸附BG是一个快速的过程,40min即达到平衡。随着初始浓度的增加,吸附量越大,达到平衡所需的时间越长;动力学数据较好地符合拟二级动力学方程。初始阶段外扩散过程对TLZO吸附BG的速率影响较大;在内扩散过程中,同一初始浓度下速率常数Kp,2>Kp,3,同一扩散阶段的速率随着初始浓度的升高而升高。TLZO对BG的等温吸附行为较好地符合Freundlich吸附等温模型。     

改性沸石吸附水中铬(Ⅵ)的试验研究

采用氯化铁改性后的沸石对溶液中的铬(Ⅵ)进行静态吸附试验,研究了溶液pH值吸附时间、吸附剂用量、铬(Ⅵ)初始浓度等因素对吸附的影响.结果表明,改性沸石吸附铬(Ⅵ)的速度比天然沸石快,1h内可达到吸附平衡;溶液pH值在偏酸性时更有利于吸附进行;用Langmuir方程拟合了吸附等温线(R=0.9999),可用二级动力学方程描述吸附动力学过程,实验条件下计算的最大吸附量为1.18mg/g.     

天然沸石对地下水中铁锰的吸附性能研究

地下水常含有铁锰,吸附法除铁除锰简单实用。采用天然沸石对地下水中铁锰进行吸附试验研究。试验结果表明:天然沸石对铁锰的吸附符合弗劳德利希吸附等温式,去除率随着沸石投加量的增大而逐渐提高;原溶液浓度越高,铁、锰的吸附量则越大;原溶液浓度不同时,铁的去除率随原溶液浓度增加而逐渐下降;锰的去除率在溶液浓度5 mg/L时呈现下降趋势;铁和锰的最佳吸附时间分别为30 min和20 min,铁锰吸附时间大于相应最佳吸附时间时,则两者吸附量都会下降。为期70 d的试验表明,天然沸石除锰效果不好,出水水质最低含锰量超过0.1 mg/L,出水水质基本都没达到国家标准(≤0.1 mg/L),而除铁的出水水质基本都在国家饮用水卫生标准值0.3 mg/L以内,最低值接近0.0 mg/L,其整体除铁效果要好于除锰。     

天然沸石对氨氮的吸附作用及其影响因素

通过实验研究天然沸石对氨氮的吸附作用及其影响因素。结果表明,沸石对氨氮的吸附过程遵循准二级动力学模型;沸石对氨氮的等温吸附可用Langmuir和Freundlich等温模型拟合,相关系数R2达到极显著相关(P0.01);随着天然沸石粒径与投加量的减小,沸石对氨氮的吸附量显著增加;在pH值中性时,去除效果最好;温度升高有利于沸石对氨氮的吸附。     

天然沸石的改性及其除氟性能

于研究天然沸石的改性及其除氟性能,可以达到使除氟的方法既经济又高效。实验采用优质天然沸石,对其进行高温焙烧、酸、碱及盐的处理,使其对氟离子的吸附容量大大提高,并对其吸附机理进行研究,通过各种仪器检测其微观结构。     

粉煤灰滤料的制备与应用研究

采用2％无机造孔添加剂、50％粉煤灰和48％粘土于900℃烧制2 h得到了一种强度高比表面积大的滤料。该滤料可用于吸附氟离子,吸附类型属于Freundlich型,是一种中等覆盖度的多层吸附。将该滤料填装于玻璃柱中进行动态过滤模拟试验,过滤高氟饮用水,滤出水pH增加、浊度降低。对进水浓度和温度等影响因素进行研究,结果表明,随着进水氟离子浓度的增加,产水量减少,滤料的除氟率增加;而随着温度的增加,产水量会增加,除氟率也会增加。     

铁/铝复合氧化物对氟离子的吸附

水体中氟离子超标严重危害人们的健康,为了寻求廉价、高效的氟离子吸附剂,本文通过共沉淀-焙烧的方法制备了铁铝复合金属氧化物吸附剂,并将之应用于氟离子废水的吸附。探讨了氧化物配比、吸附时间、吸附剂投加量、溶液初始浓度、溶液p H等因素对氟离子吸附效果的影响。结果表明:当铁铝复合氧化物中铁氧化物与铝氧化物摩尔比为1∶2,氟离子溶液初始浓度100 mg/L,固液比为4 g/L,溶液p H为6.0,吸附时间为30 min时,该吸附剂对氟离子的吸附效果最佳,此时氟离子的去除率为92.5%。     

锰砂与粉末活性炭对印染废水脱色的研究

利用除铁用锰矿砂(PGM)为处理剂进行罗丹明B与甲基橙模拟废水的静态脱色试验,并与粉末活性炭(PAC)进行对比。结果表明:PAC与染料的作用机理是物理吸附,脱色率受pH影响较小,对甲基橙和罗丹明B分别符合Langmuir和Freundlich方程。PGM在酸性条件下对染料的脱色是氧化与吸附的综合作用,较低的pH、较高的投量和恰当的反应时间可提高PGM的脱色效能,pH是影响PGM脱色能力的关键因素,pH=1.2时,符合Langmuir方程。酸性条件下较大的吸附容量和较短的平衡时间使PGM有可能应用于染料废水深度处理。     

Adsorption of Zn(II) on dialdehyde m-phenylenediamine starch

A new chelating material dialdehyde m-phenylenediamine starch (DASMPA) was synthesized by reacting m-phenylenediamine with dialdehyde starch. The obtained material was characterized by element analysis and Fourier transform infrared (FT-IR) spectra. The FT-IR of DASMPA showed an absorption peak at 1605.95 cm(-1) indicating the formation of a Schiff base (C=N). Adsorption activity of DASMPA for Zn(2+) was also investigated in terms of contact time, pH, the initial Zn(II) concentration and temperature, the results revealed that pH = 5, t = 1 h were the optimal conditions. With the degree of substitution (DS) of the DASMPA increased, the adsorption capacity increased gradually. The adsorption equilibrium data correlated well with Freundlich isotherm. Moreover, lower temperature was preferable for the process as it was exothermic.     

Factors influencing phosphorus adsorption onto sediment in a dynamic environment

The adsorption of phosphorus onto sediment in a batch reactor and a dynamic flume was studied experimentally. The effect of velocity, sediment transport patterns, sediment supply, and phosphorus added to water was investigated in the two systems. Results showed that the equilibrium isotherm adsorption was better described using the Langmuir model. The adsorption amount increased as the initial phosphorus concentration in water increased before reaching saturation state, which was described as maximum amount of adsorption; the rate of increase in adsorption however decreased because of the limit adsorption sites and the increasing desorption. The kinetics of soluble reactive phosphorus (SRP) in water over time in both the batch reactor and the dynamic flume were well described using a pseudo-second order equation that gave good predictions of both the adsorption rate at the initial stage and the amount of adsorption in a state of quasi-equilibrium. The amount of adsorption per unit mass of sediment in the quasi-equilibrium state increased as the initial phosphorus concentration in water increased or as the sediment concentration decreased. In the quasi-equilibrium state, the adsorption amount of the SRP fluctuated within a larger range in the dynamic flume than in the batch reactor, because of continuous exchange between the suspended sediment and the bed sediment in the flume. The adsorption rate of the suspended sediment was greater than that of the bed sediment. The amount of adsorption decreased as the velocity increased when the phosphorus concentration was low, while it increased when the phosphorus concentration was high, as a result of a different concentration gradient at the water–sediment interface. The distribution coefficient and the adsorption rate coefficient both decreased as the initial phosphorus concentration increased when the sediment concentration was fixed. The variation of the distribution coefficient (K_D) indicated that the adsorption amount at equilibrium in the dynamic flume was larger than that in a quiescent environment when the phosphorus concentration was low, while the difference between the two systems was small when the phosphorus concentrations were high. However, the K_D value in both the flume and in static conditions was smaller than the value for the continuous disturbed environment in the batch reactor, indicating that the adsorption capacity was over-estimated in the latter.     

镧沸石控制人工湖泊沉积物磷释放的试验研究

环境条件的变化会引起沉积物中的磷向上覆水释放,从而引发富营养化。投加镧系钝化剂可以有效控制沉积物中磷的释放。然而,目前应用最为广泛的锁磷剂 Phoslock存在着 La3+释放的风险;此外,由于锁磷剂吸附量较小,形成的钝化剂层较厚,氧气从上覆水向沉积物的传质也会被阻碍。使用具有较大吸附量和较低 La3+释放风险的新型材料———镧沸石作为钝化剂,考察了其对人工湖泊沉积物中磷释放的控制效果。通过等温吸附线和 Langmuir 模型拟合,发现镧沸石对磷的最大吸附量为71. 94 mg /g,是 Phoslock的 7 倍。吸附动力学试验表明,镧沸石对磷的吸附速率较快,0. 5 h 内可以利用 81%的吸附位。磷形态分析发现,镧沸石吸附的磷 85%以上为酸溶态或残渣态磷,说明其与磷的结合具有较好的稳定性。投加镧沸石后,沉积物中磷在 pH 值为 10. 8 时的释放量可以降低 30%;厌氧条件下沉积物中磷的释放可以被镧沸石完全抑制。40 d 模拟钝化试验发现,投加质量百分比1. 65%的镧沸石可以显著降低上覆水中溶解性可反应磷( SＲP) 和总磷( TP) 的浓度,其中 SＲP 浓度的降低幅度大于 TP。模拟钝化试验中,非稳定形态的磷被转化为较为稳定的酸溶态磷和残渣态磷。结果表明,镧沸石在沉积物内源磷控制方面具有良好的应用前景。     

铝污泥吸附水中磷的影响因素及响应面法优化

为提高铝污泥的利用效率,将其更好地应用于富营养化水体的修复之中,以给水厂脱水铝污泥为吸附材料对水中的磷进行吸附,考察铝污泥投加量、铝污泥颗粒粒径、体系pH、水样磷浓度对吸附效果的影响。拟合了等温吸附方程,并借助响应面分析中的BBD(Box-Behnken Design)模型确定吸附时间、pH和铝污泥投加量这3种因素对吸附反应影响的显著性及交互作用的强弱,同时利用此模型对实验条件进行优化。结果表明:①上述4种因素均对吸附过程有所影响,Langmuir等温吸附方程拟合效果较好,铝污泥对磷的理论饱和吸附量为1.487 mg/g(温度298 K)。②铝污泥投加量对吸附的影响最为显著,pH和反应时间产生的交互作用最强。③当水体中磷浓度为10 mg/L时,其最佳工艺条件为铝污泥投加量12 g/L、pH=4.5及反应时间48 h,最大去除率为92.38%。     

Biosorption of Methylene Blue onto spent corncob substrate: kinetics, equilibrium and thermodynamic studies

This study focuses on the possible use of the spent corncob substrate (SCS), an agricultural waste used after the cultivation of white rot fungus Pleurotus ostreatus, to adsorb Methylene Blue (MB) from aqueous solutions. A batch adsorption study was carried out with variable solution pH, adsorption time, temperature and initial MB concentration. It was found that MB uptake was favorable at pH ranging from 4.0 to 12.0 and the equilibrium adsorption capacity can be reached promptly within about 180 min. The biosorption data were also calculated by the pseudo-second-order kinetic model and Langmuir isotherm model. Thermodynamic parameters show that the adsorption is a spontaneous and endothermic process. The study highlighted a new pathway to develop potential low-cost biosorbent for the removal of dye pollutants from wastewater.     

人工湿地填料除砷效率及影响因素试验研究

人工湿地是净化含砷水体的重要途径之一,而填料是决定人工湿地除砷效果的关键因素。通过填料如砾石、锰砂、沸石和陶粒的理化性质的测定,以及各种填料的吸附动力学、吸附等温线和吸附影响因素试验,研究了填料的除砷性能及影响因素。结果表明:4种填料均能在24 h内达到吸附平衡,一级动力学方程和二级动力学方程能很好地拟合其吸附过程;锰砂、陶粒、沸石和砾石最大吸附容量依次为36.62,25.39,11.96,7.04 mg/kg,Freundlich方程能较好地拟合填料的等温吸附过程;在0.25~0.50 mm范围内,粒径对锰砂和陶粒吸附砷影响不显著;溶液中氨氮浓度在0.50~2.50 mg/L范围内几乎不影响填料对砷的吸附;当砷初始浓度低于0.4 mg/L时,磷酸盐在0.25~0.50 mg/L范围内对填料吸附砷的影响不显著;砷初始浓度高于0.4 mg/L时,随着磷酸盐浓度从0.25 mg/L增加至0.50 mg/L时,陶粒对砷的最大吸附量降低了2.57 mg/kg,对锰砂的吸附量降低了1.85 mg/kg。     

The sorption of lead, cadmium, copper and zinc ions from aqueous solutions on a raw diatomite from Algeria

The adsorption of Cu(2+), Zn(2+), Cd(2+) and Pb(2+) ions from aqueous solution by Algerian raw diatomite was studied. The influences of different sorption parameters such as contact pH solution, contact time and initial metal ions concentration were studied to optimize the reaction conditions. The metals ions adsorption was strictly pH dependent. The maximum adsorption capacities towards Cu(2+), Zn(2+), Cd(2+) and Pb(2+) were 0.319, 0.311, 0.18 and 0.096 mmol g(-1), respectively. The kinetic data were modelled using the pseudo-first-order and pseudo-second-order kinetic equations. Among the kinetic models studied, the pseudo-second-order equation was the best applicable model to describe the sorption process. Equilibrium isotherm data were analysed using the Langmuir and the Freundlich isotherms; the results showed that the adsorption equilibrium was well described by both model isotherms. The negative value of free energy change ΔG indicates feasible and spontaneous adsorption of four metal ions on raw diatomite. According to these results, the high exchange capacities of different metal ions at high and low concentration levels, and given the low cost of the investigated adsorbent in this work, Algerian diatomite was considered to be an excellent adsorbent.     

不同生态河道基质材料对氮磷的吸附对比研究

生态河道构建是一种有效的河流水体修复技术,选择合适的基质材料构建生态河道,能改善其对污染物质的净化效果.对比研究了砾石、砂子和沸石3种不同生态材料在不同氮磷水平下对氮磷的强化吸附性能,并对其吸附机理进行了初步探讨.试验结果表明,Freundlich等温吸附方程能较好地描述3种材料的吸附性能,对于氮、磷的饱和吸附能力依次为沸石＞砾石＞砂子.开发利用吸附能力较强的砾石或是利用吸附能力更强的沸石作为生态河道基质材料,是构建生态河道的一种有效措施.