间歇反应器内污泥衍生吸附剂去除水溶液中镉、镍离子

利用城市污水厂的污泥化学活化法热解产生的吸附剂 ,在间歇反应器内对水溶液中Cd2 和Ni2 离子进行吸附性能的研究 .考察了溶液的pH值、接触时间、吸附剂的投加量及吸附质初始浓度对吸附效果的影响 ,结果表明 ,Cd2 ,Ni2 离子吸附达到平衡时的接触时间为 60min,pH值为 5 5— 6 0 ,溶液的初始浓度为 40mg·l- 1 和 30mg·l- 1 ,吸附剂的投加量不少于 1 0g·l- 1 和 2 0g·l- 1 .     

Biodegradation during contaminant transport in porous media: 1. mathematical analysis of controlling factors

Interest in coupled biodegradation and transport of organic contaminants has expanded greatly in the past several years. In a system in which biodegradation is coupled with solute transport, the magnitude and rate of biodegradation is influenced not only by properties of the microbial population and the substrate, but also by hydrodynamic properties (e.g., residence time, dispersivity). By nondimensionalizing the coupled-process equations for transport and nonlinear biodegradation, we show that transport behavior is controlled by three characteristic parameters: the effective maximum specific growth rate, the relative half-saturation constant, and the relative substrate-utilization coefficient. The impact on biodegradation and transport of these parameters, which constitute various combinations of factors reflecting the influences of biotic and hydraulic properties of the system, are examined numerically. A type-curve diagram based on the three characteristic parameters is constructed to illustrate the conditions under which steady and non-steady transport is observed, and the conditions for which the linear, first-order approximation is valid for representing biodegradation. The influence of constraints to microbial growth and substrate utilization on contaminant transport is also briefly discussed. Additionally, the impact of biodegradation, with and without biomass growth, on spatial solute distribution and moments is examined.     

复合功能吸附树脂对双组分萘系化合物的竞争吸附研究

1-氨基 -2 -萘酚 -4 -磺酸 ( 1,2 ,4-酸 )和 2 -萘酚自不同双组分吸附体系中吸附至复合功能吸附树脂 AL -1上的吸附等温线符合 F reundlich等温模型。1,2 ,4-酸的吸附为吸热过程 ,而 2 -萘酚的吸附为放热过程。固相上的 2 -萘酚几乎不影响 1,2 ,4-酸的吸附 ,而固相上的 1,2 ,4-酸大大削弱了 2 -萘酚的吸附。两种溶质在吸附位点上的竞争为主要作用机制。     

多孔填充材料的防火防爆机理及应用

在液化气体、燃料储罐内填充多孔材料,可有效地减少或避免储罐发生爆炸事故.本文分析了这类材料的防爆机理并简要介绍了其应用情况.     

A novel two-dimensional model for colloid transport in physically and geochemically heterogeneous porous media

A two-dimensional model for colloid transport in geochemically and physically heterogeneous porous media is presented. The model considers patchwise geochemical heterogeneity, which is suitable to describe the chemical variability of many surficial aquifers with ferric oxyhydroxide-coated porous matrix, as well as spatial variability of hydraulic conductivity, which results in heterogeneous flow field. The model is comprised of a transient fluid flow equation, a transient colloid transport equation, and an equation for the dynamics of colloid deposition and release. Numerical simulations were carried out with the model to investigate the colloid transport behavior in layered and randomly heterogeneous porous media. Results demonstrate that physical and geochemical heterogeneities markedly affect the colloid transport behavior. Layered physical or geochemical heterogeneity can result in distinct preferential flow paths of colloidal particles. Furthermore, the combined effect of layered physical and geochemical heterogeneity may result in enhanced or reduced preferential flow of colloids. Random distribution of physical heterogeneity (hydraulic conductivity) results in a random flow field and an irregularly distributed colloid concentration profile in the porous medium. Contrary to random physical heterogeneity, the effect of random patchwise geochemical heterogeneity on colloid transport behavior is not significant. It is mostly the mean value of geochemical heterogeneity rather than its distribution that governs the colloid transport behavior.     

甲萘酚和甲萘胺在超高交联吸附树脂上的协同吸附行为

研究了水溶液中甲萘酚和甲萘胺在超高交联吸附树脂NDA103、NDA100上的协同吸附行为.实验结果表明,在较高平衡浓度范围内该吸附树脂对双组分水溶液中甲萘酚和甲萘胺双组分(摩尔比分别为3∶1、1∶1、1∶3)的吸附总量大于相同平衡浓度下对单组分水溶液中甲萘酚和甲萘胺的吸附量,呈现协同吸附现象,其主导机制是2种吸附质分子之间的氢键作用.单组分甲萘酚或甲萘胺水溶液和双组分共存水溶液中吸附质分子在吸附树脂上的吸附等温线均符合Langmuir模型.吸附温度由293K升至313K时,甲萘酚和甲萘胺在NDA103上的协同吸附效应的变化明显大于NDA100.NDA103树脂结构上的胺基既加强了对甲萘酚的吸附亲和力又增加了甲萘酚的协同吸附系数.     

氨基酸修饰的高交联吸附树脂对Cu(Ⅱ)和磺胺嘧啶的吸附机制研究

采用络氨酸修饰氯球树脂（PS-DVB）并进行后交联反应制备了氨基酸修饰的高交联吸附树脂（PSTY）.研究了PSTY树脂对Cu（Ⅱ）和磺胺嘧啶（SDZ）的协同吸附性能及交互影响机制.单组分体系中,树脂对Cu（Ⅱ）的吸附随pH值的增加而增加,对SDZ的吸附随着pH值的增加先增后减;共存体系中,SDZ的共存微弱促进了树脂对Cu（Ⅱ）吸附,Cu（Ⅱ）的共存抑制了树脂对SDZ的吸附,且pH大于6后抑制更为明显.PSTY对Cu（Ⅱ）和SDZ的吸附等温线可采用Langmuir和Freundlich方程进行拟合,共存低浓度的SDZ使Cu（Ⅱ）的饱和吸附量略有增加,而高浓度的SDZ使其下降.Cu（Ⅱ）的增强去除主要是阴离子SDZ^-与树脂的质子化基团的静电作用减弱了对Cu（Ⅱ）的静电斥力,Cu（Ⅱ）与SDZ分别与PSTY中的极性基团发生配位作用和氢键作用进行竞争吸附,但Cu（Ⅱ）的配位结合力更强,虽然吸附到树脂上的Cu（Ⅱ）还可以通过桥连作用吸附SDZ,但作用较弱,因此,共存的Cu（Ⅱ）抑制了PSTY树脂对SDZ的吸附,Cu（Ⅱ）浓度越大抑制程度越高.     

Simultaneous removal of Congo red and cadmium(II) from aqueous solutions using graphene oxide–silica composite as a multifunctional adsorbent

Graphene oxide is a very high capacity adsorbent due to its functional groups and π?π interactions with other compounds. Adsorption capacity of graphene oxide, however, can be further enhanced by having synergistic effects through the use of mixed-matrix composite. In this study, silica-decorated graphene oxide (SGO) was used as a high-efficiency adsorbent to remove Congo red (CR) and Cadmium (II) from aqueous solutions. The effects of solution initial concentration (20 to 120 mg/l), solution pH (pH 2 to 7), adsorption duration (0 to 140 min) and temperature (298 to 323 K) were measured in order to optimize the adsorption conditions using the SGO adsorbent. Morphological analysis indicated that the silica nanoparticles could be dispersed uniformly on the graphene oxide surfaces. The maximum capacities of adsorbent for effective removal of Cd (II) and CR were 43.45 and 333.33 mg/g based on Freundlich and Langmuir isotherms, respectively. Langmuir and Freundlich isotherms displayed the highest values of Q_max for CR and Cd (II) adsorption in this study, which indicated monolayer adsorption of CR and multilayer adsorption of Cd (II) onto the SGO, respectively. Thermodynamic study showed that the enthalpy (ΔH) and Gibbs free energy(ΔG) values of the adsorption process for both pollutants were negative, suggesting that the process was spontaneous and exothermic in nature. This study showed active sites of SGO (π-π, hydroxyl, carboxyl, ketone, silane-based functional groups) contributed to an enormous enhancement in simultaneous removal of CR and Cd (II) from an aqueous solution, Therefore, SGO can be considered as a promising adsorbent for future water pollution control and removal of hazardous materials from aqueous solutions.     

Adsorption/desorption behavior between a novel amphoteric granular lignin adsorbent and reactive red K-3B in aqueous solutions

A novel amphoteric granular lignin adsorbent(AGLA) was prepared using magnesium lignosulfonate as a raw material which was provided by a straw sulfite pulp mill in Guangdong Province, China. A reactive dye(red K-3B) was used as an adsorbate to investigate the adsorption behavior by static and mobile ways. The removal of reactive red K-3B was found to be initially pH and concentration dependent.Moreover, an increase of solution temperature ranging from 5℃ to 60℃ helped to enhance the rate of intraparticle diffusion of adsorbate and changes in the size of the pores of the adsorbent and thus to reduce the adsorption time. The total breakthrough adsorption capacity was 531 mg/g, and the saturated adsorption capacity was 560 mg/g, which prevailed over the activated carbons evidently. The reactive red K-3B adsorbed on AGLA could be recovered with a mixture of alcohol, NaCI and HCI aqueous solutions. The recovery percentage could reach 92.4%.     

Natural and synthesised iron-rich amendments for As and Pb immobilisation in agricultural soil

The immobilisation of heavy metals in contaminated soils is a promising alternative to conventional remediation techniques. Very few studies have focused on the use of iron-rich nanomaterials and natural materials for the adsorption of toxic metals in soils. Synthesised iron-rich nanomaterials (Fe and Zr–Fe oxides) and natural iron-rich materials (natural red earth; NRE) were used to immobilise As and Pb in contaminated agricultural soil. Total concentrations of As and Pb in the initial soil (as control) were 170.76 and 1945.11 mg kg^?1, respectively. Amendments were applied into the soil at 1, 2.5 and 5% (w/w) in triplicate and incubated for 150 days. Except for the NRE-amended soil, soil pH decreased from 5.6 to 4.9 with increasing application rates of Fe and Zr–Fe oxides. With addition of Fe and Zr–Fe oxides at 5%, the ammonium acetate (NHO₄Ac)-extractable Pb was greatly decreased by 83 and 65% compared with NRE addition (43%). All subjected amendments also led to a decrease in NHO₄Ac-extractable As in the soils, indicating the high capacity of As immobilisation. Soil amended with NRE showed a lower ratio of cy19:0 to 18:1ω7c, indicating decreased microbial stress. The toxicity characteristic leaching procedure produced results similar to the NHO₄Ac extraction for As and Pb. The NRE addition is recommended for immobilising heavy metals and maintaining biological soil properties.