铁氧化物改性黏土对Cr(Ⅵ)的吸附性能研究

利用铁氧化物对黏土进行了包覆改性,采用静态吸附法对该改性黏土吸附Cr(Ⅵ)的特性进行了研究,并考虑了反应时间、pH、浓度、温度对吸附的影响。实验结果表明,整个吸附过程基本在3h内完成;改性黏土对Cr(Ⅵ)的吸附量随溶液初始pH的增大而明显减小;随着溶液初始浓度和温度的增大而增大。同时,在初始pH为3.0的条件下,研究了改性黏土吸附Cr(Ⅵ)的动力学和热力学特性,结果表明,改性黏土对Cr(Ⅵ)吸附能较好地符合准二级动力学方程和Langmuir等温式。由Langmuir等温式得出,在293K、初始pH为3.0条件下的单层饱和吸附量为12.91 mg•g-1。确定了改性黏土吸附Cr(Ⅵ)的热力学参数,表明该吸附过程是一个吸热的自发过程。与原土的对比实验表明,改性黏土对Cr(Ⅵ)的吸附能力大大增强。     

无机-有机复合絮凝剂PST处理印染废水效果研究

以模拟印染废水和实际印染废水为实验对象,检验了一种新合成有机-无机复合絮凝剂(PST)的絮凝效果。结果表明,PST具有良好的絮凝性能。在受试条件下,絮凝效果与絮凝剂投加量、染料浓度有较大相关性。废水的pH值应用范围较宽;搅拌时间对COD去除率和脱色率没有显著影响。采用PST处理广东省高明市某印染厂的印染废水后,COD去除率为75.16%,脱色率为76.18%,处理效果良好,处理成本明显低于目前市场上普遍使用的聚铝等絮凝剂。     

Application of magnetic particles modified with amino groups to adsorb copper ions in aqueous solution

A magnetic adsorbent can be easily recovered from treated water by magnetic force,without requiring further downstream treatment.In this research,amine-functionalized silica magnetite has been synthesized using N-[3-(trimethoxysilyl)propyl]-ethylenediamine(TPED) as a surface modification agent.The synthesized magnetic amine adsorbents were used to adsorb copper ions in an aqueous solution in a batch system,and the maximum adsorption was found to occur at pH 5.5 ± 0.1.The adsorption equilibrium data fitted t...     

改性膨润土处理污水处理厂二级出水的实验研究

研究基于再生水回灌地下、补充地下水水源的目的,使用河南信阳某膨润土厂生产的钠基膨润土,通过酸改性、铝柱撑改性和微波-硫酸亚铁改性制得三种改性膨润土,用于处理城市污水处理厂的二级出水.实验结果显示,经XRD衍射分析可知,三种方法制备的改性膨润土,其矿物结构都有不同程度上的变化,膨润土层间距都较膨润土原矿有所增大,可见其改...     

上吸式生物质气化炉焦油成分的分析

文章在10 KWth上吸式生物质气化炉上进行木屑的气化实验,通过改变床层高度和气化剂空气的量,将产生的生物质焦油进行取样。经GC-MS分析得出上吸式气化炉焦油的主要成分为初级和二级焦油,其中以酚类焦油所占比重最多,大约为总量的38%~60%;在同样床高的条件下,随着空气量的增加,酚类焦油含量有所降低,但仍然是焦油中比重较大的。     

杉木木屑对废水中Hg2+的静态吸附研究

研究了未改性、HNO3改性和NaOH改性杉木木屑对水中Hg2+的吸附特性,并探讨Hg2+初始浓度、pH值、吸附时间和木屑用量对吸附率的影响.结果表明,杉木木屑对水中Hg2+具有较好的吸附效果,吸附率可达90%以上.杉木木屑对Hg2+的吸附动力学可用拟二级动力学方程描述.研究表明,利用酸碱改性杉木木屑制备废水中Hf2+吸附材料具有广阔的应用前景.     

生物炭输入对土壤污染物迁移行为的影响

重点综述了生物炭输入对土壤中污染物的吸附固持作用及生物有效性的影响,分析其作为土壤添加剂消减土壤污染风险的有效性,为生物炭在土壤中的应用研究提供依据。     

有机改性膨润土在印染废水处理中的应用

膨润土是一种非常有用的非金属矿物原料,其有机改性得到的有机改性膨润土可以较好地去除印染废水中的有机污染物和色度。本文综述了有机改性膨润土的制备方法及其在印染废水处理中的应用现状。     

改性小麦秸秆的制备及其对水中亚甲基蓝的吸附性能

用碳酸钾(K2CO3)溶液活化法成功地制备改性小麦秸秆。采用傅里叶红外光谱仪(FT-IR)、扫描电子显微镜(SEM)和静态吸附试验对改性前后样品的组成、形貌和吸附性能进行表征和测定,对比了秸秆改性前后的结构和组成变化。结果表明:改性后小麦秸秆半纤维素被部分溶解,出现了多孔疏松的结构。改性小麦秸秆用量、溶液p H和亚甲基蓝的浓度在一定范围内增大有助于改性小麦秸秆对亚甲基蓝吸附速率的提高,吸附类型符合Langmuir吸附等温方程模型且属于拟二级动力学吸附过程。     

Removal of polycyclic aromatic hydrocarbons from aqueous solution by raw and modified plant residue materials as biosorbents

Removal of polycyclic aromatic hydrocarbons （PAHs）, e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorpfion kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains （i.e., exposed aromatic core）. By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorpfion coefficients （Kd） were negatively correlated with the polarity index [（O＋N）/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater.