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501.
探讨了改性松针(GXLsp)作为吸附剂对水体中铅离子的吸附性能,考察了吸附时间、溶液pH值、吸附剂用量、盐离子浓度、Pb(II)初始浓度及温度对改性松针吸附Pb(II)的影响。利用Langmuir和Freundlich等温线模型对实验数据进行非线性拟合分析,结果表明,Freundlich等温线模型能很好地描述松针对Pb(II)的吸附过程。热力学参数表明吸附是一个自发的吸热过程。改性松针对铅的吸附行为符合拟二级动力学方程,表明吸附过程是以化学吸附为主。在293K时松针对Pb(II)的饱和吸附量为318.3 mg/g,因此,GXLsp可作为一种高效低值生物质吸附剂以去除水体中重金属Pb(II)的污染。 相似文献
502.
粉煤灰吸附除磷的改性研究 总被引:9,自引:4,他引:5
研究了粉煤灰的最佳改性条件及其吸附理论模型.获得了粉煤灰用于吸附含磷量为5 mg P/L的模拟二级出水的3种改性的最佳条件(21℃):(1)0.25 mol/L盐酸改性的粉煤灰对磷的去除率为76.0%,出水含1.20 mg P/L;(2)300℃下煅烧的粉煤灰对磷的去除率为93.8%,出水中磷含量达到了0.31 mg P/L;(3)低火(119 W)改性的粉煤灰的磷去除率达95.4%,出水含0.23 mg P/L.试验结果表明:Langmuir方程能很好地解释两种改性粉煤灰的吸附动力学(R2=0.9188,S.E=0.0032),而Simple Elovieh方程在描述两者的吸附动力学试验数据上显示出优越性(R2=0.9427,S.E=0.029). 相似文献
503.
504.
以玉米淀粉为原料,经过交联、醚化、胺化和亲核加成等步骤合成了一种新型重金属吸附剂——二硫代氨基甲酸改性淀粉(DTCS)。改性淀粉的结构采用红外光谱和扫描电镜进行表征。DTCS是一种性能优良的重金属吸附剂,对Cu2+、Pb2+和Zn2+的饱和吸附容量随着pH(pH=2~6)的增加而增大。在有EDTA络合剂存在和酸性废水pH小于3的情况下,DTCS对Cu2+、Pb2+和Zn2+仍有较高的去除率,分别达到90%、75%和50%以上,说明DTCS在含重金属离子的实际废水体系具有一定的实用价值。 相似文献
505.
D. Fernández-Calviño P. Soler-Rovira M. Arias-Estévez 《Environmental pollution (Barking, Essex : 1987)》2010,158(12):3634-3641
The main purpose of this work was to identify the role of soil humic acids (HAs) in controlling the behavior of Cu(II) in vineyard soils by exploring the relationship between the chemical and binding properties of HA fractions and those of soil as a whole. The study was conducted on soils with a sandy loam texture, pH 4.3-5.0, a carbon content of 12.4-41.0 g kg−1 and Cu concentrations from 11 to 666 mg kg−1. The metal complexing capacity of HA extracts obtained from the soils ranged from 0.69 to 1.02 mol kg−1, and the stability constants for the metal ion-HA complexes formed, log K, from 5.07 to 5.36. Organic matter-quality related characteristics had little influence on Cu adsorption in acid soils, especially if compared with pH, the degree of Cu saturation and the amount of soil organic matter. 相似文献
506.
Activated carbons derived from oil palm empty-fruit bunches: Application to environmental problems 总被引:1,自引:1,他引:0
Md. Zahangir ALAM Suleyman A. MUYIBI Mariatul F. MANSOR Radziah WAHID 《环境科学学报(英文版)》2007,19(1):103-108
Activated carbons derived from oil palm empty fruit bunches (EFB) were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process, Two types of activation namely; thermal activation at 300, 500 and 800℃and physical activation at 150℃ (boiling treatment) were used for the production of the activated carbons. A control (untreated EFB) was used to compare the adsorption capacity of the activated carbons produced from these processes. The results indicated that the activated carbon derived at the temperature of 800℃ showed maximum absorption capacity in the aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon at 800℃. It was observed that the adsorption capacity was higher at lower values of pH (2-3) and higher value of initial concentration of phenol (200-300 mg/L). The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of phenol adsorption onto activated carbons were also studied to evaluate the adsorption rate. The estimated cost for production of activated carbon from EFB was shown in lower price (USD 0.50/kg of activated carbon) compared the activated carbon from other sources and processes. 相似文献
507.
Black carbon (BC) can strongly adsorb hydrophobic organic compounds (HOCs).The HOC sorption to coated BC could be attenuated in soil and sediment compared with that of the parent BC.To study the potential causes of the sorption attenuation,humic acid (HA) and BC were isolated.Phenanthrene (PHE) was selected as the representative of HOCs.BC was coated with the precipitated HA.The PHE sorption to the HA-coated BC was determined.The HA coatings on BC could result in the significant sorption attenuation of PHE to BC.The attenuation varied in different HA origin and was positively correlated to the aromaticity of HA.The attenuation could be explained by the direct competition between HA and PHE for the available sorption sites on BC and the reduction of the available sorption sites as a result of the pore blockage of BC caused by the HA coatings.Therefore,the HA coatings on BC was one potential cause of the attenuation of HOC sorption to BC in soil and sediment. 相似文献
508.
509.
510.
The objective of this study was to examine the effect of biosurfactant on the sorption of phenanthrene (PHE) onto the original or
H2O2-treated black loamy soil (typic isohumisols) and red sandy soil (typic ferralisols). The sorption isotherms were performed with
the original and “soft” carbon-removed soils in the presence and absence of biosurfactant (200 mg/L). The sorption and degradation
of biosurfactant were investigated. The result showed that organic matter played an important role in PHE sorption onto the black
loamy and red sandy soils, and the PHE sorption isotherms on the “soft” carbon-removed soils exhibited more nonlinearity than those
on the original soils. The values of partition coe cient (Kd) on the original black loamy soil with or without 200 mg/L biosurfactant
were 181.6 and 494.5 mL/g, respectively. Correspondingly, in the red sandy soil, Kd was 246.4 and 212.8 mL/g in the presence or
absence of biosurfactant, respectively. The changes of Kd suggested that biosurfactant inhibited PHE sorption onto the black loamy
soil, but facilitated PHE sorption onto the red sandy soil. The nonlinearity of PHE sorption isotherm was decreased in the presence
of biosurfactant. Site specific sorption might occur during PHE sorption onto both the original and the “soft” carbon-removed soils in
the presence of biosurfactant. It was noted that biosurfactant could also be sorbed onto soils. The maximal sorption capacity of the
red sandy soil for biosurfactant was (76.9 0.007) g/g, which was 1.31 times that of black loamy soil. Biosurfactant was degraded
quickly in the two selected soils, and 92% of biosurfactant were mineralized throughout the incubation experiment for 7 d. It implied
that biosurfactant should be added frequently when the remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils was
conducted through PAH desorption approach facilitated by biosurfactant. 相似文献