VOC的回收与处理技术简介

介绍了几种以VOC废气中回收溶剂的方法，其分析其优缺点和适用范围，对回收有困难或不经济的含VOC废气，建议采用焚烧法或催化燃烧法进行处理。     

Insight into the adsorption of tetracycline onto amino and amino–Fe functionalized mesoporous silica: Effect of functionalized groups

In order to study the influences of functionalized groups onto the adsorption of tetracycline (TC), we prepared a series of amino and amino–Fe^3 + complex mesoporous silica adsorbents with diverse content of amino and Fe^3 + groups (named N,N-SBA15 and Fe-N,N-SBA15). The resulting mesoporous silica adsorbents were fully characterized by X-ray powder diffraction, Fourier transform infrared spectrometer and N₂ adsorption/desorption isotherms. Furthermore, the effects of functionalized groups on the removal of TC were investigated. The results showed that the periodic ordered structure of SBA-15 was maintained after modification of amino/Fe^3 + groups. The functionalized amino groups decreased the adsorption capacity while the coordinated Fe^3 + increased the adsorption capacity. The adsorption kinetics of TC fitted pseudo-second-order model well and the equilibrium was achieved quickly. The adsorption isotherms fitted the Langmuir model well and with the Fe^3 + content increased from 3.93% to 8.26%, the Q_max of the adsorbents increased from 102 to 188 mmol/kg. The solution pH affected the adsorption of TC onto amino complex adsorbents slightly while influenced the adsorption onto Fe-amine complex adsorbents greatly. The adsorption of TC on SBA15 and N,N-SBA15 may be related to the formation of outer-sphere surface complexes, while the adsorption of TC onto Fe-N,N-SBA15 was mainly attributed to the inner-sphere surface complexes. This study could offer potential materials that have excellent adsorption behavior for environmental remediation and suggested useful information for the preparing other adsorbents in environmental applications.     

土壤吸附铬的特性及影响因素研究进展

铬污染问题越来越突出,尤其是铬渣的堆存造成严重的土壤铬污染。介绍了铬进入土壤后的存在形态及化学行为,论述了土壤对Cr(Ⅲ)和Cr(Ⅵ)的吸附特征,着重讨论了土壤吸附铬的影响因素。铬在土壤中的吸附是一个复杂的过程,受多方面因素的影响,土壤对铬的吸附依赖于土壤的类型、土壤物理化学性质,如土壤的矿物特性、有机组成pH、Eh、等,也与外加阴阳离子、有机质等有关。研究土壤吸附铬的影响因素为土壤铬污染治理提供科学依据,今后的研究可结合周围环境对铬污染的影响展开。     

Lead removal from water using organic acrylic amine fiber (AAF) and inorganic-organic P-AAF, fixed bed filtration and surface-induced precipitation

Granular porous sorbents were normally used for heavy metals removal from water. To search for the new commercial sorbent and treatment strategy, an organic acrylic amine fiber (AAF) and phosphorus loading inorganic-organic AAF (P-AAF) were prepared and used for lead (Pb) removal from water. A new strategy of inorganic-organic coupling technology was proposed for Pb removal, based on the hypothesis of surface-induced precipitation mechanism. The AAF showed a Pb adsorption capacity of 417 mg/g from the Langmuir fitting, while the column filtration technology was further applied to measure the adsorption edge and applications. Effects of different initial Pb concentrations, hydraulic retention time, and co-existing P were considered in the filtration experiments. The presence of 0.8 mg/L P in water significantly improved the Pb breakthrough point from 15,000 to 41,000 bed volumes of water spiked with 85 µg/L Pb, while the P-AAF fixed bed showed better removal of Pb than AAF SEM/EDX and XRD spectra were employed for determining the surface functional groups and the formation of surface-induced precipitation of pyromorphite (Pb₅(PO₄)₃OH) on AAF. This study verified the application of AAF sorbent for Pb removal and the enhanced effect of coating P on AAF, thus improved our fundamental understanding and application of the surface chemistry process of Pb with P.     

两性磁化炭添加比例对河流沿岸土吸附Cu2+的影响

将两性(十二烷基二甲基甜菜碱)修饰磁化炭分别以质量分数0、1％和2％加入嘉陵江流域(川渝段)内苍溪(CX)、南部(NB)、嘉陵(JL)和合川(HC)沿岸土中,考察各混合土样对Cu2+的等温吸附和热力学特征.结果表明:混合土样对Cu2+的最大吸附量为58.36 mmol/kg～366.85 mmol/kg,添加等量两性磁...     

Adsorption and desorption of steroid hormones on saline soil

● Organic matter content significantly affected adsorption of E2/EE2 on saline soil. ● EE2 possessed higher competition intensity for adsorption sites than E2. ● The adsorption of E2/EE2 on saline soil was a spontaneous exothermic process. ● Desorption capacity of EE2/E2 accounted for 40%/78% of the total adsorption capacity. Soil organic matter content was the main driving factor affecting adsorption and desorption process of 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) on saline soil. The adsorption and desorption of E2 and EE2 on three saline soils showed the similar behavior that soil with the highest organic content possessed the highest adsorption capacity and the lowest desorption capacity for E2 and EE2. The adsorption capacity of untreated soil samples (with organic matter) was larger than that of soil samples without organic matter. For soil with the largest adsorption capacity, adsorption capacity of E2/EE2 on the untreated soil and soil colloid (with organic matter) respectively reached 0.15/0.30 μg/g and 0.16/0.33 μg/g while the soil and soil colloid without organic matter hardly adsorbed pollutants. The adsorption capacity of E2/EE2 at the initial concentration of 100 μg/L was 25/15 times higher than that at the initial concentration of 5 μg/L. E2 and EE2 had the same adsorption sites on saline soil while EE2 possessed higher competition intensity for adsorption sites than E2. Pseudo-first-order model (R² = 0.995–0.986) and Langmuir model (R² = 0.989–0.999) could better fit the adsorption process of E2 or EE2. The thermodynamic study further showed that the adsorption of E2/EE2 on saline soil was a spontaneous exothermic process. The desorption capacity of EE2/E2 accounted for 40%/78% of the total adsorption capacity to possibly exert potential risk to the groundwater. The variation of the salinity led to the variation of soil organic carbon which subsequently changed the adsorption and desorption behaviors of endocrine disrupting chemicals in coastal saline soil. This study provides a new insight on the interfacial behavior of endocrine disrupting chemicals on saline soil.