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排序方式: 共有505条查询结果,搜索用时 36 毫秒
1.
含氟废水深度处理的研究   总被引:18,自引:1,他引:18  
以火力发电厂的废树脂为载体 ,制备了负载锆水合氧化物的氟离子吸附树脂 ,并探讨了该负载树脂对氟离子的吸附和脱附性能 .结果表明 :制备该负载树脂的适宜锆浓度为 0 5mol L ,负载树脂吸附和脱附的适宜pH值分别为4 0和 12 0 .该负载树脂的吸附符合Langmuir型吸附等温线 ,通过这种等温线可以得出 ,CF- =1mg L时负载树脂的平衡吸附量qe 为 5 0 0 0mg L .利用该负载树脂对模拟火电厂的含氟废水进行处理 ,取得了较好的效果 .  相似文献   
2.
为探讨发生铝污染的白浆土中金属铝的解吸特性,采用平衡振荡法,研究铝在白浆土中的解吸行为及不同因素的影响。结果表明:在720min后,白浆土中的铝解吸基本达到平衡;25℃下,土壤有机质含量为42.2g/kg,铝在白浆土中的解吸量仅为吸附量的1.5%;用Langmuir方程可很好地拟合白浆土中铝解吸等温曲线(r=0.985 9**),说明表面均匀单层解吸占主导;热力学参数ΔG0,ΔH0,ΔS0,表明铝的解吸是自发、吸热和熵增加的过程。土壤有机质由42.2g/kg降至27.8g/kg时,白浆土中铝的最大解吸量由25.87mg/kg升至66.11mg/kg,且导致解吸滞后现象的加剧。pH降至3时,铝的解吸量升至226.4mg/kg,是pH在5~7时的8倍以上。随着解吸液中NaCl和Na_2SO_4浓度的增加,铝的解吸量增加。总之,吸附到白浆土中的铝解吸能力较弱,但pH和有机质含量降低,无机盐含量升高,铝的解吸量大幅增加,污染风险急剧上升。  相似文献   
3.
为了探明土壤及针铁矿、水铁矿对马尿酸(HA)的吸附解吸特性,并为其在环境中的风险性评价提供理论依据。通过批平衡吸附试验,对马尿酸(HA)在土壤、针铁矿、水铁矿中的吸附解吸行为进行了研究。结果表明,Langmuir模型可以对马尿酸在物质上的吸附和解吸数据进行良好的非线性拟合,平均拟合系数为0.992,试验中马尿酸在3种物质上的吸附和解吸不同程度地偏离线性模型;通过拟合得出的水铁矿和针铁矿对HA的最大吸附量分别为434.5 mg/kg和103.5 mg/kg,为土壤最大吸附量的20.89倍和5.22倍,而水铁矿是针铁矿的4.20倍;吸附容量lgKf顺序为水铁矿 > 针铁矿 > 土壤;HA在土壤、针铁矿、水铁矿中的解吸存在滞后现象。由此可见,水铁矿对马尿酸(HA)吸附能力及吸附强度均最强。  相似文献   
4.
The adsorption capacity and release behavior of sulfamethoxazole (SMZ) were determined on three types of activated carbon: AC-0 (commercial activated carbon), AC-Fe (activated carbon/iron oxide composites) and AC-Mn (activated carbon/manganese oxide composites). The adsorption fitted to the Freundlich, Langmuir and Langmuir-Freundlich models. The Langmuir-Freundlich model had been found most suitable for equilibrium data. The presence of iron oxide and manganese oxide did not significantly affect the surface area or pore structure of activated carbon, in addition, which had little effect on the adsorption capacity of activated carbon. Compared to AC-Fe and AC-Mn, AC-0 had a higher efficiency of SMZ desorption. Adsorption probably occurred through a surface complexation mechanism and was accompanied by degradation of some SMZ, which would play significant role in improving the ability of AC-Fe and AC-Mn adsorbing SMZ.  相似文献   
5.
乙烯脱除剂处理对杏果实常温贮藏品质的影响   总被引:3,自引:0,他引:3  
以新疆库买提杏果实为试材,研究了常温(25℃)条件下乙烯脱除剂处理对杏果实贮藏品质的影响。结果表明,乙烯脱除剂处理可有效降低杏果实贮藏前期的呼吸及乙烯释放速率,减缓细胞膜透性、MDA的上升及VC含量的下降速度,减少贮藏期内营养物质的消耗,延长杏果实的贮藏保鲜期,但贮藏5天后效果不明显。  相似文献   
6.
A way to enhance coal bed methane desorption and seepage by sonic vibrating of cavitataion water jets is proposed because the gas coal seams have the intrinsic properties of micro-porosity, low permeability and high adsorption. The mechanisms of how the sonic vibrating effects promote methane desorption and seepage are analyzed, and the contrast experiments of methane desorption and seepage under sonic vibrating effects are also provided. The results show: when the cavitation number is 0.020 0, under sonic vibrating effects, the volume of coal bed methane desorption increases by 36.9%, and the time for coal bed methane desorption reduces by 19.6%. The speed of coal seams methane seepage is significantly increased by 35.3% and arrives at 0.383 3 ml/s.  相似文献   
7.
分离纯化柿子多糖的树脂筛选及纯化工艺的响应面优化   总被引:1,自引:1,他引:1  
为解决优化大孔树脂纯化柿子多糖工艺的问题,在对8种大孔树脂进行筛选的基础上,采用三因素三水平响应面法,以动态吸附率和解吸附率为指标进行试验,最终所得优化结果为:树脂AB-8具有较好的分离纯化柿子多糖的性能。优化后的动态吸附试验条件为,样液浓度4.34 mg/mL,上样速率1.89 BV/h,样液体积3.41 BV(柱体积);解吸附试验条件为:洗脱剂中乙醇浓度55.41%,洗脱速率3.50 BV/h,洗脱剂用量3.54 BV。此条件下,动态吸附率和解吸附率的预测值分别达到89.87%和96.59%,验证值误差均在5%左右。  相似文献   
8.
9.
我国某些土壤中硫素的氧化   总被引:3,自引:0,他引:3  
The status and activities of boron in soils were studied by the approach of electro-ultrafiltration(EUF).The samples of soils,including brown-red soil and calcareous alluvial soil,were collected from Hubei Province of China.The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment.Filtration and extraction were conducted in accordance with routine process,but fractions in anode and cathode were all collected.Analyses of B,K^ ,Mg^2 ,Ca^2 ,Cl^- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion -pair with cations partly in acidic soil,and borate was the primary form existing in the calcareous soil.In studying desorption kinetics with EUF,the boron content of Fractions 2-6 was accumulated.and the accumlative quantities were fit to time factors in three kinetic equations:the zero-order,first-order,and parabolic diffusion equations,Fit degree of the parabolic diffusion equation was the best,followed by the zero-order equation,and the first-order equation was the worst。  相似文献   
10.
This study was carried out to assess, for the first time, the effect of water treatment residual nanoparticles (nWTR) on mobility, fractionation and speciation of Hg in two arid zone soils. Nanoscale water treatment residual application markedly reduced cumulative Hg released from soils studied, with the effect increasing as the nWTR application rate increases. The power function kinetic model well described the desorption process from soils and soils with nWTR. Meanwhile, application of nWTR greatly increased the association of Hg with the residual fraction and increased the most stable Hg species (Hg (OH)2 amor), which in turn enhanced Hg immobilization in the studied soils. Fourier transmission infrared spectroscopy analysis indicated the involvement of nWTR in the retention of Hg (II) and revealed that sorption occurred mainly through OH groups, which suggest inner‐sphere adsorption of Hg ions to surface functional groups on nWTR. These results demonstrated the feasibility of using a green and low‐cost nWTR as best management practice to retain and immobilize excess Hg in contaminated soils. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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