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431.
使用离子色谱法,论述了测定降水中F-、CL-、NO3-、SO42-测量不确定度的方法,同时指出测量中可能导致不确定度的来源。 相似文献
432.
选定淮南大通垃圾填埋场土壤与垃圾渗滤液,自行设计填埋场土壤与渗滤液间的常规离子吸附作用实验。实验研究结果表明:土壤对Ca2+、Mg2+、SO42-的吸附率表现为负吸附,吸附率绝对值较大,并随渗滤液的稀释倍数(n)的增大而减小,呈对数关系;土壤对Cl-的吸附率表现为正吸附,吸附率较小,并随渗滤液的稀释倍数(n)的增大而增大不明显,呈直线关系;深部土壤对不同稀释倍数的渗滤液中的Ca2+、Mg2+、SO24-的吸附能力大于浅部土壤,但深部土壤对不同稀释倍数渗滤液中的Cl-的吸附能力与浅部土壤对不同稀释倍数渗滤液中的Cl-的吸附能力几乎一致,都表现为正吸附。 相似文献
433.
选用美国戴安公司ICS-1000型离子色谱;IonPacCG12A分离柱;CSRS3004mm抑制器;对环境水样中氨氮指标进行检验并与纳氏试剂光度法做比较以分析其可行性。经实测分析结果看离子色谱法的线性相关性能够满足分析要求,环境标准平行双样的相对标准偏差(RSD)均在质控分析要求范围之内;各个样品加标回收率均在要求控制范围之内;与钠氏试剂光度法测定结果比较,两种方法测定结果没有显著性差异,表明该方法精密度高、准确性好。本方法线性范围广,测定结果准确,操作简便,尤其更适用于大批样品多项目的测定。 相似文献
434.
钙和钙离子通道阻断剂对丛枝菌根真菌吸收镉的影响 总被引:1,自引:0,他引:1
本试验以三叶草(Trifolium repense L.)为宿主植物,Glomusintra radices为供试菌种,通过分室系统将外生菌丝与植物根系分隔开,并对菌丝室加以不同含量水平的Ca2+、Cd2+和Ca2+通道阻断剂(Verapamil、LaCl3)进行处理,研究在菌丝吸收过程中Cd2+与Ca2+以及Ca2+通道之间的关系.试验结果表明,高Cd2+和LaCl3处理可促进菌丝发育;高Cd2+和Verapamil、LaCl3处理不同程度地降低了菌丝对Ca2+的吸收;高Ca2+和LaCl3处理则可提高菌丝对Cd2+的吸收.根据本试验结果可以认为,Cd2+在菌丝上的跨膜转运不是通过Ca2+通道完成,而且高Ca2+水平有利于Cd2+被菌丝吸收. 相似文献
435.
436.
The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L, respectively, and the other three acids are ranging from 0.48 to 0.82μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively. 相似文献
437.
438.
A mesocosm experiment was conducted to investigate whether plant coexistence affects cadmium (Cd) uptake by plant in contaminated soil.Tobacco (Nicotiana tabacum L.var.K326) and Japanese clover (Kummerowia striata (Thunb.) Schindl.) were used.Cadmium was applied as 3CdSO 4 ·8H 2 O in solution at three levels (0,1,and 3 mg/kg soil) to simulate an unpolluted soil and soils that were slightly and moderately polluted with Cd.Tobacco (crop),Japanese clover (non-crop),and their combination were grown under each C... 相似文献
439.
Zequn Liu Xiaomin Yan Mary Drikas Danong Zhou Dongsheng Wang Min Yang Jiuhui Qu 《环境科学学报(英文版)》2011,23(3):381-387
The contamination of surface and ground water by bentazone has attracted increasing global concern in recent years. We conducted
a detailed investigation using MIEX resin to eliminate bentazone from waters. Batch experiments were carried out to evaluate the e ect
of process parameters, such as retention time, resin amount, and initial pesticide concentration, on removal e ciency of bentazone.
Results showed the sorption process was fast and bentazone could be e ciently removed in 30 minutes. The kinetic process of
bentazone sorption on MIEX resin was well described by pseudo second-order model and intraparticle di usion was the rate controlling
step. The MIEX resin possessed the highest sorption capacity of 0.2656 mmol/mL for bentazone according to Langmuir fitting.
Bentazone is a hydrophobic ionizable organic compound, and both ionic charge and hydrophobic aromatic structure governed the
sorption characteristics on MIEX resin. The di erent removal e ciencies of ionic and non-ionic pesticides, combined with the charge
balance equations of bentazone, SO4
2??, NO3?? and Cl??, indicated that removal of bentazone using MIEX resin occurred primarily via
ion exchange. 相似文献
440.
Material conversion from paper sludge ash (PSA) in NaOH solution was attempted to synthesize the adsorbent for removal of
inorganic pollutants, such as Pb2+, NH4
+ and PO4
3?? from aqueous solution. PSA of 0.5 g was added into 10 mL of 3 mol/L NaOH
solution, and then heated at 80, 120, and 160°C for 6–48 hr to obtain the product. PSA mainly composed of two crystalline phases,
gehlenite (Ca2Al2SiO7) and anorthite (CaAl2Si2O8), and amorphous phase. Hydroxysodalite (Na6Al6Si6O24 8H2O) was formed at
80°C, and anorthite dissolved, whereas gehlenite remained una ected. Katoite (Ca3Al2SiO4(OH)8) was formed over 120°C, and
hydroxycancrinite (Na8(OH)2Al6Si6O24 2H2O) was formed at 160°C, due to the dissolution of both gehlenite and anorthite. Specific
surface areas of the products were almost same and were higher than that of raw ash. Cation exchange capacities (CECs) of the products
were also higher than that of raw ash, and CEC obtained at lower temperature was higher. Removal abilities of products for Pb2+, NH4
+,
and PO4
3?? were higher than that of raw ash.With increasing reaction temperature, the removal e ciencies of Pb2+ and NH4
+ decreased
due to the decrease of CEC of the product, while removal e ciency for PO4
3?? was almost same. The concentrations of Si and Al in the
solution and the crystalline phases in the solid during the reaction explain the formation of the product phases at each temperature. 相似文献