两性修饰红薯渣对紫色土吸附Cu2+的影响

采用十二烷基二甲基甜菜碱对红薯渣（R）做两性修饰，修饰比例分别为0、100%和200%，将得到的3种两性修饰红薯渣（R、100BS-R和200BS-R）以1%质量分数加入紫色土（PS）中，制成PS（对照）、PSR、PS100BS-R和PS200BS-R 4种混合土样。用批量处理法探究各供试土样对Cu2+的吸附等温特征，并考察温度、pH值和离子浓度对Cu2+吸附的影响。结果表明：各混合土样对Cu2+的吸附等温线均符合Langmuir模型，最大吸附量为99.46 mmol/kg~136.53 mmol/kg，Cu2+吸附量呈现PS200BS-R>PS100BS-R>PSR>PS的趋势。温度和pH值升高均有利于Cu2+被吸附，当离子浓度为01 mol/L时吸附效果最佳。     

入侵植物凋落物浸提液对紫色土吸附金霉素的影响

用3种入侵植物的地上(O)和地下(U)凋落物浸提液(Le)对紫色土进行修饰，采用批处理法研究各Le修饰土样对金霉素(CTC)的等温吸附特征，分析pH值、离子强度和温度对CTC吸附的影响。结果表明：各Le修饰紫色土对CTC的吸附等温线最适用于Freundlich模型描述；当pH值为2，离子强度为0.1 mol/L和试验温度40 ℃时，一年蓬(Conyzaannumus)Le修饰紫色土对CTC的吸附效果最佳，最大吸附量为1.68 mmol/kg~7.94 mmol/kg；当Le修饰比例为100%时，OLe和ULe修饰紫色土对CTC的吸附量均达到最大，且OLe修饰紫色土对CTC的吸附效果相比ULe更佳。     

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Cu^2+的等温吸附和热力学特征。结果表明:混合土样对Cu^2+的最大吸附量为58.36 mmol/kg~366.85 mmol/kg,添加等量两性磁化炭时各混合土样对Cu^2+吸附量表现为JL>NB>CX>HC的趋势,且添加比越高吸附能力越强。各混合土样对Cu^2+的吸附为自发、吸热和熵增的反应过程,对Cu^2+的吸附量与温度和pH值均呈正相关关系。当离子强度为0.1 mol/L时,各混合土样(除HC外)对Cu^2+的吸附量最大。     

3种材料添加对紫色土吸附四环素的影响

采用批量处理法探究活性硅酸钙（S）、膨润土（B）、硅藻土（D）的添加对紫色土（P）吸附四环素（TC）的影响。结果表明：各供试土样对TC的吸附符合Langmuir模型，最大吸附量qm在564 mmol/kg~5413 mmol/kg之间，且当材料添加质量分数为5%时土样对TC吸附效果最佳；相同材料添加比例下，土样对TC的吸附量均呈现出P-B＞P-S＞P-D＞P；热力学参数表明，TC吸附是一个自发、吸热和熵增的反应，当pH值为5、离子浓度为01 mol/L时吸附量达到最大。     

均质化莲子草根系分泌物对黏土吸附四环素的影响

在不同比例空心莲子草粗根(TR)和细根(FR)分泌物均质化条件下,研究膨润土和高岭土对四环素(TC)的等温吸附特征,并分析pH值、温度和离子浓度对TC吸附的影响.结果表明,分泌物均质化后黏土对TC的吸附符合Henry模型,FR均质化对TC吸附的促进作用比TR均质化更强,高岭土对TC吸附的增长幅度比膨润土更大;在pH值2...     

改良河岸带土壤对Cu2+吸附的环境影响机制

通过添加质量比1%的生物炭（空心莲子草制备）、生物炭负载两性黏土两种材料改良川东北地区嘉陵江、渠江和涪江沿岸土壤,探索环境因素对改良土壤吸附Cu2+的影响。结果表明：当各改良河岸土样pH值为5、离子强度为0.05 mol/L、温度40℃时对Cu2+的吸附量达到最高,最大吸附量（q m）为85.38 mmol/kg～257.54 mmol/kg;Cu2+的吸附符合Langmuir等温吸附模型,是一个自发、吸热和熵增的过程;土壤改良效果表现为涪江>渠江>嘉陵江;土样CEC和比表面积是影响Cu2+吸附能力的主要因素。     

负载咪唑型离子液体硅胶吸附材料制备及应用研究

制备了3种取代咪唑键合的硅胶负载型离子液体(甲基咪唑-SIL、氨丙基咪唑-SIL及十二烷基咪唑-SIL),比较了其对水中双酚A(BPA)的吸附能力。在该研究的实验条件下,BPA在十二烷基咪唑-SIL与水溶液之间的分配系数K_d值高达(2.58±0.02)×10³ L/kg,氨丙基咪唑-SIL、甲基咪唑-SIL的K_d值也分别达到(2.26±0.28)×10、(2.71±0.16)×10 L/kg。采用甲醇为洗脱液,可以对十二烷基咪唑-SIL相中的BPA进行有效回收,2次洗脱的合并回收率为106.7%±4.8%。以十二烷基咪唑-SIL作为被动采样装置的接收相,对污水处理厂出水中BPA进行了被动采样监测应用的微宇宙实验研究。结果表明,在实验周期内,十二烷基咪唑-SIL被动采样器对水体中BPA的被动采集呈线性,其采集速率为0.33 L/d,与以HLB为接收相的商品化被动采样器接近,并且同HLB固相萃取填料相比,离子液体接收相对BPA的采集更具选择性,基质效应较小,可作为被动采样监测装置的理想接收相材料。     

粉煤灰吸附净化含铅废水实验研究

以粉煤灰为吸附材料,模拟含铅离子废水,探讨吸附时间、p H值、温度、投灰量、离子浓度5个因素对粉煤灰吸附重金属效率的影响;并设计五因素四水平的正交实验,经过均值分析和方差分析数据得出最佳水平组,结果表明:当离子质量浓度60 mg/L、吸附时间90 min、投灰量5.0 g、p H值6.0、温度20℃时吸附效果最好。单因素分析得出,当吸附时间90 min、p H值6.0、温度50℃、投灰量5.0 g、离子质量浓度30 mg/L时吸附效果相对较好,单因素方差分析也证明以上5种因子对粉煤灰吸附铅离子具有显著性差异。     

炭负载膨润土对河岸土铜迁移的影响模拟

采用质量分数为1%的生物炭(C)和生物炭负载膨润土( CB )改良嘉陵江、渠江和涪江(川渝段)8个不同河岸土样,并以土柱实验模拟铜在各改良土样中的迁移和形态变化特征(原土样作为对照)。结果表明：C和CB 的添加均有利于沿岸土对铜的吸附,吸附能力和穿透时间表现为CB 改良土样>C改良土样>原土样;各改良沿岸土样对铜吸附能力表现为上游土样强于下游。供试土柱中铜累积量为16.43 g/kg~56.54 g/kg,且表现为CB改良土样>C改良土样>原土样的趋势。铜结合形态以碳酸盐结合态比例最大,铁锰氧化态次之,可交换态和有机态较少。     

磁性凹凸棒土的制备及其对水中铅离子的吸附

利用化学共沉淀法制备了磁性凹土复合吸附剂(ATP/Fe_3O_4),通过静态吸附实验研究了该材料对水中Pb~(2+)的吸附性能。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、红外光谱仪(FTIR)和振动样品磁强计(VSM)对复合吸附剂进行表征,并考察了吸附剂投加量、溶液初始pH值及吸附时间等因素对Pb~(2+)吸附效果的影响。结果表明,Fe_3O_4颗粒负载在凹土表面,复合吸附剂的比饱和磁化强度为29.22 emu/g,可有效实现固液分离的目标。Pb~(2+)吸附实验表明,ATP/Fe_3O_4对Pb~(2+)具有良好的吸附效果,当Pb~(2+)初始浓度为50mg/L、溶液pH为5.0、吸附剂用量为3.0 g/L时,去除率可达87.35%。ATP/Fe_3O_4对Pb~(2+)的吸附行为符合准二级动力学方程。     

Preparation of 2-mercaptobenzothiazole-derivatized mesoporous silica and removal of Hg(ii) from aqueous solution

Mesoporous silicas (SBA-15 and MCM-41) have been functionalized by two different methods. Using the heterogeneous route the silylating agent, 3-chloropropyltriethoxysilane, was initially immobilized onto the mesoporous silica surface to give the chlorinated mesoporous silica Cl-SBA-15 or Cl-MCM-41. In a second reaction a multifunctionalized N,S donor compound (2-mercaptobenzothiazol) was incorporated to obtain the functionalized silicas denoted as MBT-SBA-15-Het and MBT-MCM-41-Het. Using the homogeneous route, the functionalization was achieved via the one step reaction of the mesoporous silica with an organic ligand containing the chelating functions, to give the modified mesoporous silicas denoted as MBT-SBA-15-Hom or MBT-MCM-41-Hom. The functionalized mesoporous silicas were employed as adsorbents for the regeneration of aqueous solutions at pH 6 contaminated with Hg(ii) at room temperature. Results obtained indicate that mercury adsorption was higher in the mesoporus silicas prepared by the homogeneous method, and the maximum adsorption value (0.24 +/- 0.02 mmol Hg(ii) g(-1)) was obtained for MBT-SBA-15-Hom. The chemically stability in acid medium of the functionalized silicas, possibility its regeneration washing with concentrate HCl, resulting in the reuse of the adsorbent material for several cycles.     

Distribution and sources of mercury in soils from former industrialized urban areas of Beijing, China

Fifty-seven typical surface soils and 108 deeper soils were collected from five former industrial sites in Beijing and concentrations of total Hg (SigmaHg) as well as pH, total carbon (TC), total nitrogen (TN), total sulfur, and dissolved organic carbon concentrations determined. The mean concentration of SigmaHg in surface soils was significantly greater than background concentrations in the vicinity of Beijing. Forty-eight percent of the samples exceeded the "critical" concentration of 1.0 mg Hg/kg, dry weight in soils, which has been established by the Chinese government. At depths of 0-80 cm in the soil, profile concentrations of SigmaHg also exceeded the background value. There were significant correlations between concentrations of SigmaHg, TC, and TN in the industrial soils. The greater concentration of SigmaHg in most soils could have been due in part to combustion of coal and leakage from industrial processes.     

硝酸镧改性聚丙烯酸对水中氟离子的吸附试验探讨

以丙烯酸为原料,乙二醇二甲基丙烯酸酯为交联剂制得聚丙烯酸树脂(PAA),用于制备表面粗糙、介孔丰富的镧(Ⅲ)改性聚丙烯酸复合树脂(La-PAA)。试验表明,当500 mg/L氟离子溶液pH值为5、吸附时间为300 min时,La-PAA对氟离子的去除率在90%以上。Langmuir方程能较好地拟合氟离子在La-PAA上的吸附等温线,最大吸附量为159.24 mg/g,吸附动力学过程符合准二级动力学方程。     

土壤中铁氧化物对铅吸附-解吸的影响

选择上海地区广泛分布的水稻土,通过静态吸附平衡试验,比较土壤去除非晶质氧化铁和去除游离氧化铁后对Pb2+的吸附-解吸行为,采用数学模型拟合,探讨3种土壤的最佳拟合方程、最大吸附的理论值和亲和能力,进而研究非晶质氧化铁和游离氧化铁对Pb2+吸附-解吸的影响。结果表明,去除氧化铁后吸附能力和亲和能力均减弱,原土的最大吸附量为29.21 g/kg,非晶质氧化铁的贡献值为3.52 g/kg,游离氧化铁的贡献值为8.32 g/kg。     

Adsorption characteristics of a phenoxy acetic acid herbicide on activated carbon

The adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) by two powdered coal activated carbons was studied in aqueous solution. The modelling of the adsorption equilibrium showed that the adsorption of 2,4-D fitted a Langmuir isotherm. Adsorption was influenced by the activated carbon type, adsorbent concentration and solution characteristics. The adsorption was found to decrease with an increase in pH over the range 1.5-9. Maximum adsorption occurred at pH approximately 2.5, which corresponds to the 2,4-D pKa value. The amount of 2,4-D adsorbed was also found to depend on the NaCl concentration.     

有机改性对凹凸棒黏土吸附四环素类抗生素的影响

采用OECD guideline 106批量平衡吸附法研究四环素类抗生素在十六烷基三甲基溴化铵改性凹凸棒黏土(CTAB-ATP)上的吸附作用,并考察了溶液pH、吸附剂的投加量、离子强度对吸附过程的影响。结果表明,CTAB-ATP对四环素、土霉素、金霉素3种四环素类抗生素的吸附容量随着溶液pH的增加而增加;随着吸附剂投加量的增大而减小;随着离子强度的增加呈现缓慢减小的趋势。CTAB-ATP对四环素、土霉素、金霉素的吸附过程均符合准二级动力学模型(r0.998),吸附等温线较好地符合Langmuir等温式。有机改性凹凸棒黏土的疏水性增强,提高了对有机污染物的吸附能力,其沉降性能良好,这使其作为一种吸附剂用于实际抗生素废水的处理成为可能。     

不同酸碱度土壤阳离子交换量的测定研究

为了能够快速准确测定不同酸碱度土壤中的阳离子交换量,弥补现行标准方法的不足,对三氯化六氨合钴浸提-分光光度法中的土壤称样量、pH、浸提时间、浸提温度和离心时间等条件进行了优化。优化后的方法检出限为0.43 cmol^+/kg,测定下限为1.72 cmol^+/kg,方法实验室内精密度为0.2%~1.8%,适用于大批量土壤样品中阳离子交换量的测定。     

Adsorption and leaching of novel fungicide pyraoxystrobin on soils by <Superscript>14</Superscript>C tracing method

Pyraoxystrobin, (E)-2-(2-((3-(4-chlorophenyl)-1-methyl-1H-pyrazole-5-yloxy)methyl)phenyl)-3-methoxyacrylate, is a newly developed strobilurin fungicide with high antifungal efficiency. It has high potential to enter soil environments that might subsequently impact surface and groundwater. Therefore, ¹⁴C-labeled pyraoxystrobin was used as a tracer to study the adsorption/desorption and migration behavior of this compound under laboratory conditions in three typical agricultural soils. The adsorption isotherms conformed with the Freundlich equation. Single factor analysis showed that organic matter content was the most important factor influencing the adsorption. The highest adsorption level was measured in soil with low pH and high organic carbon content. Once adsorbed, only 2.54 to 6.41% of the adsorbed compound could be desorbed. In addition, the mobility results from thin-layer chromatography and column leaching studies showed that it might be safe to use pyraoxystrobin as a fungicide without causing groundwater pollution from both runoff and leaching, which might be attributed to its strong hydrophobicity. High organic matter content enhanced pyraoxystrobin adsorption and desorption because of the rule of similarity (lipid solubility). In the column leaching study, 95.02% (minimum value) of the applied ¹⁴C remained within the upper 4.0-cm layer after 60 days.     

Occurrence of Giardia and Cryptosporidium in Italian water supplies

A total of 21 samples: raw water (RW) samples; water samples after coagulation with aluminium sulfate (clarified water: CW); and water after chlorination (treated water: TW) from a water purification plant that treats river surface water from the neighbourhood of Foggia (Italy), were analysed for the presence of Giardia cysts and Cryptosporidium oocysts. Bacteriological indicator of faecal contamination (total and faecal coliforms, faecal streptococci,), total bacterial count at 22 and 36 degrees C and physicochemical parameters (turbidity, temperature, pH) were evaluated. Cryptosporidium oocysts were not found in any samples examined, while Giardia cysts were found only in RW samples, with the maximal concentration of 8 cysts/100 l. A positive correlation was found between the Giardia densities and quality parameters such as TC, FC and TBC at 22 degrees C. Giardia levels in raw water samples correlated (p < 0.05) with TC, FC and with temperature. No other water quality parameters was consistently correlated with cysts level.