Adsorption behavior of phosphate on Lanthanum（III） doped mesoporous silicates material

A series of lanthanum doped meosoporous MCM-41 (LaxM41, x is Si/La molar ratio) was prepared by sol-gel method. The surface structure of the materials was investigated with X-ray diffraction and N2 adsorption/desorption technique. The content of La in the materials was determined by ICP. It was found that the La content of La25M41, La50M41 and La100M41 was 7.53%, 3.89% and 2.32%, respectively. The phosphate adsorption capacities increased with increasing amount of La incorporation. With 0.40 g La25M41 99.7% phosphate could be removed. The effects of Si/La molar ratio, LaxM41 dose, pH, initial concentration of phosphate solution, co-ions on phosphate adsorption were also evaluated. The phosphate adsorption kinetics of LaxM41 could be well-described by the pseudo second-order model, and Langmuir isotherm fit equilibrium data much better than the Freundlich isotherm.     

Measurement of in-vehicle volatile organic compounds under static conditions

The types and quantities of volatile organic compounds (VOCs) inside vehicles have been determined in one new vehicle and two old vehicles under static conditions using the Thermodesorber-Gas Chromatograph/Mass Spectrometer (TD-GC/MS).Air sampling and analysis was conducted under the requirement of USEPA Method TO-17.A room-size,environment test chamber was utilized to provide stable and accurate control of the required environmental conditions (temperature,humidity,horizontal and vertical airflow velocity,and background VOCs concentration).Static vehicle testing demonstrated that although the amount of total volatile organic compounds (TVOC) detected within each vehicle was relatively distinct (4940μg/m~3 in the new vehicle A,1240μg/m~3 in used vehicle B,and 132μg/m~3 in used vehicle C),toluene,xylene,some aromatic compounds,and various C_7-C_(12) alkanes were among the predominant VOC species in all three vehicles tested.In addition,tetramethyl succinonitrile,possibly derived from foam cushions was detected in vehicle B.The types and quantities of VOCs varied considerably according to various kinds of factors,such as,vehicle age, vehicle model,temperature,air exchange rate,and environment airflow velocity.For example,if the airflow velocity increases from 0.1 m/s to 0.7 m/s,the vehicle's air exchange rate increases from 0.15 h~(-1) to 0.67 h~(-1),and in-vehicle TVOC concentration decreases from 1780 to 1201μg/m~3.     

前置反硝化-硝化生物滤池工艺物料平衡分析

针对前置反硝化(DN)-硝化(CN)生物滤池工艺进行碳(COD)、氮、磷平衡分析,建立了该工艺的物料衡算方法。分析结果表明:DN池中反硝化的碳源主要是甲醇,占DN池反硝化碳源量的70.8%。入流总氮中有13.7%通过CN池的同步硝化反硝化过程去除;入流COD中有46.4%通过CN池中异养菌的好氧氧化去除;入流磷总量约有75.9%被微生物利用。CN池中硝化过程耗氧量为29.0%,占供氧量的比例最大。     

不同母质发育土壤团聚体分布对外源输入秸秆的响应及其与有机碳矿化的关系

土壤团聚体的形成和稳定对于有机碳的转化和积累具有重要意义,然而不同母质发育土壤团聚体对有机碳的物理保护作用及其与有机碳矿化之间的关系仍不清楚.本文以石灰岩、第四纪红土、花岗岩、玄武岩和红砂岩母质发育的典型土壤为对象,研究添加玉米秸秆7 d和184 d时土壤团聚体和各组分有机碳的变化规律,分析不同母质土壤有机碳矿化的主要影响因素.结果表明,不添加秸秆时,所有母质土壤以1.0～0.5、 0.5～0.25和0.25 mm粒级团聚体为主,添加玉米秸秆有效促进了2 mm和2～1 mm粒级团聚体的形成.石灰岩、第四纪红土和玄武岩土壤形成水稳性大团聚体并且保持其稳定的能力高于花岗岩和红砂岩土壤.添加玉米秸秆培养184 d,石灰岩、第四纪红土和玄武岩土壤有机碳的累积矿化率显著(P0.05)低于花岗岩和红砂岩土壤.相关性分析表明,土壤有机碳的累积矿化率与游离态有机碳的比例极显著(P0.01)正相关,而与0.25 mm团聚体有机碳的比例极显著(P0.01)负相关.利用~(13)C核磁共振(~(13)C-NMR)技术对土壤有机碳进行结构表征,结果显示团聚体内轻组有机碳的分解程度低于游离态轻组有机碳,且石灰岩、第四纪红土和玄武岩土壤这两个组分有机碳的分解程度都低于其他母质土壤,直接证实了团聚体对于有机碳的物理保护作用.成土母质通过控制土壤胶体的数量和性质致使团聚体及有机碳分布对输入外源有机物质的响应存在较大差异,进而影响有机碳的矿化.石灰岩、第四纪红土和玄武岩土壤中团聚体稳定性高且对有机碳的保护容量大,有利于有机碳的积累和稳定.     

Preparation and characterization of a lipoid adsorption material and its atrazine removal performance

A novel adsorbent named lipoid adsorption material (LAM), with a hydrophobic nucleolus (triolein) and a hydrophilic membrane structure (polyamide), was synthesized to remove hydrophobic organic chemicals (HOCs) from solution. Triolein, a type of lipoid, was entrapped by the polyamide membrane through an interfacial polymerization reaction. The method of preparation and the structure of the LAM were investigated and subsequent experiments were conducted to determine the characteristics of atrazine (a type of HOC) removal from wastewater using LAM as the adsorbent. The results showed that LAM had a regular structure compared with the prepolymer, where compact particles were linked with each other and openings were present in the structure of the LAM in which the fat drops formed from triolein were entrapped. In contrast to the atrazine adsorption behavior of powdered activated carbon (PAC), LAM showed a persistent adsorption capacity for atrazine when initial concentrations of 0.57, 1.12, 8.31 and 19.01 mg/L were present, and the equilibrium time was 12 hr. Using an 8 mg/L initial concentration of atrazine as an indicator of HOCs in aqueous solution, experiments on the adsorption capacity of the LAM showed 69.3% removal within 6–12 hr contact time, which was close to the 75.5% removal of atrazine by PAC. Results indicated that LAM has two atrazine removal mechanisms, namely the bioaccumulation of atrazine by the nucleous material and physical adsorption to the LAM membrane. Bioaccumulation was the main removal mechanism.     

不同配比复合材料对农田镉污染土壤的修复效果

通过盆栽试验研究了3种不同配比复合材料SC(石灰+有机复混肥以2∶3配施)、LS(硫酸亚铁+石灰以1∶1配施)和LB(硫酸亚铁+生物炭以1∶1、1∶2、1∶3、1∶4和1∶5配施)在不同添加量下对土壤Cd的生物有效性、小麦各部位Cd累积分布及产量的影响.结果表明:①添加3种复合材料均显著降低了土壤有效态Cd含量,降幅分别为50. 2%～81. 8%(SC)、29. 4%～48. 1%(LS)和18. 7%～42. 2%(LB);添加3种复合材料显著提高了土壤pH值,增幅分别为1. 37～2. 28(SC)、0. 41～0. 86(LS)和0. 14～0. 17(LB)个单位.②Cd在小麦各部位的累积分布规律为根叶茎颖壳籽粒,小麦各部位对Cd的转运能力表现为根颖壳茎叶.③与对照相比,添加0. 67%的SC显著增产56. 4%,添加0. 67%的LS显著增产51. 2%;添加复合材料LB可显著提高小麦产量,增幅为39. 6%～51. 2%.④相关分析表明,土壤pH值与土壤有效态Cd、小麦各部位Cd含量呈显著负相关关系;土壤有效态Cd含量与小麦各部位Cd含量呈显著正相关,相关系数分别为0. 711(籽粒)、0. 817(颖壳)、0. 593(茎)、0. 630(叶)和0. 622(根);同时,小麦各部位Cd含量之间也存在显著或极显著正相关关系.⑤综合比较,添加0. 93%的SC使土壤pH增幅最大为2. 28个单位;土壤有效态Cd含量降幅最大为81. 8%.因此,添加0. 93%的SC最适用于农田Cd污染土壤的修复治理.     

赛都金矿成矿地球化学环境

赛都糜棱岩型金矿是阿尔泰地区重要的金矿类型。本文较系统地论述了该类型金矿的成矿物质来源，成矿流体的地球化学，成矿作用过程中的稳定同位素地球化学等成矿地球化学环境，并推测了其成矿时代。     

秦山三期核电工程气象相关实验研究及其在选址评价中的应用

１９９５年９、１０月间在秦山三期核电厂址进行了气象相关实验，即在秦山一、二、三期进行低空风、温与地面风的同步观测，在三期厂址进行平衡球测扩散参数，风洞模拟实验测量建筑群与对流与扩散参数的影响。并探讨如何应用气象相关实验结果由已建厂址的气象数据来估算新建厂址年均扩散因子的方法与公式。     

二胺基改性有序多孔SBA-15对溶液中Cd2+离子的吸附研究

具有高度有序孔道结构的SBA-15是一种广受关注的新型吸附材料,为增加其对溶液重金属离子的吸附性能,选用水热-后期接枝的合成方法,制备出二胺基改性多孔二氧化硅2N-SBA-15,并用透射电镜、X射线衍射、氮气吸附-解吸和红外光谱等手段对其结构进行了表征.并以其为吸附剂,通过批实验的方法讨论了吸附时间、体系初始pH值、吸附剂用量和温度等因素对水溶液中Cd2+吸附的影响,同时结合Zeta电势和XPS分析对其吸附机制进行了探讨.结果表明,合成的SBA-15具有规则多孔特征,SBA-15对Cd2+的吸附受体系pH控制;未改性的SBA-15对Cd2+的吸附量较小,胺基改性可以显著增强SBA-15对Cd2+的吸附能力.在100 mL 25 mg.L-1的Cd2+溶液中,2N-SBA-15的用量在7.5～20 mg之间均能对Cd2+的吸附能力约达95%左右.2N-SBA-15对溶液中Cd2+的吸附很迅速,并在30 min内达到吸附平衡;随着体系温度从25℃增加到35℃,2N-SBA-15对溶液中Cd2+的吸附率从94.73%增加到98.22%.吸附等温线可用Langmuir模型描述,在298 K时Cd2+的最大吸附量为0.9 mmol.g-1,0.1 mol.L-1HCl溶液对Cd2+的洗脱率接近93%.结合pH、温度、Zeta电势和XPS分析结果,可以推测出2N-SBA-15对Cd2+的吸附机制是包含物理吸附、离子交换和络合反应等的复杂吸附过程.2N-SBA-15是一种对水体Cd2+具有较好吸附能力的吸附材料.     

高分子材料用于我国大气环境严酷度比较的研究

在大气环境腐蚀性分类分级的研究中,利用高分子材料来评价大气环境严酷度的研究并不多见。因此,尝试了利用高分子材料的老化模型来定量评价大气环境的严酷度。结果表明,广州、琼海、拉萨3个自然暴晒试验点中,琼海和拉萨的严酷度接近,约为广州的1．2倍左右。