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741.
随着大量汽车进入报废期,如何对报废汽车进行资源化再利用成为人们面临的重要课题.报废汽车上的非金属材料,由于种类多、组成复杂,资源化再利用的难度较大,大多被废弃,会造成资源浪费、环境污染等一系列问题.塑料、橡胶、玻璃是汽车中主要的非金属材料,这些物质的资源化利用,对改善环境、节约资源,具有极大的社会经济效益.着重对报废汽... 相似文献
742.
试验研究一种新型的复合材料对废水脱氮的能力,该种材料主要是由分子筛和几种有机和无机材料通过一定的条件合成,以达到节约成本提高利用率的作用。采用溶胶一凝胶法制备分子筛/SiO2复合材料,采用纳试试剂光度法为检测方法,考察了分子筛/SiO2在静态条件下对水中氨氮的吸附性能。通过几组对比试验,如分子筛单体脱氮的实验,分子筛/SiO2复合材料和二氧化硅单体脱氮的实验,实验中测定了时间、pH值、投加量等因素对脱氮除磷的影响,得出最佳吸附条件。结果表明,pH在4~7时对氨氮有较好的吸附性能,吸附符合Langmuir吸附模型,产生了复合效应。 相似文献
743.
Adsorption behavior of phosphate on Lanthanum(III) doped mesoporous silicates material 总被引:1,自引:0,他引:1
Jianda Zhang Zhemin Shen Wenpo Shan Ziyan Chen Zhijian Mei Yangming Lei Wenhua Wang 《环境科学学报(英文版)》2010,22(4):507-511
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. 相似文献
744.
YOU Ke-wei GE Yun-shan HU Bin NING Zhan-wu ZHAO Shou-tang ZHANG Yan-ni XIE Peng 《环境科学学报(英文版)》2007,19(10):1208-1213
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. 相似文献
745.
746.
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. 相似文献
747.
不同配比复合材料对农田镉污染土壤的修复效果 总被引:2,自引:6,他引:2
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. 相似文献
748.
赛都金矿成矿地球化学环境 总被引:1,自引:0,他引:1
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。 相似文献
749.
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. 相似文献
750.