Highly Efficient and Selective Removal of Pb（II） ions by Sulfur-Containing Calcium Phosphate Nanoparticles

A facile one-step co-precipitation method was demonstrated to fabricate amorphous sulfurcontaining calcium phosphate （SCP） nanoparticles, in which the sulfur group was in-situ introduced into calcium phosphate. The resulting SCP exhibited a noticeable enhanced performance for Pb（II） removal in comparison with hydroxyapatite （HAP）, being capable of easily reducing 20 ppm of Pb（II） to below the acceptable standard for drinking water within less than 10 min. Remarkably, the saturated removal capacities of Pb（II） on SCP were as high as 1720.57 mg/g calculated by the Langmuir isotherm model, exceeding largely that of the previously reported absorbents. Significantly, SCP displayed highly selective removal ability toward Pb（II） ions in the presence of the competing metal ions （Ni（II）, Co（II）, Zn（II）, and Cd（II））. Further investigations indicated that such ultra-high removal efficiency and preferable affinity of Pb（II） ions on SCP may be reasonably ascribed to the formation of rodlike hydroxypyromorphite crystals on the surface of SCP via dissolution-precipitation and ion exchange reactions, accompanied by the presence of lead sulfide precipitates. High removal efficiency, fast removal kinetics and excellent selectivity toward Pb（II） made the obtained SCP material an ideal candidate for Pb（II） ions decontamination in practical application.

Immobilization of Cd and Pb in soils by polymeric hydroxyl ferric phosphate

A polymeric hydroxyl ferric phosphate(PHFP)was prepared by using a byproduct of titanium dioxide containing ferrous sulfate and phosphates under alkaline condition.The PHFP was used to immobilize lead(Pb)and cadmium(Cd)in soils.Fourier transform infrared spectra,X-ray diffraction were applied to revealing the characteristics of PHFP,and the modified Tessier sequential extraction and column leaching experiment with simulated acid rain were used to assess the effectiveness of immobilization of Cd and Pb in soils by PHFP.The results showed that PHFP was indeed a polymer with complicated OH-Fe-P structure and consisted of Fe6(OH)5(H2O)4(PO4)4(H2O)2and Fe25(PO4)14(OH)24.Moreover,the removal rates of DTPA-extractable Cd and Pb in soils reached up to33%and45%,and the water-soluble Cd and Pb decreased by56%and58%,respectively,when PHFP was added in soils at4%dosage.In addition,the immobilization of Cd and Pb contributed to transforming water soluble,exchangeable and carbonate-bonded fractions to Fe and Mn oxides-bonded,organic-bonded and residual fractions.Under leaching with simulated acid rain,Cd and Pb release amount in PHFP amended soil declined by53%and52%,respectively,as compared with non-treated soil.The result implied that PHFP had a potential application for the remediation of Cd-and Pb-contaminated soils.

A Novel Photoproduct of 1, 3-Dimethyluracil in Phosphate Buffered-saline

1, 3-Dimethyluracil （DMU） in phosphate buffered-saline （PBS, pH=8） was irradiated by a medium pressure mercury lamp （MPML） and produced a novel compound C6H9N2O6P. The composition and structure of the compound has been identified by elemental analysis, EIMS, UV, IR, ^1H and ^31P-NMR.

A Novel Photoproduct of Uracil in Phosphate-Buffered Saline

The photolysis of uracil in phosphate-buffered saline (PBS, pH 8.0) under the irradiation pf medium pressure mercury lamp (MPML) leads to the production of a novel compound C4H5N2O6P. The composition and structure of the compound has been identified by elemental analysis, EI-MS, UV, IR, H-1, C-13, P-31-NMR.

A Novel Photoproduct of Thymine in Phosphate-buffered Saline under Far UV Irradiation

The photolysis of thymine in phosphate-buffered saline (PBS, pH 8.0) under the irradiation of medium pressure mercury lamp (MPML) produces a novel compound C5H7N2O6P. The composition and structure of the compound have been identified by elemental analysis, EI-MS, UV, IR, 1H, 13C, 31P-NMR.

江苏沉积变质型磷矿带含磷岩系LA-ICP-MS锆石U-Pb年龄及其地质意义

江苏沉积变质型磷矿带位于大别—苏鲁造山带东段,锦屏岩组是带内唯一赋矿地层,因其遭受过多期强烈的变形变质作用改造,层序杂乱,勘查难度大,研究程度低,目前其形成时代尚无定论。本文应用LAICP-MS锆石U-Pb定年方法,对锦屏岩组各类岩性进行测试,获得绿色片岩类岩石原岩年龄为(956±7)Ma~(691±14)Ma,浅色片岩类岩石原岩年龄不早于(833±39)Ma,片麻岩类岩石原岩年龄不早于(772±31)Ma。结合成矿带内含磷岩系中古生物化石资料,将锦屏岩组原岩形成时代界定为新元古代,将磷矿原始沉积时间限定在震旦纪,为江苏磷矿勘查与研究提供了新的基础资料。

酸改性污泥基复合陶粒对Pb^(2+)的吸附性能研究

以污泥、磷尾矿和赤泥为原料制备陶粒,用盐酸、硝酸和柠檬酸进行改性,研究陶粒对水中Pb^(2+)的吸附效果,并通过扫描电镜(SEM)、表面基团、零电荷点(pHPZC)和傅里叶红外光谱(FTIR)分析陶粒对Pb^(2+)的吸附机理。结果表明,低浓度盐酸或硝酸改性陶粒对Pb^(2+)的去除率更好,柠檬酸改性陶粒对Pb^(2+)的去除率低于未改性陶粒。酸改性陶粒具有比表面积大、孔隙结构发达、酸性基团含量多、等电点低等特点,对Pb^(2+)的吸附同时存在物理吸附和化学吸附过程,可用作含Pb^(2+)废水的处理材料。

The surface morphologies of (Pb,Sr)TiO_3 thin film fabricated on Si-buffered Pt/Ti/SiO_2/Si substrate

(Pb,Sr)TiO3 （PST） thin film are fabricated by RF magnetron sputtering on Si-buffered Pt/Ti/SiO2/Si substrates with different buffer layer deposition time. Surface morphologies of the buffer layer indicate an improving surface roughness and larger grains with the prolongation of sputtering time. Deposition of PST thin films shows excellent surface fluctuation filling ability to improve the surface roughness of substrates. PST surface morphologies exhibit apparently different grain forms according to the preparation time durance of buffer layer.

磷基及铁基钝化剂对Pb、Cd、As复合污染土壤的修复效果及其工艺条件优化

通过DTPA和Na HCO3浸提方法评价磷基、铁基钝化剂对Pb、Cd、As复合污染土壤的钝化修复效果。结果表明,磷基钝化剂中磷酸二氢钙对有效态Pb、Cd固定效果较好,35 d后其去除率分别为61%、38%;铁基钝化剂中以硫酸高铁对有效态As固定效果最好,28d后其去除率达74.6%。工艺条件优化结果表明,随磷酸二氢钙用量增加,土壤中有效态Pb、Cd含量明显下降;随硫酸高铁用量增加,对有效态As的固定效果明显增加,当硫酸高铁添加量为土壤中As总物质的量的3.06倍时,28 d后土壤中有效态As的去除率高达74.5%。土壤水分含量在最大田间持水量的60%~80%时,对有效态Pb固定影响不大,但均略高于最大田间持水量30%~50%时的Pb去除率;土壤水分含量在最大田间持水量的60%~80%时,有效态Cd固定效果较好。当磷酸二氢钙用量为土壤中Pb、Cd总物质的量的10倍,土壤水分含量为最大田间持水量的60%时,21 d后有效态Pb、Cd去除率分别达到93%和39%。铁基与磷基钝化剂复配可以同时固定土壤中的Pb、Cd、As。当Fe3＋与PO3-4物质的量的比为7.2∶1时,7 d后土壤有效态Pb、Cd、As去除率分别为99%、41%、69%。

两种改良剂对矿区重金属污染土壤中Pb、Cd、Zn的固定效果

对重金属污染土壤分别施加膨润土和磷酸二氢钙2种改良剂,研究了这两种改良剂对土壤中Pb、Cd、Zn的固定效果。实验结果表明:(1)膨润土和磷酸二氢钙均可以降低土壤中交换态Pb、Cd的含量,对交换态Zn含量的影响不明显。(2)随着膨润土的加入量的增加,交换态Pb含量先减少,当施入量为2.0 g.kg-1时,其减少量最大,减少了0.48%,随后交换态Pb含量又呈增高趋势;而交换态Cd、Zn的含量则呈降低趋势,最大减少量分别为7.75%、0.41%。(3)随着磷酸二氢钙施加量的增加,交换态Pb、Cd含量均有明显的降低,且都呈现先减少而后逐渐上升的趋势。当加入4.0 g.kg-1时,交换态Pb减少量最大,减少量为1.31%;当加入1.0 g.kg-1时,交换态Cd含量减少最大,减少了7.99%。而加入的磷酸二氢钙使交换态Zn量增加了,因此磷酸二氢钙不利于Zn的固定。(4)磷酸二氢钙对Cd、Pb的固定效果优于膨润土。

AZ31镁合金板在PBS模拟体液中的腐蚀行为和拉伸性能

将AZ31镁合金板浸泡于磷酸盐缓冲液(PBS)模拟体液中,对其腐蚀行为和拉伸性能随浸泡时间的变化规律进行了研究。结果表明:AZ31镁合金板的弹性模量和断后伸长率与腐蚀速率的变化规律一致,均随浸泡时间的延长呈指数规律下降;浸泡28d后,弹性模量和断后伸长率分别下降了约10%和20%,抗拉强度的下降不足5%。

一株铜绿假单胞菌的溶磷特征及其对底泥中Pb的固定化

通过纯培养和模拟实验研究一株铜绿假单胞菌JM1对磷酸钙的溶解特征及其对底泥中Pb的固定化作用.结果表明:菌株JM1对磷酸钙和磷酸铝均具有溶解作用,96h内释放的溶解性正磷酸盐的质量浓度分别为240.63,92.73mg/L,培养液pH值分别下降至4.64,5.12,菌株JM1还可以利用卵磷脂进行生长但不释放磷酸根离子;菌株JM1使灭菌底泥与不灭菌底泥中固定化Pb的质量比分别增加至14.02,11.83mg/kg,即菌株JM1对底泥中的Pb具有较强的固定能力.

施加氮磷肥及Pb胁迫对小白菜Pb含量的影响研究

为了研究施肥对小白菜Pb含量的影响,采用盆栽试验种植小白菜,分析土壤中不同浓度氮肥、磷肥及Pb胁迫对小白菜地上部分和根系吸收Pb的影响。结果表明,无Pb胁迫下,在土壤中施加氮肥对小白菜株高、根长和鲜质量均有一定的促进作用,有Pb胁迫(300mg/kg,下同)下,施氮肥对小白菜株高和鲜质量有促进作用,但对根长有抑制作用。无Pb胁迫下,在土壤中施加一定量的磷肥能促进小白菜鲜质量的增长,但却对株高有一定的抑制作用;中高质量浓度施磷处理(150~225mg/kg)会抑制小白菜地上部分对Pb的吸收,低质量浓度施磷处理(≤75mg/kg)则会促进小白菜地上部分和根系对Pb的吸收;有Pb胁迫下,施加磷肥对小白菜的株高和鲜质量均有一定的促进作用,且抑制了小白菜根系对Pb的吸收。研究土壤氮肥最佳施用量为300mg/kg,磷肥最佳施用量为150mg/kg,此时小白菜的鲜质量达到最大,且小白菜地上部分对Pb的吸收量相对较小。

聚丙烯酰胺磷酸锆对Pb^(2+)的吸附性质研究

使用溶胶-凝胶法合成聚丙烯酰胺磷酸锆,研究其对Pb^(2+)的吸附行为。结果表明,0.10 g聚丙烯酰胺磷酸锆,加入0.20 g/L Pb^(2+)溶液20.00 mL,24 h时已基本吸附饱和,q_e=18.50 mg/g,η=84.49%。当Pb^(2+)初始浓度增加到0.70 g/L时,吸附容量达到最大,在pH=3.72时吸附容量最大。混合金属溶液吸附实验表明,聚丙烯酰胺磷酸锆对Pb^(2+)具有高的选择性,k_(dPb)/k_(dNi)=23.76,k_(dPb)/k_(dCu)=6.680。吸附速率符合准二阶动力学方程。吸附等温线符合Langmuir吸附模型和Freundlich吸附模型。

改性磷矿粉修复Pb/Zn污染土壤的研究进展

为了明确磷矿粉在Pb/Zn污染土壤修复领域的研究现状,根据大量国内外文献中有关磷矿粉在土壤环境修复方面文献的相关报道,对磷矿粉修复Pb/Zn污染土壤的机理进行了总结,归纳了磷矿粉的改性方法.分析结果表明:磷矿粉是一种具有工程应用前景的重金属污染土壤修复剂,具有成本低廉、环境友好等优点;磷矿粉主要通过吸附和沉淀等方式固化土中的重金属,进而达到修复重金属污染土的目的;有关磷矿粉的实际工程应用报道还相对较少;关于磷矿粉与Pb/Zn污染土壤的相互作用机理尚缺少进一步研究,有待加深开展此方面的研究工作.

PBS-co-Glu共聚酯与磷酸酯淀粉共混制得复合材料性能

以L-谷氨酸(Glu)对聚丁二酸丁二醇酯(PBS)进行亲水改性,制得不同Glu含量(以丁二酸的物质的量为基准,下同)的共聚酯,标记为PBS-co-Glun%(n=O、1、2、3、4、5),并运用乳液一浇注成型法将PBS-co-Glun%与磷酸酯淀粉(PPS)共混,制备了PBS-co-Glun%/PPS复合材料。采用FTIR、1HNMR表征了PBS-co-Glun%共聚酯的化学结构;采用XRD、POM、SEM、光透过率和拉伸实验对共聚酯的亲水性、结晶性能及复合材料的表面形貌、光透过率和力学性能进行了测试,脂肪酶降解实验测试了复合材料的降解性能。结果表明:随Glu含量的增加,PBS-co-Glun%/PPS复合材料的断裂伸长率和降解率均有所增加;当Glu含量为4%时,PBS-co-Glu4%/PPS复合材料断裂伸长率达到最大值98%;与PBS/PPS复合材料酶降解率36.80%相比,PBS-co-Glu5%/PPS复合材料酶降解率提高到42.79%;所有材料中PBS-co-Glu2%/PPS复合材料的光透过率最大。

含重金属Pb的磷酸钾镁水泥性能

测试了掺Pb(NO_3)_2的磷酸钾镁水泥(MKPC)浆体的流动度、凝结时间、抗压强度、收缩变形和重金属Pb的浸出质量浓度,分析了MKPC浆体的水化放热特性、物相组成和微观形貌.结果表明:复合缓凝剂和适量Pb(NO_3)_2可有效延缓MKPC浆体的凝结时间;掺入适量Pb(NO_3)_2虽然会降低MKPC浆体的抗压强度,并使其收缩变形略微增加,但掺10%(质量分数)Pb(NO_3)_2的MKPC浆体28d抗压强度仍大于20MPa,其收缩变形仍比硅酸盐水泥砂浆小1个数量级;在相同水化龄期,MKPC浆体中重金属Pb的浸出质量浓度随着Pb(NO_3)_2掺量的增加逐步升高,但在掺10%Pb(NO_3)_2的MKPC浆体中,重金属Pb的浸出质量浓度仍远低于GB 5085.3—2007标准要求.

NZP族磷酸盐材料对Pb^(2+)的吸附研究

利用NZP族磷酸盐材料结构上的特点,将其作为一种新型吸附材料应用于吸附溶液中的Pb2+,研究了静态吸附容量、吸附动力学及吸附容量与静置时间的关系。结果证明NZP族磷酸盐材料对Pb2+离子确有明显的吸附作用,且吸附动力学符合Langmuir等温线。

几种改良剂对Cd和Pb污染土壤小白菜生长的影响

采用盆栽试验研究了稀土镧、熟石灰、钙镁磷肥和柠檬酸4种改良剂对小白菜在重金属Cd和Pb污染土壤上生长的影响。结果表明:受Cd和Pb污染的土壤明显使小白菜受到毒害,但经稀土镧、熟石灰、钙镁磷肥和柠檬酸处理后,小白菜生物学产量增加,幼苗体内超氧化物歧化酶活性降低,丙二醛含量减少。其中,稀土镧对缓解Cd和Pb胁迫有较好效果。