氢氧化镧改性介孔稻壳生物炭除磷性能

通过共沉淀法将氢氧化镧固定在高介孔率的稻壳生物炭上,重点研究了生物炭孔结构、溶液pH和共存物质对氢氧化镧改性介孔稻壳生物炭吸附磷酸盐的影响.结果表明,镧负载量与生物炭介孔率呈正相关,生物炭介孔率越高,对磷酸盐的吸附速率越快,镧浸出量越低.吸附过程符合伪二级动力学模型,且受颗粒内扩散控制.Langmuir模型能够较好地描述氢氧化镧改性介孔稻壳生物炭对磷酸盐的吸附过程,理论最大吸附量分别为41.22、43.26和45.62 mg·g^-1,镧利用率较高,P/La量比均大于1.5.此外,氢氧化镧改性介孔稻壳生物炭能在pH 3~9的范围内有效吸附磷酸盐.共存物质影响实验表明,氢氧化镧改性介孔稻壳生物炭对磷酸盐表现出良好的选择吸附性,共存Ca²⁺会强化其对磷酸盐的吸附,而共存Mg²⁺则会抑制吸附过程.     

High phosphate removal using La(OH)3 loaded chitosan based composites and mechanistic study

Our present study was to prepare a biomass-supported adsorbents with high adsorptive capacity and high selectivity to prevent the accelerated eutrophication in water body. To this end, different metal hydroxide (La, Zr and Fe) first was successfully loaded on chitosan microspheres. Then the quaternary ammonium group with different content was introduced into the adsorbent by polymerization. By comparison of adsorption properties, chitosan-La(OH)₃-quaternary ammonium-20% (CS-La-N-20%) has strong adsorption to phosphate (160 mg/g) by immobilizing nano-sized La(OH)₃ within a quaternary-aminated chitosan and it maintain high adsorption in the presence of salt ions. The pH results indicated that the CS-La-N-20% would effectively sequestrate phosphate over a wide pH range between 3 and 7 without significant La³⁺ leaching. What's more, adsorption capacity on the introduce of positively charged quanternary-aminated groups was significantly higher than that of the unmodified adsorbents at alkaline conditions. The column adsorption capacity reached 1300 bed volumes (BV) when phosphate concentration decreased until 0.5 mg/L at 6 BV/hr. The column adsorption/desorption reveals that no significant capacity loss is observed, indicating excellent stability and repeated use property. Characterizations revealed that phosphate adsorption on CS-La-N-20% through ligand exchange (impregnated nano-La(OH)₃) and electrostatic attraction (positively charged quanternary-aminated groups). All the results suggested that CS-La-N-20% can serve as a promising adsorbent for preferable phosphate removal in realistic application.     

KOH活化-微波热解制备污泥炭及其结构演化

伴随着国内水处理行业的迅速发展,产量巨大的污泥亟需找到高效的资源化方式。以污泥吸附剂的表面结构及吸附性能参数为考察指标,利用正交实验方法对制备污泥吸附剂的几项影响因素进行考察和分析。结果表明,吸附剂属于中孔吸附剂,表面碱性能团占主导。微波功率、时间、KOH浓度及碱泥比均会显著影响吸附剂的表面官能团、孔结构以及吸附性能,但影响程度各不相同。吸附质以及吸附剂的结构特性均会影响吸附性能,污泥炭吸附剂对碘、亚甲基蓝以及酸性品红均有着较好的吸附效果,污泥吸附剂的最优制备工艺条件为功率420 W,处理时间8 min,KOH浓度20%,碱泥比为0.5∶1。     

硝普钠对镧胁迫下黑麦草幼苗光合特性及矿质元素吸收的影响

为了探讨一氧化氮(NO)对镧(La)胁迫下牧草生理响应的调节作用,采用水培方法,研究了外源NO供体硝普钠(SNP)对300μmol·L-1LaCl3胁迫下黑麦草幼苗光合特性及矿质元素吸收的影响.结果表明,在La胁迫下,喷施50μmol·L-1SNP显著提高了黑麦草根尖和叶片中NO的含量,叶片光合色素含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、气孔限制值(Ls)、PSⅡ最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSⅡ)、光化学猝灭(qP)和地上部K、Ca、Mg、Cu、Fe、Zn、Mn及根系K、Ca、Mg、P、Zn、Fe含量显著提高;叶片胞间CO2浓度(Ci)、非光化学猝灭(NPQ)及地上部La、P和根系Mn含量明显降低.表明NO可通过改善叶片光合活性,维持矿质元素平衡,从而缓解La胁迫对黑麦草光合作用的抑制.     

Enhanced removal of I− on hierarchically structured layered double hydroxides by in suit growth of Cu/Cu2O

To further improve the removal ability of layered double hydroxide(LDH) for iodide(I~-) anions from wastewater, we prepared hierarchically porous Cu_5Mg_(10)Al_5-LDH and used as a matrix for in suit growth of Cu/Cu_2O on its surface, forming Cu/Cu_2O-LDH, which was characterized and applied as an adsorbent.Results displayed high I~-saturation uptake capability(137.8 mg/g) of Cu/Cu_2O-LDH compared with Cu_5Mg_(10)Al_5-LDH(26.4 mg/g) even thermal activated LDH(76.1 mg/g).Thermodynamic analysis showed that the reaction between I~-anions and Cu/Cu_2O-LDH is a spontaneous and exothermic.Uptake kinetics analysis exhibited that adsorption equilibrium can be reached after 265 min.Additionally, the adsorbent showed satisfactory selectivity in the presence of competitive anions(e.g., SO_4~(2-)), and could achieve good adsorption performance in a wide pH range of 3–8.A cooperative adsorption mechanism was proposed on the basis of the following two aspects:(1) ion exchange between iodide and interlayer anions;(2) the adsorption performance of Cu, Cu(Ⅱ) and Cu_2O for I~-.Meanwhile, the difference between the adsorption mechanism of Cu/Cu_2O-LDH, Cu_5Mg_(10)Al_5-LDH and Cu_5Mg_(10)Al_5-CLDH adsorbents was also elaborated and verified.     

Adsorption and desorption of lanthanum at sulfide mineral surface

Batch adsorption experiment with four sulfide minerals - Chalcocite galena, pyrite and sphalerite - were used to study for the adsorption and desorp-tion behavior of La (III) in the presence of EDTA, a model humic matter. Linear adsorption was found in all cases.The presence of soluble organic complexing ligand should reduce the mobility of La (III) in porous media and its transport to groundwater in the percolating soil solution. Binding mechanism is proposed to account for this preferential binding behavior.     

粉煤灰分选工艺及产品性能

通过对粉煤灰物理性能，化学性能分析，采用适当的物理方法分选出微珠，漂珠，磁铁物等，以化学方法分离生产出Ａｌ（ＯＨ）３和β－Ｃ２Ｓ，分选出β－Ｃ２Ｓ和另几种物质可作为生产高标号水泥及特种水泥的添加剂。     

干旱季节水库水质pH值增高原因探析

随着水库蓄水量的减少,水生生物快速大量生长,破坏了水体中碳酸氢盐的水解平衡,伴随生物利用水中二氧化碳进行光合作用的过程,水中氢氧根离子含量增加,氢氧根离子又使碳酸氢根的电离平衡向生成碳酸根离子方向移动,导致水中碳酸根离子浓度增大,总碱度增加,同时湖库底质盐碱土和草甸土的碳酸氢盐以及碳酸盐的平衡释放也使水体的碳酸氢盐得到外源补充.周而复始使水体的碳酸盐碱度和总碱度不断增加,pH也逐步增高.在相对往年引入嫩江水容量较少的情况下,干旱、高温、少雨、水体表面的物理蒸发和生物蒸腾作用,水库水容量急剧减少,上述情况进一步加剧.并通过对水库出口的碱度进行修正,推算出水体的生物量,和理论生物量计算值相符合.     

Enhanced phosphate removal using zirconium hydroxide encapsulated in quaternized cellulose

Zirconium-based materials are efficient adsorbent for aqueous phosphate removal. However, current zirconium-based materials still show unsatisfied performance on adsorption capacity and selectivity. Here, we demonstrate a zirconium hydroxide encapsulated in quaternized cellulose (QC–Zr) for the selective phosphate removal. Zirconium hydroxide nanoparticles were simultaneously generated in situ with the QC framework and firmly anchored in the three-dimensional (3D) cross-linked cellulose chains. The maximum P adsorption capacity of QC–Zr was 83.6 mg P/g. Furthermore, the QC–Zr shows high P adsorption performance in a wide pH range, generally due to the electrostatic effects of quaternized cellulose. The enhanced adsorption of P was also achieved in the presence of competing anions (including Cl^?, NO₃^?, ${\text{SO}}_4^{2?}$, ${\text{SO}}_4^{\mathrm{4}?}$) and humic acid (HA) even at a molar ratio up to 20 levels. The column adsorption capacity of QC–Zr reached 4000 bed volumes (BV) at EBCT = 0.5 min as the P concentration decreased from 2.5 to 0.5 mg/L. Mechanism study revealed that both –N⁺(CH₃)₃ groups and zirconium hydroxide were involved in phosphate adsorption via electrostatic interactions between –N⁺(CH₃)₃ and phosphate, and the formation of zirconium hydrogen phosphate (Zr(HPO₄)x). The ³¹P nuclear magnetic resonance (NMR) study implied that P surface–precipitated and inner–sphere complexed with zirconium hydroxide at a ratio of 3:1.     

氢氧化镁对水溶性阴离子染料废水脱色的研究

本文研究了氢氧化镁对水溶性阴离子染料模拟废水的脱色规律及机理。结果表明镁盐法具有优异的脱色效果。例如,染料浓度１００ｍｇ．ｌ＾－１,镁盐投加量１０００ｍｇ．ｌ＾－１用ＣａＯ调至ＰＨ１０．９－１１．５十种被研究的水溶性阴离子染料的脱色平均值在９９％以上。吸附机理属于离子吸附。