铁改性杭锦土对磷的吸附及对沉积物磷释放的控制

以天然粘土矿物杭锦土(HJ)为原料,采用浸渍法制备表面负载铁氧化物的铁改性杭锦土(FHJ)吸附剂.采用BET、SEM、XRD等技术对其进行表征,并考察了铁负载比例、pH、共存离子对FHJ除磷的影响.结果表明,浸渍法成功将铁氧化物负载在杭锦土表面;溶液pH越低越有利于FHJ对磷酸盐的吸附;除磷性能受CO32-、SiO32...     

沂河典型沉积物剖面磷的浓度和形态特征

用柱状采样器在沂河上、中、下游采集3个沉积物柱,利用连续提取法对沉积物中磷的浓度和形态进行了研究.结果表明:沂河水系沉积物总磷(TP)含量在321～734 mg/kg之间.钙结合态磷(Ca-P)含量最高,约占TP的40％以上;其次为铁结合态磷(Fe-P)和残渣态磷(RES-P),第三为闭蓄态磷(RS-P)和铝结合态(A...     

活化煤系高岭土吸附城市生活污水中磷的研究

分别考察了焙烧温度、硫酸浓度和煤系高岭土用量对城市生活污水中磷的吸附率的影响,在此条件下又考察了吸附等温线、吸附动力学和吸附热力学.结果表明,当焙烧温度为700 ℃,硫酸浓度为70%,煤系高岭土用量为0.75g(每50 mL污水)时,煤系高岭土对城市生活污水中磷元素的吸附率分别达到最大.通过对吸附等温线、吸附动力学曲线和吸附热力学曲线的处理,得出硫酸活化煤系高岭土对磷的吸附行为更符合Freundlich模型,液膜扩散是其对磷吸附的主控步骤,且吸附是一个放热过程.     

典型建筑废弃物对磷的吸附特征及其在复合垂直潜流人工湿地中的应用研究

采用典型建筑废弃物(废弃粉煤灰砖、红砖等)为吸附剂,研究其对正磷酸盐态磷(PO43--P)的静态吸附特性、作为多级垂直流人工湿地(MVSF-CWs)填料的可行性及不同运行时间与水温条件下的除磷性能。结果表明,粉煤灰砖(粉末)和红砖(粉末)对PO43--P的吸附行为符合Langmuir吸附等温式,利用该式计算出其对PO43--P的吸附容量分别为44.72和35.54 mg/g。MVSF-CWs系统由4级组成,平均水力负荷0.038 m3/(m2·d)、平均水力停留时间16.7 d。MVSF-CWs系统进水TP的质量浓度为(5.83±2.36)mg/L、出水为(0.85±0.48)mg/L,平均去除率为85.4%。各级人工湿地对TP去除的贡献率分别为33.6%、55.8%、2.5%、8.1%,其中第2级(废弃粉煤灰砖为填料)对磷的去除最为显著。不同水温条件下,MVSF-CWs系统除磷结果表明:当水温θ30℃、20℃θ30℃、10℃θ20℃及θ10℃时,TP的平均去除率分别为91.83%、87.52%、82.61%及78.39%。TP去除率随水温下降而降低,表明水温对多级垂直流人工湿地除磷效率有显著影响。     

基于海绵城市理念下的生态河道治理初探——以上海临港春涟河及紫飞港工程为例

"海绵城市"作为新一代的雨洪管理概念从2012年被首次提出后就广受关注,国家大力倡导并补贴海绵城市的建设.如何基于海绵城市理念进行生态河道的治理,目前成为部分海绵试点城市亟待解决的问题,亦是将来海绵城市深入开展面临的一项议题.文中以上海临港春涟河及紫飞港生态河道设计工程为例,在现状问题分析的基础上,结合其海绵化考核指标...     

以类水滑石为前驱体制备的复合氧化物同时吸附烟道气中SO2和NO研究

采用共沉淀法制备NiMgAlO、CuMgAlO、ZnMgAlO和FeMgAlO类水滑石复合氧化物，并用于常压下同时氧化吸附模拟烟道气中的SO2和NO。模拟烟道气中SO₂的摩尔分数为1%, NO的摩尔分数为0.2%，O₂以及He作为载气。研究结果表明，这四种催化剂对烟道气中的SO₂和NO具有良好的同时氧化吸附效果。比较四种催化剂的吸附效果发现，NiMgAlO和CuMgAlO要优于ZnMgAlO和FeMgAlO，且NiMgAlO对SO₂和NO的吸附效果最佳。     

断陷盆地中砂质滩坝沉积物的岩性特征与粒度特征分析——以尼日尔地区A区块为例

滩坝是发育在滨岸带非常重要的一种油气储集体,具有近油源、储集性能好等有利的富集条件,是近年来勘探开发的重点目标.通过综合分析滩坝的岩性资料与粒度数据,研究并总结其特征,得出了滩坝沉积物的成熟度、岩性特征,确定了两种滩坝的典型粒度概率曲线.该研究可以更好地区分滩坝沉积与其它沉积体,以帮助更进一步的认识地质情况,进行后期地...     

城市更新中交通体系构建的探讨——以南京玄武门地区城市设计研究为例

城市发展常常伴随着交通与用地功能的矛盾,为城市更新提供了契机。城市设计的目标是多重的,解决交通问题是其中之一。交通影响着用地功能和空间形态,进而影响到城市的运行效率和活力。在南京玄武门地区,交通问题的解决应结合城市设计的其它任务:用地性质调整、功能配置、空间形象塑造、历史文化保护、环境优化等。解决局部的交通问题还应与城市整体交通联系在一起,建立一个完整的交通体系,这个体系包括道路系统、静态交通设施和交通管理规章的实施。     

城市黑臭河道底泥氨氮吸附解吸性能研究

以城市黑臭河道底泥沉积物为研究对象,探讨其NH4+-N吸附解吸性能,为城市黑臭河道内源氮控制提供技术参考。研究结果表明,在实验浓度范围(0~70 mg·L-1)内,随着NH4+-N平衡浓度的升高,底泥对NH4+-N的吸附量逐渐增加,且Freundlich模型适用于描述此热力学吸附现象,其n值为0.640,说明该热力学吸附过程较难进行;底泥对上覆水NH4+-N的动力学吸附及解吸过程分别在30 min和5 h内快速进行,而后均逐渐趋于平衡,二级动力学模型适用于描述底泥对NH4+-N的动力学吸附与解吸过程;底泥NH4+-N解吸性能强于吸附性能,具有"难吸附易解吸"的特性。     

凹凸棒石对液相磷素的吸附-解吸性能研究进展

磷是引起水体富营养化的限制性因子,同时,由于凹凸棒石具有良好的吸附性能,因此,利用其吸附净化液相磷素成为研究的热点.本文综合分析国内外学者对凹凸棒石研究成果基础之上,介绍了凹凸棒石的矿物学特性,详细阐述了凹凸棒石吸附液相磷素机理.文章首次重点探讨了吸附过程的关键影响因素及酸碱度对磷素净化效果的复合影响机制,同时,讨论了吸附动力学和热力学以及解吸过程,这对凹凸棒石在环境领域的应用具有重要的科学理论价值及实际意义.     

城市内河受污染底泥的固定化效果试验研究

城市内河由于长期承纳污染物导致其底泥受到污染,特别是重金属污染严重。为达到资源再利用要求,研究了3种不同配方的固化剂对其固化的效果。结果表明,随着固化时间的延长,固化淤泥的含水率降低,无侧限抗压强度(UCS)升高。重金属得到很好的固定化处理,重金属的浸出量、浸出率均有明显降低而且达到标准要求。     

砂岩对浸出铀的吸附解吸试验

通过批试验,对砂岩对浸出铀的吸附解吸做了研究,研究了不同pH、不同液固比条件下,砂岩对浸出铀的吸附和解吸效果。结果表明,pH在1.5~2.0范围内,吸附量与pH成正相关,解吸量与p H成负相关;液固比2∶1和5∶1两种条件下,液固比越大,吸附量和解吸量都增大。     

The Adsorption and Desorption Characteristics of EDTA-Chelated Copper Ion by Activated Carbon

Abstract

This paper addresses the effect of EDTA, a strong agent, on the removal of copper ion from solutions using activated carbon adsorption. Experimental studies indicate the presence of EDTA significantly altered the adsorption behavior of copper on the activated carbon due to the formation of copper chelate species in the solution. The adsorption isotherms and kinetics were found to be strong functions of solution pH and the ratio of copper ion and EDTA concentrations. Adsorption of EDTA-Cu chelates was found to be more favorable than those of free copper ion and unbound EDTA species in the solution. Experimental results indicated that the desorption of chelated copper ion from activated carbon by NaOH and HClO⁴ solutions was influenced by the initial adsorption conditions. A significantly higher quantity of copper ion was recovered with HClO⁴ than with NaOH. Combining the adsorption and desorption data of copper and EDTA, and an understanding of the species distribution of copper in the presence of EDTA, the behavior of the adsorption of EDTA-chelated copper on the activated carbon was described. The predominant adsorbed copper species was the chelated form, CuEDTA^2-, which can be adsorbed on activated carbon surfaces with either the Cu end or the EDTA end bonding directly to the surface.     

不同人工湿地基质对磷的吸附特性研究

以石灰石、沸石、粉煤灰和煤渣四种人工湿地基质为研究对象,研究了其对磷的吸附特性。结果表明:粉煤灰、沸石和石灰石对磷的吸附用Langmuir吸附等温方程描述较好;而煤渣对磷的吸附用Freundlich吸附等温方程描述较好;四种基质对磷吸附能力大小为:煤渣﹥粉煤灰﹥沸石﹥石灰石。     

Water Vapor Adsorption and Desorption on Materials Hydrothermally Solidified from Clay Minerals

Water vapor isotherms were examined and ¹H-magic-angle spinning nuclear magnetic resonance (¹H-MAS NMR) analysis was conducted to determine the amount of water vapor adsorbed and desorbed on hydrothermally solidified materials derived from clay minerals. The amount of water vapor adsorbed and desorbed decreased with increasing mesopore volume of the materials, which disagreed with the estimation obtained using the Kelvin equation. Water vapor was physisorbed on alumina-like sites in the materials. An increase in the binding energy between water vapor and the materials led to an improvement in the water vapor adsorption–desorption properties of materials.     

铜离子在印迹壳聚糖/Al2O3上的吸附-脱附特性

采用表面接枝和表面印迹技术,以正硅酸乙酯改性后的Al2O3粉末为载体、壳聚糖为功能单体,制备了Cu2+印迹复合材料(IIP/Al2O3),用于选择性分离Cu2+. 研究了IIP/Al2O3对Cu2+的动态吸附,利用Thomas, Yoon-Nelson和Wolborska模型分析IIP/Al2O3吸附Cu2+过程,考察了动态条件下Cu2+的最佳洗脱条件. 结果表明,当Cu2+浓度100 mg/L、柱高37.25 mm、流速1.0 mL/min和pH=5时,IIP/Al2O3的穿透吸附容量和动态吸附容量分别为4.03和15.68 mg/g,Cu2+去除率为45.55%;Thomas和Yoon-Nelson模型能很好地拟合IIP/Al2O3对Cu2+的吸附;在柱高37.25 mm、洗脱液流速1.0 mL/min的条件下,15 mL 0.6 mol/L盐酸溶液对Cu2+的脱附率高达99.54%,脱附作用时间短,Cu2+易回收.     

Influence of Long-term Use of Fertilizers and Farmyard Manure on the Adsorption–Desorption Behaviour and Bioavailability of Phosphorus in Soils

An understanding of the adsorption–desorption behaviour of phosphate (P) in soils after three decades of long-term fertilization would be an invaluable supplement to our knowledge of the chemistry of P in soils and would assist in developing P application strategies for successive crops. With this objective and within the framework of a long-term experiment, we collected surface soil samples (0–0.15 m) from agricultural crop land on which a rotation of maize-wheat-cowpea (fodder) crops had been grown for 32 years. The soil samples were investigated for adsorption and desorption behaviour of P, and the buffering capacities of soil samples were computed from the adsorption data. Soils differed widely in their P supply characteristics. Phosphate adsorption increased while percentage P adsorbed decreased gradually with increasing levels of added P. Adsorption maxima and the extent of P adsorption was at its maximum in unfertilized soil, and P adsorption decreased with increased P applications. The incorporation of farmyard manure with optimal P levels decreased P adsorption even more than a super-optimal application of P fertilizers. Bonding energy and Freundlich constant ȁ8nȁ9 also decreased with increased P application and with the incorporation of farmyard manure. The adsorption and desorption of applied P were inversely related, and the soils that adsorbed P the most readily released it the least into the soil solution, and vice-versa. Computation of maximum buffering capacities (MBC) indicated that increased levels of P application decreased MBC and increased P supply in soil. The beneficial effects of an annual incorporation of farmyard manure with optimal P levels were clearly pronounced, and P availability in these soils was found to be even higher than the soil receiving the super-optimal application of P fertilizers. Various adsorption–desorption parameters were significantly related with the P uptake of different summer (rice, maize, soybean) and winter (wheat, berseem and raya) crops. Adsorption maxima, desorption maxima and maximum buffering capacity are the major parameters governing P availability in soils.