生物表面活性剂强化植物修复重金属污染土壤的可行性

利用有机配体强化植物修复重金属污染土壤是提高植物修复效果的常用措施．但大部分有机配体会引起二次污染而限制了其在土壤重金属修复中的应用。如果能将生物表面活性剂强化植物修复不仅会弥补这一不足．而且还能降低费用。生物表面活性剂在重金属污染土壤修复中的应用以及生物表面活性剂去除重金属的机理表明,将其强化植物修复是完全可行的,并且可以增加植物细胞膜透性,更好地促进植物对重金属的吸收。     

复掺轻骨料纤维喷射混凝土力学及导热性能试验研究*

为有效隔绝高地温公路隧道、深部高温巷道施工过程中的围岩散热,利用正交试验方法,以不同复合陶粒、陶砂掺量、聚丙烯纤维为影响因素,设计出1种隔热效应的轻骨料纤维喷射混凝土（Lightweight Aggregate Fiber Shotcrete,LAFS）,进行含水率、抗压、劈裂抗拉及导热性能试验,并借助X射线衍射、扫描电镜对LAFS进行机理分析。结果表明:3种因素对LAFS力学及导热性能的影响程度均为陶粒掺量>陶砂掺量>聚丙烯纤维掺量,本试验条件下,复合双掺陶粒、陶砂分别取代石子、砂子的最佳体积率为12%,6%,聚丙烯纤维的最佳掺量范围为0.2%~0.3%。建立的LAFS各性能预测模型可为工程应用LAFS确定其配比时提供试验依据。     

杂色云芝漆酶和发酵液降解对苯二酚研究

测定和分析了杂色云芝漆酶和杂色云芝发酵液对对苯二酚的降解反应.通过对不同底物质量浓度下杂色云芝漆酶酶学反应动力学特征分析,求得漆酶Lac A对对苯二酚的酶反应动力学方程V=1.52Cs/(16.55 Cs)和底物抑制反应速率方程γs=1.02/(1 12.86/Cs Cs/137.17).发酵液对对苯二酚的降解反应进程符合一级反应动力学方程lnC=-kt 6,发酵液对对苯二酚的降解反应动力学基本符合Michelis-Menten酶学反应动力学方程Vf=1.77Cs/(3.63 Cs),研究表明Lac A与发酵液对对苯二酚的酶学反应动力学具有较大的相似性,也存在着底物抑制现象,其底物抑制的动力学方程为γs'=1.40/(1 5.75/Cs Cs/278.26).比较漆酶纯酶Lac A和发酵液对对苯二酚反应的Km和Vmax数值,发现杂色云芝发酵液Km较小而Vmax数值较大,说明发酵液较漆酶纯酶具有更高的底物亲和力和催化效率.     

有机膨润土对敌敌畏的吸附性能研究

采用批量平衡实验,研究了阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)改性的有机膨润土及原土对有机磷农药DDVP的吸附性能,并考察了pH、温度以及CaCl<,2>浓度对吸附的影响.结果表明,改性膨润土对水中DDVP的去除能力优于原土,并且吸附量随着改性剂量的增加而增大,即1.0CEC>0.6CEC>0.3CEC>0...     

Soil-profile distribution of carbon and associated properties in no-till along a precipitation gradient in the central Great Plains

No-till (NT) farming is considered as a potential strategy for sequestering C in the soil. Data on soil-profile distribution of C and related soil properties are, however, limited, particularly for semiarid regions. We assessed soil C pool and soil structural properties such as aggregate stability and strength to 1 m soil depth across three long-term (≥21 year) NT and conventional till (CT) experiments along a precipitation gradient in the central Great Plains of the USA. Tillage systems were in continuous winter wheat (Triticum aestivum L.) on a loam at Hutchinson and winter wheat-sorghum [Sorghum bicolor (L.) Moench]-fallow on silt loams at Hays and Tribune, Kansas. Mean annual precipitation was 889 mm for Hutchinson, 580 mm for Hays, and 440 mm for Tribune. Changes in profile distribution of soil properties were affected by differences in precipitations input among the three sites. At Hutchinson, NT had 1.8 times greater SOC pool than CT in the 0-2.5-cm depth, but CT had 1.5 times greater SOC pool in the 5-20-cm. At Hays, NT had 1.4 times greater SOC pool than CT in the 0-2.5-cm depth. Differences in summed SOC pool for the whole soil profile (0-1 m depth) between NT and CT were not significant at any site. The summed SOC pool with depth between NT and CT were only significant above the 5 cm depth at Hutchinson and 2.5 cm depth at Hays. At Hutchinson, NT stored 3.4 Mg ha⁻¹ more SOC than CT above 5 cm depth. At Hays, NT stored 1.35 Mg ha⁻¹ more SOC than CT above 2.5 cm depth. Moreover, NT management increased mean weight diameter of aggregates (MWDA) by 3 to 4 times for the 0-5-cm depth at Hutchinson and by 1.8 times for the 0-2.5-cm depth at Hays. It also reduced air-dry aggregate tensile strength (TS) for the 0-5-cm depth at Hutchinson and Hays and for the 0-2.5-cm depth at Tribune. The TS (r = −0.73) and MWDA (r = 0.81) near the soil surface were more strongly correlated with SOC concentration at Hutchinson than at Hays and Tribune attributed to differences in precipitation input. Results suggested NT impacts on increasing SOC pool and improving soil structural properties decreased with a decrease in precipitation input. Changes in soil properties were larger at Hutchinson (880 mm of precipitation) than at Hays and Tribune (≤580 mm). While NT management did not increase SOC pool over CT for the whole soil profile, the greater near-surface accumulation of SOC in NT than in CT was critical to the improvement in soil structural properties. Overall, differences in precipitation input among soils appeared to be the dominant factor influencing NT impacts on soil-profile distribution of SOC and soil structural properties in this region.     

稀土掺杂钨钼酸盐类荧光粉水热法合成及结构与性能的研究

利用水热法制备了A0.925（MoO4）0.5（WO4）0.5∶Dy03.＋05（A=Ca、Sr、Ba）固溶体微晶。通过X射线衍射（XRD）、扫描电镜（SEM）、荧光分析（FA）等测试手段对微晶结构、形貌和发光性能进行了表征。结果表明A0.925（MoO4）0.5（WO4）0.5∶Dy03＋.05（A=Ca、Sr、Ba）复合钨钼酸盐微晶均呈现典型的四方晶相白钨矿结构。荧光光谱中的480nm处的偶合双峰和575nm处的锐而强的黄发射峰,分别对应于稀土离子Dy3＋的4F9/2→6 H15/2和4F9/2→6 H13/2跃迁。其中具有球状颗粒（尺寸为0.7μm）形貌的Ca0.925（MoO4）0.5（WO4）0.5∶Dy03.＋05微晶的发射峰强度最强,在光学材料中具有潜在应用。     

油气田压裂返排液治理技术研究现状

概述了压裂的目的、压裂液以及压裂返排液的来源和和水质特征。综述了近十年来絮凝沉降法、生物及生化法、高级氧化技术和Fe/C微电解组合工艺的水处理作用原理及其在压裂返排液治理中的应用进展。分析并指出了压裂返排液处理技术中存在的问题和今后的主要发展方向。     

农业土壤中水溶性氟的分布特征与影响因素分析——以湖北省荆州市为例

土壤中氟是人体必需元素,但过量的氟摄入影响人体健康。本研究以湖北省荆州地区为例,通过该地区典型利用方式和土壤类型共177个代表性样点取样分析,摸清了该地区农业土壤水溶性氟含量状况,探讨了土壤基本理化性质与土壤水溶性氟含量的关系。结果表明,该区域土壤水溶性氟在0.22 mg/kg~4.57 mg/kg之间,平均值为1.74 mg/kg,变异系数高达50%。潮土中水溶性氟含量最高(1.86 mg/kg),其次是水稻土(1.76 mg/kg),棕红壤(0.55 mg/kg)水溶性氟含量最低。土壤水溶性氟含量在pH值低于7.5时与土壤pH值呈极显著正相关关系。旱地与草地土壤的水溶性氟含量随着有机质的增加而显著增加,但水稻土有机质含量与土壤水溶性氟含量无明显相关性,表明研究区内土壤高氟含量的形成与当地的母质主要为冲积母质有直接关系。     

低温焦化废水铁炭微电解-AO的研究

在4～13℃低温环境中,Fe∶C=10∶1、pH=1.5空气搅拌条件下,Fe-C微电解对高浓度焦化废水COD的去除率为19.7％,B/C值从0.236提高到0.571.未加稀释水的条件下,Fe-C预处理后焦化废水厌氧COD去除率与常规补加稀释水的效果相当,静态自然消解速率为123.1 mg/L·d.处理后的焦化废水CO...     

不同灌溉方法下保护地土壤盐分分布特征的研究

通过渗灌、滴灌、沟灌3种灌溉方法对保护地土壤pH、全盐含量及水溶性离子组成的影响,探讨了3种灌溉方法在保护地土壤酸化、盐化过程中的演化规律.结果表明:渗灌、滴灌、沟灌:3种处理方法中滴灌处理比渗灌处理和沟灌处理效果更好,表层水溶性盐分和硝酸盐积累较轻,酸化较轻,有利于土壤环境的可持续性发展和有效地保护土壤资源.