马托格罗索州原地红土中金的富集

所研究的金富集出现在巴西马托格罗索州境内覆盖在前寒武系库亚巴组片岩上的红土中。这些红土从底部到顶部可分为五层:(1)灰蓝色蚀变片岩;(2)红色泥质蚀变砂矿物层;(3)以在富氢氧化铁的基质和粘土中富含氢氧化铁的砾石和石英碎屑为特征的层;(4)铁壳;(5)现代土壤。人们发现,紧贴在铁壳下面的第三层的金含量最有意义。根据地质研究和金颗粒形态的观测结果,目前所开采的这种金矿被认为是两种作用共同作用的结果,即赋存在片岩中的石英矿脉的铁铝蚀变作用和红色泥质蚀变砂矿物层联合作用所致,这种蚀变砂矿物层起到了不透水构造的作用,使大的金颗粒在机械富集过程中不再向下远移。     

免疫传感器用于环境中痕量有害物质检测的研究进展

随着免疫测定技术与传感技术的发展,人们开发了以固定化的抗体(抗原)为识别元件,基于特异性的免疫反应原理的免疫传感器.该传感器灵敏度高、选择性好,可实现对农药分子、工业有机污染物、重金属、生物毒素等有害物质的实时、在体、在线测定,在环境污染监测中具有巨大的应用前景.本文对免疫传感器的原理、制备、分类作了简要介绍,综述了近年来用于痕量有害物质检测的免疫传感器在固定化方法和传感技术等方面的最新研究成果,并探讨了免疫传感器在环境监测中的应用和发展方向.     

垃圾堆肥高效复合微生物菌剂的制备

将康氏木霉、白腐菌、变色栓菌与EM菌、固氮菌、解磷菌、解钾菌按一定配比扩大培养制成5组复合微生物菌剂,比较其产脱氢酶、淀粉水解酶和纤维素分解酶能力大小以及在实际堆肥中的应用效果,从中选出一组高效复合微生物菌剂Ⅴ,其配比为:康氏木霉∶白腐菌∶变色栓菌∶EM菌∶固氮菌∶解磷菌∶解钾菌=15∶15∶15∶25∶10∶10。      

Dietary exposure to di-isobutyl phthalate increases urinary 5-methyl-2′-deoxycytidine level and affects reproductive function in adult male mice

Phthalates are a large family of ubiquitous environmental pollutants suspected of being endocrine disruptors. Epidemiological studies have associated phthalate metabolites with decreased reproductive parameters and linked phthalate exposure with the level of urinary 5-methyl-2′-deoxycytidine(5mdC, a product of methylated DNA). In this study, adult male mice were exposed to 450 mg di-isobutyl phthalate(DiBP)/(kg·day) via dietary exposure for 28 days. Mono-isobutyl phthalate(Mi BP, the urinary metabolite) and reproductive function parameters were determined. The levels of 5mdC and 5-hydroxymethyl-2′-deoxycytidine(5hmdC) were measured in urine to evaluate if their contents were also altered by DiBP exposure in this animal model. Results showed that DiBP exposure led to a significant increase in the urinary 5mdC level and significant decreases in sperm concentration and motility in the epididymis, accompanied with reduced testosterone levels and downregulation of the P450 cholesterol side-chain cleavage enzyme(P450scc) gene in the mice testes. Our findings indicated that exposure to DiBP increased the urinary 5mdC levels,which supported our recent epidemiological study about the associations of urinary 5mdC with phthalate exposure in the male human population. In addition, DiBP exposure impaired male reproductive function, possibly by disturbing testosterone levels; P450scc might be a major steroidogenic enzyme targeted by DiBP or other phthalates.     

Using lysosomal membrane stability of haemocytes in Ruditapes philippinarum as a biomarker of cellular stress to assess contamination by caffeine, ibuprofen, carbamazepine and novobiocin

Although pharmaceuticals have been detected in the environment only in the range from ng/L to g/L, it has been demonstrated that they can adversely affect the health status of aquatic organisms. Lysosomal membrane stability (LMS) has previously been applied as an indicator of cellular well-being to determine health status in bivalve mussels. The objective of this study is to evaluate LMS in Ruditapes philippinarum haemolymph using the neutral red retention assay (NRRA). Clams were exposed in laboratory conditions to caffeine (0.1, 5, 15, 50 μg/L), ibuprofen (0.1, 5, 10, 50 μg/L), carbamazepine and novobiocin (both at 0.1, 1, 10, 50 μg/L) for 35 days. Results show a dose-dependent effect of the pharmaceuticals. The neutral red retention time measured at the end of the bioassay was significantly reduced by 50% after exposure to environmental concentrations (p < 0.05) (caffeine = 15 μg/L; ibuprofen = 10 μg/L; carbamazepine = 1 μg/L and novobiocin = 1 μg/L), compared to controls. Clams exposed to these pharmaceuticals were considered to present a diminished health status (retention time < 45 min), significantly worse than controls (96 min) (p < 0.05). The predicted no environmental effect concentration (PNEC) results showed that these pharmaceuticals are very toxic at the environmental concentrations tested. Measurement of the alteration of LMS has been found to be a sensitive technique that enables evaluation of the health status of clams after exposure to pharmaceuticals under laboratory conditions, thus representing a robust Tier-1 screening biomarker.     

三峡库区回水区营养盐和叶绿素a的时空变化及其相互关系

为探讨三峡水库调度运行背景下,库区回水区营养盐和叶绿素a时空变化及其相互关系,于2013年5月~2014年5月在三峡库区北岸最大、也是库区水华频发的支流——澎溪河的回水区高阳平湖进行了定点和高频监测.结果表明水体热分层是高阳平湖水华发生的诱导因素.高阳平湖水体热分层发生于春季(3月初),消亡于夏末(9月中旬),冬季没有分层.2014年春季,随着水体分层的发生和发展,表层叶绿素a在69 d内从14.92μg·L-1骤增至183.73μg·L-1,并暴发水华,之后叶绿素a随着混合层深度增加而下降.水体没有分层时,表、中和底层营养盐浓度相近;水体分层之后,各层磷浓度有了明显差异,表层和底层总磷浓度相差(0.18±0.04)mg·L-1.高水位期(9月至次年4月),高阳平湖硝氮和溶解性磷高于低水位期(5~8月)的含量,分别占总氮、总磷浓度的71.4%~95.4%和42.7%~94.4%,是总氮和总磷的主要组成部分,干流倒灌输入的硝氮和溶解性磷是其主要来源.     

气溶胶粒子在毛细管中沉积与再悬浮

采用亚微米单分散聚苯乙烯球形硬气溶胶粒子和脉冲进样技术,测定了气溶胶粒子在管道中的沉积率,研究了沉积率与流体速度、管道长度、管道直径和气溶胶粒子大小之间的关系.结果发现,在相同条件下,沉积率随管长增加而增大;随流体速度增加而减小.在相同体积流量下,沉积率与管径关系不大;而沉积率与气溶胶粒子大小之间的关系比较复杂.沉积的气溶胶粒子如果在更大流速冲击下,将发生反弹,部分气溶胶粒子从黏附表面上分离再次悬浮于流体中.     

蠕虫在膜生物反应器和活性污泥法中的污泥减量研究

通过长达345d的中试规模试验,研究比较了蠕虫在膜生物反应器(MBR)和活性污泥法(CAS)的生长状况及其导致的污泥减量效果.CAS中的蠕虫生长状况明显优于MBR的蠕虫生长状况.MBR曝气池中平均蠕虫密度(10条·mg-1)远低于CAS曝气池中平均蠕虫密度(71条·mg-1),并且CAS中蠕虫连续保持高密度(>30条·mg-1)生长达172d.CAS中红斑瓢体虫和仙女虫交替成为优势蠕虫.蠕虫生长对MBR的污泥产率(0 40kg·kg-1)和污泥沉降性能(污泥沉降指数133mL·g-1)影响很小,但却能显著减少CAS的污泥产率(0 17kg·kg-1)和改善污泥沉降性能(污泥沉降指数为60mL·g-1).仙女虫比红斑瓢体虫能更大地减少污泥产量和更好地改善污泥沉降性能.蠕虫生长不影响MBR的COD去除率和出水水质,但却显著影响CAS的COD去除率和出水水质.     

卡林型金矿床中金和硫化物的热液搬运和沉积的地球化学

本文对卡林型金矿床的Au、As、Hg、Sb、T1和Fe相的溶解度资料作了评述,根据矿物组合确定了矿化的物理化学环境,对控制矿石沉积的化学条件也作了述评。结论是卡林型金矿床的成矿温度为150°—200℃,成矿流体为中—弱酸性、低盐度和低f_(o_2)的。     

程海冬季水华特征、成因与控制对策

报道了程海冬季水华发生时间、分布、聚集状况、优势种和现存量。认为:营养物质积累、特殊的水动力、适宜的水温和光照是刺激铜绿微囊藻水华暴发的原因,近期应采取流域生态系统管理、削减污染物入湖量、增强生态系统功能三方面的控制对策减轻水华危害。