湖北茶园茶叶氟含量及土壤氟分组

测定了湖北省14个茶园土壤和14种茶叶的氟含量和土壤氟的分组特征,探讨了各分组土壤氟含量与土壤理化性质及茶叶氟含量的相关性.结果表明,湖北地区茶园老叶氟含量为321.1-2273.9 mg·kg-1,嫩叶氟含量为56.6-1805.7 mg·kg-1.同一茶园内老叶氟含量大于嫩叶,老茶叶氟积累明显.随着土壤深度的增加,...     

“一锅法”制备Ag/Fe_3O_4及其催化还原对硝基苯酚的性能

以硫酸亚铁和硝酸银为原料,水合肼作为助剂,采用"一锅法"制备了Ag/Fe_3O_4催化剂。用XRD对催化剂进行了表征。结果表明,催化剂中的Fe_3O_4为纯相,Ag在催化剂中分散较好,催化剂中Ag质量分数大于等于7%时会出现Ag的衍射峰。以硼氢化钠还原对硝基苯酚为模型反应,考察了Ag/Fe_3O_4催化剂的活性,Ag负载量为7%的Ag/Fe_3O_4具有较高的活性。催化剂具有较好的重复使用性,使用10次后活性有一定的下降。     

饱和砂土场地‑地铁车站地震响应参数敏感性分析∗

为进一步研究饱和砂土场地?地铁车站结构体系地震动响应的参数敏感性问题,以某单层双跨地铁车站为研究对象,采用 u-p 格式饱和两相介质有效应力动力求解方法,建立了饱和砂土场地?地铁车站结构体系耦合动力数值分析模型,选取土体剪切模量、渗透系数、内摩擦角和地震动强度作为敏感性影响参数,在基准值误差分析的基础上进一步开展灰色关联分析,得到了地震动响应影响因素的灰色关联度序列。计算分析结果表明：近场特征点动孔压比峰值对地震动强度和土体剪切模量的变化更为敏感,而加速度峰值对地震动强度和内摩擦角变化更为敏感,中柱上下端动剪力与动弯矩对内摩擦角和地震动强度的变化更为敏感。此参数敏感性分析流程方法,可为地铁车站抗震设计和减灾预测评估提供参考。     

Changes in different organic matter fractions during conventional treatment and advanced treatment

XAD-8 resin isolation of organic matter in water was used to divide organic matter into the hydrophobic and hydrophilic fractions. A pilot plant was used to investigate the change in both fractions during conventional and advanced treatment processes. The treatment of hydrophobic organics (HPO), rather than hydrophilic organicas (HPI), should carry greater emphasis due to HPO’s higher trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP). The removal of hydrophobic matter and its transmission into hydrophilic matter reduced ultimate DBP yield during the disinfection process. The results showed that sand filtration, ozonation, and biological activated carbon (BAC) filtration had distinct influences on the removal of both organic fractions. Additionally, the combination of processes changed the organic fraction proportions present during treatment. The use of ozonation and BAC maximized organic matter removal e ciency, especially for the hydrophobic fraction. In sum, the combination of pre-ozonation, conventional treatment, and O3-BAC removed 48% of dissolved organic carbon (DOC), 60% of HPO, 30% of HPI, 63% of THMFP, and 85% of HAAFP. The use of conventional treatment and O3-BAC without pre-ozonation had a comparable performance, removing 51% of DOC, 56% of HPO, 45% of HPI, 61% of THMFP, and 72% of HAAFP. The e ectiveness of this analysis method indicated that resin isolation and fractionation should be standardized as an applicable test to help assess water treatment process e ciency.     

关于建设项目竣工环境保护验收几点问题探讨

在开展建设项目自主验收过程中,发现建设项目存在产能设计、环保设施风量不合理及建设内容存在重大变动等问题。针对存在问题提出一些折中解决方案,以期能够给验收工作继续开展提供解决思路,同时期望从业者能够识别焦点问题,能够全过程规范环评设计、审批及竣工环保验收工作。     

地下水除铁除锰技术研究进展

对地下水铁锰污染现状及危害进行了介绍,概述了地下水铁锰去除技术方法:主要包括自然氧化法、接触氧化法、生物氧化法等。重点综述了生物法除铁锰的研究进展,从滤料、微生物筛选及驯化、运行条件等方面进行强化以提高除铁除锰效率,是该研究方向的重点。     

Effects of soil properties on production and bioaccumulation of methylmercury in rice paddies at a mercury mining area, China

Rice paddy soil is recognized as the hotspot of mercury(Hg) methylation, which is mainly a biotic process mediated by many abiotic factors. In this study, effects of key soil properties on the production and bioaccumulation of Hg and methylmercury(MeHg) in Hg-contaminated rice paddies were investigated. Rice and soil samples were collected from the active Hg smelting site and abandoned Hg mining sites(a total of 124 paddy fields) in the Wanshan Mercury Mine, China. Total Hg(THg) and MeHg in soils and rice grains, together with sulfur(S),selenium(Se), organic matter(OM), nitrogen(N), phosphorus(P), mineral compositions(e.g., SiO_2, Al_2O_3 and Fe_2O_3) and pH in soils were quantified. The results showed that long-term Hg mining activities had resulted in THg and MeHg contaminations in soil-rice system. The newly-deposited atmospheric Hg was more readily methylated relative to the native Hg already in soils, which could be responsible for the elevated MeHg levels in soils and rice grains around the active artificial Hg smelting site. The MeHg concentrations in soils and rice grains showed a significantly negative relationship with soil N/Hg, S/Hg and OM/Hg ratio possibly due to the formation of low-bioavailability Hg–S(N)–OM complexes in rhizosphere. The Hg–Se antagonism undoubtedly occurred in soil-rice system, while its role in bioaccumulation of MeHg in the MeHg-contaminated rice paddies was minor. However, other soil properties showed less influence on the production and bioaccumulation of MeHg in rice paddies located at the Wanshan Mercury Mine zone.     

湖泊水环境高空间遥感影像污染点源信息提取研究

传统的污染点源信息提取技术存在权重因子各指标取值范围广、提取精准度不准确、植被覆盖率检测效果差等问题,为此,采用高空间遥感影像对湖泊水环境污染点源信息提取进行研究.针对信息的选择和预处理,需要先获取污染点源信息,并利用多项式对遥感影像图中的畸形几何进行修正;通过利用TM影像技术分析波段组合和单独使用波段的分类效果;根据影像中不同的隶属度,构建水体规则,分析水体差异指数,由此提高信息提取的精度,进而完成污染点源信息的提取.通过选取验证区域,进行实验,实验结果表明,使用该技术能够缩小权重因子各指标取值范围,并提高污染点源信息提取的精准度与植被覆盖率检测的效率,实用性较强.     

Enhancement of exopolysaccharides production and reactive oxygen species level of Nostoc flagelliforme in response to dehydration

Environmental Science and Pollution Research - Nostoc flagelliforme is a remarkable drought-resistant terrestrial cyanobacterium whose exopolysaccharides (EPS) have been found to exert important...     

抗水稻主要真菌病害的H50的分类鉴定

从水稻田土壤中筛选到一株编号为H50的链霉菌，表现了对水稻纹枯病和水稻稻瘟病病菌有强烈的拮抗作用，其次生代谢产物对病菌菌丝有断裂，扭曲，缢缩等有效致畸效应。根据菌株形态特征，细胞壁化学成分，培养特征及生理生化特性，鉴定该菌株为：球孢链霉菌（Streptomyces globisporus)。图3表2参7