三沙永乐龙洞内沉积物细菌种群特征

三沙永乐龙洞是世界已知最深的海洋蓝洞,洞内存在有别于一般海洋环境的生物群落和物质循环。本文采用高通量测序技术获得三沙永乐龙洞内沉积物中的细菌种群组成特征,以期为揭示细菌在蓝洞内物质循环中的作用提供基础数据。2017年3月在三沙永乐龙洞内约150 m深处斜坡相距10 m（152 m和162 m深处）和洞底300 m三个深度收集沉积物样品,采用Illumina MiSeq测序技术,比较研究三个不同深度沉积物中的细菌种群特征。测序共获得121690条优质序列,分类分析共检测出53个门、301个属和546种细菌。152 m、162 m和300 m深度沉积物中的细菌种群Shannon多样性指数分别为5.66、5.72和5.55。三个深度沉积物细菌种群在组成及其相对丰度上都存在明显差异,同时物种组成上又存在一定相似性和重叠情况,如Chloroflexi（绿弯菌门）和Proteobacteria（变形菌门）在三个深度沉积物中都为优势门,但其相对丰度不同,Chloroflexi的相对丰度分别为44.73%（152 m）、18.42%（162 m）和4.98%（300 m）,Proteobacteria的相对丰度分别为13.29%（152 m）、23.00%（162 m）和44.88%（300 m）。分类分析还发现了很多参与硫素循环的菌类,如绿硫细菌、脱硫酸盐还原菌、脱硫酸盐菌、脱硫球菌、硫微螺菌等,它们在不同深度沉积物中的相对丰度存在明显差异,表明在龙洞沉积物中硫素循环非常活跃,同时在不同深度沉积物中细菌参与的硫素循环步骤明显不同。     

不同地域的阳光光谱分布特性

目的研究阳光的光谱能量分布特性。方法对高原、西北沙漠、热带海洋等3个地域200~800 nm波段的阳光进行光谱测量,分析不同地区、不同天气状况、不同扫描速度下的阳光光谱能量分布特性。结果高原地区阳光光谱中的紫外-可见波段的辐照强度明显比西北沙漠和热带海洋地区高,多云时200~800 nm波段的辐射总量与晴天相比降低1/4,200~400 nm的紫外波段的辐射总量仅为晴天时的54%。光谱测量仪的扫描速度对光谱测定结果基本无影响。结论研究获得的阳光紫外截止点、340 nm处的辐照强度、不同波段的辐照量,可为实验室光源暴露试验中的光源选择、光谱能量控制提供参考。     

镉砷在针铁矿界面共吸附的相互作用机制

通过吸附动力学和吸附热力学结合表面物理化学表征等手段,研究了As(Ⅴ)和Cd(Ⅱ)在针铁矿界面上的相互作用过程,解析了As(Ⅴ)和Cd(Ⅱ)在针铁矿界面共吸附过程中形成三元络合物的形态.结果表明：(1) As(Ⅴ)和Cd(Ⅱ)在针铁矿界面的吸附过程均符合准二级动力学模型,吸附以化学吸附为主;(2) As(Ⅴ)在针铁矿界面吸附均以内圈吸附为主,具有单层吸附的典型特征,Cd(Ⅱ)在针铁矿界面单吸附过程与As(Ⅴ)类似,而添加了As(Ⅴ)的共吸附过程则出现了外圈吸附,呈现多层吸附的典型特征;(3) As(Ⅴ)和Cd(Ⅱ)共存时可通过静电作用以及形成三元络合物的方式相互促进对方在针铁矿界面上的吸附;(4)通过对比各种表征结果,推导As(Ⅴ)和Cd(Ⅱ)在针铁矿上共吸附过程中生成了“Fe-As-Cd”形式的三元络合物.研究结果进一步丰富了对土壤-氧化铁界面重金属元素微化学相互作用过程的理解.     

兰州市黄河风情线地表积尘及周边绿地土壤重金属污染特征及风险评价

为研究城市滨河公园景区地表积尘和周边绿地土壤重金属污染状况及潜在生态风险和健康风险,选择兰州市黄河风情线沿线的游园、广场和主题公园为研究区,分别采集了27个地表积尘和26个周边绿地表土样品.采用地累积指数(I_geo)、单因子污染指数(P_i)、内梅罗综合污染指数(P_N)和改进的潜在生态风险指数(RI)评估Cr、 Ni、 Cu、 Zn、 As、 Cd、 Hg和Pb这8种重金属污染特征和潜在生态风险程度,并利用暴露风险模型进行健康风险评价.结果表明,研究区地表积尘和周边绿地土壤As含量的平均值略低于甘肃省土壤元素背景值,但地表积尘的其余元素均高于甘肃省和兰州市元素背景值,而周边绿地除Cr和Ni元素略低于甘肃省和兰州市的背景值之外,其余Cu、 Zn、 Cd、 Hg和Pb含量的平均值却高于两者的背景值.地累积指数和单因子污染指数显示,研究区地表积尘受到Cr、 Cu、 Zn、 Cd、 Hg和Pb的污染,沿途绿地土壤存在不同程度的Cu、 Zn、 Cd、 Hg和Pb的污染.内梅罗综合污染指数表明,研究区地表积尘和周边绿地土壤的综合污染程...     

RATIONAL INDUSTRIAL WATER REUSE RATIOS1

ABSTRACT: This work begins by defining rational water use, and then discusses important factors that most strongly influence it. A general model is then developed to enable factories to quantify the ratio of rational industrial water reuse based on the least cost method. The model is established to minimize the cost of water with reference to gross water use and three subsystems ‐ the intake, reuse, and discharge of industrial water. Discharge cost is determined using data from a 1997 survey of 38 factories, and reuse costs are ranked and expressed by a step function. The model is verified using data from a typical semiconductor factory in northern Taiwan's Hsinchu Science Based Industrial Park, whose effective rational water reuse ratio is about 38 percent. A sensitivity analysis shows that improving water reuse technology is the most important factor in determining the rational water reuse ratio, and the price of water is the second most important. When water costs over NT$30 (New Taiwan Dollar, US$1 = NT$34) per cubic meter, increasing reuse becomes significant. The model provides a step towards the scientific management of industrial water.     

微波法处理含铬废渣的可行性分析

微波辐照解毒铬渣是一项新技术，为考察该技术应用的可行性，本文对铬渣解毒前后性状的变化进行了讨论。结果表明，该技术能较完全地使高价铬转化为低价铬，解毒渣中铬主要以三价形态存在，铬渣毒性得到消除；解毒渣浸出液中Cr^6＋浓度远低于国家危险废物鉴别标准，解毒渣已不属于危险固体废弃物，其在环境条件下可安全存放。说明该技术具有应用前景。     

低山丘陵区水土保持治理与生态环境效应

分析了低山丘陵区水土流失等级分布，水土流失的形成原因及危害，指出低山丘陵区水土流失综合治理要以小流域综合治理为主，阐明小流域水土流失的规律性，以及根据小流域3个地貌单元类型按“三条带”模式进行综合治理：山顶林草防治、山腰经济林带整治、山脚坡改梯治理的技术措施，着重论述综合治理的生态环境效应：明显地保水保土保肥，在降雨量相同的情况下等高种植、坡改梯、封山育林雨强明显小于坡耕地，起始产流时间延迟，径流量减少近2/3，土壤侵蚀量明显比坡耕地少得多。土壤侵蚀携带养分，坡耕地损失量最大，等高种植全氮、全磷的损失量最小；坡改梯有机质、有效氮、速效钾流失量较少，说明坡改梯的保肥效果优于等高种植。林草植被对改善生态系统的环境效应和提高生物多样性功能，为低山丘陵区生态环境恢复和农业可持发展奠定基础。     

AN LP-10 MODEL FOR COORDINATING MULTI-GROUP INPUTS IN RESOURCE PLANNING1

ABSTRACT A model for guiding public as well as multi-discipline inputs about the development of water and related natural resources has been developed. Optimal location of economic activities can be achieved by iterative use of the model. An example illustrating the manner the model can be used is included in the paper.     

Methylmercury, total mercury and total selenium in four common freshwater fish species from Ya-Er Lake, China

Snakehead fish (Ophiocephalus argus cantor), silver carp (Hypophthalmichthys molitrtix), crucian carp (Carassius carassius), and common carp (Cyprinus carpio) are four common freshwater fish species in China. In this study, the level of methylmercury (MeHg), total mercury (T-Hg), and total selenium (T-Se) in muscle samples of these four fish species from Ya-Er Lake, China, were analyzed using atomic fluorescence spectrometry coupled with high-performance liquid chromatography, and inductively coupled plasma mass spectrometry. The concentrations of MeHg in all the fish species were significantly correlated with those of T-Hg. Higher T-Hg and MeHg concentrations had accumulated in the snakehead fish, which is a strongly predatory fish, than in the other three species. The concentration ratios of MeHg and T-Hg in the muscles of these four fish species were almost equal. Conversely, there was negative correlation between the concentrations of T-Hg and T-Se, which implies that there is a competition between these two elements with respect to bioaccumulation. It is noteworthy that of all the muscle samples tested, the level of T-Hg exceeded the maximum allowable limit in fish [0.4 mg kg⁻¹ (w/w) recommended by the World Health Organization] in 38.46% of those of the silver carp, 18.18% of those of the crucian carp, and 100% of those of snakehead fish. These results show that the consumption of contaminated fish is a potential threat to human health and that necessary preventive measures to safeguard public health should be emphasized.     

生物滴滤塔脱除污泥干化尾气中的SO2

以市政污泥干化尾气中的主要含硫物质二氧化硫(SO2)为处理对象,从市政污泥中筛选出高效脱硫菌——嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f),搭建了实验室规模的生物滴滤塔,考察了进气质量浓度、气体停留时间、营养液喷淋密度和营养液中Fe2+浓度对生物滴滤塔脱除SO2的影响....