水杨酸对多氯联苯污染土壤的修复和微生物群落结构的影响

以浙江省台州电子垃圾拆解地附近多氯联苯污染的农田土壤为研究对象,考察了施肥基础上添加不同剂量水杨酸(5、10、20 mmol·kg-1)对土壤中多氯联苯的去除、脱氢酶活、微生物群落结构及联苯双加氧酶基因相对丰度的影响.结果表明,施肥和施肥基础上添加水杨酸均能显著提高多氯联苯的去除率(p0.05),其中,三氯联苯的去除率最高(28.98%~34.53%).土壤脱氢酶活与多氯联苯去除率随水杨酸添加量的升高呈先增大后减小的趋势,均在10 mmol·kg-1水杨酸处理中达到最大.PCR-DGGE结果显示,水杨酸处理土壤中新增伯克氏菌属(Burkholderia)、潘多拉菌属(Pandoraea)、噬油脂极小单胞菌属(Pusillimonas)、鞘脂菌属(Sphingobium)、甲基杆菌属(Methylobacterium)和青枯菌属(Ralstonia).Shannon指数表明,10 mmol·kg-1水杨酸处理下土壤微生物最为丰富(p0.05).荧光定量PCR显示,bph A基因在不同处理间没有显著差异,但施肥和施肥基础上添加10、20 mmol·kg-1的水杨酸处理都显著提高了bph D.1.B、bph D.1.C、bph D.2.A和bph D.2.A/B基因的相对丰度.     

PDMDAAC改性膨润土处理染料废水的实验研究

膨润土是一种以蒙脱石为主要成分的粘土,被广泛应用于染料废水脱色、有机废水处理等领域.实验以寻求一种新型水处理剂为目标,采用膨润土为原料,PDMDAAC为改性剂,制备新型改性膨润土——PDMDAAC改性膨润土,并应用于染料废水处理中.PDMDAAC改性膨润土最佳制备条件为改性剂为6 g原土投加量为12 g、改性时间为40 min、改性温度为45℃.单因素实验确定PDMDAAC改性膨润土处理分散深蓝染料废水100 mL的最佳处理工艺条件为:改性膨润土投加量为3 g、pH9、搅拌时间为45 min、搅拌速度250 r/min,分散深蓝染料废水原水浓度为100 mg/L.正交实验对工艺条件进行验证,结果表明:分散深蓝染料废水100 mL,分散深蓝染料废水原水浓度小于150 mg/L,改性膨润土投加量为3 g,搅拌时间60 min,搅拌速率为250 r/min,pH为9,在此基础上进行实验,染料废水脱色率可达98％.     

外浮顶原油储罐VOCs排放核算参数对排放量的影响

依据美国环保署颁布的储罐VOCs排放量核算公式,从环境参数、原油参数和储罐结构参数3个方面对外浮顶储罐VOCs排放的影响进行了研究,其中包括了边缘密封排放挂壁排放、浮盘附件排放和浮盘着陆期间排放等几个相关排放核算数学公式。结果表明:环境风速增大,环境温度升高或太阳辐射强度提高均导致排放量增大;原油温度升高或原油周转量增加也导致排放量增加;储罐直径增加,罐漆颜色浅,或者罐壁锈蚀情况好会降低VOCs排放量。     

Founder need to belong,tertius iungens orientation and new venture performance

In this study, we examine the role of founders' need to belong and tertius iungens orientation (i.e., the tendency of bringing people together and coordinating among others) in the context of new ventures. We propose and document evidence that a founder's tendency to engage in tertius iungens oriented networking is positively associated with new venture performance. We also reveal that a founder's need to belong is a significant motivational antecedent of the founder's tertius iungens orientation. Further, the need to belong–networking orientation linkage is stronger for founders in new ventures at the early product development stage than those at the late product development stage. We tested our hypotheses using survey data collected with a two‐wave sample of new ventures in China. We discuss the theoretical significance of studying the need to belong and tertius iungens orientation for social networks and entrepreneurship literatures, as well as the practical implications for managing a successful new venture.     

水环境质量区间隶属度评价法

通过对水环境质量综合评价中的灰色关联分析法进行分析,认为水环境质量评价标准是区间概念,将评价标准处理成点的传统灰色关联分析法存在一定的缺陷。为克服这种缺陷,提出一种水环境质量区间隶属度评价法,该方法借鉴了模糊综合评价法的距离计算原理,但比模糊综合评价法更为简单、直观,具有较强的适用性。     

安徽省乔木林固碳能力研究

以安徽省第六次森林资源连续清查结果为依据,对安徽省不同类型乔木林固碳能力进行了研究。结果表明,不同林种乔木固碳能力依次为：用材林（薪炭林（特种用途林（防护林;不同发育阶段乔木林固碳能力依次为：幼龄林（中龄林（近成熟林（成熟林（过成熟林;不同优势树种组乔木林固碳能力依次为：针叶林（阔叶林（针阔混交林;不同优势树种乔木林固碳能力依次是：杉木林（马尾松林（杨树林;同时,得出相同龄组但不同优势树种或相同优势树种但不同龄组的乔木林固碳能力也不同,其中杉木的幼龄林固碳能力最大,达到19.75 t/（hm^2.a）。     

中国气候状况及应对气候变化方案和措施

由于受人类活动和自然因素的综合影响,自20世纪50年代以来,中国年平均气温已升高了0.68℃,其中黄河以北地区平均升高了0.8℃～1.2℃,黄河以南地区平均下降了0.2℃～0.8℃;而北方年降水量减少,南方却增加,南涝北旱加剧。经模拟预测后认为,中国从1987年开始的气候变暖将持续到2015年,将于2016年转入低温期,2039年又将转入高温期。到2020年全国年平均气温将比20世纪50年代升高1.68℃,西北地区平均升高2.22℃;南方年平均降水量增加28 mm,北方变化不大;2030年海平面将升高5.3 cm～14.2 cm,气候将向暖、干的趋势发展。因此中国发布《中国应对气候变化国家方案》及对此采取综合对策。     

旋转流厌氧附着膜膨胀床运行及水力流态研究

试验以树脂为载体,用自行设计的旋转流厌氧附着膜嘭胀床处理高浓度有机废水.经过启动、中等负荷稳定运行及高负荷稳定运行等阶段,成功地培养出高效生物膜颗粒,最高有机负荷达46.4 kg/(m3·d).相应的COD去除率大于80%.在反应器运行过程中采用脉冲示踪法,以LiCl作示踪剂,对反应器的水力流态规律进行了系统的试验研究.研究表明,水力上升流速及气体负荷是影响反应器容积利用率及反应器内固液两相混合程度的重要因素.     

混凝土生态膜法污水处理工艺生物相及其水处理实验研究

研究了混凝土生态膜污水处理工艺的循环挂膜过程.综合考察了混凝土膜片表面生物膜的生长变化情况、细菌数量及其微型动物的组成演化.生物膜成熟以后,投加实际生活污水连续运行:COD的平均去除率为76.0%;BOD5平均去除率为94.9%,出水均小于8.00 mg/L;NH3-N的去处理效果明显,第5周达到54.1%,出水可达到广东省一级排放标准中的相关规定.     

Occurrence and risk assessment of currently used organophosphate pesticides in overlying water and surface sediments in Guangzhou urban waterways,China

Organophosphate pesticides (OPPs) are one type of the most massively used pesticides and ubiquitously detected in aquatic environments, which may pose potential risks to the aquatic organisms and human health. In the present study, the spatiotemporal distribution and potential risks of OPPs were investigated in overlying water and surficial sediments from urban waterways of Guangzhou. For all studied sites, in general, four target OPPs (i.e., malathion, chlorpyrifos, terbufos, and diazinon) were present in the overlying water, with malathion and chlorpyrifos as major components. Higher concentrations of the four OPPs were found for the water and sediments collected in the dry season compared to the wet season, possibly because of the dilution effect of heavy rains. The results of Pearson’s analyses and principal coordinate analyses (PCoA) suggested similar sources for target OPPs in the water and sediments across the Guangzhou urban waterways. Potential ecological risks of the OPPs to three representative taxons (algae, aquatic invertebrates, and fish) were evaluated via toxic units (TUs) and risk quotients (RQs), while risk assessment on human health was performed using hazard index (HI). Although TU results showed no acute risks to the aquatic organisms in the overlying water and surface sediments, RQ results of the mixture showed high risks to the aquatic invertebrate and fish in all water samples. Individual HI values and cumulative HI values were on the order of 10^?6–10^?3 for children and adults, suggesting no potential risks to either children or adults through drinking and bathing.

Graphical abstract