基于GOCI数据的太湖叶绿素a浓度反演和蓝藻水华遥感监测

太湖蓝藻水华是广为关注的环境问题,迫切需要实现蓝藻水华的动态监测。利用静止轨道海洋水色遥感器(GOCI)遥感数据构建了太湖叶绿素a反演的三波段模型,使用归一化植被覆盖指数(NDVI)进行蓝藻水华监测,并进行了富营养化评价。结果表明:(1)三波段模型优于波段比值模型,可以用于GOCI遥感数据反演太湖叶绿素a浓度。(2)2019年6月3日太湖叶绿素a大致呈湖心和西部浓度低,北部和西南沿岸浓度高的空间分布;从10:15至15:15,叶绿素a浓度先升高后降低。(3)竺山湖和椒山周边水域水华聚集情况较为严重,是当天重度水华的主要发生区域;水华的时间变化规律同叶绿素a浓度变化规律一致。(4)对2019年4月和6月的GOCI遥感数据进行富营养化评价发现,太湖富营养化水平总体呈西部高东部低、北部高南部低、边缘高中间低的趋势;6月较4月富营养化水平明显加剧。     

太湖蓝藻水华的遥感监测研究

随着太湖蓝藻水华的日益严重,实现藻类的时空动态监测成为湖泊水质保护亟待解决的问题.利用遥感技术可以快速、直观地获取整个水域水质的时空变化情况,为实现藻类的动态监测提供了有效的途径.在太湖蓝藻水华遥感监测研究结果的基础上,总结分析了现有研究中所使用的遥感数据源、遥感监测方法以及遥感反演的水质参数,讨论了现有研究中存在的问题,并对将来的发展趋势进行了展望.     

南太湖富营养化调查及评价

2009年4月至2010年4月,综合利用TN、可溶性无机氮(DIN)、叶绿素a(Chl-a)、透明度(SD)、TP和浮游植物等指标,通过参数法、综合营养状态指数法及浮游植物优势种法评价了南太湖富营养化水平。结果表明:(1)南太湖夹浦、新塘、小梅口、幻溇4个断面的TN质量浓度为1.80~2.53 mg/L,TP质量浓度为0.08~0.11 mg/L,DIN质量浓度为0.55~1.10 mg/L,Chl-a质量浓度为6.4~19.2μg/L。(2)夹浦、新塘和小梅口3个断面的综合营养状态均为轻度富营养,幻溇断面为中营养。南太湖综合营养状态水平呈现出由西南向东北逐级递减的趋势。(3)南太湖的浮游植物优势种的演替过程为鱼腥藻(Anabeana)→微囊藻(Microcystis)→拟浮丝藻(Planktothricoides),但均属于蓝藻。因此,浮游植物优势种法评价的南太湖富营养化水平为重富营养化,但该方法由于不确定性较大,一般只作为参考。     

北方典型干旱缺水型河流氮磷时空分布特征与富营养化评价

以北方典型干旱缺水型河流-滏阳河流域邢台段为研究对象,通过为期1年(2013年6月—2014年5月)的水质监测,阐述了流域内氮磷时空变化特征及富营养化水平。结果表明,流域内水体TN的平均质量浓度为28.27 mg·L~(-1)(其中NH_4~+-N占67.94%),TP的平均质量浓度为1.37 mg·L~(-1)(其中SRP占62.01%);流域内氮磷时空分布特征明显:在时间尺度上,水体中氮磷浓度均呈现出旱季(9月—次年5月)高于雨季(6—8月);空间尺度上,氮磷质量浓度分布差异明显且均呈现出市区流域高于市郊流域,沿河流流向逐渐减少的趋势;对数型幂函数普适指数公式对水体富营养化的评价结果显示:无论从时间尺度上还是空间尺度上,所有采样点都处于极富营养状态,其变化趋势与氮磷有明显的一致性,同时富营养化程度与地区污染水平呈现一定的相关性。水资源匮乏以及河流湖库化严重是造成该地区水体富营养化问题突出的主要原因。     

浙江省太湖交界断面藻类预警应急监测指标特征分析

太湖藻类的爆发呈现一定的阶段性,根据2008年太湖藻类的时空分布,将藻类爆发划分为5个阶段。在太湖流域藻类预警应急监测期间,连续监测湖州市新塘港与太湖交界断面的8项水质指标,研究藻类爆发不同阶段交界断面水质指标的变化情况,采用Pearson相关分析法分析各水质指标间的相关性,探讨不同时期太湖流域藻类预警应急监测应重点关注的水质指标,为浙江省太湖流域藻类防控提供理论依据。     

模糊物元识别模型在巢湖水体富营养化评价中的应用研究

选取TN、TP、Chl-a、COD、BOD5、DO和SD等7项指标,应用模糊物元识别模型对2000~2007年巢湖的12个水质监测点的富营养化等级进行了模糊识别。通过与巢湖同期水质浓度变化及其分布区域进行对比分析,验证了模糊物元识别模型在巢湖水体富营养化评价中的适用性。巢湖富营养化评价结果表明,2000~2007年富营养化呈逐年加重的趋势,据采样点模糊物元计算结果得知西巢湖(1#~6#)的富营养化状况比东巢湖(7#~12#)更严重,西巢湖贴近度最高值为0.9974,接近极富营养状态,而东巢湖的最高值仅为0.5866。从年际变化上看,2000~2007年东巢湖富营养化状况变化不大,营养状态级处在较低的水平,而西巢湖的富营养状况变化则较大,营养状态级则处在较高水平。     

改进的TLI指数法及其在巢湖营养状态评价中的应用

对巢湖2000—2008年的监测数据运用SPSS做统计分析,得出叶绿素a与总氮、总磷和透明度的相关系数。通过得出的权重结果,分析出与26个湖泊的差异性,构建了改进的综合营养状态指数(TLI)评价方法,并提出评价的4个步骤。以巢湖为例,运用该方法对湖泊的营养状态进行评价,且对巢湖的富营养化程度做了年际和年内变化的综合评价,评价结果显示各营养物指标的相关关系在近30年有了较大变化,巢湖的富营养化现象已日益严重,已从轻度富营养化状态转变为中度富营养化状态。     

基于RDALR模型分析气象条件对太湖蓝藻水华发生的影响及预报

近年来,太湖水体出现多次严重的蓝藻水华过程,所以探索气象条件引发蓝藻水华的暴发机制及预报方法有着重要的理论意义及实际价值。由于chl-a含量的动态变化可反映水华与否,可利用粗糙集决策调节回归模型(rough decision-adjusted logistic regression model,RDALR)将粗糙集理论与二元逻辑回归(binary logistic regression,BLR)结合起来,用来建立气象条件和太湖chl-a含量二者之间的联系,为蓝藻暴发期水华预报提供一可行方法,且该方法具有一定可移植性。2012年5月1日—9月5日,对东山24项气象数据和东太湖6个取水口水质监测数据分析表明:RDALR模型解释了东太湖128 d水华监测日71.6%的chl-a动态变化,与BLR模型相比,将39次水华暴发的预报精度提高15%。对RDALR模型分析得出,当模型显著性水平小于0.05时,东太湖水域水华强度与平均风速、平均相对湿度呈显著正相关,与日降水量(P)呈显著负相关,同时水华强度与气温(T)、日照时数(SD)及最大风速风向(WD)等其他气象条件相关不显著。     

中国省际能源利用-经济发展-环境保护系统的时空耦合协调度分析

基于Super-SBM模型测算中国2000—2017年省际能源效率,并在此基础上构建能源利用-经济发展-环境保护(3E)系统综合评价体系,采用变异系数法、三元系统耦合协调模型与灰色GM(1,1)预测模型分析中国3E系统耦合协调度的空间布局及动态演变趋势。结果表明:(1)研究期内能源效率整体呈先降后升趋势,2000—2014年由0.564降至0.422,2014—2017年由0.422升至0.440,呈东部、中部、西部递减的空间分布特征;(2)研究期内中国3E系统耦合协调度由0.483升至0.672,三大区域差异明显,呈由东部沿海地区向周边省份发展的时空规律;(3)预测结果表明2018—2022年各省3E系统耦合协调度均有所提升。     

再生水补水人工湖水域聚类划分及水质指标时空分布特征

以天津临港生态湿地公园人工湖水质和水文的调查数据为依据,运用相关性分析和聚类分析将研究水体划分为3类水域。研究了不同聚类水域水温、DO、p H、氮磷营养元素以及Chla的时空分布特征。结果显示,DO、硝态氮、TN、TP与流速呈显著正相关,水温、SS与流速呈显著负相关。Chla与水深呈显著正相关,TN、硝态氮与水深呈显著负相关。断面宽度与所有理化指标均没有显著相关性。3种水域在监测期间N/P比(TN/TP)显示湖泊正在从氮营养元素限制型(N/P7)向适宜藻类生长的营养类型过渡。富营养化评价显示,再生水为补水的临港人工湖在监测期间水质已处于中度富营养,主要贡献因子为COD和TP。     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

Evaluation of the presence of drugs of abuse in tap waters

A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L⁻¹, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L⁻¹. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L⁻¹). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L⁻¹ (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L⁻¹, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L⁻¹). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L⁻¹ (Spain) and 0.3 ng L⁻¹ (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.     

不同泥源对厌氧氨氧化反应器启动的影响

采用2套上流式生物膜反应器,分别接种少量厌氧氨氧化污泥和大量硝化污泥,考察其对厌氧氨氧化反应器启动的影响。污泥接种入反应器后,测得接种厌氧氨氧化污泥的反应器(R1)内MLSS为0.22 g/L,另一个反应器(R2)MLSS为2.7 g/L。与直接接种厌氧氨氧化污泥相比,R1经过72 d的运行才显现出厌氧氨氧化特性。经过114 d的培养,前者氮去除速率由0.23 kg/(m3.d)提升到5.29 kg/(m3.d),总氮去除率大于89%;R2的氮去除速率由0.01 kg/(m3.d)提升到1.1 kg/(m3.d),总氮去除率大于84.6%。说明普通污泥启动需要一个较长的筛选过程,直接接种少量的厌氧氨氧化污泥比接种普通的污泥能够更快启动厌氧氨氧化反应器。     

Mechanisms of biodegradation of dibenzoate plasticizers

Biodegradation mechanisms were elucidated for three dibenzoate plasticizers: diethylene glycol dibenzoate (D(EG)DB), dipropylene glycol dibenzoate (D(PG)DB), both of which are commercially available, and 1,6-hexanediol dibenzoate, a potential green plasticizer. Degradation studies were done using Rhodococcus rhodochrous in the presence of pure alkanes as a co-substrate. As expected, the first degradation step for all of these systems was the hydrolysis of one ester bond with the release of benzoic acid and a monoester. Subsequent biodegradation of the monobenzoates of diethylene glycol (D(EG)MB) and dipropylene glycol (D(PG)MB) was very slow, leading to significant accumulation of these monoesters. In contrast, 1,6-hexanediol monobenzoate was quickly degraded and characterization of the metabolites indicated that the biodegradation proceeded by way of the oxidation of the alcohol group to generate 6-(benzoyloxy) hexanoic acid followed by β-oxidation steps. This pathway was blocked for D(EG)MB and D(PG)MB by the presence of an ether function.The use of a pure hydrocarbon as a co-substrate resulted in the formation of another class of metabolites; namely the esters of the alcohols formed by the oxidation of the alkanes and the benzoic acid released by hydrolysis of the original diesters. These metabolites were biodegraded without the accumulation of any intermediates.     

造纸废水混凝处理中SFT助凝替代性研究

中小造纸厂废水处理常用PAC作混凝剂 ,PAM作助凝剂。由于PAM成本很高 ,影响了处理设备的投运率。用超细滑石粉 (SFT)替代PAM助凝 ,与混凝剂PAC配合 ,其混凝处理效果基本相当 ,但是处理成本降低 0 .10元 /m3 。由于SFT属环境无害材料 ,不会给排泥带来二次污染     

混凝试验搅拌器的研制

影响混凝效果的因素众多,混凝沉淀烧杯试验是进行水的混合、絮凝、沉淀工艺研究、设计和生产指导的最有效方法之一,阐述了智能型混凝试验搅拌器的设计原理和技术性能.     

生物质快速热裂解主要参数对生物油产率的影响

以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%(质量百分比).反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径＜1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径.     

Visualisation of the complexity of EUSES

The interdependencies of parameters applied in the models of EUSES are visualised in a directed connectivity graph. The parameters (inputs, defaults, state variables, outputs) are represented by boxes (nodes) and their relations by lines (edges). The visualisation, on the one hand, clarifies the complexity of the models in EUSES and, on the other hand, creates an overview and transparency. The parameters’ relations to each other can be recognised faster, and the models can be better understood. The complexity was quantified by the number (variety), kind (substance parameter, physico-chemical parameter, concentration, other parameters), and depth (dimension) of the parameter and the number of relations (connectivity). The variety of EUSES (without the modelsSimple Treat andSimple Box whose interior structure is not documented and without the effect and risk characterisation) amounts to 466, the connectivity to 961, and the maximal dimension is 21.