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。     

西安某人工湖水质时空分布特征及其荧光特性

2013年10月到2014年9月,通过对西安某人工湖水温、DO、SD、pH、TN、TP、COD、叶绿素a等10项水质指标进行监测,评价了水体的营养状态,分析了水质的时空分布特征及其可能污染来源,并对其进行三维荧光光谱分析。结果表明,实验期间,该人工湖在5—7月处于中度富营养化状态,其他月份均处于轻度富营养化状态。在时间上,NO-3-N、NH+4-N和TN在14年2月到5月明显高于其他月份,其中NO-3-N是构成TN的主要存在形态,TP含量变化无明显规律,COD在14年3月到5月含量较高,5—7月是人工湖的藻类暴发期,叶绿素a较其他月份高,在空间上,NO-3-N、NH+4-N和TN各采样点间没有显著差异,TP、COD和叶绿素a波动较大,这可能与采样点附近的局部污染有关。9月份湖内的溶解性有机物主要是腐殖酸类,主要来源是微生物的生命活动和死亡分解,含量沿湖体采样点下降。     

深圳大工业区初期雨水水质污染特征研究

为研究深圳大工业区初期雨水水质污染特征,分别选择深圳大工业区6个功能区作为监测点监测初期雨水中污染物浓度。结果表明:深圳大工业区居住区和商业区初期雨水COD污染最严重,COD最高分别达到1 467.00、1 333.00mg/L;出口加工区及高科技工业和现代物流业区域的初期雨水TN、TP浓度略低于其他区域。初期雨水中COD、氨氮、TP浓度与SS浓度存在线性相关关系,而TN浓度与SS浓度的线性相关性较差,不同区域随降雨历时变化规律波动各异。深圳大工业区附近河流SS、COD、TN、氨氮、TP浓度受初期雨水影响较大。     

生态塘?生态沟渠耦合系统低温条件的运行效果研究

构建生态塘/生态沟渠耦合系统的中试工程并在低温条件下连续运行,考察耦合系统对微污染水体的净化效果。结果表明,生态塘/生态沟渠耦合系统在低温运行阶段对COD、TN、氨氮及TP的平均去除率分别为54.50%、37.43%、53.00%、44.20%。pH对COD和TP的去除率影响不明显,与氨氮呈正相关关系,线性相关系数R2=0.705 92;耦合系统中DO供给充足,因此DO对COD、TN、TP去除率的影响并不明显,DO仅与氨氮去除率呈显著正相关,线性相关系数R2=0.771 64。     

最大光能转化效率F_V/F_M用于城市人工水体藻华的监控预警

结合2012年5—10月对上海市区2个典型城市人工水体藻华过程叶绿素、最大光能转化效率FV/FM变化,及其与水质指标的关系,研究FV/FM用作城市人工水体藻华监控预警指标的可行性。结果表明,曲阳公园、黄兴公园的FV/FM分别在0.57~0.71和0.58~0.63之间;人工模拟昼夜日照和温度变化培养曲阳公园藻华的水藻得到,藻类生长适应期FV/FM<0.60,对数期FV/FM>0.60,FV/FM与藻类生物量无显著相关性,仅反映藻类所处生长阶段。分析FV/FM和叶绿素a与浊度、COD、TN、TP的相关性得到,FV/FM能兼顾藻类在富营养化水体中的生理环境和生长特性,综合反映了藻华在城市人工水体形成相关的物理、化学、生长特性等因素,对研究水体FV/FM=0.63可作为预警水体藻华发生的阈值。研究成果为城市人工水体藻华暴发的监控、预警提供新的途径和方法。     

冬季西安某人工湖污染物分布特征及其相关性分析

以西安某人工湖为研究对象,在湖体中布设9个采样点,并且在2013.12—2014.1期间采样3次,对其中TN、TP、COD、NH+4-N和NO-3-N等污染物分布及其与叶绿素a浓度的相关性进行了相应的研究。结果表明,湖体中NH+4-N、NO-3-N、TN、TP、COD和叶绿素a的浓度分别为:0.8~1.7 mg/L、1.1~2.9 mg/L、2.5~4.8 mg/L、0.04~0.14 mg/L、20~24.8 mg/L和0.82~2.14μg/L。人工湖进、出水口污染物浓度整体较低,在靠近车流量较大的3座交通桥的采样点4、5和8采样后所测各项污染指标均较其他点高,由此说明在研究期间交通桥可能成为此人工湖的点污染源。污染物相关性分析结果显示,在冬季低温条件下(4~6℃)叶绿素a与TN、TP、NH+4-N、NO-3-N的相关系数分别为:R2=0.55~0.75,P0.05;R2=0.4~0.65,P0.05;R2=0.48~0.62,P0.05;R2=0.15~0.44,P0.05;COD和浊度呈极显著相关:R2=0.67~0.85,P0.01。     

池塘养殖水体pH、营养盐、叶绿素a及3种磺胺类抗生素分布特征及其相关性分析

为了解农村池塘养殖水体的水质情况,分析了湖北宜东平原34个农村分散养殖鱼塘水体中pH、叶绿素a、总氮(TN)、总磷(TP)及3种磺胺类抗生素(SAs,即磺胺二甲嘧啶、磺胺甲噁唑及磺胺异噁唑),并讨论了它们之间的相关性.结果表明,所监测鱼塘水体pH值差异较小,范围为7.26 ～8.96,但鱼塘之间的TN、TP及叶绿素a含量差别大,其含量范围分别为0.074 ～47.185 mg/L、0.007 ～ 1.311 mg/L及4～421 μg/L.其中有85.29％的鱼塘水体TN含量劣于地表水Ⅴ类标准,17.65％ TP劣于Ⅴ类,只有3个鱼塘的叶绿素a含量小于10 μg/L,水体富营养化严重.鱼塘水中3种SAs的浓度范围为23 ～ 828 ng/L,其检出率顺序为磺胺异噁唑(47％)＞磺胺甲噁唑(18％)＞磺胺二甲嘧啶(6％).对所考察因子的相关性研究表明,鱼塘养殖水体的pH、TN及TP无相关,但磺胺二甲嘧啶与TN/TP呈显著正相关(r=0.345,P=0.05).叶绿素a与水体中TN及TP的关系呈较好的幂指数函数关系,而且TP为浮游植物的生长限制因子.     

不同工况条件对Carrousel氧化沟脱氮除磷影响研究

采用Carrousel氧化沟处理实际生活污水，考察了DO、TCOD/TN和污泥回流比对氧化沟单沟内同步脱氮除磷效果的影响。结果表明，在相同HRT、污泥回流比、TCOD/TN比的工况下，氧化沟系统对TN、TP的去除率随着DO浓度的增加而降低；在相同HRT、污泥回流比、DO的工况下，氧化沟系统对TN、TP的去除率随着TCOD/TN比的增加而提高；在相同HRT、DO和TCOD/TN比的工况下，氧化沟系统对TN的去除率随着回流比的增加而提高，而对TP的去除率随着回流比的增加而降低。     

巢湖水质时空分布模式研究

依据2004~2006年12个采样点11个水质指标数据,应用主成分分析(PCA)、聚类分析(CA)、判别分析(DA)和基于G IS平台的克里格插值法,对巢湖水质时空分布模式进行研究。通过统计分析将巢湖11个水质指标概括为4个主成分:第一主成分COD、BOD5和Chl-a;第二主成分电导率、NH4+-N、TN和TP;第三主成分温度和DO;第四主成分pH和SD。在空间尺度上分为2组,分别对应于东西半湖。除了DO指标,空间上西半湖周边区域的水质指标浓度显著高于东半湖;东西半湖TP和COD空间分布相似;在时间尺度上,可分为1月~3月份、12月份一组和4月~11月份一组;TP、COD、DO和SD指标第一时期浓度高于第二时期,温度、电导率和Chl-a指标则相反;溶解氧和温度两者的时间差异性呈现明显的负相关。并对采样点和采样频次进行了适当优化。     

长春南湖营养盐与叶绿素a的分布与富营养化评价

在研究长春南湖水体中TP、TN和叶绿素a的时空分布及相关性的基础上,采用综合富营养化指数法对南湖水体进行评价。结果表明:(1)常温期,TP、TN和叶绿素a含量均为9月5月;9月的TP、TN为表层底层,叶绿素a含量为底层表层;5月的TP、TN和叶绿素a的含量均为底层表层;TP为渔场保护区人为活动区荷花池区,TN和叶绿素a含量均为渔场保护区荷花池区人为活动区。(2)冰封期,TP、TN和叶绿素a含量为水层冰层;TP、叶绿素a含量为渔场保护区人为活动区,TN为人为活动区渔场保护区。与常温期相比,TP、TN和叶绿素a含量总体上均为9月5月2月;各区水体中TP和叶绿素a含量的分布与常温期保持一致,而TN的分布有一定的变化。(3)相对于氮,磷含量的高低是控制藻类及浮游生物生长更为关键的因子。(4)9月的营养级别是中度富营养,2月的营养级别是中营养,5月的营养级别是轻度富营养。综合营养状态指数大小依次为9月5月2月。常温期不同功能区的营养级别均属轻度富营养。     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

Radionuclides and trace elements in fish collected upstream and downstream of Los Alamos national laboratory and the doses to humans from the consumption of muscle and bone

Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for ³H, ⁹⁰Sr, ¹³⁷Cs, ^totU, ²³⁸Pu, ^239,240Pu, and ²⁴¹Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of ⁹⁰Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g^‐1 [126E‐02 Bq kg^‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g^‐1 [518E‐02 Bq kg^‐1]). The differences in ⁹⁰Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y^‐1 (1.0 ± 1.0 μSv y^‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y^‐1 (1000 μSv y^‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.     

Observations on the influence of water and soil pH on the persistence of insecticides

Abstract

The pH‐disappearance rate profiles were determined at ca. 25°C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water‐ethanol (99: 1 v/v). Half‐lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (>1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1–2 days for trichlorfon and oxamyl to >1 year for fensulfothion and cyper‐methrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

Radionuclides in deer and elk from Los Alamos national laboratory and the doses to humans from the ingestion of muscle and bone

Abstract

This paper summarizes radionuclide concentrations (³H, ⁹⁰Sr, ¹³⁷Cs, ²³⁸Pu, ^239,240Pu, ²⁴¹Am, and ^totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y^‐1 (2.2 μSv y^‐1), deer bone = 3.8 mrem y^‐1 (38 μSv y^‐1), elk muscle = 0.12 mrem y^‐1 (1.2 μSv y^‐1), and elk bone = 1.7 mrem y^‐1 (17 μSv y^‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y^‐1 (1000 μSv y^‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.     

Radionuclides in pinon pine (Pinus edulis) nuts from los alamos national laboratory lands and the dose from consumption

Abstract

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of ³H, ¹³⁷Cs, ⁹⁰Sr, ^totU, ²³⁸Pu, ^{239, 240}Pu, and²⁴¹ Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of ³H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.     

Degradation and sorption of imidacloprid in dissimilar surface and subsurface soils

Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. This research characterized the degradation and sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) in Drummer (silty clay loam) and Exeter (sandy loam) surface soils and their corresponding subsurface soils using sequential extraction methods over 400 days. By the end of the incubation, approximately 55% of imidacloprid applied at a rate of 1.0 mg kg^?1 degraded in the Exeter sandy loam surface and subsurface soils, compared to 40% of applied imidacloprid within 300 days in Drummer surface and subsurface soils. At the 0.1 mg kg^?1 application rate, dissipation was slower for all four soils. Water-extractable imidacloprid in Exeter surface soil decreased from 98% of applied at day 1 to > 70% of the imidacloprid remaining after 400 d, as compared to 55% in the Drummer surface soil at day 1 and 12% at day 400. These data suggest that imidacloprid was bioavailable to degrading soil microorganisms and sorption/desorption was not the limiting factor for biodegradation. In subsurface soils > 40% of ¹⁴C-benzoic acid was mineralized over 21 days, demonstrating an active microbial community. In contrast, cumulative ¹⁴CO₂ was less than 1.5% of applied ¹⁴C-imidacloprid in all soils over 400 d. Qualitative differences in the microbial communities appear to limit the degradation of imidacloprid in the subsurface soils.