综合权重的集对分析模型在污水处理厂改造决策中的应用

针对污水处理厂升级改造的多目标决策问题,运用集对分析理论,构建了污水处理厂运行效果综合评价模型。通过引入熵权法和层次分析法确定指标权重,构造了一种新的计算指标综合权重的方法。应用该模型对上海市11座污水处理厂进行综合评价,与模糊综合法的评价结果做了比较。结果表明:基于综合权重的集对分析模型具有更高的准确性和合理性,为污水处理厂的升级改造决策提供了一种较为可靠的评价方法。     

盐城海岸带土壤重金属污染风险评价比较研究

以盐城海岸带为研究区,分别采用地质累积指数法、内梅罗指数法和潜在生态危害指数法对土壤重金属污染进行风险评价,分析不同方法在评价同一研究区时结果的差异性。结果表明,研究区Cr、Ni、Zn、Cd质量浓度平均值超过盐城海岸带环境背景值。地质累积指数法显示研究区土壤重金属在中度污染到强污染;内梅罗指数法显示研究区土壤重金属为重度污染;潜在生态危害指数法显示研究区土壤重金属处于中度潜在生态危害程度。3种方法评价结果的严重程度为:内梅罗指数法地质累积指数法潜在生态危害指数法。3种评价方法均有一定缺陷与局限性,相对于单一方法的污染评价,采用多种方法评价土壤重金属污染可使评价结果更加客观。     

大气环境中PM_(2.5)在线监测及评价理论研究

基于光散射法研制了一种PM_(2.5)在线监测系统,运用该系统对PM_(2.5)质量浓度进行实时监测。鉴于PM_(2.5)在空气质量评价中仅作为一个参考指标,专门针对PM_(2.5)的评价机制研究较少,将层次分析法与模糊评价法相结合,对一段时间内PM_(2.5)的浓度进行评价,得到时段内空气PM_(2.5)的质量状况。模糊评价法可很好地反映评价等级划分的模糊性和连续性,层次分析法能够将复杂的系统进行定量处理,评价结果符合实际情况。     

基于内梅罗指数的阳宗海湖滨湿地水环境质量评价

在采集阳宗海湖滨湿地水样并测定水样中富营养化指标和重金属指标的基础上,用内梅罗指数法对不同湖滨湿地区域的水环境质量进行评价。结果表明:TP总平均质量浓度为0.095mg/L,是《地表水环境质量标准》(GB 3838—2002)Ⅲ类水标准(0.05mg/L)的1.9倍;COD总平均质量浓度为19.59mg/L,未超过GB 3838—2002Ⅲ类水标准(20mg/L);阳宗海湖滨湿地As污染最为严重,总平均质量浓度为0.112mg/L,超过了GB 3838—2002Ⅴ类水标准(0.10mg/L),Zn、Cu、Cr未超过GB 3838—2002Ⅲ类水标准,Cd、Mn、Ni、Pb、Co未检出;4个湖滨湿地区域富营养化指标的内梅罗指数评价结果均为良好,空间上表现为北部东部南部西部;重金属指标的内梅罗指数评价结果为东部和北部中度污染水平,南部和西部重度污染水平,空间上表现为南部西部东部北部。     

天津海域海上化学品事故环境风险评估

以天津港水域为主要研究对象,建立了基于层次分析法的多级模糊综合评价模型,对天津海域船舶化学品事故发生风险进行评估。同时,选取了天津港附近海域环境风险影响评价指标,采用了基于危害后果指数法,推导出事故发生对区域海洋环境造成的危害程度。为海事主管部门摸清天津海域船舶化学品事故的风险特征,建立可靠的防范应急机制提供了技术支持。     

三峡水库蓄水运行后入出库断面水质评价与预测

三峡工程运行后库区水质问题关系库区环境安全和当地社会经济发展,把握三峡库区水质变化趋势是水污染治理的基础。采用内梅罗污染指数法,基于2004—2016年三峡库区长江干流入库断面(重庆朱沱)和出库断面(湖北宜昌南津关)水体DO、高锰酸盐指数和氨氮的水质监测数据评价库区水质,并利用差分自回归移动平均模型(ARIMA模型)建立入出库断面水质变化趋势模型。结果表明:2004—2016年入库断面梅罗污染指数(Ip)为1.72～3.22,水质属轻污染—重污染,变化波动大;出库断面Ip为0.82～1.46,水质属清洁—轻污染,总体保持平稳;入库断面水质指标逐年偏向《地表水环境质量标准》(GB 3838—2002)中Ⅱ级标准,出库断面水质指标逐年偏向Ⅰ级标准,入出库断面首要污染物是氨氮,ARIMA模型预测显示未来入出库断面水质好转。     

X市土壤重金属污染空间特性分析与风险评价

主要采用内梅罗综合指数和潜在生态风险指数对X市土壤重金属Cd、Hg、As和Pb污染程度进行评价,并通过地统计学、地理信息系统(GIS)评价法以及空间自相关分析法研究土壤重金属分布空间特性。结果表明:X市土壤中Cd、Hg、As和Pb质量浓度均值分别为0.509 8、0.162 8、8.774 7、34.601 5mg/kg,受人为影响较大,特别是As和Pb;内梅罗综合污染指数得出,有8.8%、5.2%、7.8%样点分别属于轻度、中度和重度污染;总潜在生态风险指数得出,有8.7%、5.2%样点分别存在中等危害和强危害生态风险;Cd、Hg、As和Pb都存在较强的空间自相关性,总体上呈现南高北低或东高西低分布的现象,东南部的p镇有较严重的土壤重金属污染问题。     

基于支持向量机的地下水质量综合评价

提出基于支持向量机(SVM)机器学习算法的地下水质量评价模型。首先给出了训练样本生成和数据规范化处理的具体方法,然后采用支持向量机的多分类算法构建模型,并使用k折交叉核实方法对参数进行验证优化。最后通过实证分析,并与单因子指数法、模糊综合评价法和BP神经网络法的评价结果对比分析可知,该方法简便易行,评价结果客观且准确度较高,具有很强的实用性。     

内梅罗污染指数在运河水质评价中的应用

应用内梅罗污染指数公式,计算了１９９４－１９９８年运河（杭州段）各监测点位的污染指数,用较直观的数据来评价运河（杭州段）的污染状况。     

战略环境评价有效性评价指标体系与方法探讨

近年来,战略环境评价(SEA)的有效性研究逐渐受到关注,但是当前国内外研究缺乏对SEA有效性评价指标和评价方法的探讨.针对SEA评价模式,初步构建了包括背景有效性、程序有效性、目标有效性和增量有效性等4项一级指标和11项二级指标的评价指标层次结构,提出采用层次分析法和模糊综合评价法对SEA的有效性进行综合评价.在此基础上,尝试性地以天津滨海新区SEA为例,应用模糊评价法对其有效性进行定量分析,为进一步建立SEA有效性评价标准提供思路,为完善SEA有效性评价方法和模型提供理论支持.     

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.     

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.     

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.     

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.     

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.     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

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.     

Biochemical interaction of six op delayed neurotoxicants with several neurotargets

Abstract

Five organophosphorous insecticides: Leptophos, EPN, Cyano‐fenphos, trichloronate and salithion proved to cause irreversible ataxia not only to chicken but also to mice and sheep. TOCP was included as a reference. Cyanofenphos blocked the catecholamine B‐receptor binding activity with ³H‐norepinephrine at a level similar to that of the specific inhibitor propranolol in the mouse heart preparation. In the lamb heart preparation, the B‐receptor was more sensitive to Leptophos, salithion and TOCP than to propranolol. The six compounds and their oxons were screened for their in‐vitro inhibition to monamine oxidase (MAO), acetyl cholinesterase (AChE) and neurotoxic esterase (NTE) in the brain of either mouse, lamb or chicken. It is believed that their AChE inhibition stands for their acute toxicity, while NTE inhibition is responsible for their paralytic ataxia.     

Phytoextraction of lead-contaminated soil using vetivergrass (<Emphasis Type="Italic">Vetiveria zizanioides</Emphasis> L.), cogongrass (<Emphasis Type="Italic">Imperata cylindrica</Emphasis> L.) and carabaograss (<Emphasis Type="Italic">Paspalum conjugatum</Emphasis> L.)

Background, Aims and Scope The global problem concerning contamination of the environment as a consequence of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contributes to a variety of health effects such as decline in mental, cognitive and physical health of the individual. An alternative way of reducing Pb concentration from the soil is through phytoremediation. Phytoremediation is an alternative method that uses plants to clean up a contaminated area. The objectives of this study were: (1) to determine the survival rate and vegetative characteristics of three grass species such as vetivergrass, cogongrass and carabaograss grown in soils with different Pb levels; and (2) to determine and compare the ability of the three grass species as potential phytoremediators in terms of Pb accumulation by plants. Methods The three test plants: vetivergrass (Vetiveria zizanioides L.); cogongrass (Imperata cylindrica L.); and carabaograss (Paspalum conjugatum L.) were grown in individual plastic bags containing soils with 75 mg kg⁻¹ (37.5 kg ha⁻¹) and 150 mg kg⁻¹ (75 kg ha⁻¹) of Pb, respectively. The Pb contents of the test plants and the soil were analyzed before and after experimental treatments using an atomic absorption spectrophotometer. This study was laid out following a 3 × 2 factorial experiment in a completely randomized design. Results On the vegetative characteristics of the test plants, vetivergrass registered the highest whole plant dry matter weight (33.85–39.39 Mg ha⁻¹). Carabaograss had the lowest herbage mass production of 4.12 Mg ha⁻¹ and 5.72 Mg ha⁻¹ from soils added with 75 and 150 mg Pb kg⁻¹, respectively. Vetivergrass also had the highest percent plant survival which meant it best tolerated the Pb contamination in soils. Vetivergrass registered the highest rate of Pb absorption (10.16 ± 2.81 mg kg⁻¹). This was followed by cogongrass (2.34 ± 0.52 mg kg⁻¹) and carabaograss with a mean Pb level of 0.49 ± 0.56 mg kg⁻¹. Levels of Pb among the three grasses (shoots + roots) did not vary significantly with the amount of Pb added (75 and 150 mg kg⁻¹) to the soil. Discussion Vetivergrass yielded the highest biomass; it also has the greatest amount of Pb absorbed (roots + shoots). This can be attributed to the highly extensive root system of vetivergrass with the presence of an enormous amount of root hairs. Extensive root system denotes more contact to nutrients in soils, therefore more likelihood of nutrient absorption and Pb uptake. The efficiency of plants as phytoremediators could be correlated with the plants’ total biomass. This implies that the higher the biomass, the greater the Pb uptake. Plants characteristically exhibit remarkable capacity to absorb what they need and exclude what they do not need. Some plants utilize exclusion mechanisms, where there is a reduced uptake by the roots or a restricted transport of the metals from root to shoots. Combination of high metal accumulation and high biomass production results in the most metal removal from the soil. Conclusions The present study indicated that vetivergrass possessed many beneficial characteristics to uptake Pb from contaminated soil. It was the most tolerant and could grow in soil contaminated with high Pb concentration. Cogongrass and carabaograss are also potential phytoremediators since they can absorb small amount of Pb in soils, although cogongrass is more tolerant to Pb-contaminated soil compared with carabaograss. The important implication of our findings is that vetivergrass can be used for phytoextraction on sites contaminated with high levels of heavy metals; particularly Pb. Recommendations and Perspectives High levels of Pb in localized areas are still a concern especially in urban areas with high levels of traffic, near Pb smelters, battery plants, or industrial facilities that burn fuel ending up in water and soils. The grasses used in the study, and particularly vetivergrass, can be used to phytoremediate urban soil with various contaminations by planting these grasses in lawns and public parks. ESS-Submission Editor: Dr. Willie Peijnenburg (wjgm.peijnenburg@rivm.nl)