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681.
Organic pollutants in compost and digestate. Part 1. Polychlorinated biphenyls, polycyclic aromatic hydrocarbons and molecular markers 总被引:1,自引:0,他引:1
Brändli RC Bucheli TD Kupper T Furrer R Stahel WA Stadelmann FX Tarradellas J 《Journal of environmental monitoring : JEM》2007,9(5):456-464
In Europe, 9.3 x 10(6) t(dry weight (dw)) of compost and digestate are produced per year. Most of this is applied to agricultural land, which can lead to considerable inputs of organic pollutants, such as polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) to soil. This paper presents an inventory of the pollutant situation in source-separated composts, digestates and presswater in Switzerland by a detailed analysis of over 70 samples. PCB concentrations ( summation PCB 28, 52, 101, 118, 138, 153, 180) were significantly higher in urban (median: 30 microg kg(-1)dw, n = 52) than in rural samples (median: 14 microg kg(-1)dw, n = 16). Together with low concentrations in general, this points to aerial deposition on compost input material as the major contamination pathway. Enantiomeric fractions of atropisometric PCB were close to racemic. Median PAH concentration was 3010 microg kg(-1)dw( summation 15PAH, n = 69), and one quarter of the samples exhibited concentrations above the relevant Swiss guide value for compost (4000 microg kg(-1)dw). The levels were influenced by the treatment process (digestate > compost), the season of input material collection (spring-summer > winter > autumn), the particle size (coarse-grained > fine-grained), and maturity (mature > less mature). The main source of PAH in compost was pyrogenic, probably influenced mainly by liquid fossil fuel combustion and some asphalt abrasion, as suggested by multiple linear regression. This study, together with a companion paper reporting on other organic contaminates including emerging compound classes, provides a starting point for a better risk-benefit estimation of the application of compost and digestate to agricultural soil in Switzerland. 相似文献
682.
本文从分析我国传统的经济增长方式入手,通过对资源近视症”的表现及后果的分析,提出西部西地区,特别是西部少数民族地区只有树立全面的资源观,立足优势,面向市场,抓住机遇,合理开发资源和利用资源,才能走出一条符合本民族,本地区实际的可持续发展之路。 相似文献
683.
Liu S Tao S Liu W Dou H Liu Y Zhao J Little MG Tian Z Wang J Wang L Gao Y 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):651-656
Passive air sampling (PAS) was employed to study the occurrence of gaseous and particle-bound PAHs in the North Chinese Plain. The averaged concentrations of gaseous and particle-bound PAHs were 485 ± 209 ng/m3 and 267 ± 161 ng/m3, respectively. The PAHs concentrations at urban sites were generally higher than those at rural ones with ratios <1.5 in spring, summer and fall, but differences between them were not significant for the wintertime and annually averaged concentrations. This urban-rural distribution pattern was related to the PAHs emission sources. PAHs spatial variation can be partially (49%) explained by emission with a simple linear regression method. Both the gaseous and particle-bound PAHs were highest in winter and lowest in summer, with winter/summer ratios of 1.8 and 8, respectively. Emission strength was the most important factor for the seasonality. 相似文献
684.
利用MgSO4·7H2O和Na2HPO4·12H2O作为试验药剂,通过正交试验和单因素优化试验,对化学沉淀法处理甲胺生产废水中氨氮的工艺条件进行优化.结果表明,在pH=9.4、反应时间15 min、搅拌速度150 r/min、Mg:N(摩尔比值)=1.1、P:N(摩尔比值)=1.0时,化学沉淀法处理300 mL甲胺生产废水,氨氮去除率维持在92%以上,COD去除率可达37%以上.同时为验证工艺条件适应性和沉淀物(MgNH4PO4)作为农作物肥料使用的价值性,对最优条件下得到的沉淀物进行研究.与MgNH4PO4纯度为100%相比,沉淀物MgNH4PO4纯度达到86%以上.因此,化学沉淀法处理氨氮不仅具有良好的效果,而且得到的MgNH4PO4含有较高N、P,可以用作农作物肥料. 相似文献
685.
The organic-inorganic hybrid halide compounds have emerged as one of the most promising photoelectric material for their superior optoelectronic properties and hold great prospects for renewable energy substitutes and environmental protection as photocatalysis. Here, we report the optical properties of the Sb-based organic-inorganic hybrid ferroelectric materials: pyridine-4-aminium tetrachloroantimonate ((C5H7N2)SbCl4, sample 1), piperidin-1-aminium tetrachloroantimonate ((C5H13N2)SbCl4, sample 2) and tris(trimethylammonium) nonachlorodiantimonate (((CH3)3NH)3Sb2Cl9, sample 3), which are a kind of exploited efficient photocatalysts. Samples 2 and 3 exhibit distinct photoelectric respond, which are mainly ascribed to their minor narrow band-gap compared with sample 1. For the ferroelectrics, the intrinsic of spontaneous polarization of sample 3 at room temperature is favourable for the separation of photogenerated electrons and holes within the photorespond process. Moreover, sample 3 shows the highest efficiency of photo-decomposed Rhodamine B (90.2% within 80 min) and Methyl Orange (MO) (97.4% within 50 min), thanks to the photo-excited electrons and holes promoting the formation of oxidative radical species during the photo-redox progress. These findings prove that the development of a novel Sb-based organic-inorganic hybrid halide compounds with good stability in the degradation of organic dyes paves a way to designing new photocatalyst. 相似文献
686.
687.
用微孔填充理论研究活性炭对有机气体的吸附性能 总被引:1,自引:1,他引:1
用微孔填充理论研究了活性炭C40/4对丙酮、甲苯、二氯甲烷有机气体的吸附性能,测试了该活性炭对3种有机气体在不同温度下(288.15,293.15,298.15K)的吸附结果。用D—R方程处理了实验数据,建立了3种有机气体在活性炭C40/4上的等温吸附模型,并将实验测试值与理论预测值进行了比较。实验结果表明:微孔填充理论及D—R方程可很好地描述活性炭C40/4对有机气体的吸附性能,理论预测值与实验测试值的平均相对误差小于3%;有机气体分压较高时,由于发生毛细凝聚,理论预测值较实验测试值偏低。 相似文献
688.
689.
根据海上围油栏围油原理,使用小型围油设备模拟出在围油栏除油后海上剩余溢油的质量M。收集稻壳、小米壳、小麦壳3种农作物废料作为吸油材料,室温下分别测出3种吸油材料对质量为M的溢油的饱和吸附时间。在吸附平衡的条件下,利用紫外分光光度计分别测出3种吸油材料吸附海水表面M质量溢油后的平衡吸附浓度ce。根据物理吸附理论,由平衡吸附浓度ce和平衡吸附量qe分别得出3种材料的Freundlich吸附等温式,从Freundlich吸附等温式比较了3种农作物废料的吸油性能。结果表明:稻壳的吸油性能最佳。 相似文献
690.