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991.
Adel Ashur S. Banana N. A. Nik Norulaini Jamilah Baharom M. Y. Lailaatul Zuraida Mohd. Rafatullah Mohd. Omar Ab Kadir 《Journal of Material Cycles and Waste Management》2013,15(3):393-403
The aim of this study was to investigate the efficiency of dry sterilization by microwave in the inactivation of pathogenic bacteria in blood wastes. Eight bacteria strains were selected for this purpose and these are S. aureus, Salmonella sp., E. faecalis, K. pneumonia, P. aeruginosa, E. coli, Streptococcus Group B and Bacillus sp. Sterilization by microwave was carried out at 385, 450 and 700 watts for 1, 5 and 10 min, respectively. Isolation and enumeration of pathogenic bacteria before and after treatments were carried out using direct plate technique and inactivation was determined in terms of log reduction. Increasing the running time and power to 10 min and 700 watts did not increase log reduction of most of pathogenic bacteria especially of gram negative bacteria. Revival of pathogenic bacteria during the storage period might be aided by the presence of a low moisture content which helps bacterial cells to revive but not to reproduce or over-grow. It can be concluded that dry sterilization of blood wastes by microwave reduces the number and limited re-growth of these pathogenic bacteria during storage time, due to the lower moisture content in the blood wastes. 相似文献
992.
Hanlon EA Fan XH Gu B Migliaccio KW Li YC Dreschel TW 《Journal of environmental quality》2010,39(5):1724-1733
Restoration of the Florida Everglades is important for the health of the natural system, including both the "River of Grass" and its downstream estuaries. Water quality improvement is one indicator of successful restoration in this complex ecosystem. Using the period of record of 1977 through 2005, we evaluated data from seven inflow sites to the Everglades National Park (ENP) for temporal trends of various forms of phosphorus (P) and nitrogen (N) and analyzed them using principal component analysis and factor analysis without flow adjustments. Locally estimated scatter plot smoothing (LOESS) trend lines identified two inflection points (three time periods) of changing trend in total P (TP) concentration at the seven sites. Results indicated that overall water quality in ENP inflow improved from 1977 to 2005, with significant downward trends in TP concentration. The overall trend ofTP is probably mediated by hydrology, which is evident by a negative relationship between flow and annual average TP concentration at the majority of stations within the available data, although additional changes in vegetation due to hydroperiod may have some effects. Total N (TN), total Kjeldahl N, and total organic N concentrations also generally decreased at inflow sites. Water quality standards for TP, TN, and NH4+ -N were exceeded at selected sites during the study period. Principle component analysis and factor analysis detected a grouping of sampling sites related to the water delivery system that could be used as indicators to better manage monitoring resources. Study results suggest that water quality data analyses could provide additional insight into the success of a restoration management plan and on how monitoring may be modified for more efficient use ofresources. 相似文献
993.
Abstract A novel photocatalytic oxidation reactor, using Degussa P‐25 TiO2 as a stationary phase with a thickness of 1.5–2.0 um on the blades of agitator, was developed to study the photocatalytic oxidation of xenobiotics. Particularly in this device, separation of photocatalyst from the purified water after oxidation reaction was not necessary, and no other aeration equipment was required to supply oxygen. To examine the efficiency of this device, photocatalytic degradation of xenobiotic organics such as carbofuran was studied as an example. Results indicated that carbofuran could be degraded completely with mineralization efficiency of 20 % after 6 hours of oxidation under the imposed conditions. The mineralization rate of carbofuran was found to follow the pseudo‐first order reaction kinetics. Moreover, the rate constant of mineralization was found to be proportional to TiO2 film area and the square root of UV light intensity. These results implied the mineralization efficiency of carbofuran could be improved through increasing TiO2 film area and UV light intensity. Accordingly, this novel device showed potential application for degrading xenobiotics in water. 相似文献
994.
一种新型微生物菌剂处理生活污水 总被引:1,自引:0,他引:1
利用从食材中筛选纯化的特定微生物制成复合菌剂,在自然、厌氧和曝气3种不同的供氧条件下,添加不同比例的菌剂处理生活污水,以COD和氨氮浓度为参考指标,考察菌剂对污水的净化效果,并分析其原因。结果表明:(1)菌剂投加量在0.5‰~1‰时对污水中COD的去除具有明显促进作用,自然、厌氧和曝气3种条件下,COD去除率最大分别提高了8.77%、11.22%和11.11%;(2)氨氮的去除效果受反应条件影响很大,厌氧条件下菌剂对污水中氨氮的去除作用不明显,自然和曝气条件下,菌剂对氨氮去除效果显著,去除率增幅最高分别达到22.6%和52.28%;(3)以0.5‰的菌剂投加量曝气处理2 d,COD和氨氮的去除率可以分别提高11.11%和14.13%,初步研究显示,该菌剂对生活污水具有较好的净化效果。 相似文献
995.
Eberhard Morgenroth Daniel P.Y. Chang Kate M. Scow 《Journal of the Air & Waste Management Association (1995)》2013,63(4):300-308
Abstract A laboratory-scale compost-based biofilter was operated over a six-month period to study the requirements for removal of n-hexane from air. Hexane is a relatively short chain aliphatic hydrocarbon with a high Henry's coefficient and a low water solubility. Acclimation of the biofilter was slow, but removal efficiencies around 80% were achieved after one month of operation. However, performance decreased during the next two months of operation to 50% removal efficiency. Nutrient limitation was proposed as a reason for the decrease in reactor performance. After the addition of a concentrated nitrogen solution, reactor performance increased almost immediately to >99%. Removal efficiency remained above 99% for the following two months of operation at inlet concentrations of 0.7 g/m3 (200 ppmv), at superficial bed velocities approaching 50 m/h, and empty bed residence times of about one minute. Thus, nutrient availability may well limit biofilter performance even in compost- based units. It was shown that nutrients can be added effectively in a soluble form if compost quality is poor and a method is proposed for the evaluation of compost quality. 相似文献
996.
Trace Metal Contents (Al, Cu and Zn) of Tea: Tea and Soil from Two Tea Plantations, and Tea Products from Different Provinces of China 总被引:4,自引:0,他引:4
The present project aims to investigate the possible contamination of teas with the trace metals: Al, Cu and Zn. Tea bushes sampled from two tea plantations in the northern part of Guangdong Province accumulated higher concentrations of Cu and Zn in young leaves, and of Al in old leaves. The analysis of the three metals in tea produced in different provinces indicated higher Al levels in those obtained from Guangdong and Yunnan Provinces, which may be due to the lower soil pH in these areas. Green tea had the lowest Al concentration among the four types of tea studied, as only the bud and two young leaves are used, whereas older leaves are used for other types of tea (black, Oolong and Puerh tea). The transfer of Al, Cu and Zn from soil to different parts of tea bushes was low in general, except for Zn at Lechang tea plantation which next to a Pb/Zn mine, where a higher transfer was observed from young leaves to tea products, indicating possible metal contamination during tea processing. However, low concentrations of Cu and Zn (less than 0.07 mg Cu L-1 and 0.17 mg Zn L-1), and moderate amounts of Al (2.1-2.5 mg L-1) were obtained in the tea liquor (1% hot water extracts). 相似文献
997.
Applicability of the Charm II system for monitoring antibiotic residues in manure-based composts 总被引:2,自引:0,他引:2
S.I. KwonG. Owens Y.S. OkD.B. Lee W.-T. JeonJ.G. Kim K.-R. Kim 《Waste management (New York, N.Y.)》2011,31(1):39-44
The effluence of veterinary antibiotics (VAs) to aquatic and terrestrial environments is of concern due to the potential adverse effects on human health, such as the production of antibiotic resistant bacteria. One of the main pathways for antibiotics to enter the environment is via the application of manure and/or manure-based composts as an alternative organic fertilizer to agricultural lands. While a wide diversity of manure-based composts are produced in Korea, there is currently no regulatory guideline for VA residues. Hence, monitoring and limiting the concentration of VA residues in manure and/or manure-based composts prior to application to the lands is important to mitigate any environmental burden. The current study was conducted to examine the applicability of the Charm II antibiotic test system for monitoring tetracyclines, sulfonamides and macrolides in manure-based composts. The Charm II system was a highly reproducible method for determining whether VA residue concentrations in manure-based compost exceeded specific guideline values. A wide range of manure-based composts and liquid fertilizers commercially available in Korea were examined using the Charm II system to monitor the residues of the target VAs. For this, the guideline concentrations of VA residues (0.8 mg kg−1 for tetracyclines, 0.2 mg kg−1 for sulfonamides, and 0.1 mg kg−1 for macrolides) stated in ‘Official Standard of Feeds’ under the ‘Control of Livestock and Fish Feed Act’ in Korea were adopted to establish control points. Of the 70 compost samples examined 12 exceeded 0.8 mg kg−1 for tetracyclines and 21 exceeded 0.2 mg kg−1 for sulfonamides. Of the 25 liquid fertilizer samples examined most samples exceeded these prospective guidelines. 相似文献
998.
W. S. KUO Y. H. CHIANG L. S. LAI 《Journal of environmental science and health. Part. B》2013,48(6):937-948
The effect of the presence of photosensitizers, methylene blue (MB) and rose Bengal (RB), on the degradation of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) in water in a solar photocatalytic system was investigated. It was found that as compared to MB, RB generally showed a stronger effect on the decomposition of carbofuran under comparable conditions. Among the conditions studied, adding 2 × 10?6 M of RB, that corresponding to 2% of the initial concentration of carbofuran solution in the system, rendered the most effective degradation of carbofuran. As a result, a carbofuran removal percentage of 69.9%, a mineralization efficiency of 28.0%, and a microtoxicity reduction of 65.0% could be achieved. The degradation and mineralization of carbofuran was found to follow the pseudo-first order reaction kinetics. The decomposition mechanism of carbofuran was further investigated through identification of the intermediates to elaborate the influence of dye photosensitizer on the solar photocatalysis of carbofuran in water. On the basis of the intermediates identified, including carbofuran phenol, 3-hydroxy carbofuran phenol, and substituted alcohols (3-phenoxy 1-propanol, 2-ethyl 1-hexanol, 2-butoxyl ethanol), it appears that hydrolysis and hydroxylation were the two key mechanisms for decomposing carbofuran during the process of solar photocatalysis with the aid of dye photosensitizer. 相似文献
999.
210Pb deposition in the far East Asia: controlling factors of its spatial and temporal variations 总被引:1,自引:0,他引:1
Hirose K Kikawada Y Doi T Su CC Yamamoto M 《Journal of environmental radioactivity》2011,102(5):514-519
In order to better understand the behavior of 210Pb deposition in Far East Asia, comprehensive data of monthly 210Pb deposition, which includes several time-series and spatial distribution data at 14 stations in Japan and 2 stations in Taiwan, were analyzed. Pb-210 deposition at most of the sites exhibited a typical seasonal change with higher values in winter and lower values in summer; especially, the greatest 210Pb deposition in the world occurred in winter at sites beside the Japan Sea. The deposition behavior of 210Pb in Far East Asia differed between winter and summer. The meteorological phenomenon peculiar to winter of the Japan Sea side, i.e., formation of the Japan Sea convergence zone, might cause the high 210Pb concentration in rainwater, as may heavy snowfall. The 210Pb concentration in rainwater showed long-term variability, although this differed between winter and summer. This long-term variability may be related to climatological factors such as El Niño. 相似文献
1000.
Ji Y. Hu Bi Z. Dong Zi H. Zhen 《Journal of environmental science and health. Part. B》2013,48(5):385-389
A simple and efficient residue analysis method for direct determination of ioxynil octanoate in maize and soil was developed and validated with High Performance Liquid Chromatography-Ultra Violet (HPLC-UV). The samples were extracted with mixtures of acetonitrile and deionized water followed by Solid Phase Extraction (SPE) to remove co-extractives prior to analysis by HPLC-UV. The recoveries of ioxynil octanoate extracted from maize and soil samples ranged from 86 %–104 % and 84 %–96 %, respectively, with relative standard deviation (RSD) less than 7.84% and sensitivity of 0.01 mg kg?1. The method was applied to determine the residue of ioxynil octanoate in maize and soil samples from experimental field. Data had shown that the dissipation rate in soil was described as pseudo-first-order kinetics and the half-life (t1/2) was less than 1.78 days. No ioxynil octanoate residue (<0.01 mg kg?1) was detected in maize at harvest time withholding period of 60 days after treatments of the pesticide. Direct confirmation of the analytes in field trial samples was realized by Liquid Chromatography-Mass Spectrometry (LC-MS). 相似文献