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351.
Monika Tomkiel Małgorzata Baćmaga Agata Borowik Jan Kucharski 《Journal of environmental science and health. Part. B》2018,53(2):97-107
Herbicides pose a significant threat to the natural environment, in particular in soils that are most exposed to plant protection agents. Prolonged herbicide use leads to changes in soil metabolism and decreases soil productive potential. In this study, the influence of carfentrazone-ethyl (CE) on the microbiological and biochemical properties of soil and the yield of Triticum aestivum L. was evaluated. Carfentrazone-ethyl was applied to sandy loam (pHKCl – 7.0) in doses of 0.000, 0.264, 5.280, 10.56, 21.18, 42.24, 84.48 and 168.96 µg kg?1 DM soil. Soil samples were subjected to microbiological and biochemical analyses on experimental days 30 and 60. Carfentrazone-ethyl disrupted the biological equilibrium in soil by decreasing the abundance and biodiversity of soil-dwelling microorganisms, the activity of soil enzymes, the values of the biochemical activity indicator and spring wheat yields. Carfentrazone-ethyl had the most adverse effects when applied in doses many fold higher than those recommended by the manufacturer. The toxic effects of CE were also determined by its soil retention time. Soil treated with CE was characterized by higher counts of oligotrophic bacteria, organotrophic bacteria, bacteria of the genus Azotobacter, actinomycetes and fungi on day 60, and spore-forming oligotrophic bacteria on day 30. The activity of dehydrogenases, urease, alkaline phosphatase and β-glucosidase was higher on day 30 than on day 60. 相似文献
352.
微生物固定化技术与污水处理 总被引:1,自引:0,他引:1
简要介绍了几种常用微生物固定化方法,重点讨论了微生物固定化技术在污水处理方面的应用,并对未来的发展方向进行了展望。 相似文献
353.
354.
Phospholipid fatty acid patterns of microbial communities in paddy soil under different fertilizer treatments 总被引:1,自引:0,他引:1
The microbial communities under irrigated rice cropping with different fertilizer treatments, including control (CK), PK, NK, NP, NPK fertilization, were investigated using phospholipid fatty acid (PLFA) profile method. The results of this study revealed that the fertilizer practice had an impact on the community structure of specific microbial groups. The principal components analysis (PCA) showed that proportion of the actinomycete PLFAs (10Me 18:0 and 10Me 16:0) were the lowest in the PK treatment and the highest in the NPK treatment, which means that soil nitrogen status affected the diversity of actinomycetes, whereas nitrogen cycling was related to the actinomycets. Under CK treatment, the ratio of Gram-positive to Gram-negative bacteria was lower compared with that in fertilizer addition treatments, indicating that fertilizer application stimulated Gram-positive bacterial population in paddy soil. The fatty acid 18:2to6,9, which is considered to be predominantly of fungal origin, was at low level in all the treatments. The ratio of cyl9:0 to 18:1 to7, which has been proposed as an indicator of stress conditions, decreased in PK treatment. Changes of soil microbial community under different fertilizer treatments of paddy soil were detected in this study; however, the causes that lead to changes in the microbial community still needs further study. 相似文献
355.
A combination system of biotrickling filter (BTF) and biofilter (BF), adopting surfactant-modified clinoptilolite and surfactant- modified wood chip as the media respectively, was applied to treat H2S and NH3 simultaneously. The identification and sole carbon sources utilization patterns of isolates in the combination system were studied by Biolog system. The isolates were identified as Bacillus sphaericus, Geobacillus themoglucosidasius (55℃) and Micrococcus luteus (ATCC 9341) in BTF, and Aspergillus sydowii (Bainier & Sartory) Thom& Church in BE Among 95 substrate classes supplied by Biolog system, the carboxylic acids and methyl esters had the highest utilization extent for the four species, followed by the amino acids and peptides. The descending sequence of carbon sources utilization capability of isolates was A. sydowii (52.6%), M. luteus (39.5%), B. sphaericus (21.6%), and G. thermoglucosidasius (17.7%). 相似文献
356.
357.
CHENG Jin-ping ZHANG Lan-ying WANG Wen-hu YANG Yi-chen ZHENG Min JU Su-wei 《环境科学学报(英文版)》2004,16(6):894-897
A strain saccharomycete STSM-I with high flocculanting activity was isolated from activated sludge with conventional methods.The high production rate and the low cost STSM-I medium was obtained by selecting different kinds of media, carbon source, nitrogen source and inorganic salt ion. The best flocculant-producing conditions were found by changing medium initial pH, culture temperature and ventilation flow. The best flocculating effect was obtained by changing positive ion types, density and concentration of flocculant. 相似文献
358.
Maria Bokern Petra Raid Hans Harms 《Environmental science and pollution research international》1998,5(1):21-27
4-Nonylphenol, a compound with estrogenic activity, has been shown to occur in sewage sludges and effluents of sludge treatment.
This, as well as its use in the formulation of pesticides, may result in the contamination of crop plants and may therefore
have an impact on the quality of food or feedstuff. The toxicity, uptake and metabolism of 4-n-nonylphenol (4-n-NP) were investigated as14C-labeled 4-n-NP in root cultures under septical and aseptical conditions and with intact plants grown in containers with soil and aseptically
grown in nutrient media. 4-n-NP was toxic to all plant systems tested. The presence of microorganisms and the developmental state of the plant material
appeared to have an influence on the EC50 values. 4-n-NP was taken up by the roots and a metabolism to polar compounds was observed in the cases where sufficiently high uptake
rates. With intact plants a transport from roots to the shoots was evident. Metabolism in roots changed quantitatively in
the presence of microorganisms. The mineralization of 4-n-NP to14CO2 only occurred with microorganisms. 相似文献
359.
The U.S. Environmental Protection Agency has proposed permitting ballast water discharges—a benefit of which would be to reduce
the economic damages associated with the introduction and spread of aquatic invasive species. Research on ship-borne aquatic
invasive species has been conducted in earnest for decades, but determining the economic damages they cause remains troublesome.
Furthermore, with the exception of harmful algal blooms, the economic consequences of microscopic invaders have not been studied,
despite their potentially great negative effects. In this paper, we show how to estimate the economic benefits of preventing
the introduction and spread of harmful bacteria, microalgae, and viruses delivered in U.S. waters. Our calculations of net
social welfare show the damages from a localized incident, cholera-causing bacteria found in shellfish in the Gulf of Mexico,
to be approximately $706,000 (2006$). On a larger scale, harmful algal species have the potential to be transported in ships’
ballast tanks, and their effects in the United States have been to reduce commercial fisheries landings and impair water quality.
We examine the economic repercussions of one bloom-forming species. Finally, we consider the possible translocation within
the Great Lakes of a virus that has the potential to harm commercial and recreational fisheries. These calculations illustrate
an approach to quantifying the benefits of preventing invasive aquatic microorganisms from controls on ballast water discharges.
The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S.
Environmental Protection Agency. 相似文献
360.
Due to frequent drinking water pollution accidents in the past decade, it is common that mountain reservoirs were used as the source of drinking water in China. However, some coastal areas frequently suffer from typhoon with extreme precipitation, which results in the water quality deterioration of the reservoirs. The influence of typhoons with extreme precipitation on Jiaokou reservoir and the emergency treatment process of Maojiaping water treatment plant in the past three typical typhoons with extreme precipitation from the year of 2012–2015 were studied. It was found that the degradation of water quality, such as the increase of turbidity and bacteria index, may not merely appear during the events, but last for several days. Changing the dosage of water purification agent, such as coagulant and disinfectant at right time and place may be an efficient emergency water treatment process. Based on the analysis of water quality variation rule during and after the events, it was also found that emergency treatment can be fully prepared before the arrival of a typhoon with extreme precipitation. And in order to better respond to the typhoon with extreme precipitation, several suggestions are also proposed in this paper as follows: establishing vegetated buffers at right place, such as macrophanerophytes, shrub or herbage, increasing investments in infrastructure management, merging or cancelling the small-scale water treatment plants, preparing adequate water purification agent before the typhoon comes, etc. 相似文献