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军山湖流域农业非点源污染氮、磷入湖负荷估算 总被引:5,自引:0,他引:5
参照国内外相关湖泊研究的方法,在开展流域调查的基础上,按照畜禽养殖污染、农业种植业流失、水产养殖污染和农村生活污染4类途径,结合各乡镇流域面积所占比例、污染源产生量、排放系数和流失系数等估算了军山湖流域农业非点源污染氮、磷的入湖负荷.结果表明,农业种植业流失和畜禽养殖污染是军山潮流域农业非点源污染入湖氮的主要来源,分别占入湖氮总量的37.5%和34.7%,其次为水产养殖污染,占23.2%;畜禽养殖污染是入湖磷的主要来源,占50.8%,其次为农业种植业流失和水产养殖污染,分别占24.4%和20.0%;农村生活污染对入湖氮、磷的贡献率最小. 相似文献
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郊区畜禽养殖对环境的污染越来越严重.以国内某城市周边畜禽养殖业为例,通过确定主要畜禽(猪、牛、鸡、羊)污染物的产污系数,估算了2009年北方某城市各区县的主要畜禽粪污中COD、TN、TP含量,分别约为1.1×106、5.4×104、9×103 t.在不同区县中,G区单位耕地面积N、P负荷最大,分别为309.5、52.7 kg/hm2,远远超出土壤的消纳能力;在靠海的主要3个区(A、B、C区)中,其中C区的畜禽粪污对水体潜在污染负荷最高,COD、TN、TP分别达4 858.4、252.4、47.9t,可能造成水质的污染. 相似文献
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近年来,随着中国畜禽养殖业的快速发展,落后的养殖模式和污染防治设施,使畜禽养殖污染日趋严重,畜禽养殖污染已居农业污染源之首,已成为中国环境污染的重要因素,对环境质量乃至人体健康都会产生不良影响。文中采用UASB—SBR组合工艺处理畜禽养殖废水,通过试验探讨SBR反应器启动方法及最佳运行模式,同时研究UASB反应器的启动方法。结果表明,SBR运行的最佳模式为进水0.5 h、反应8 h、沉淀1 h、出水0.5 h、闲置14 h。经过一段时间的启动,UASB和SBR反应器均成功启动,UASB—SBR组合工艺在处理畜禽养殖废水时可获得稳定的处理效果,COD、氨氮、总磷等出水水质均达到《畜禽养殖业污染物排放标准》(GB18596-2001)要求,为畜禽养殖废水处理的工程化应用提供了参考依据。 相似文献
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The sorption and desorption of Cu and Cd by two species of brown macroalgae and five species of microalgae were studied. The two brown macroalgae, Laminaria japonica and Sargassum kjellmanianum, were found to have high capacities at pHs between 4.0 and 5.0 while for microalgae, optimum pH lay at 6.7. The presence of other cations in solution was found to reduce the sorption of the target cation, suggesting a competition for sorption sites on organisms. Sorption isotherms obeyed the Freundlich equation, suggesting involvement of a multiplicity of mechanisms and sorption sites. For the microalgae tested, Spirulina platensis had the highest capacity for Cd, followed by Nannochloropsis oculata, Phaeodactylum tricornutum, Platymonas cordifolia and Chaetoceros minutissimus. The reversibility of metal sorption by macroalgae was examined and the results show that both HCl and EDTA solutions were very effective in desorbing sorbed metal ions from macroalgae, with up to 99.5% of metals being recovered. The regenerated biomass showed undiminished sorption performance for the two metals studied, suggesting the potential of such material for use in water and wastewater treatment. 相似文献
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A R Main 《Journal of environmental science and health. Part. B》1983,18(1):29-63
The kinetic and structural relationships of eight electrophoretically pure mammalian serum and liver serine carboxylesterases (CE) and cholinesterases (ChE) have been studied. Eight CE's and ChE's, which were fully resolved but only partially purified, provided additional information. Five of the electrophoretically pure esterases were monomeric, and of these, four belonged to a new and widely distributed class. These four monomeric esterases hydrolyzed choline esters, but at widely differing rates. Thus two were termed monomeric butyrylcholinesterases, mBuChE I and II, and two were monomeric CE's (mCE). The rabbit liver mCE was not a subunit of the oligomeric CE (oCE), although the oCE also hydrolyzed choline esters at a very low rate. The complex kinetics of the mCE's, mBuChE's, oCE's, and of the oligomeric BuChE's of horse and human serum could be interpreted according to a single reaction scheme involving an allosteric site and the equation derived from it. Thus activation and inhibition at high substrate concentrations, together with sigmoidal activity versus substrate concentration plots, all of which characterize the reactions of these esterases, could be interpreted by a single scheme and equation. Structural and kinetic comparisons showed a progressive transition of properties from the oCE's through the mCE's to the oBuChE's. One of the purified mCE's was from horse serum, and it exhibited physical and kinetic properties unlike those of the liver mCE's or oCE's. 相似文献
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Soudamini Mohapatra 《Journal of environmental science and health. Part. B》2013,48(7):513-520
The persistence and dissipation kinetics of trifloxystrobin and tebuconazole on onion were studied after application of their combination formulation at a standard and double dose of 75 + 150 and 150 + 300 g a.i. ha?1. The fungicides were extracted with acetone, cleaned-up using activated charcoal (trifloxystrobin) and neutral alumina (tebuconazole). Analysis was carried out by gas chromatograph (GC) and confirmed by gas chromatograph mass spectrometry (GC-MS). The recovery was above 80% and limit of quantification (LOQ) 0.05 mg kg?1 for both fungicides. Initial residue deposits of trifloxystrobin were 0.68 and 1.01 mg kg?1 and tebuconazole 0.673 and 1.95 mg kg?1 from standard and double dose treatments, respectively. Dissipation of the fungicides followed first-order kinetics and the half life of degradation was 6–6.6 days. Matured onion bulb (and field soil) harvested after 30 days was free from fungicide residues. These findings suggest recommended safe pre-harvest interval (PHI) of 14 and 25 days for spring onion consumption after treatment of Nativo 75 WG at the standard and double doses, respectively. Matured onion bulbs at harvest were free from fungicide residues. 相似文献
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STEFANO POLATI FABIO GOSETTI VALENTINA GIANOTTI MARIA CARLA GENNARO 《Journal of environmental science and health. Part. B》2013,48(6):765-779
The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested. 相似文献
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Polati S Gosetti F Gianotti V Gennaro MC 《Journal of environmental science and health. Part. B》2006,41(6):765-779
The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested. 相似文献
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Singh Nishi Kumari Choudhary Sangeeta 《Environmental science and pollution research international》2021,28(42):58819-58836
Environmental Science and Pollution Research - Hydrocarbon is a primary source of energy in the current urbanized society. Considering the increasing demand, worldwide oil productions are declining... 相似文献
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《Atmospheric environment (Oxford, England : 1994)》2007,41(37):8228-8240
Isocyanatocyclohexane and isothiocyanatocyclohexane are becoming relevant compounds in urban and industrial air, as they are used in important amounts in automobile industry and building insulation, as well as in the manufacture of foams, rubber, paints and varnishes. Glass multi-sorbent tubes (Carbotrap, Carbopack, Carboxen) were connected to LCMA-UPC pump samplers for the retention of iso- and isothiocyanatocyclohexanes. The analysis was performed by automatic thermal desorption (ATD) coupled with capillary gas chromatography (GC)/mass spectrometry detector (MSD). TD-GC/MS was chosen as analytical method due to its versatility and the possibility of analysis of a wide range of volatility and polarity VOC in air samples. The method was satisfactory sensitive, selective and reproducible for the studied compounds. The concentrations of iso- and isothioisocyanatocyclohexanes were evaluated in different urban, residential and industrial locations from extensive VOC air quality and odour episode studies in several cities in the Northeastern edge of Spain. Around 200–300 VOC were determined qualitatively in each sample. Higher values of iso- and isothiocyanatocyclohexane were found in industrial areas than in urban or residential locations. The concentrations ranged between n.d.−246 and n.d.−29 μg m−3 for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively, for industrial areas. On the other hand, urban and residential locations showed concentrations ranging between n.d.−164 and n.d.−29 μg m−3 for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively. The site location (urban or industrial), the kind and nearness of possible iso- and isothiocyanatocyclohexane emission activities (industrial or building construction) and the changes of wind regimes throughout the year have been found the most important factors influencing the concentrations of these compounds in the different places. 相似文献
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The degradation and ecotoxicity of sulfonylurea herbicide rimsulfuron and its major metabolites were examined in batch samples of an alluvial sandy loam and in freshwater. An HPLC-DAD method was adapted to simultaneously identify and quantify rimsulfuron and its metabolites, which was successfully validated by GC-MS analysis. In aqueous solutions, pure rimsulfuron was rapidly hydrolyzed into metabolite 1 (N-(4,6-dimethoxypyrimidin-2-yl)-N-(3-(ethylsulfonyl)-2-pyridinylurea)), which itself was transformed into the more stable metabolite 2 (N-((3-(ethylsulfonyl)-2-pyridinyl)-4,6-dimethoxy-2-pyrimidineamine)), with half-life (t(1/2)) values of 2 and 2.5 days, respectively. Hydrolysis was instantaneous under alkaline conditions (pH = 10). In aqueous suspensions of the alluvial soil (pH = 8), formulated rimsulfuron had a half-life of 7 days, whereas that of metabolite 1 was similar to that in water (about 3.5 days). The degradation of the two major metabolites was also studied in soil suspensions with the pure compounds at concentrations ranging from 1 to 10 mg l(-1). The half-life of metabolite 1 ranged from 3.9 to 5 days, close to the previous values. Metabolite 2 was more persistent and its degradation is strongly dependent on the initial concentration (C0): half-life values ranged from 8.1 to 55 days at 2-10 mg l(-1), respectively. These values are higher than those determined from the kinetics of metabolite 1 transformation into metabolite 2 (t(1/2) = 8-19 days). The ecotoxicity of the three chemicals was evaluated through their effect on Daphnia magna and Vibrio fischeri (Microtox bioassay). No effect was observed on D. magna with 24 and 48 h acute toxicity tests. Similarly, no toxic effect was observed with the Microtox test for the three chemicals in the range of concentrations tested that included the field application dose. Thus, being of low persistence and lacking acute toxicity, these chemicals present a low environmental risk. However, chronic effects should be studied in order to confirm the safety of rimsulfuron and its major metabolites. 相似文献
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PCDD and PCDF were found in urban air particulates from St. Louis and Washington, D.C., and in sediments from the Great Lakes and Siskiwit Lake, Isle Royale. The similarity between the PCDD and PCDF found in air particulates and sediment samples and the presence of PCDD and PCDF in sediment from Siskiwit Lake (a location which can receive only atmospheric inputs) suggest that these compounds are emitted to the atmosphere from combustion sources. The historical input of PCDD and PCDF to dated sediment cores shows a strong increase since 1940, and this suggests that the incineration of chlorinated organic compounds is an important source of PCDD and PCDF to the environment. 相似文献