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Evaluation of nitrification inhibitor 3,4-dimethyl pyrazole phosphate on nitrogen leaching in undisturbed soil columns 总被引:3,自引:0,他引:3
The application of nitrogen fertilizers leads to various ecological problems such as nitrate leaching. The use of nitrification inhibitors (NI) as nitrate leaching retardants is a proposal that has been suggested for inclusion in regulations in many countries. In this study, the efficacy of the new NI, 3,4-dimethyl pyrazole phosphate (DMPP), was tested under simulated high-risk leaching situations in two types of undisturbed soil columns. The results showed that the accumulative leaching losses of soil nitrate under treatment of urea with 1.0% DMPP, from columns of silt loam soil and heavy clay soil, were 66.8% and 69.5% lower than those soil columns tested with regular urea application within the 60 days observation, respectively. However, the losses of ammonium leaching were reversely increased 9.7% and 6.7% under the former treatment than the latter one. Application of regular urea with 1.0% DMPP addition can reduce about 59.3%-63.1% of total losses of inorganic nitrogen via leaching. The application of DMPP to urea had stimulated the inhibition effects of DMPP on the ammonium nitrification process in the soil up to 60 days. It is proposed that the DMPP could be used as an effective NI to control inorganic N leaching losses, minimizing the risk of nitrate pollution in shallow groundwater. 相似文献
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Sun Zhigao Li Jiabing He Tao Ren Peng Zhu He Gao Hui Tian Liping Hu Xingyun 《Environmental science and pollution research international》2017,24(29):23080-23095
Environmental Science and Pollution Research - Sediment samples were collected in five marshes (C1, Phragmites australis marsh; C2, P. australis and Cyperus malaccensis marsh; C3, C. malaccensis... 相似文献
36.
研究了KBrO3对二茂铁(Fc)非均相Fenton效能的影响,深入考察了KBrO3对体系中Fc溶解、H2O2分解和羟基自由基(·OH)生成的影响。结果表明,KBrO3的加入对不同反应阶段Fc/Fenton体系的效能均有明显的促进作用,初始阶段主要是由于KBrO3对·OH产生的促进作用所致,后期主要是由于KBrO3促进了体系中Fc的溶解,使得体系中溶解态的Fc催化的均相Fenton反应的比例增加,体系中H2O2的分解加快,·OH的表观生成率增加,进而促进了反应的进行。无KBrO3添加,pH=4,MB初始浓度为10 mg/L,Fc的量为1.6×10-3mol/L,[H2O2]/[MB]=3.14时,45 min时,MB的剩余率为9.1%,105 min时为0。当KBrO3的用量为3×10-4mol/L时,反应45 min后MB的去除率即可达到100%。随着KBrO3浓度的增加,其对Fc/Fenton效能的促进作用增强。 相似文献
37.
Effect of humic acids on physicochemical property and Cd(II) sorption of multiwalled carbon nanotubes 总被引:1,自引:0,他引:1
Zinc pyrithione is used as an antifouling agent. However, the environmental impacts of zinc pyrithione have recently been of concern. Zinc induces diverse actions during oxidative stress; therefore, we examined the effect of zinc pyrithione on rat thymocytes suffering from oxidative stress using appropriate fluorescent probes. The cytotoxicity of zinc pyrithione was not observed when the cells were incubated with 3 μM zinc pyrithione for 3 h. However, zinc pyrithione at nanomolar concentrations (10 nM or more) significantly increased the lethality of cells suffering from oxidative stress induced by 3 mM H2O2. The application of zinc pyrithione alone at nanomolar concentrations increased intracellular Zn2+ level and the cellular content of superoxide anions, and decreased the cellular content of nonprotein thiols. The simultaneous application of nanomolar zinc pyrithione and micromolar H2O2 synergistically increased the intracellular Zn2+ level. Therefore, zinc pyrithione at nanomolar concentrations may exert severe cytotoxic action on cells simultaneously exposed to chemicals that induce oxidative stress. If so, zinc pyrithione leaked from antifouling materials into surrounding environments would be a risk factor for aquatic ecosystems. Alternatively, zinc pyrithione under conditions of oxidative stress may become more potent antifouling ingredient. 相似文献
38.
The present study employed ozonation process to treat the bamboo industry wastewater (BIWW). The impact of ozone dosage and initial organic concentration on color, COD and TOC removal rates were studied along with characterization of the major organics in raw and treated wastewater. The results suggested the ozone dosage of 3.15 g h−1 (concentration 52.5 mg L−1) was suitable for the treatment. After 25 min ozonation of 1 L raw wastewater, the color, COD and TOC removal efficiencies were 95%, 56% and 40%, respectively, with an influent COD concentration of 835 mg L−1. The ratio of kg O3 kg−1 COD at 3.15 g h−1 was 2.8 (<3), revealing that ozonation was a cost effective process for tertiary treatment of BIWW. Longer oxidization time was required to achieve similar results for raw wastewater with higher COD concentration. The chromatogram from gel permeation chromatography revealed that ozonation resulted in the breakdown of high molecular weight compounds into lower molecular weight components but could not completely mineralize the organic matter. The majority of these compounds were identified in both raw and ozonated samples via GC-MS analysis. In addition to ester derivatives as the main intermediates of ozonation, 1-chloroctadecane, methyl stearate, benzophenone and α-cyperone were identified as the by-products of ozonation. 相似文献
39.
Lead tolerance and physiological adaptation mechanism in roots of accumulating and non-accumulating ecotypes of Sedum alfredii 总被引:1,自引:0,他引:1
Huang H Gupta DK Tian S Yang XE Li T 《Environmental science and pollution research international》2012,19(5):1640-1651
Background, aim and scope
Lead (Pb) accumulation in soils affects plants primarily through their root systems. The aim of this study was to investigate early symptoms of the loss of membrane integrity and lipid peroxidation in root tissues and physiological adaptation mechanism to Pb in accumulating ecotypes (AE) and non-accumulating ecotypes (NAE) of Sedum alfredii under Pb stress in hydroponics.Methods and results
Histochemical in situ analyses, fluorescence imaging, and normal physiological analysis were used in this study. Pb accumulation in roots of both AE and NAE increased linearly with increasing Pb levels (0?C200???M), and a significant difference between both ecotypes was noted. Both loss of plasma membrane integrity and lipid peroxidation in root tissues became serious with increasing Pb levels, maximum tolerable Pb level was 25 and 100???M for NAE and AE, respectively. Pb supplied at a toxic level caused a burst of reactive oxygen species (ROS) in root cells in both ecotypes. However, the root cells of AE had inherently higher activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), and lipoxygenase (LOX) in control plants, and the induction response of these antioxidant enzymes occurred at lower Pb level in AE than NAE. AE plants maintained higher ascorbic acid and H2O2 concentrations in root cells than NAE when exposed to different Pb levels, and Pb induced more increase in dehydroascorbate (DHA), catalase (CAT), and ascorbate peroxidase (APX) in AE than NAE roots.Discussion and conclusion
Results indicate that histochemical in situ analyses of root cell death and lipid peroxidation under Pb short-term stress was sensitive, reliable, and fast. Higher tolerance in roots of accumulating ecotype under Pb stress did depend on effective free oxygen scavenging by making complex function of both constitutively higher activities and sensitive induction of key antioxidant enzymes in root cells of S. alfredii. 相似文献40.
Bai M Zhang Z Tian Y Bai M 《Journal of the Air & Waste Management Association (1995)》2012,62(4):393-397
A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying *OH radicals is presented in this paper With a physical method of strong electric-field discharge, large numbers of *OH radicals were produced by the oxygen activated particles of O2+, O(1D), O(3P), etc., and the introducing reagent HO2-. The gram-positive bacteria Bacillus subtilis, the gram-negative bacteria Serratia marcescens, and Bacillus spores were used for the eliminating experiments. Results show that the different microorganisms were rapidly killed by *OH radicals with a concentration of 0.8 mg/L and spraying density of 21 microL/m2 within 4 sec. Cell morphological changes were also observed under microscope. The cells of B. subtilis and Bacillus spores in their cellular wall, cellular membrane, or cell protoplasm were greatly destroyed when being exposed to a killing dosage of *OH radicals. 相似文献