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711.
呼伦贝尔地区草原表层土壤中总有机碳与有机质初探 总被引:1,自引:0,他引:1
通过非分散红外线吸收法测定呼伦贝尔地区具有代表性的16个草原表层土壤(0~20 cm)中总有机碳、溶解性有机碳,使用重铬酸钾容量法测定有机质,并对其总有机碳与有机质水平及两者相关性进行了分析。初步分析了造成各样品之间总有机碳水平差异的原因。结果表明,只以打草场作为利用方式的土壤总有机碳含量较常年放牧场的总有机碳含量高。从草原类型和土壤类型上看,草甸草原总有机碳含量明显高于典型草原,黑钙土总有机碳含量明显高于栗钙土。综上,过度放牧会使草原土壤总有机碳大量释放。总有机碳含量与有机质含量有显著正相关性,相关系数达到0.902。 相似文献
712.
采用 SUMMA罐采集空气样品,在预浓缩系统中经3级冷阱捕集后,用气相色谱-质谱联用技术测定环境空气中7种痕量有机硫化物。对试验条件进行优化,使得甲硫醇、乙硫醇、甲硫醚、二硫化碳、噻吩、乙硫醚和二甲二硫醚等7种有机硫化物在21.47μg/m3~336.43μg/m3范围内线性良好。试验表明,7种有机硫化物的方法检出限为0.004μg/m3~0.036μg/m3;标准气体平行测定6次结果的 RSD为2.7%~6.2%,加标回收率为92.2%~97.5%。用该方法测定实际空气样品,并与傅立叶红外光谱法测定的结果进行比对,结果令人满意。 相似文献
713.
建立了同时测定水中27种有机农药的LLE-GC-MS法。该法前处理前需调节水样pH值2,不加甲醇作为改性剂,以1:1(V/V)正己烷-石油醚为萃取溶剂进行液液萃取,GC-MS法进行检测。方法在各目标化合物质量浓度0.010~0.500 mg/L范围内线性良好,相关系数R2均0.995,检出限为0.021~0.250μg/L,加标回收率为73.6%~113.6%,相对标准偏差RSD为4.0%~14.1%,适用于水中27种有机农药的检测。 相似文献
714.
Xinyi Hu Ting Yang Chen Liu Jun Jin Bingli Gao Xuejun Wang Min Qi Baokai Wei Yuyu Zhan Tan Chen Hongtao Wang Yanting Liu Dongrui Bai Zhu Rao Nan Zhan 《Frontiers of Environmental Science & Engineering》2020,14(4):66
715.
Faouzi Herzi Natacha Jean Huiyu Zhao Stéphane Mounier Hassine Hadj Mabrouk Asma Sakka Hlaili 《Chemosphere》2013
In this study, metal contamination experiments were conducted to investigate the effects of copper and cadmium on the growth of the marine toxic dinoflagellate Alexandrium catenella and on the production of dissolved organic matter (Dissolved Organic Carbon: DOC; Fluorescent Dissolved Organic Matter: FDOM). This species was exposed to increasing concentrations of Cu2+ (9.93 × 10−10–1.00 × 10−7 M) or Cd2+ (1.30 × 10−8–4.38 × 10−7 M), to simulate polluted environments. The drastic effects were observed at pCu2+ = 7.96 (Cu2+: 1.08 × 10−8 M) and pCd2+ = 7.28 (Cd2+: 5.19 × 10−8 M), where cyst formation occurred. Lower levels of Cu2+ (pCu2+ > 9.00) and Cd2+ (pCd2+ > 7.28) had no effect on growth. However, when levels of Cu2+ and Cd2+ were beyond 10−7 M, the growth was totally inhibited. The DOC released per cell (DOC/Cell) was different depending on the exposure time and the metal contamination, with higher DOC/Cell values in response to Cu2+ and Cd2+, comparatively to the control. Samples were also analyzed by 3D-fluorescence spectroscopy, using the Parallel Factor Analysis (PARAFAC) algorithm to characterize the FDOM. The PARAFAC analytical treatment revealed four components (C1, C2, C3 and C4) that could be associated with two contributions: one, related to the biological activity; the other, linked to the decomposition of organic matter. The C1 component combined a tryptophan peak and a characteristic humic substances response, and the C2 component was considered as a tryptophan protein fluorophore. The C3 and C4 components were associated to marine organic matter production. 相似文献
716.
SUNITA GAIND ALOK KUMAR PANDEY LATA 《Journal of environmental science and health. Part. B》2013,48(2):177-187
Compost was prepared from wheat straw enriched with Rajasthan rock phosphate and Aspergillus awamori. The resulting phospho-compost along with phosphorus enriched FYM, mineral fertilizer (rock phosphate) and super phosphate were evaluated for their individual contribution in improving organic matter status, P availability, and enzymatic activities of soil under wheat crop grown in a micro plot. The results showed that total organic carbon, nitrogen, microbial biomass, and humus content (an index of organic matter status of soil) of soil was highest when farmyard manure (FYM) after its enrichment with 12.5% rock phosphate was applied. Microbial enriched phospho-compost was the product yielding highest soil available phosphorus, phosphorus uptake, urease, and cellulase activities. However, FYM amended with 25% rock phosphate resulted in the greatest enhancement of β-glucosidase. Measured parameters indicated a sure improvement of chemical and biological activities of soil after the application of phosphorus enriched organic amendments compared to the commercial fertilizer commonly used by the Indian farmers. 相似文献
717.
The crop models in the Decision Support System for Agrotechnology Transfer (DSSAT) have served worldwide as a research tool for improving predictions of relationships between soil and plant nitrogen (N) and crop yield. However, without a phosphorus (P) simulation option, the applicability of the DSSAT crop models in P-deficient environments is limited. In this study, a soil-plant P model integrated to DSSAT was described, and results showing the ability of the model to mimic wide differences in maize responses to P in Ghana are presented as preliminary attempts to testing the model on highly weathered soils. The model simulates P transformations between soil inorganic labile, active and stable pools and soil organic microbial and stable pools. Plant growth is limited by P between two concentration thresholds that are species-specific optimum and minimum concentrations of P defined at different stages of plant growth. Phosphorus stress factors are computed to reduce photosynthesis, dry matter accumulation and dry matter partitioning. Testing on two highly weathered soils from Ghana over a wide range of N and P fertilizer application rates indicated that the P model achieved good predictability skill at one site (Kpeve) with a final grain yield root mean squared error (RMSE) of 535 kg ha−1and a final biomass RMSE of 507 kg ha−1. At the other site (Wa), the RMSE was 474 kg ha−1 for final grain yield and 1675 kg ha−1 for final biomass. A local sensitivity analysis indicated that under P-limiting conditions and no P fertilizer application, crop biomass, grain yield, and P uptake could be increased by over 0.10% due to organic P mineralization resulting from a 1% increase in organic carbon. It was also shown that the modeling philosophy that makes P in a root-free zone unavailable to plants resulted in a better agreement of simulated crop biomass and grain yield with field measurements. Because the complex soil P chemistry makes the availability of P to plants extremely variable, testing under a wider range of agro-ecological conditions is needed to complement the initial evaluation presented here, and extend the use of the DSSAT-P model to other P-deficient environments. 相似文献
718.
气田水是天然气开采过程中采出的地层水,因其来源广泛、类型众多以及成分复杂等原因导致其很难达标处理,且容易对土壤、地表水以及地下水造成污染。因此,本文以川东地区气田水为研究对象,通过常规水质分析和GC-MS等技术手段对其进行全面分析,结果表明:①川东地区气田水特征污染物为氯化物、COD、SS、阴离子表面活性剂以及硫化物等物质;②根据其水质特性可以将川东地区气田水分为两类,一类是高矿化度、高含有机物气田水;另一类是高含硫、高含有机物气田水;③川东地区气田水中共有17种有机污染物,主要为烷烃类、醇类、酯类以及少量酸类等物质。 相似文献
719.
Xinyi Liu Caichao Wan Xianjun Li Song Wei Luyu Zhang Wenyan Tian Ken-Tye Yong Yiqiang Wu Jian Li 《Frontiers of Environmental Science & Engineering》2021,15(4):54
720.
Z. Krivcsy A. Hoffer Zs. Srvri D. Temesi U. Baltensperger S. Nyeki E. Weingartner S. Kleefeld S. G. Jennings 《Atmospheric environment (Oxford, England : 1994)》2001,35(36):3569
The mass concentrations of inorganic ions, water-soluble organic carbon, water-insoluble organic carbon and black carbon were determined in atmospheric aerosol collected at three European background sites: (i) the Jungfraujoch, Switzerland (high-alpine, PM2.5 aerosol); (ii) K-puszta, Hungary (rural, PM1.0 aerosol); (iii) Mace Head, Ireland (marine, total particulate matter). At the Jungfraujoch and K-puszta the contribution of carbonaceous compounds to the aerosol mass was higher than that of inorganic ions by 33% and 94%, respectively. At these continental sites about 60% of the organic carbon was water soluble, 55–75% of the total carbon proved to be refractory and a considerable portion of the water soluble, refractory organic matter was composed of humic-like substances. At Mace Head the mass concentration of organic matter was found to be about twice than that of nonsea-salt ions, 40% of the organic carbon was water soluble and the amount of highly refractory carbon was low. Humic-like substances were not detected but instead low molecular weight carboxylic acids were responsible for about one-fifth of the water-soluble organic mass. These results imply that the influence of carbonaceous compounds on aerosol properties (e.g. hygroscopic, optical) might be significant. 相似文献