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121.
黄河入河沙漠颗粒物对磷酸盐的吸附特征 总被引:1,自引:0,他引:1
研究了黄河入河沙漠颗粒物在天然水(河水和海水)中对磷酸盐的吸附行为,用改进的Langmuir和Freundlich等温吸附模型对实验数据进行了拟合.结果表明,①改进的Langmuir等温吸附模型更适用于描述黄河入河沙漠颗粒物对磷酸盐的吸附特征,其物理意义更明确,得到的拟合参数更合理;②颗粒物对磷的最大吸附容量Qmax变化范围为41.322~357.143mg.kg-1,其中居延海颗粒物Y2的Qmax最大.Qmax与颗粒物(Y1~Y5)的有机质有着极显著的正相关关系;③除巴丹吉林沙漠颗粒物Y1外,颗粒物的临界磷平衡浓度EPC0值均大于其相应水体的磷浓度.Y1在黄河水中吸附磷的EPC0小于相应水体的磷浓度0.0100.053 mg.L-1,而在渤海海水中却大于相应水体的磷浓度0.1090.074 mg.L-1,表明Y1吸附了黄河水中的磷,进入渤海后Y1原有吸附可交换态磷NAP转移到海水中.其它颗粒物与相应水体进行磷交换的过程中存在着解吸磷的现象,具有向相应水体释放磷的能力;④黄河入河沙漠颗粒物对磷酸盐的吸附等温线是过溶液浓度轴0.00的交叉型等温线,这种新型交叉型吸附-解吸模型较好地解释了其吸附特征和天然粒子的双重性作用. 相似文献
122.
浅谈欧盟化学品新法规及其对我国石油化工行业的影响 总被引:3,自引:0,他引:3
介绍了即将实施的欧盟化学品新法规出台背景和主要内容,并浅析了新法规对我国石油化工行业的影响. 相似文献
123.
The nitrogen (N) biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009.
Results showed that soil N had significant seasonal fluctuations and vertical distribution. The N/P ratio (15.73±1.77) of S. salsa was
less than 16, indicating that plant growth was limited by both N and P. The N absorption coefficient of S. salsa was very low (0.007),
while the N utilization and cycle coefficients were high (0.824 and 0.331, respectively). The N turnover among compartments of S.
salsa marsh showed that N uptake from aboveground parts and roots were 2.539 and 0.622 g/m2, respectively. The N translocation
from aboveground parts to roots and from roots to soil were 2.042 and 0.076 g/m2, respectively. The N translocation from aboveground
living bodies to litter was 0.497 g/m2, the annual N return from litter to soil was far less than 0.368 g/m2, and the net N mineralization
in topsoil during the growing season was 0.033 g/m2. N was an important limiting factor in S. salsa marsh, and the ecosystem was
classified as unstable and vulnerable. S. salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat, and the
nutrient enrichment due to N import from the Yellow River estuary would be a potential threat to the S. salsa marsh. Excessive nutrient
loading might favor invasive species and induce severe long-term degradation of the ecosystem if human intervention measures were
not taken. The N quantitative relationships determined in our study might provide a scientific basis for the establishment of effective
measures. 相似文献
124.
Sedimentary record of polycyclic aromatic hydrocarbons in Lake Erhai,
Southwest China 总被引:1,自引:0,他引:1
Jianyang Guo Zhang Liang Haiqing Liao Zhi Tang Xiaoli Zhao Fengchang Wu 《环境科学学报(英文版)》2011,23(8):1308-1315
The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in a sediment core from Lake Erhal in Southwest China using gas-chromatography/mass spectrometry (GC/MS) method.The total organic carbon (TOC) normalized total PAHs concentrations (sum of US Environmental Protection Agency proposed 16 priority PAHs) ranged from 31.9 to 269 μg/g dry weight (dw),and were characterized by a slowly increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments.The PAHs in the sediments were dominated by low molecular weight (LMW) PAHs,suggesting that the primary source of PAHs was low- and moderate temperature combustion processes.However,both the significant increase in high molecular weight (HMW) PAHs in the upper sediments and the vertical profile of diagnostic ratios pointed out a change in the sources of PAHs from low-temperature combustion to high-temperature combustion.The ecotoxicological assessment based on consensus-based sediment quality guidelines implied that potential adverse biological impacts were possible for benzo(ghi)perylenelene and most LMW PAHs.In addition,the total BaP equivalent quotient of seven carcinogenic polycyclic aromatic hydrocarbons (BaA,CHr,BbF,BkF,BaP,DBA and INP) was 106.1 ng/g,according to the toxic equivalency factors.Although there was no great biological impact associated with the HMW PAlls,great attention should be paid to these PAH components based on their rapid increase in the upper sediments. 相似文献
125.
The Cu2+-loaded montmorillonite clays (MMT-Cu) may be a good material for the adsorbed and eliminated pathogenic bacteria from aqueous solution. 相似文献
126.
Effect of C/N ratio, aeration rate and moisture content on ammonia and greenhouse gas emission during the composting 总被引:3,自引:0,他引:3
Gaseous emission (N2O, CH4 and NH3) from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon (TOC) was lost in the form of CO2 and 0.8% to 7.5% of TOC emitted as CH4. Most of the nitrogen was lost in the form of NH3, which account for 9.6% to 32.4% of initial nitrogen. N2O was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH3 (p = 0.0189), CH4 (p = 0.0113) and N2O (p = 0.0493) emissions significantly. Higher aeration rates reduce the CH4 emission but increase the NH3 and N2O losses. C/N ratio could affect the NH3 (p = 0.0442) and CH4 (p = 0.0246) emissions significantly, but not the N2O. Lower C/N ratio caused higher NH3 and CH4 emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio. 相似文献
127.
Laboratory scale experiments were conducted to study the characteristics of N and P removal under different influent organic carbon concentration in a sequencing batch reactor (SBR) with simple anaerobic/aerobic operating mode. Experimental results indicated that, under the operating condition of influent N concentration of 89 mg/L and P concentration of 15 mg/L, when the influent C/N ratio increased from 1.5 to 6.9 (influent C/P ratio from 9 to 41), total N and P removal efficiency improved from 50% and 46% to 78% and 96% respectively. Track studies of N, P and other operating parameters demonstrated that N removal of the SBR was realized through simultaneous nitrification and denitrification (SND) in the aeration phase and anoxic denitrificaiton in the filling phase, P removal was accomplished through conventional anaerobic P release and aerobic P taken-up process. Keeping dissolved oxygen (DO) concentration during the first two aeration hours as low as 0.1-0.6 mg/L is essential for the simultaneous occurrences of nitrification, denitrification and P-taken up. 相似文献
128.
129.
质量控制是贯穿环境监测全过程的技术手段和管理程序,文章通过对建设项竣工验收监测质量控制进行阐述,其目的是为了提高我们的监测水平和能力,更好的保护好我们的生态环境。 相似文献
130.