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951.
根据技术的复杂程度和系统性,经济效益,削减废弃物的潜力、环境效益、实施难易程度等5个方面,以权重打分综合的方法进行方案筛选,筛选出5个备选方案作经济、技术和环境评估。在此基础上,推存主要工段联合改造方案,并对此方案作出一步经济分析,表明该方案的实施是可行的。 相似文献
952.
The Hg(0) oxidation ability and reusability of Cu(x)Co(3-x)O(4) were investigated in an attempt to improve SO(2) anti-poisoning ability of metal oxide and produce more economic and effective sorbents for the control of Hg(0) emission from combustion processes. The influence of copper content on Cu(x)Co(3-x)O(4)'s (0.75< or = x < or =2.25) oxidation ability of Hg(0) in the presence of SO(2) was investigated. According to the X-ray diffraction, Brunauer-Emmett-Teller (BET) and mass balance analysis on mercury, we found that Cu(1.5)Co(1.5)O(4) showed the highest S(BET) and best Hg(0) oxidation ability. With continuous increase of x from 0.75 to 2.25, Cu(x)Co(3-x)O(4)'s SO(2) anti-poisoning ability increased. The analysis results of the X-ray photoelectron spectroscopy manifested that the adsorptive mercury species on spent Cu(1.5)Co(1.5)O(4) was HgO. The spent Cu(1.5)Co(1.5)O(4) could be regenerated by thermal decomposition at 673K and regenerated Cu(1.5)Co(1.5)O(4) showed higher Hg(0) oxidation ability due to Hg-doping. Regenerated enrichment Hg(0) was collected using activated carbon at an ambient temperature to eliminate the secondary pollution. 相似文献
953.
954.
大口径毛细管柱气相色谱法在聚酯废气组成分析中的应用 总被引:1,自引:0,他引:1
采用直接进样大口径毛细管柱气相色谱法,可同时测定聚酯废气中乙烯、乙醛、乙酸、2-甲基-1,3-二氧戊环、三聚乙醛等污染物含量。进样量为1mL时,方法对乙烯、乙醛、乙酸、2-甲基-1,3-二氧戊环、三聚乙醛的最低检出浓度分别为1.0mg/m^3,2.3mg/m^3,7.3mg/m^3,2.7mg/m^3,3.3mg/m^3,回标回收率为92.0%-97.9%,相对标准偏差为1.8%-2.9%。对某煤厂聚酯废气进行实测,取得了较为满意的结果。 相似文献
955.
Shang G Shen G Wang T Chen Q 《Journal of the Air & Waste Management Association (1995)》2012,62(8):873-879
The characteristics and mechanisms of hydrogen sulfide (H2S) adsorption on a biochar through pyrolysis at various temperatures (100 to 500 degrees C) were investigated. The biochar used in the current study was derived from the camphor tree (Cinnamomum camphora). The samples were ground and sieved to produceparticle sizes of 0.4 mm to 1.25 mm, 0.3 mm to 0.4 mm, and <0.3 mm. The H2S breakthrough capacity was measured using a laboratory-designed test. The surface properties of the biochar were characterized using pH and Fourier-transform infrared spectroscopy (FTIR) analysis. The results obtained demonstrate that all camphor-derived biochars were effective in H2S sorption. Certain threshold ranges ofthepyrolysis temperature and surfacepH were observed, which, when exceeded, have dramatic effects on the H2S adsorption capacity. The sorption capacity ranged from 1.2 mg/g to 121.4 mg/g. The biochar with 0.3 mm to 0.4 mm particle size possesses a maximum sorption capacity at 400 degrees C. The pH and FTIR analysis results showed that carboxylic and hydroxide radical groups were responsible for H2S sorption. These observations will be helpful in designing biochar as engineered sorbents for the removal of H2S. 相似文献
956.
天然和CPB改性沸石对Hg2+的吸附特征 总被引:1,自引:1,他引:1
通过静态实验研究溴代十六烷基吡啶(CPB)改性沸石和天然沸石对废水中Hg2+的吸附特性,探讨了吸附动力学、吸附平衡和吸附热力学机制。研究表明:Langmuir方程能较好地描述2种沸石对Hg2+的吸附,CPB改性沸石对Hg2+的吸附率得到显著提高。实验条件下,改性沸石对Hg2+的吸附率从67.5%提高到98.9%,吸附容量从0.521 mg/g提高到3.07 mg/g。利用准一级动力学方程、假二级动力学方程、颗粒内扩散模型和Elovich方程分别对动力学过程进行拟合,发现2种沸石对Hg2+的吸附均满足假二级动力学方程,且离子的颗粒内扩散对整个吸附过程有影响。动力学拟合、D-R方程拟合和热力学研究综合表明:2种沸石对Hg2+的吸附既存在化学吸附又存在物理吸附,吸附吉布斯自由能变(△G0)、焓变(ΔH0)、熵变(ΔS0)均小于0,反应为自发的放热反应,低温有利于吸附的进行。 相似文献
957.
958.
High concentrations and dry deposition of reactive nitrogen species at two sites in the North China Plain 总被引:2,自引:0,他引:2
J.L. Shen A.H. Tang X.J. Liu A. Fangmeier K.T.W. Goulding F.S. Zhang 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3106-3113
Atmospheric concentrations of major reactive nitrogen (Nr) species were quantified using passive samplers, denuders, and particulate samplers at Dongbeiwang and Quzhou, North China Plain (NCP) in a two-year study. Average concentrations of NH3, NO2, HNO3, pNH4+ and pNO3− were 12.0, 12.9, 0.6, 10.3, and 4.7 μg N m−3 across the two sites, showing different seasonal patterns of these Nr species. For example, the highest NH3 concentration occurred in summer while NO2 concentrations were greater in winter, both of which reflected impacts of N fertilization (summer) and coal-fueled home heating (winter). Based on measured Nr concentrations and their deposition velocities taken from the literature, annual N dry deposition was up to 55 kg N ha−1. Such high concentrations and deposition rates of Nr species in the NCP indicate very serious air pollution from anthropogenic sources and significant atmospheric N input to crops. 相似文献
959.
Zhang Y Deng S Liu Y Shen G Li X Cao J Wang X Reid B Tao S 《Environmental pollution (Barking, Essex : 1987)》2011,159(3):694-699
Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAHLMW4) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAHLMW4 within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. 相似文献
960.