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411.
半干半湿法烟气脱硫技术的工业应用研究 总被引:4,自引:0,他引:4
探讨了日本半干半湿法脱硫除尘系统和中国环境科学研究院半干半湿法烟气脱硫除尘示范系统的主要差别 ,研究了半干半湿法烟气脱硫技术在出塔烟气温度、钙硫摩尔比和循环粉煤灰返灰等方面对脱硫效率的影响。结果表明 ,在脱硫塔出口烟气温度为 78℃、m(循环粉煤灰返灰 )∶ m(石灰 )为 1∶ 4、n( Ca)∶ n( S) <1.2时 ,脱硫效率达 85 .1%;在 n( Ca)∶ n( S) =1.4时 ,脱硫效率可达 88.3 %。 相似文献
412.
在夏季对上海郊区一典型的中、小河流河网水质进行监测 ,结果表明 :(1)河流水体普遍有很高的氮磷和有机负荷 ,其CODcr、总磷、总氮等指标均数倍于《地面水环境质量标准》中规定的V类水最大允许值 ,水体正处于严重的富营养化状态。位于集镇居民区和养殖场附近河流的污染更为严重。 (2 )受富营养化和河流底泥污染物释放的影响 ,河流水质还存在分层现象 ,尤其是水流滞缓、水深不足两米的小河流更为明显。主要表现为 :底层水氨氮 ,TRP(总反应态磷 )和SRP(溶解反应态磷 )的含量明显高于表层水 ;而表层水的 pH和DO高于底层水 ;同时 ,由于底层水处于厌氧的环境下 ,NO- 3-N、NO- 2 -N含量低于表层水。 (3)由于长期受纳污水、污物 ,中、小河流底泥有很高的氮磷累积 ,凯氏氮平均达 3.5 2 6 (N ,mg) / g ;总磷平均达 2 0 5 2 .2 5 0 (P ,mg) /kg。集镇居民区河流底泥总磷含量高达 5 813.838(P ,mg) /kg ;养殖场附近河流底泥凯氏氮高达 5 .96 4 (N ,mg) / g。底泥孔隙水中的NO- 3-N、NO- 2 -N含量很低 ;NH+4的含量是河流底层水的 3~ 2 4倍 ;SRP的含量约是河流底层水的 2~ 16倍。由于底泥有机污染重 ,耗氧量大 ,处于厌氧的环境 ,其交换态Fe2 +的含量很高 相似文献
413.
由于水资源分布不均、水污染日趋严重,调水工程已不仅用以解决城市资源型缺水,也成为一些地区缓解水质型缺水问题的途径,但是这些耗资巨大的调水工程往往对周围自然生态环境可能产生巨大影响,可能带来的环境成本不容忽视。以千岛湖配水工程为例,通过在调水地进行实地调研和问卷调查,运用Tobit模型分析影响居民支付意愿的因素,基于意愿调查法(CVM)分析了建德市人民对千岛湖配水工程的生态环境影响的支付意愿,并以此估算该工程的环境成本。结果表明,调水地居民对恢复和改善可能破坏的生态环境的平均支付意愿约为每人每年377.6~542.1元,按照年配水量9.78亿 m3可以计算每吨水的环境成本约为0.15~0.21元。由此估算,工程期内千岛湖配水工程可能造成的环境成本总计约为5.80~8.28亿元,高于2014年公布的《杭州市第二水源千岛湖配水工程环境影响报告书》(下文简称《报告书》)中对该工程的环境经济影响评价3.70亿元。千岛湖配水工程的环境成本不容忽视,必须建立科学的生态补偿机制,加强监管;同时受水地也应积极加强污染治理和节约用水,共同解决城市水质型缺水问题。 相似文献
414.
Hongjun Chen Chunhu Yu Zeyang Xue Pengxiang Wang Zi Wang Qianmin Cong 《毒物与环境化学》2020,102(7-8):356-385
Abstract Lithium-doped bismuth oxide nanoplates with the thickness of 50–150?nm and tetragonal bismuth oxide, monoclinic lithium bismuthate phases have been synthesized via a simple hydrothermal process using lithium acetate and sodium bismuthate as the raw materials. Cobalt nanoparticles modified lithium-doped bismuth oxide nanoplates hybrids were obtained by an in situ photo-deposition route. The cobalt nanoparticles-modified nanoplates hybrids display significantly enhanced photocatalytic activity toward gentian violet compared with the nanoplates. Gentian violet solution can be totally degraded by the hybrids within 60?min under ultraviolet–visible light irradiation. The superior photocatalytic activity of the cobalt nanoparticles modified nanoplates hybrids originates from the superior charge transfer capacity and the energy band structure of the hybrids. The excellent photocatalytic performance makes the cobalt nanoparticles modified nanoplates hybrids a promising candidate as the photocatalyst for wastewater treatment. 相似文献
415.
Haiyan Jiang Hongxing Dai Xue Meng Lei Zhang Jiguang Deng Yuxi Liu Chak Tong Au 《环境科学学报(英文版)》2012,24(3):449-457
Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100℃ with poly(vinyl pyrrolidone) (PVP) and urea (pH = 2) and at 160℃ with NaHCO3 (pH = 7 and 8), respectively. The PVP-derived BiVO4 showed much higher surface areas (5.0-8.4 m2/g) and narrower bandgap energies (2.45-2.49 eV). The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture. 相似文献
416.
Arsenic dynamics in the rhizosphere and its sequestration on rice roots as affected by root oxidation 总被引:3,自引:0,他引:3
A pot experiment was conducted to investigate the effects of root oxidation on arsenic (As) dynamics in the rhizosphere and As sequestration on rice roots. There were significant differences (P 〈 0.05) in pH values between rhizosphere and non-rhizosphere soils, with pH 5.68-6.16 in the rhizosphere and 6.30-6.37 in non-rhizosphere soils as well as differences in redox potentials (P 〈 0.05). Percentage arsenite was lower (4%-16%) in rhizosphere soil solutions from rice genotypes with higher radial oxygen loss (ROL) compared with genotypes with lower ROL (P 〈 0.05). Arsenic concentrations in iron plaque and rice straw were significantly negatively correlated (R = -0.60, P 〈 0.05). Genotypes with higher ROL (TD71 and Yinjingmanzhau) had significantly (P 〈 0.001) lower total As in rice grains (1.35 and 0.96 mg/kg, respectively) compared with genotypes with lower ROL (IAPAR9, 1.68 mg/kg; Nanyangzhan 2.24 mg/kg) in the As treatment, as well as lower inorganic As (P 〈 0.05). The present study showed that genotypes with higher ROL could oxidize more arsenite in rhizosphere soils, and induce more Fe plaque formation, which subsequently sequestered more As. This reduced As uptake in aboveground plant tissues and also reduced inorganic As accumulation in rice grains. The study has contributed to further understanding the mechanisms whereby ROL influences As uptake and accumulation in rice. 相似文献
417.
418.
甲型H1N1流感病毒:猪流感是由猪流感病毒引起的一种急性呼吸道传染病,这种病在猪中经常发生,但很少导致猪的死亡。通常情况下,人类很少感染猪流感病毒。 相似文献
419.
Zhu Jinfeng Xue Huifeng. School of Management Xi’an University of Technology Xi’an Shaanxi China . Business School Xi’an International Studies University Xi’an Shaanxi 《中国人口.资源与环境(英文版)》2009,7(1):15-22
Taking 248 A-share manufacturing listed companies in 2006 Shanghai Stock Exchange as example, using "index method" to measure level of environmental protection information disclosure, this paper examines the factors influencing level of environmental protection information disclosure. The findings show that the disclosure level has improved, but the overall level is still low and unable to satisfy information users; there is positive correlation between corporate size, industry type, accounting firm's type and corporate environmental disclosure index. The companies of large scale and heavy pollution and those audited by international "Big 4" and domestic "Big 10" accounting firms have a high level of environmental disclosure, while the profitability and financial leverage has no impact on the disclosure level. Finally some suggestions are put forward to establish environmental information disclosure system in China. 相似文献
420.
提高资源环境绩效是我国生态恢复与重建的核心和关键.利用资源环境绩效指数(REPI)对我国西部生态环境脆弱区的新疆维吾尔自治区资源环境绩效进行了系统分析,结果表明:新疆仍然为我国资源环境绩效水平最为落后的地区之一.综合绩效指数由2000年的212.8逐步下降为2006年的148.1,资源综合绩效虽有提高,但仍然处于全国(西藏除外)第27位.建设用地占用强度明显下降,COD排放强度逐步下降,工业固体废弃物产生强度和能源消耗强度有所增加,用水强度降幅明显,能源消耗总量显著提高,用水总量略有上升.建设用地总量先降后升.SO2总体绩效均高于西部平均水平,SO2排放绩效指数呈现"S"型曲线.COD排放绩效指数下降不够明显,基本保持88.44的均值水平.绩效高于2000-2006年西部平均水平和2000-2003年中部平均水平,但远低于东部和全国平均水平.提高新疆资源环境综合绩效任重而道远.资源环境指数与经济发展水平和发展阶段密切相关,而且成为影响区域竞争力的重要因素.新疆建设节约型社会不能超越现有发展阶段和基本国情、区情,但是通过加大结构调整和技术创新力度以及采用综合配套措施完全有可能缩短目前能源、资源密集型的发展阶段,提升新疆在我国西部地区的综合竞争力,进而实现可持续发展. 相似文献