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燃煤烟气脱硫副产物在酸性土上的农用价值与利用原理 总被引:11,自引:0,他引:11
燃煤烟气脱硫副产物作为废弃物对环境的潜在威胁,促使人们对其资源化利用研究的重视。文章针对红壤地区土壤普遍缺乏营养元素的问题,通过分析盆栽和田间试验结果,探讨燃煤烟气脱硫副产物在酸性土壤上的农用价值与利用原理。结果表明,燃煤烟气脱硫副产物富含作物所需的营养元素,而红壤地区土壤又普遍缺乏这些元素;它具有独特的形态特征和理化性能,在酸性土壤中可以产生协同效应,因而具极高的农用价值。在酸性土壤上适量施用,可以提高土壤养分含量,改善土壤理化性质,提高土壤供肥性能和持水能力,促进作物对养分的吸收,从而达到废弃物农业资源化利用的目的。 相似文献
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在人工配制的污水中投入一定量的基质,不同条件下振荡培养,评价沸石、炉渣和陶瓷滤料3种基质在不同因素影响下对氨氮(NH4+-N)和总磷(TP)的吸附能力。结果表明,不同吸附时间时,沸石对NH4+-N的吸附效果最好,陶瓷滤料对TP的吸附效果最好;进水浓度对沸石吸附NH4+-N的影响较大,其吸附量随进水浓度的增大而增大,进水浓度对炉渣和陶瓷滤料吸附NH4+-N及炉渣吸附TP影响不大;3种基质对NH4+-N和TP的吸附量均是随吸附剂量的增加而降低,要达到较好的去污效果,应根据实验结果考虑基质投入量;pH值对沸石吸附NH4+-N影响显著,pH值6~7范围内吸附效果最好,pH值8~12的碱性条件有利于基质对TP的吸附。 相似文献
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染色体步行PCR技术 总被引:3,自引:0,他引:3
染色体步行是一种常用的克隆已知基因旁侧序列的技术.本文综述了现有的染色体步行PCR技术,如反向PCR、锅柄PCR、连接介导PCR、热不对称PCR、SON PCR等,并在此基础上提出了一种新的染色体步行PCR技术的构思.它运用特异引物与随机引物的搭配,在普通PCR程序下扩增目的序列.实验中设置相应随机引物的RAPD对照,识别非目的扩增产物.文中介绍了新方法的原理,分析了这种方法的优缺点.这种方法可能是一种新的有效进行染色体步行的PCR技术,国内外尚未见相关报道.图2参26 相似文献
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Jingqiu Mao Xinrong Ren Shuang Chen William H. Brune Zhong Chen Monica Martinez Hartwig Harder Barry Lefer Bernhard Rappenglück James Flynn Michael Leuchner 《Atmospheric environment (Oxford, England : 1994)》2010,44(33):4107-4115
Both similarities and differences in summertime atmospheric photochemical oxidation appear in the comparison of four field studies: TEXAQS2000 (Houston, 2000), NYC2001 (New York City, 2001), MCMA2003 (Mexico City, 2003), and TRAMP2006 (Houston, 2006). The compared photochemical indicators are OH and HO2 abundances, OH reactivity (the inverse of the OH lifetime), HOx budget, OH chain length (ratio of OH cycling to OH loss), calculated ozone production, and ozone sensitivity. In terms of photochemical activity, Houston is much more like Mexico City than New York City. These relationships result from the ratio of volatile organic compounds (VOCs) to nitrogen oxides (NOx), which are comparable in Houston and Mexico City, but much lower in New York City. Compared to New York City, Houston and Mexico City also have higher levels of OH and HO2, longer OH chain lengths, a smaller contribution of reactions with NOx to the OH reactivity, and NOx-sensitivity for ozone production during the day. In all four studies, the photolysis of nitrous acid (HONO) and formaldehyde (HCHO) are significant, if not dominant, HOx sources. A problematic result in all four studies is the greater OH production than OH loss during morning rush hour, even though OH production and loss are expected to always be in balance because of the short OH lifetime. The cause of this discrepancy is not understood, but may be related to the under-predicted HO2 in high NOx conditions, which could have implications for ozone production. Three photochemical indicators show particularly high photochemical activity in Houston during the TRAMP2006 study: the long portion of the day for which ozone production was NOx-sensitive, the calculated ozone production rate that was second only to Mexico City's, and the OH chain length that was twice that of any other location. These results on photochemical activity provide additional support for regulatory actions to reduce reactive VOCs in Houston in order to reduce ozone and other pollutants. 相似文献
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本文报道在0.1M亚硝酸钠,1.5×10~(-3)M的1,2-丙二胺,pH9.0—9.5底液中铬在—1.76伏处(对饱和甘汞电极)产生-催化波,测定范围在0.1ng/ml内,铬的浓度与导数波高成良好线性关系,测定下限为8×10~(-10)M(相当于0.04ng/ml)。经实验证明,在1,2-丙二胺-亚硝酸盐或硝酸盐两体系中,铬都在—1.76伏处产生催化波,因此,可认为铬的催化机理可能与文献[3]报道的在CyDTA-NO_3体系中三价铬产生催化波的机理相似即: Cr~(6 ) 3e—→Cr~(3 ); Cr~(3 ) y—→Cr~(3 )—y; Cr~(2 )—y e—→C~(2 )—y; Cr~(2 )—y NO_3~—→Cr~(3 )—y No_2~-其中:y代表1,2-丙二胺。将自来水进行简单的前处理后,可以直接应用本法测定水中六价、三价铬的含量以及水中的总铬量。 相似文献
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通过田间小区试验研究有机肥施用量对菜心产量、土壤磷形态的影响,分析土壤磷形态之间的相关性,评估菜地红壤磷污染风险。结果表明,有机肥施用并未提高菜心的产量和生物量,而超过一定使用量之后,反而降低菜心产量和生物量;土壤无机磷形态以Fe-P和Al-P为主,占土壤无机磷质量分数的90%以上。有机肥施用提高土壤各形态无机磷的质量分数,且有机肥用量越高,土壤Fe-P、Al-P、Ca-P和O-P质量分数越高。有机肥过量施用显著提高土壤速效磷和水溶性磷质量分数;分别对Olsen-P和CaCl2-P与各形态磷进行逐步回归分析,只有Olsen-P和CaCl2-P与Ca-P具有线性关系(p〈0.05),方程为Y1=36.95+0.622 1X,Y2=-0.102 5+0.048 6X。表明施用有机肥下,Ca-P是菜地土壤有效磷的最直接来源,可以作为红壤磷污染风险评价指标。 相似文献