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971.
972.
金山店铁矿平行矿体地下开采地表沉降物理模拟预测研究 总被引:3,自引:0,他引:3
根据金山店铁矿张福山矿区平行矿体的赋存特点,采用物理相似模拟方法,研究和预测了矿体地下开采过程中地表的沉降和位移规律。研究结论对于矿山安全地安排井下采矿生产、适时地进行地面建(构)筑物的搬迁以及土地的征购等,具有指导意义。 相似文献
973.
主要以某公司9000t/a碱锰型电解二氧化锰技改项目环境影响评价为例,结合验收监测数据,简要介绍碱锰型电解二氧化锰生产的环境影响与环保措施.该公司采用氧化锰矿和硫铁矿混合硫酸溶液浸出--电解的生产工艺生产碱锰型电解二氧化锰,生产过程中大气污染源主要有锅炉排放的烟气,化合、电解工序产生的硫酸雾;生产废水主要有锅炉除尘废水、漂洗水及炭黑生产废水;废渣主要是压滤锰渣. 相似文献
974.
可逆配仓带式输送机除尘方法分析及应用 总被引:1,自引:0,他引:1
叙述了可逆配仓带式输送机扬尘污染的特点,以及目前常用的几种除尘方法,介绍了移动式通风口装置技术在这方面的应用实例。 相似文献
975.
Lloyd R. Stark Robert P Brooks Frederick M. Williams S. Edward. Stevens Luise K Davis 《Journal of the American Water Resources Association》1994,30(4):639-650
ABSTRACT: Flow rates, pH, iron concentration, and manganese concentration were measured during several storm events at two constructed wetlands receiving mine water. During a substantial rain event, flow rates at both the wetland outlets surpassed flow rates at the wetland inlets, reflecting incident rainfall and differences in wetland area at the two sites. A significant positive correlation existed between local rainfall and outflow rates at the larger wetland, but not between rainfall and inflow rates. During storm events, outlet pH, relative to inlet pH, was slightly elevated at the larger wetland, and depressed at the smaller wetland. However, over the course of one year, rainfall was uncorrelated to outlet pH in the larger wetland. A substantial rain event at the smaller wetland resulted in a temporary elevation in outlet iron concentrations, with treatment efficiency reduced to near zero. However, in the larger wetland, outlet iron concentrations were not significantly affected by storm events. Although rainfall and outlet iron concentration were not significant correlates at the larger wetland, flow rate was positively correlated to outlet iron concentration. A normal manganese treatment efficiency of 50 percent at the smaller wetland was reduced to zero during a heavy rain. 相似文献
976.
为了解济南市大气颗粒物的粒径分布特征,于2009年10月利用多级撞击式颗粒物采样器(MOUDI)进行了大气颗粒物采集,采用离子色谱仪分析了其中水溶性离子浓度.结果表明,SO42-、NO3-、NH4+和Ca2+是主要的水溶性离子,浓度总和约占总水溶性离子浓度的92%.SO42-、NO3-、NH4+、K+和Cl-浓度随时间变化较为显著,浓度变化主要原因是受风速以及气流来源方向的影响.SO42-和NH4+主要集中在细粒子中,其浓度呈单模态分布,随着颗粒物中含量的升高其峰值从0.32~0.56 μm粒径段逐渐移动到1~1.8 μm粒径段.NO3-浓度呈双峰分布,细粒子中的NO3-随着浓度的升高峰值从0.56~1μm粒径段移动到1~1.8μm粒径段,粗粒子中的峰值出现在3.2~5.6μm粒径段. NH4+可以完全中和细粒子中的SO42-和NO3-,在细粒子中主要以(NH4)2SO4和NH4NO3的形式存在. 相似文献
977.
The ambient air in vicinity of different industrial sources for PCDD/PCDFs was sampled by TSP/PM10 active samplers and
passive PUF disk samplers in Tangshan City, a metropolis containing clusters of various industrial plants. The TEQ concentrations
of PCDD/PCDFs ranged from 44.2 to 394.1 fg I-TEQ/m3 with an average of 169.9 fg I-TEQ/m3. 2,3,4,7,8-PeCDF was the dominant
contributor to PTEQ, contributing 41% (12% to 55%), while 1,2,3,4,6,7,8-HpCDF, OCDD and OCDF were the major congeners for
the total concentrations. The ratios of PPCDF/PPCDD reached 2.54 on average, suggesting that de novo synthesis in thermal processes
played an important role to the airborne pollution of PCDD/PCDFs. The similarities congener profiles indicated that TSP and PM10
active sampling methods are comparable for the determination of the PCDD/PCDFs in ambient air, and the ratios of concentrations
determined by the two methods suggested that the PCDD/PCDFs tended to stay in fine particles. It was found that 2,3,7,8-TCDF and
OCDD were the dominating congeners in the passive PUF disks samples. Through principal components analysis, the coke industry
was suggested to be a relatively high potential emission source for PCDD/PCDFs in the ambient air of Tangshan, which was possibly
formed by de novo synthesis mechanism. In this study, the atmospheric impacts to the environment from di erent industrial sources
could be ranked as follows (from high to low): coking, iron sintering, steel making, power generation and chlorinate alkali chemical
production industries. 相似文献
978.
We investigated the characteristics of ambient particles and their relationships with various environmental factors, including
gaseous pollutants (CH4, non-methane hydrocarbons (NMHC), total hydrocarbons (THC), NOx, CO, SO2), meteorological parameters
(humidity, temperature), and time (day/night, workday/weekend). We used an electrical low-pressure cascade impactor to measure
the number and size distributions of ambient particles (0.007–10 m) that were collected approximately 1 km northwest of Hsinchu
Science Park in Taiwan between February and May 2007. The number concentrations of particles were enhanced through photochemical
reactions during the day. In addition, high traffic flow during workdays increased the formation of particulates. Except for SO2, all of
the gaseous pollutants we studied (CH4, NMHC, THC, NOx, CO) correlated positively with the total number concentrations of ambient
particles during daytime, indicating that they might contribute to the particulate burden. The poorer relationship between the SO2 level
and the total number concentration of particles suggests that SO2 might participate indirectly in the nucleation process during particle
formation, The high enrichment factors for Zn, Pb, Cu, and Mn, which mostly comprised the ultrafine particles (diameter: < 0.1 m)
and fine particles (diameter: 0.1–1 m), presumably arose from emissions from traffic and high technology factories. Heterogeneous
reactions on solid particles might play a role in the removal of SOx and NOx from the atmosphere. Sulfides and nitrides can further
react with these local pollutants, forming specific Cu-containing compounds: CuO (39%), CuSO4 (34%), and Cu(NO3)2 (27%), within
the ambient particles in this industrial area. 相似文献
979.
980.
摘要:采用水培的方法,研究了不同浓度Mn(0.0003、0.5、1、2、4、8 mmol•L-1)对Mn超富集植物短毛蓼(Polygonum pubescens Blume)和水蓼(Polygonum hydropiper L.)叶片铵态氮、硝态氮、游离脯氨酸、可溶性蛋白质含量及氮素代谢关键酶:硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合酶(GOGAT)和谷氨酸脱氢酶(GDH)活性的影响。结果表明,随着Mn处理浓度的增加,短毛蓼和水蓼的根、茎、叶中Mn含量显著增加(p < 0.05),在相同Mn处理浓度下短毛蓼中的Mn含量均大于同部位水蓼中的Mn含量。在Mn处理浓度小于1 mmol•L-1时,Mn对短毛蓼的株高、株重影响不明显,但对水蓼的影响显著(p < 0.05),表明短毛蓼比水蓼更耐Mn污染。Mn处理显著降低了短毛蓼硝态氮含量(p < 0.05),提高了可溶性蛋白质含量,8 mmol•L-1的Mn处理显著提高了水蓼硝态氮、铵态氮、可溶性蛋白质含量以及短毛蓼、水蓼游离脯氨酸含量,在Mn浓度为8 mmol•L-1时,短毛蓼、水蓼叶片中游离脯氨酸的含量分别为对照的1.18倍和1.68倍,表明游离脯氨酸在解Mn毒害过程中起重要作用。Mn引起了短毛蓼和水蓼氮素代谢关键酶活性的变化,显著降低了水蓼叶片NR、短毛蓼叶片GS活性(p < 0.05);在Mn处理浓度为1 mmol•L-1时,短毛蓼叶片NR活性最高,为对照的1.91倍,而2、4、8 mmol•L-1 Mn处理显著降低了短毛蓼和水蓼GOGAT活性(p<0.05)。另外,Mn处理显著提高了短毛蓼和水蓼叶片GDH活性(p < 0.05),在Mn处理浓度为8 mmol•L-1时,短毛蓼、水蓼叶片GDH的活性分别为对照的16.29倍和1.29倍。 相似文献