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941.
本研究采用上流式厌氧污泥床滤层反应器对蛋鸡场鸡粪混合液离心出水进行处理,试验结果:在中温25℃,进水COD_(cr)18000mg/L和氨氮1600mg/L的条件下,COD_(cr)去除率74.08%,BOD_5去除率83.78%,水力停留时间26.15h,容积负荷15.60kg·COD_(cr)/m~3·d,产气率0.52m~3/去除km·COD_(cr).反应器运行状况良好.  相似文献   
942.
渤海湾淤泥质海岸带典型地区景观空间格局分析   总被引:1,自引:0,他引:1  
以景观多样性、景观破碎度和景观分离度作为评价指标,分析渤海湾淤泥质海岸带典型地区景观空间格局以及人类活动对景观结构的影响。将研究区域分为耕地、荒地、村镇、盐田、虾池、滩涂、库塘以及河流沟渠8个景观要素。分析表明,景观多样性主要受耕地和荒地的影响和支配;耕地和荒地的破碎度大,分离度小;盐田和河流沟渠的破碎度最小;村镇和滩涂的分布状况导致其分离度大。  相似文献   
943.
应用11种限制性内酶BamHⅠ、BstEⅡ、EcoRⅠ、EcoRⅤ、HindⅢ、KpnⅠ、PstⅠ、SalⅠ、SstⅠ、XbaⅠaⅠ和XⅠⅠ和XhoⅠ分别将中国棉铃虫核多角体病毒(单粒包埋HaSNPV)湖北株基因组D组DNA酶切为10、12、22、21、13、6、6、40、6、21、6个片段,并求得基因组大小平均为1什什Mr≈79.1×106.以家委核多角体病毒BmNPV多角体基因为探针,利用Southern杂交技术将病毒多角体基因定位在SalⅠ4.2×103b左右的片段上.与棉铃虫核多角体病毒其它株系酶切图谱比较结果表明,本株病毒与上海等株系及美洲棉铃虫核多角体病毒HaSNPVElkar株系酶切图谱相似,它们之间的条带数和大小差异较小,而与已发现的所有多粒包埋型病毒HaSNPV酶切图主谱差异较大.据此认为HaSNPV和HaMNPV属于基因型不同的两类病毒,而HaSNPV不同分离株的同源性很高  相似文献   
944.
The combustion of vinyl chloride (VC) after the train derailment accident in Ohio, USA in February, 2023 has caused widespread concern around the world. This paper tried to analyze several issues concerning the accident, including the appropriateness of the VC combustion in the emergency response in this accident, the meanings of so-called “controlled combustion”, the potential environmental risks caused by VC and combustion by-products, and follow-up work. In our view, this accident had surely caused environmental and health risks to some extent. Hence, a comprehensive environmental risk assessment is necessary, and then the site with risk should be comprehensively remediated, hazardous waste should be harmlessly treated as soon as possible. Finally, this accident suggests that further efforts should be taken to bridge the gap between chemical safety management and their environmental risk management.  相似文献   
945.
Fang  Siyuan  Zhang  Wei  Sun  Kai  Hu  Yun Hang 《Environmental Chemistry Letters》2023,21(3):1287-1295
Environmental Chemistry Letters - Antibiotics are water and soil contaminants causing the development of multi-resistant bacteria, calling for advanced water treatments. For instance,...  相似文献   
946.
用煤矸石和鼓风炉淤泥制备聚硅酸铁铝混凝剂   总被引:12,自引:0,他引:12  
研究了以煤矸石和鼓风炉淤泥为原料,在常压条件下制备高效混凝剂凝剂聚硅酸铁铝的方法,确定了合理的生产工艺和操作条件,用该混凝剂处理实际废水,并与聚合硫酸铁的处理效果进行比较,结果表明,出水COD和色度去除率均提高约30%,SS去除率提高约10%,同时探讨了该混凝剂处理废水的反应机理。  相似文献   
947.
Anthropogenic Calcium Particles Observed in Beijing and Qingdao, China   总被引:2,自引:0,他引:2  
Analysis of individual particles collected at Beijing in northern China revealed that particles abundant in calcium (Ca) always constituted a large fraction of mineral particles in the urban atmosphere. The particles were characterized by cubic morphologies. The major mineral element in the particles was Ca and few or no other mineral elements were detected. A large number of the particles were in the range of diameter <1 μm, where common natural mineral particles were rarely detected. The contribution of the Ca particles to the volume of total mineral particles greatly exceeded that of other mineral particles during non-dust-storm periods and was comparable to that during dust-storm periods. Reagent film tests showed that particulate sulfate and nitrate formation on the Ca particles was similar to that on common mineral particles. These results indicate that a large portion of Ca in the atmospheric particulate matter in Beijing was from anthropogenic sources rather than from natural sources, and the anthropogenic Ca particles acted as a significant medium for the formation of sulfate and nitrate. Similar particles were also detected at Qingdao, a coastal city in northern China. Data of a dust storm event showed that Ca-abundant particles from East China arrived there and moved out of the continent, similarly to Asian dust storm particles, suggesting possible contributions of anthropogenic Ca even in Asian dust storm samples in the downstream areas. Therefore, Ca may not be a good indicator of Asian dust from natural sources. However, the Ca particles, due to their unique shapes and elemental compositions, may provide an indicator for the atmospheric dispersion of anthropogenic particulate matters in East Asia.  相似文献   
948.
Renewable resource-based composites were prepared with acorn powder and Thermoplastic resin poly(lactic acid) (PLA) by twin-screw extrusion followed by injection molding processing or hot-compression molding processing. The study of the composites microstructure showed poor adhesion between acorn powder and PLA matrix. The hygroscopicity, mechanical properties and melt flow property of composites were promising even though the composites had a 70 wt% content of acorn powder. Silane coupling agent, 4,4′-Methylenebis (phenyl isocyanate) and PLA grafted with maleic anhydride did not show obvious effect on mechanical properties of composites. The impact resistance strength of reinforced composites with steel fiber webs were improved greatly in comparison with those having no steel fiber webs. Thermal properties results of DSC and DMA showed that the presence of acorn powder significantly affected the crystallinity, crystallization temperature (Tc), glass transition temperature (Tg) and melting temperature (Tm) of PLA matrix. The study results proved that composites had superior mechanical properties, enough to partially replace the conventional thermoplastic plastics.  相似文献   
949.
阐述了挥发性有机物(VOCs)控制技术的评价原则、评价步骤和影响 VOCs 控制技术评价的因素,从技术、经济、社会和其他方面初步构建了 VOCs 控制技术的评价指标体系.进一步介绍了评价指标的量化方法.VOCs控制技术评价指标体系的建立,为科学、全面、客观地评价和筛选 VOCs 控制技术奠定坚实的基础.  相似文献   
950.
利用2005年9~10月渭河流域内各气象站和水文站的资料,对2005年渭河流域致洪暴雨的雨情、水情及灾情进行分析。对洪水的特征,水情、河道的概况,特大洪灾的降水特点进行总结,得出“05.10”洪水具有降水范围广、水位高、洪水倒灌、灾害重等特征,造成的经济损失严重。揭示了洪灾形成的主要原因,从而对减少洪灾的形成和流域的治理提出有关建议,达到防灾减灾的目的。  相似文献   
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