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291.
中国能源消费碳排放影响因素分析 总被引:7,自引:0,他引:7
利用改进的主成分回归分析技术考察1990年以来中国人口和经济因素对化石能源消费碳排放的影响作用。研究发现:以人口总量、人口城市化和居民收入水平为代表的人口因素和以经济规模、产业结构、能耗结构及碳排放强度为代表的经济因素对碳排放均具有显著的正向影响;其中,经济规模和人口总量是能源消费碳排放的关键决定因子。研究结果为国家制订合理的节能减排政策、协调人地关系提供了参考依据。 相似文献
292.
Fluidized pellet bed (FPB) has been successfully applied in water and wastewater treatment. However, the removal mechanism of
contaminants especially the soluble ones, is still unclear. This study aimed to evaluate the e ectiveness of FPB reactor for removing
soluble contaminants from synthetic wastewater. By only coagulation through jar test operation with addition of polyaluminium chloride
(PACl) as primary coagulant and polyacryamide (PAM) as coagulant-aid, the removals of soluble chemical oxygen demand (COD),
total phosphorus (TP), and NH4
+-N were found to be only 2.2%–7.5%, 5.7%–25.5%, and 9.9%–18.5%, respectively. However, by FPB
operation under the same dosage of coagulants, these values increased to 82.7%, 37.2%, and 50%, indicating that the formation of
pellets in the FPB e ectively enhanced the removal of soluble contaminants. By careful comparison of the settleablility and filterability
of the pollutants after coagulation, the originally soluble contaminants could be divided into three groups, namely: (1) coagulated-andsettleable,
(2) coagulated-but-nonsettleable, and (3) uncoagulable. It was found that not only the first two groups but also a large part of
the third group could be e ectively removed by FPB operation. However, the mechanism for the removal of the uncoagulable pollutants
by FPB operation still needs further investigation. 相似文献
293.
294.
因填充柱装柱繁琐,柱效低,最低检出浓度高,不能判别无组织废气中氯乙烯的浓度是否达到《大气污染物综合排放标准》(GB16297—1996)排放限值的要求;用毛细管柱能满足分析的要求。 相似文献
295.
296.
Single and joint toxic e ects of polycyclic musks including 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-
benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN) and cadmium (Cd) on seed
germination and seedling growth of wheat (Triticum aestivum) were investigated. The results showed that the toxicity sequence of
HHCB toxic to wheat seed germination and seedling growth was similar to that of AHTN, that is, germination rate > shoot elongation
> root elongation, while the toxicity of Cd was in the sequence of root elongation > shoot elongation > germination rate, according
to the LC50 and EC50 values. It is suggested that polycyclic musks and Cd had di erent toxicological mechanisms. Root and shoot
elongation of wheat might be good bioindicators for the contamination of polycyclic musks and Cd in soil. The mixture of polycyclic
musks and Cd had synergistic e ects on T. aestivum according to the equi-toxic mixture approach when root elongation was selected as
the toxicological endpoint. Thus, the joint toxicity of HHCB and Cd was significantly higher than the single toxicity of HHCB or Cd,
which was also confirmed by the EC50 mix value of the mixture (EC50 mix = 0.530 TUmix). The EC50 mix value of the mixture of AHTN
and Cd was 0.614 TUmix, which indicated that the mixture toxicity was strengthened when AHTN coexisted with Cd. 相似文献
297.
The current modified electro-Fenton system was designed to develop a more convenient and e cient undivided system for practical
wastewater treatment. The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas di usion
or gas sparging to supply oxygen gas for the electrolyte solution. Key factors influencing the cathode fabrication and activity
were investigated. The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using a
spectrophotometer. It was found that the cathode generated hydrogen peroxide with high current e ciency and the hydrogen peroxide
yield of the cathode did not decay after 10 times reuse. With the Pt anode at a ferrous ion concentration of 0.5 mmol/L, a pH of 3, and
using magnetic stirring, dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was
fairly di cult. With a Fe anode, dye degradation was more complete. 相似文献
298.
基于批式呼吸计量法的溶解性COD组分划分 总被引:7,自引:3,他引:4
利用批式好氧呼吸计量法结合溶解性慢速水解COD(SH)水解动力学拟合提出了溶解性COD(SCOD)的组分划分方案.上海2个污水处理厂进水的SCOD组分划分结果表明,A厂沉砂池出水(典型生活污水)的SCOD中含有43.5%~58.6% SH、 21.8%~35.2%易生物降解COD(SS)和15.4%~30.9%溶解性惰性COD(SI); B厂沉砂池出水(长距离输送的合流制污水)SCOD中含有34.5%~45.2% SH、 29.3%~37.7% SS和25.6%~31.2% SI. 9组不同水样的试验拟合结果表明,一级动力学能够很好地描述SH的水解过程,A厂和B厂进水SH的水解速率常数分别为28.00~39.77 d-1和26.48~29.52 d-1.该组分划分方案能够实现SS积分区域的理论划分,并消除溶解性微生物产物对SI测定的影响. 相似文献
299.
城郊小河流沉积物吸附Pb2+的动力学过程 总被引:1,自引:0,他引:1
采用分批试验法,对城郊小河流沉积物吸附Pb2+过程进行了研究,探讨了Pb2+吸附的动力学过程和机制.结果表明,随着溶液中沉积物质量增大,达到吸附平衡所需时间变短,单位沉积物吸附量和达到吸附平衡后溶液中Pb2+浓度变低;沉积物含量>0.6 g·L-1时对溶液中Pb2+的去除率超过95%;Pb2+在沉积物上吸附的动力学过程符合假二级动力学模型,该模型拟合的平衡吸附量也更接近真实值;Pb2+初始吸附速率与初始溶液中沉积物质量无明显的相关性;随溶液中沉积物浓度的增加,吸附速率常数逐渐增大,化学吸附所起的作用也越显著;较高浓度沉积物吸附Pb2+的动力学机制能较好符合Elovich方程,但较低浓度沉积物时则相对较差;从吸附速率来看,溶液中沉积物质量较高时,内扩散是整个吸附过程速率的控制步骤,沉积物含量较低时,吸附速率存在多级线性过程,初始阶段非均相扩散是主要控制步骤,但随着时间的延长,其吸附过程转变为沉积物内部的扩散过程. 相似文献
300.
产品碳足迹及其绿色贸易壁垒的研究越来越得到重视,但另一方面,进口模式对碳足迹的影响研究尚不充分.本研究采用生命周期评价方法,对橱柜的国内加工阶段的碳排放、国外不同原材料生产阶段碳排放分别进行计算,并分析不同进口模式情景下上游原材料对橱柜整体碳足迹的影响.主要结论如下:1不同进口模式原材料碳排放差异较大:北欧的原材料碳排放高于中欧和美国,碳排放的主要来源材料为胶合板.2全球的原材料碳排放波动最大,最大原材料碳排放是最小原材料碳排放的7.26倍;美国的原材料碳排放波动最小;3不同进口模式对我国产品碳足迹的影响不同,从贡献结构上看,除了北欧最大碳排放进口模式和全球最大碳排放进口模式是外源型以外,其余模式的产品碳足迹来源皆为内源型,即主要贡献仍为国内加工阶段.4从减排潜力看贸易策略,减排潜力最大的是全球进口模式,为30%~52%,并建议转变北欧为其它进口模式,以寻求更大的减排空间.本文结论可服务于企业绿色采购策略中原材料减排潜力的发掘,以及国家贸易政策的制定. 相似文献