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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
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Srilert Chotpantarat Say Kee Ong Chakkaphan Sutthirat Khemarath Osathaphan 《环境科学学报(英文版)》2011,23(4):640-648
This study investigated the e ects of pH on the transport of Pb2+, Mn2+, Zn2+ and Ni2+ through lateritic soil columns. Model results
by fitting the symmetric breakthrough curves (BTCs) of bromide (Br??) with CXTFIT model suggested that physical non-equilibrium
processes were absent in the columns. The heavy metal BTCs were, however, asymmetrical and exhibited a tailing phenomenon,
indicating the presence of chemical non-equilibrium processes in the columns. The retardation factors of Pb2+ were the largest of
the four metal ions at both pH 4.0 (33.3) and pH 5.0 (35.4). The use of Langmuir isotherm parameters from batch studies with
HYDRUS-1D did not predict the BTCs well. Rather the two-site model (TSM) described the heavy metal BTCs better than the
equilibrium linear/nonlinear Langmuir model. The fraction of instantaneous sorption sites ( f ) of all four metal ions on the lateritic
soil was consistently about 30%–44% of the total sorption sites. 相似文献
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极限与分配--再论环境法的本位 总被引:9,自引:0,他引:9
徐祥民 《中国人口.资源与环境》2003,13(4):23-26
环境问题是人类活动及其影响超出环境承受能力的极限所造成的后果。解决环境问题最根本的办法是分配,即把有限的环境资源在人类广泛的欲求之间做“相持而长”的分配。这种资源分配不同于收益分配,它体现的基本精神是义务。把体现义务精神的分配方法引入环境立法,必然导致环境法由传统的权利本位转变为义务本位。环境法不得不采用资源分配的办法,以义务为本位,这是由环境这种特殊的物质条件所决定的。 相似文献
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