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11.
重金属对蚯蚓的毒性毒理研究 总被引:20,自引:2,他引:20
通过室内模拟实验以及对株洲市重金属污染区农田土壤中采样,进行了重金属对蚯蚓的毒性毒理研究.毒性实验表明,各重金属元素48h的LD50分别为:Cd1000mg/kg,Pb812mg/kg,Cu633mg/kg,Hg304mg/kg,Zn528mg/kg,Cr428mg/kg.对蚯蚓毒理研究证明,重金属对蚯蚓酯酶同工酶有抑活作用,而重金属对蚯蚓过氧化物酶同工酶有激活作用.在光镜下观察,可见重金属污染可引起蚯蚓的体表溃疡及产生肿瘤,可使胃肠道粘膜层出血、背血管肿胀,同时可引起胃肠道粘膜上皮细胞产生萎缩或溃疡灶.蚯蚓特有的黄色细胞团污染程度不同而显示出消长规律.在电镜下可见到在重污染区的蚯蚓胃肠道粘膜上皮细胞中的rER肿胀、高尔基体膨大,线粒体嵴消失,甚至空泡化或解体.另可见细胞核膜间隙肿胀、断裂、核质外溢,胞质自溶.蚯蚓以上病变的大小是随土壤重金属污染区的污染级别而定;各病理变化指标均能定性地反映土壤重金属污染状况. 相似文献
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13.
麦草低污染制浆新技术 总被引:3,自引:0,他引:3
麦草低污染制浆新工艺采用亚硫酸钠-甲醛-蒽醌(加入少量催化剂)制浆(SFP-AQ法),生产吨浆的COD排放总量下降30%,色度下降60%,悬浮物总量下降50%,制浆黑液的pH值下降至7~8。采用该新工艺同时还可产生表面活性好、便于利用的木素磺酸钠和其他产品,使纤维资源得到综合利用,为解决中小型草浆造纸厂的污染问题提供一条有效途径。j 相似文献
14.
The number and distribution of pollutant concentration in a trapezoidal open channel flow with a side discharge is calculated
and effects of the bank gradient are investigated in this paper. A sigma-coordinate water quality numerical model is used
to simulate the process of both water and pollutant transportation in the trapezoidal channel open flow. The diffusion coefficient
used in the prediction is determined by two methods including constant coefficient and the depth-averaged k-epsilon turbulence
closure model. The change of the concentration with the bank gradient is acquired based on the simulation of cases with different
bank gradients. An analytical formula is derived by using the mirror image method and related diffusion theories, ignoring
the discharge momentum and the influence of the opposite bank. The formula can predict the number and distribution of pollutant
concentration with some acceptable errors. The results demonstrate that the bank gradient has great influence on the concentration
distribution which will decrease with the increase of the bank gradient approximately following a hyperbolic law. 相似文献
15.
The principle and technique were reported here to produce lignin-based sand stabilizing material (LSSM) using extracted lignin from
black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment
was carried out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field
experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plantfriendly
material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert
species (i.e., Agriophyllum squarrosum (L.) Moq. and Artemisia desertorum Spreng. etc.) could be used to form community in 2–3
yeas and to stabilize sand dune e ectively. The newly formed community was sustainable under an extremely dry climate condition.
The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K
contents in the soil was negligible. 相似文献