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481.
Physical conditioners, often known as skeleton builders, are commonly used to improve the dewaterability of sewage sludge. This study evaluated a novel joint usage of Fenton’s reagent and skeleton builders, referred to as the F-S inorganic composite conditioner, focusing on their efficacies and the optimization of the major operational parameters. The results demonstrate that the F-S composite conditioner for conditioning sewage sludge is a viable alternative to conventional organic polymers, especially when ordinary Portland cement (OPC) and lime are used as the skeleton builders. Experimental investigations confirmed that Fenton reaction required sufficient time (80 min in this study) to degrade organics in the sludge. The optimal condition of this process was at pH = 5, Fe2+ = 40 mg g−1 (dry solids), H2O2 = 32 mg g−1, OPC = 300 mg g−1 and lime = 400 mg g−1, in which the specific resistance to filtration reduction efficiency of 95% was achieved. 相似文献
482.
Transfer of Australian environmental research on the insecticide endosulfan to Anhui Province, China
Turlough F. Guerin 《环境科学学报(英文版)》1999,11(4):443-448
IntroductionTechnologytransfer,orextension(atthelocallevel),istheprocessofmovinginnovationsfromtheirorigintotheirpointofoperation.Innovationsmayincludescientificandtechnicalknowledge,ideas,services,inventionsandproducts.Technologyadoptionistheimpleme… 相似文献
483.
Leprechaunism is an autosomal recessive disease characterized by intrauterine and postnatal growth restriction, loss of glucose homeostasis, and severe insulin resistance. This disease is caused by a failure of function of the insulin receptor and is lethal early in life. Here we report the prenatal diagnosis of leprechaunism in one consanguineous family, Atl-1, in which two homozygous-affected siblings died with leprechaunism. The mutation in their insulin receptor impaired insulin binding and altered receptor signalling. Prenatal diagnosis could not be accomplished using insulin binding to cultured amniocytes, but was possible using mutational analysis of the insulin receptor gene in DNA from amniotic cells. 相似文献
484.
托盘属于典型的框架结构型铸件 ,要求铸件具有高的耐热性、耐热冲击及抗裂能力。采用不同铸造工艺方案 ,根据存在的问题 ,通过分析产生的原因 ,不断改进工艺 ,获得了合格的铸件 ,使铸件成品率达 95 %以上 相似文献
485.
“三合一”微生物燃料电池的产电特性研究 总被引:34,自引:0,他引:34
为了降低内阻,尽可能提高微生物燃料电池的输出功率,提出了一种将阳极、质子交换膜和阴极热压在一起的"三合一"膜电极形式的微生物燃料电池,并考察了其在接种厌氧污泥条件下对乙酸自配水的产电特性.该"三合一"电池在稳定运行条件下电池内阻约为10~30Ω,远低于现已报道的其它形式的微生物燃料电池的内阻.目前该"三合一"型微生物燃料电池最大输出功率密度约300 mW·m-2,库仑效率约50%.试验结果表明,在一个间歇运行周期中,电池内阻增加是引起输出电压降低的最主要原因.同时在不同的外阻条件下,需要降低极化的重点不同. 相似文献
486.
污泥脱水中PAC与PAM联合使用的试验研究 总被引:1,自引:0,他引:1
利用正交试验作单因素分析,对PAC与PAM的投加量、投加方式等因素对污泥脱水效果的影响进行了研究。结果表明:PAC,PAM用量分别为240mg·L-1,60mg·L-1,配制溶液的百分比例分别为4%,0.1%时,投加方式为先加PAC,搅拌后再加PAM,污泥脱水效果较好,形成的泥饼含固率达到22%,且药剂费比单独使用PAM经济。 相似文献
487.
植物对重金属的抗性和抗性代价 总被引:5,自引:1,他引:5
本文就植物对重金属污染的长期适应产生抗性、抗性试验技术及抗性代价几个方面的研究进行了简要论述和初步探讨。 相似文献
488.
489.
DAVID M. MARSH† GRAHAM S. MILAM† NICHOLAS P. GORHAM† NOELLE G. BECKMAN† 《Conservation biology》2005,19(6):2004-2008
Abstract: Roads can fragment animal populations by disrupting movement among formerly continuous habitats. Although models have demonstrated that disrupted movement can contribute to long-term extinction, there are few empirical data on the effects of roads on animal movement. We used displacement and homing experiments to determine whether forest roads are barriers to the movement of terrestrial salamanders. We displaced 1471 red-backed salamanders ( Plethodon cinereus ) across five forest roads and compared return rates to those of salamanders displaced equal distances toward the forest interior. Roads significantly reduced the return rate of salamanders, with a mean reduction of 51%. Steep roadside verges further reduced return rates, particularly for salamanders moving downhill across verges. The permeability of roads to salamander movement did not appear to be related to road surface type. Gravel roads had both the highest and lowest observed permeability with the two paved roads intermediate between these. We conclude that narrow forest roads are partial barriers to salamander movement and that steep roadside verges may exacerbate these effects. 相似文献
490.