全文获取类型
收费全文 | 61篇 |
免费 | 2篇 |
国内免费 | 14篇 |
专业分类
安全科学 | 3篇 |
环保管理 | 2篇 |
综合类 | 58篇 |
基础理论 | 5篇 |
污染及防治 | 8篇 |
评价与监测 | 1篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有77条查询结果,搜索用时 203 毫秒
41.
42.
Using chitosan modified soil to flocculate and sediment algal cells has been considered as a promising strategy to combat cyanobacteria blooms in natural waters. However, the flocculation efficiency often varies with algal cells with different zeta potential (ZP) attributed to different growth phases or water conditions. This article investigated the relationship between ZP of Microcystis aeruginosa and its influence to the flocculation efficiency using chitosan modified soil. Results suggested that the optimal removal efficiency was obtained when the ZP was between − 20.7 and − 6.7 mV with a removal efficiency of more than 80% in 30 min and large floc size of > 350 μm. When the algal cells were more negatively charged than − 20.7 mV, the effect of chitosan modified soil was depressed (< 60%) due to the insufficient charge density of chitosan to neutralize and destabilize the algal suspension. When the algal cells were less negative than − 6.7 mV or even positively charged, a small floc size (< 120 μm) was formed, which may be difficult to sink under natural water conditions. Therefore, manipulation of ZP provided a viable tool to improve the flocculation efficiency of chitosan modified soil and an important guidance for practical engineering of cyanobacteria bloom control. 相似文献
43.
With the objective to assess the relevance of competitive effects in respect of the humic colloid-borne migration of actinides in case of release, the influence of Al(III) on humate complexation of La(III) as an analogue of trivalent actinides was investigated for various humic materials by using 140La as a radioactive tracer, allowing measurements in very dilute systems to simulate realistic settings. Generally, competition by aluminium is not detectable unless the metal-loading capacity of the humic colloids is nearly exhausted. For average contents of organic carbon, a threshold value of 10(-6) M Al(III) can be specified. The metal exchange turned out to be kinetically hindered. Effects on co-adsorption of La(III) and humic acid were found to be less important. Immobilization by the concomitantly induced flocculation process outweighs the role of displacement effects. Comparative studies on complexation and flocculation of humic acid with Al(III), Ga(III), In(III), Sc(III), Y(III), and La(III) were undertaken in order to evaluate the influence of specific properties apart from ion charge and to characterize the mechanism of flocculation. In spite of considerable variations in the binding affinities among these metals, it can be inferred that the possibility of significant competitive effects in natural aquatic systems is confined to Al(III). Complex stabilities and flocculation efficiencies proved to be interrelated. Precipitation is thus attributed to homocoagulation of humic colloids induced by charge compensation, which is further supported by flocculation experiments with Al(III) depending on pH, ionic strength, and humic acid concentration. 相似文献
44.
A newly designed aluminum hydroxide gel-coated nanoscale zero-valent iron(AHG@NZVI)with enhanced activity and dispersibility of NZVI was successfully synthesized.The AHG@NZVI composite was synthesized via control of the surface AHG content.AHG@NZVI-1,AHG@NZVI-2 and AHG@NZVI-3 were prepared under centrifugal mixing speeds of 1000,2000 and 4000 r/min,respectively.The activity of AHG@NZVI was evaluated by its tetracycline(TC) removal efficiency.The effects of AHG content,pH value,reaction temperature,and presence of competitive anions on TC removal were investigated.TC could be removed by both adsorption and chemical reduction on AHG@NZVI-2(centrifugal speed 2000 r/min) in a short time with high removal efficiency(≥98.1%) at the optimal conditions.Such excellent performance can be attributed to a synergistic interaction between aluminum hydroxide gel and NZVI:(1) AHG could enhance the stability and dispersity of NZVI;(2) aluminum hydroxide gel could absorb a certain amount of TC and Fe~(2+)/Fe~(3+),which facilitated the mass transfer of TC onto the NZVI surface,resulting in acceleration of the reduction rate of TC by the AHG@NZVI composite;and(3) AHG-Fe~(2+)/Fe~(3+)could absorb a certain amount of TC by flocculation.The kinetics of TC removal by AHG@NZVI composite was found to follow a two-parameter pseudo-first-order model.The presence of competitive anions slightly inhibited the activity of AHG@NZVI systems for TC removal.Overall,this study provides a promising alternative material and environmental pollution management option for antibiotic wastewater treatment. 相似文献
45.
Critical review of EPS production, synthesis and composition for sludge flocculation 总被引:1,自引:0,他引:1
Klai Nouh Ram Saurabh Kumar Sellamuthu Balasubramanian Rajeshwar Dayal Tyagi 《环境科学学报(英文版)》2018,30(4):225-245
Extracellular polymeric substances(EPS) produced by microorganisms represent biological macromolecules with unfathomable potentials and they are required to be explored further for their potential application as a bioflocculant in various wastewater sludge treatment. Although several studies already exist on biosynthetic pathways of different classical biopolymers like alginate and xanthan, no dedicated studies are available for EPS in sludge. This review highlights the EPS composition, functionality, and biodegradability for its potential use as a carbon source for production of other metabolites. Furthermore, the effect of various extraction methods(physical and chemical) on compositional, structural, physical and functional properties of microbial EPS has been addressed. The vital knowledge of the effect of extraction method on various important attributes of EPS can help to choose the suitable extraction method depending upon the intended use of EPS. The possible use of different molecular biological techniques for enhanced production of desired EPS was summarized. 相似文献
46.
混凝絮凝法去除腐质酸的研究 总被引:6,自引:0,他引:6
进行了混凝絮凝法去除水中腐殖酸的研究,结果表明,同传统的絮凝剂相比,微生物絮凝剂不仅用量少,去除效果好(去除率可达60%),而且不产生二次污染,可应用于废水特别是给水中腐殖酸的去除工艺中,对絮凝剂的絮凝机理进行了初步研究,研究表明,微生物絮凝剂去除腐殖酸主要是通过架桥完成的,不同于A12(SO4)3的电中和机理。 相似文献
47.
微生物絮凝剂普鲁兰絮凝机理初探 总被引:9,自引:0,他引:9
通过试验研究了微生物絮凝剂普鲁兰对不同原水的絮凝效果,进而对其絮凝机理及应用条件进行了探讨.试验表明,普鲁兰与无机絮凝剂(特别是铝盐和铁盐)复配使用在水处理领域具有潜在的应用前景. 相似文献
48.
几种聚电解质的合成及絮凝性能研究 总被引:3,自引:0,他引:3
合成了5种水溶性聚电解质:①丙烯酰胺-二甲基二烯丙基氯化铵共聚物(AM-DM);②丙烯酰胺-三甲基烯丙基氯化铵共聚物(AM-TM);③水解聚丙烯酰胺(HPAM);④阳离子化聚丙烯酰胺(CPAM)和⑤丙烯酰胺-二甲基二烯丙基氯化铵-丙烯酸(AM-DM-AC)共聚物。对它们的结构进行了红外表征,并就絮凝能力进行了研究。结果表明:5种聚合物均具有絮凝能力且出现两个聚沉点,絮凝能力与聚合物的链结构有关。 相似文献
49.
A new flocculation model using variable fractal dimension is proposed and validated with several experimental data and an
existing model. The proposed model consists of two processes: aggregation and breakup due to flow turbulence. For aggregation
process, the aggregate structure is considered to have the characteristic of self-similarity, the main concept of fractal
theory. Under this assumption, a variable fractal dimension instead of a fixed one adopted by previous studies is utilized
here for general cohesive sediment transport. For breakup, similar concept is adopted in a more empirical manner because breakup
is too abrupt to entirely apply the concept of variable fractal dimension. By a linear combination of the formulations for
aggregation and breakup processes, a flocculation model which can describe the temporal evolution of floc size is obtained.
Flocculation model using variable fractal dimension is capable of predicting equilibrium floc size when compared with several
experimental data sets using different types of mud provided that empirical coefficients are calibrated. Through model-data
comparison with Manning and Dyer (Marine Geology 160:147–170, 1999), it is also clear that some of the empirical coefficients
may depend on sediment concentration. Model results for the temporal evolution of floc size are less satisfactory, despite
model results shows a more smooth “S-curve” for the temporal evolution of floc size as compared with the previous model using
fixed fractal dimension. The proposed model is limited to mono-size of primary particle and dilute flow condition. These other
features shall be investigated as future work. 相似文献
50.