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 15 毫秒
41.
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
42.
43.
Lisbeth M. Ottosen Eduardo Arevalo Heinz Stichnothe Wolfgang Calmano 《Environmental Chemistry Letters》2006,3(4):164-168
Wastewater from wash down of boat hulls contains typically Cu, Zn and organometallic biocides, e.g. tributyltin (TBT). In
some cases this wastewater is led directly into the marine system. In the present paper, a cheap flocculation method (iron
flocculants) for removal of Cu and Zn from the wastewater is investigated and the method was shown successful. TBT concentration
in a sample from a German dockyard was also decreased during flocculation, but the TBT removed was already associated with
small particulates in the original sample. Low concentrations of heavy metals were obtained by flocculation: <0.05 mg Cu/l
and 0.2 mg Zn/l.
An erratum to this article can be found at 相似文献
44.
The floc morphology was investigated in a continuous-flow reactor, in order to understand the evolution of flocs in practical flocculation and sedimentation processes in water utilities. Kaolin-humic acid suspension was used as the test water, and polyaluminum chloride was chosen as the coagulant. An in-situ recognition system was applied to analyze the floc size, boundary fractal dimension, and eccentricity ratios. Particle numbers and turbidity were also determined in the sedimentation stage. At a coagulant dose of 1 mg/L as Al, the average floc size increased from 62 to 78 μm and the boundary fractal dimension was around 1.14, suggesting that flocs were compact and continuously grew during the entire flocculation process. However, with the dose increased to 5 mg/L, the average floc size decreased and stabilized at around 65 μm, with the fractal dimension of 1.20. It can be concluded that the excess coagulant doses resulted in the formation of chain-shaped, lower density, and more branched structure flocs, thereby restricting flocs' further growth in the subsequent flocculation. Floc morphology analysis suggested that charge neutralization dominated in the initial flocculation stage, then the bridge and sweep mechanisms were dominant in the subsequent flocculation. In addition, compared with the traditional inclined plate settler, a novel V-shaped plate settler introduced in this study had an advantage in small size floc(less than 5 μm) removal. The V-shaped region could promote aggregate restructuring and re-flocculation; therefore, the V-shaped plate settler provides an alternative method for sedimentation. 相似文献
45.
在水资源日益紧张、含盐废水排放量日益增多的大趋势下,寻求经济有效的含盐废水处理技术已成为重要的研究课题。以厦门某食品企业水产品加工腌泡环节含盐废水为研究对象。含盐废水经氨水沉淀、离子交换树脂软化处理,废水中钙镁离子被有效脱除,出水钙镁质量浓度已经降为10.4mg·L-1,达到软水水质标准。软化后的废水经4‰聚丙烯酰胺(PAM)絮凝并通过活性炭吸附,污染密度指数值(SDI)降低至0.41,完全达到膜分离装置进水水质的要求。预处理液再经电渗析膜进一步浓缩分离后,氯化钠质量浓度可由7351mg·L-1提升到78156mg·L-1,对盐分浓缩了10倍以上,达到废水和盐分的处理回收利用。本处理工艺流程简洁,药耗少、能耗低,比较适合小规模含盐废水的综合处理。 相似文献
46.
47.
48.
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
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.