全文获取类型
收费全文 | 186篇 |
免费 | 21篇 |
国内免费 | 160篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 10篇 |
环保管理 | 15篇 |
综合类 | 180篇 |
基础理论 | 54篇 |
污染及防治 | 88篇 |
评价与监测 | 2篇 |
社会与环境 | 5篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 9篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 17篇 |
2014年 | 24篇 |
2013年 | 50篇 |
2012年 | 23篇 |
2011年 | 37篇 |
2010年 | 24篇 |
2009年 | 26篇 |
2008年 | 23篇 |
2007年 | 17篇 |
2006年 | 24篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 31 毫秒
91.
从分子质量的变化分析有机物对GAC吸附内分泌干扰物(BPA)的影响 总被引:3,自引:1,他引:2
从分子质量分布的角度研究了水中有机物对颗粒活性炭(GAC)吸附双酚A(BPA)容量及吸附速率的影响.结果表明,相对于以去离子水为本底的BPA溶液来说,GAC吸附以滤后水、臭氧后出水和原水为本底的BPA溶液的Langmuir模型的最大吸附容量qm值分别下降了29.95%、43.56%和44.44%,而其拟二级动力学模型的k2值分别下降了43.05%、49.75%和56.38%.相对分子质量3 000以上,尤其是10 000以上的有机物堵塞GAC的二级微孔;3 000以下,尤其是1 000以下的有机物与BPA分子之间存在直接的竞争吸附,是导致GAC对BPA的吸附容量以及吸附速率下降的主要原因. 相似文献
92.
Wun-Cheng Wang 《Journal of the American Water Resources Association》1974,10(4):662-671
ABSTRACT: The adsorption of phosphate on particulate matter from the Illinois and Spoon Rivers was investigated. Adsoprtion reached equilibrium after 5 to 6 days and adsorption isotherms were linear for both constant and varying amounts of particulate matter. Adsorption was maximum at pH 8.3 – 8.4 and minimum at 6.0. Rates of adsorption were influenced by the equilibrium concentration of phosphate-P and were essentially the same for the Illinois and Spoon Rivers. However, the quantity of phosphate-P adsorbed per unit weight of particulate matter differed for the two streams with that in the Illinois River exhibiting an adsorption capacity 7 times that of the Spoon River. 相似文献
93.
为预测深部或浅部煤层不同温度和不同压力条件下的吸附等温线,选用型煤以高低温试验装置为依托,测试了温度为293.15,273.15,253.15 K的吸附等温线。基于T-P模型,利用等温吸附曲线对公式中的参数进行了合理的求解,探讨了一种简单的煤对瓦斯吸附等温线预测方法。研究表明:同一吸附平衡压力下,温度越低,煤的瓦斯吸附量越大;ε-ω吸附特征曲线与温度无关,呈现对数的形式;参数m和拟合度R2满足抛物线的关系,存在拟合效果最好时的参数m值。采用T-P模型预测得到的吸附等温线与实测的吸附等温线无论是趋势还是定量结果均十分吻合,其相对误差不超过5%。 相似文献
94.
In comparison with several other reported inorganic sorbents, Camellia tree leaf and primary sludge obtained from a settling tank as a pretreatment to the activated sludge system in a Hong Kong sewage treatment plant were evaluated for removing Cu(II) from aqueous solutions. Experimental data were modeled by the Langmuir isotherm equation to estimate the maximum sorption capacity (qmax). Results show that, at pH 5.6, biosorbents, Camellia tree leaf and primary sludge in particular, exert higher sorption capacities (qmax > 40 mg g−1) than inorganic sorbents, Na-montmorillonite (qmax = 33.3 mg g−1), fly ash (qmax = 18.8 mg g−1), and goethite powder (10.3 mg g−1). Furthermore, a pseudo second-order kinetic model was found to properly describe the experimental data for both bio- and inorganic sorbents. Sorption of Cu(II) on the Camellia tree leaf and primary sludge were much faster than that on the inorganic sorbents. In addition, desorption tests revealed that the desorption capacities of the two biomaterials are higher than the other selected materials; and much more Cu(II) can be retrieved from the Cu(II)-loaded biosorbents. Finally, increasing solution pH was found to greatly increase qmax and accelerate sorption processes. 相似文献
95.
Xie Shuibo Zhang Chun Zhou Xinghuo Yang Jing Zhang Xiaojian Wang Jingsong 《Journal of environmental radioactivity》2009
Hematite, a type of inorganic-sorptive medium, was used for the removal of U (VI) from aqueous solutions. Variables of the batch experiments including solution pH, contact time, initial concentration, temperature, calcium and magnesium ions were studied. The results indicated that the adsorption capacities are strongly affected by the solution pH, contact time and initial concentration. A higher pH favors higher U (VI) removal. The adsorption was also affected by temperature and calcium and magnesium ions, but the effect is very weak. The maximum adsorption capacity (qm) only increased from 3.36 mg g−1 to 3.54 mg g−1 when the temperature was increased from 293 K to 318 K. A two-stage kinetic behavior was observed in the adsorption of uranium (VI): very rapid initial adsorption in a few minutes, followed by a long period of slower uptake. It was found that an increase in temperature resulted in a higher uranium (VI) loading per unit weight of the sorbent. The adsorption of uranium by hematite had good efficiency, and the equilibrium time of adsorbing uranium (VI) was about 6 h. The isothermal data were fitted with both Langmuir and Freundlich equations, but the data fitted the former better than the latter. The pseudo-first-order kinetic model, pseudo-second-order kinetic model and intraparticle diffusion model were used to describe the kinetic data, but the pseudo-second-order kinetic model was the best. The thermodynamic parameter ΔG0 were calculated, the negative ΔG0 values of uranium (VI) at different temperatures confirmed the adsorption processes were spontaneous. 相似文献
96.
In this study, the surface chemical functional groups of Bacillus cereus biomass were identified by Fourier transform infrared (FTIR) analytical technique. It had been shown that the B. cereus cells mainly contained carboxyl, hydroxyl, phosphate, amino and amide functional groups. The potentiometric titration was conducted to explain the surface acid-base properties of aqueous B. cereus biomass. The computer program FITEQL 4.0 was used to perform the model calculations. The optimization results indicated that three sitesthree pKas model, which assumed the cell surface to have three distinct types of surface organic functional groups based on the IR analysis results, simulated the experimental results very well. Moreover, batch adsorption experiments were performed to investigate biosorption behavior of Cu(Ⅱ) and Pb(Ⅱ) ions onto the biomass. Obviously, the adsorption equilibrium data for the two ions were reasonably described by typical Langmuir isotherm. 相似文献
97.
以海藻酸钠、明胶和海带粉为原料制备了固定化海带生物吸附剂。固定化海带生物吸附剂对Ni2+的吸附过程可分为3个阶段:快速吸附阶段、缓慢吸附阶段和吸附平衡阶段。动力学过程可用Lagergren准二级反应动力学方程描述,限速步骤为化学吸附。随Ni2+初始质量浓度的增加,固定化海带生物吸附剂的Ni2+吸附量逐渐增大,Ni2+去除率逐渐降低。吸附过程符合Langmuir和Freundlich吸附等温方程,说明该吸附体系既有物理吸附又有化学吸附,从吸附状态看属于多层吸附,由Langmuir吸附等温方程得出固定化海带生物吸附剂对Ni2+的最大吸附量为39.43mg/g,说明固定化海带生物吸附剂对Ni2+有较好的吸附性能。 相似文献
98.
99.
100.
生物膜及其各种组分对4-氯酚化合物的吸附特征 总被引:13,自引:1,他引:12
对4-氯酚化合物在生物膜不同组分上的吸附行为的实验中,生物膜不同组分包括生长有生物膜外壳的模拟水体悬浮颗粒物(高岭土)、细菌细胞、胞外多糖、高岭土及有胞外多糖存在时的高岭土.在所设计的这5种吸附体系中,前4种吸附较符合Langmuir和Freundlich等温吸附方式.在室温25℃,pH值为6.1的吸附条件下,细菌细胞和胞外多糖作为生物吸附物质,对4-氯酚的吸附明显地大于高岭土;高岭土外的生物膜外壳影响对4-氯酚的吸附,生长有生物膜外壳的高岭土对4-氯酚的吸附量高于单独高岭土体系. 相似文献