全文获取类型
收费全文 | 2256篇 |
免费 | 253篇 |
国内免费 | 2085篇 |
专业分类
安全科学 | 186篇 |
废物处理 | 99篇 |
环保管理 | 212篇 |
综合类 | 2561篇 |
基础理论 | 318篇 |
环境理论 | 1篇 |
污染及防治 | 1160篇 |
评价与监测 | 41篇 |
社会与环境 | 14篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 14篇 |
2023年 | 77篇 |
2022年 | 117篇 |
2021年 | 181篇 |
2020年 | 171篇 |
2019年 | 170篇 |
2018年 | 158篇 |
2017年 | 166篇 |
2016年 | 228篇 |
2015年 | 241篇 |
2014年 | 248篇 |
2013年 | 269篇 |
2012年 | 290篇 |
2011年 | 275篇 |
2010年 | 213篇 |
2009年 | 272篇 |
2008年 | 165篇 |
2007年 | 272篇 |
2006年 | 240篇 |
2005年 | 169篇 |
2004年 | 119篇 |
2003年 | 130篇 |
2002年 | 79篇 |
2001年 | 66篇 |
2000年 | 65篇 |
1999年 | 54篇 |
1998年 | 26篇 |
1997年 | 31篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 15篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 2篇 |
1982年 | 2篇 |
1977年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有4594条查询结果,搜索用时 0 毫秒
801.
采用血清瓶静态试验法研究了垃圾渗出污水的厌氧处理的可行性。试验表明:垃圾渗出污水对厌氧发酵微生物无抑制作用,有良好的厌氧降解性,产气率为0.321/g·COD,污水中的大部份有机物都能被厌氧消化,COD_cr去除率为78.2%,发酵过程中还能获得能源——沼气。具有良好的应用前景。 相似文献
802.
水葫芦压滤脱水与鲜汁强化除磷工艺 总被引:1,自引:0,他引:1
就地对水葫芦进行粉碎压滤能有效减少质量和体积,降低处置难度,减少运输成本。针对水葫芦鲜渣含水率高,鲜汁污染物浓度高的问题,研究不同压滤时间、压力和调理剂的添加对压滤后鲜渣的含水率的影响;同时采用化学混凝法研究不同混凝剂、pH和混凝时间以及CaO的添加对鲜汁中COD和TP的去除效果的影响。结果表明:鲜渣含水率随着压滤压力、时间的增加而降低,8 MPa压力条件下鲜渣含水率为66.35%,添加鲜货质量10%的木屑和CaO能使含水率降为46.17%和40.21%,加快鲜渣脱水速度;FeCl3、Al2(SO4)3和PAC等3种混凝剂均能有效去除鲜汁中COD和TP,去除率分别可达80%以上和85%以上,进一步添加CaO能强化TP的去除效果,去除率可达96%以上;水葫芦压滤脱水和鲜汁预处理工艺为水葫芦处置提供了一种新的途径。 相似文献
803.
于2014年4-9月,研究我国一典型南方水源溶解性有机物(DOM)的荧光特性变化与去除情况,同时分析了DOM荧光组分与三氯乙醛生成势(CHFP)的相关性。结果表明,该水源DOM主要以芳香性蛋白质类物质组成,溶解性微生物代谢产物类物质、富里酸类物质和腐殖酸类物质含量逐渐增加;5个荧光区域的积分体积(ΦⅠ,n、ΦⅡ,n、ΦⅢ,n、ΦⅣ,n和ΦⅤ,n)所占总体积(ΦT,n)平均比例依次为:13.55%、27.53%、25.00%、16.02%和17.91%;原水DOM的CHFP范围为27.06~81.20μg/L,平均值为46.60μg/L,三氯乙醛(CH)前体物含量与水体中溶解性微生物代谢产物类物质相关性最好;与常规处理工艺相比,O3/BAC深度处理工艺对于溶解性微生物代谢产物类物质的去除率大幅提高,更有利于CH的控制。 相似文献
804.
805.
Biosorption of Cr(VI) using low cost sorbents 总被引:2,自引:0,他引:2
N. Fiol I. Villaescusa M. Martínez N. Miralles J. Poch J. Serarols 《Environmental Chemistry Letters》2003,1(2):135-139
Waste products from industrial operations, such as yohimbe bark, grape stalks, cork and olive stones were investigated for
the removal of Cr(VI) from aqueous solutions. Equilibrium batch experiments at room temperature were performed. Metal uptake
showed a pH-dependent profile and optimum uptake at initial pH between 2.0–3.0. Slight influence of NaCl on metal uptake was
observed. The sorption data fitted well to the Langmuir model within the concentration range studied. Grape stalks proved
to be the most efficient sorbent followed by yohimbe bark, cork and olive stones.
N. Fiol is the recipient of the 2002 ACE Environmental Chemistry Award 相似文献
806.
A Biosurfactant-Enhanced Soil Flushing for the Removal of Phenanthrene and Diesel in Sand 总被引:2,自引:0,他引:2
In order to examine the potential of biosurfactants in soil remediation, and to investigate the effects of several operating conditions, such as flow rate, biosurfactant concentration and surfactant type, biosurfactant-enhanced soil flushing was conducted. In the biosurfactant-enhanced soil flushing process, the removal efficiency increased as the flow rate decreased. Rhamnolipid showed no effect on the removal efficiency of phenanthrene and diesel from sand in the concentration range 0.3-0.5%. However, rhamnolipid showed higher efficiencies for the removal of phenanthrene and diesel from sand than Tween 80. Based on total recovery, following an equivalent pore volume flush, it was more difficult to remove diesel than phenanthrene. In order to obtain the specific removal efficiency, more pore volumes of surfactant solution may be required in field applications. Under optimum conditions, the biosurfactant removed as much as 70% of the phenanthrene and 60% of the diesel in the sand. These results indicate that the use of biosurfactants in the flushing process is favorable, not only with respect to the environment, but also on removal efficiencies. 相似文献
807.
In dune slacks in The Netherlands, a decline of rare mesotrophic basiphilous plant species and their plant communities has
been observed in combination with an increase of more productive systems with common, taller acidophilous plant species. This
has been attributed to both natural and anthropogenic changes. In a humid climate with a precipitation surplus, as in The
Netherlands, the calcium carbonate content of a calcareous soil increases with depth. However, soils in coastal dune slacks,
may have a higher carbonate content in the topsoil horizon than in the underlying layers. Carbonates which buffer the pH can
prolong the presence of mesotrophic basiphilous plant communities which are of high conservation value.
To explain the occurrence of calcareous surface horizons in dune slacks, hydrological and micromorphological analyses were
carried out in three dune slacks. Two slacks are situated on the Wadden Sea islands in the northern part of The Netherlands;
one on Schiermonnikoog and one on Texel. The third slack is situated in the dunes on the island of Goeree in the southwestern
part of The Netherlands. In all three slacks, carbonate occurs as mollusc and gastropod fragments (silt- or sand-sized) and
as micritic nodules in the topsoil layer, due to aeolian deposition and sedimentation by water.In situ carbonate accumulation (calcitans and calcareous crusts) due to CO2 release in inundated and/or capillary rise of calcareous groundwater near, or at the soil surface. Accumulation of carbonate
also occurs as a result of biological activity by algae in the topsoil of the Goeree site. In general, hydrological processes
maintaining high levels of calcareous groundwater are a prerequisite for the maintenance of high carbonate levels in topsoils.
Such levels are necessary for the conservation and management of basiphilous pioneer vegetation. 相似文献
808.
809.
Enrique J. La Motta 《Journal of the American Water Resources Association》1995,31(2):207-216
ABSTRACT: This paper presents a discussion of the chemistry of CO2 removal in tray aerators, and different sets of equations that are applicable to several initial water chemical conditions are proposed. These chemical equations and a statistical model to predict the kinetic constant were tested with field data observed by other researchers in pilot units and in a full scale plant. The water temperature in their experiments was around 15°C. 相似文献
810.
Long-term consumption of water containing excessive fluoride can lead to fluorosis of the teeth and bones. Electrocoagulation (EC) is an electrochemical technique, in which a variety of unwanted dissolved particles and suspended matter can be effectively removed from an aqueous solution by electrolysis. Continuous flow experiments with monopolar aluminium electrodes for fluoride removal were undertaken to investigate the effects of the different parameters such as: current density (12.5-50A/m(2)), flow rate (150-400 mL/min), initial pH (4-8), and initial fluoride concentration (5-25mg/L). The highest treatment efficiency was obtained for the largest current and the removal efficiency was found to be dependent on the current density, the flow rate and the initial fluoride concentration when the final pH ranged between 6 and 8. The composition of the sludge produced was analysed using the X-ray diffraction (XRD) spectrum. The strong presence of the aluminium hydroxide [Al(OH)(3)] in the above pH range, which maximizes the formation of aluminium fluoride hydroxide complex [Al(n)F(m)(OH)(3n-m)], is the main reason for defluoridation by electrocoagulation. The results obtained showed that the continuous flow electrocoagulation technology is an effective process for defluoridation of potable water supplies and could also be utilized for the defluoridation of industrial wastewater. 相似文献