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261.
262.
垃圾焚烧发电厂垃圾渗滤液处理工艺的研究 总被引:5,自引:0,他引:5
通过对垃圾焚烧厂和垃圾填埋场垃圾渗滤液的特点比较 ,确定UASB反应器 CASS反应器复合工艺处理垃圾焚烧厂渗滤液 ,确定其最佳处理参数。结果表明 ,通过该系统处理后 ,CODCr总去除率达 98 1 % ,NH+ 4 N总去除率达96 3% ,取得较好的去除有机物和脱氮效果 相似文献
263.
To investigate the environmental safety of waste disposal landfill sites and of land reclaimed from such sites, we evaluated
the toxicity of leachate from these sites by a combination of bioassays in the Japanese killifish medaka Oryzias latipes. We tested for lethal toxicity in adult and larval medaka and for hatching inhibition of embryos from eggs. As biochemical
evidence of the effects of leachate exposure, CYP1A (EROD activity) and vitellogenin (Vtg) were induced. We also bioassayed
water-treated leachate and downstream river water. Leachate solution was lethal to larval and adult medaka. Embryo hatchability
was inhibited, and abnormal hatching, spinal deformity and anisophthalmia occurred in embryos exposed to leachate solution.
CYP1A was induced by exposure to leachate solution diluted to 1.0%, and EROD activity was significantly higher than in control.
Vtg and unknown proteins were induced in the sera of male medaka exposed to the diluted leachate solution. Conventional water
treatments worked effectively to remove toxic compounds but did not work well to remove element ions, including heavy metals.
Treated leachate produced neither lethal toxicity nor hatching abnormalities during the exposure period. Fish toxicity tests
for leachate would be useful for monitoring the environmental safety of landfill sites. 相似文献
264.
265.
pH对电解处理垃圾渗滤液的影响 总被引:2,自引:0,他引:2
在不同的pH值条件下对氯离子和重金属离子含量不同的渗滤液和邻硝基苯酚人工模拟废水进行了电解处理,着重考察了不同pH值条件下氯离子浓度和重金属离子种类对有机物电解去除效果的影响。结果表明,电解处理过程中, pH值对有机物电解去除效果的影响与渗滤液的水质有关,尤其与渗滤液中氯离子和重金属离子浓度以及重金属离子种类有关。在pH=2的条件下电解处理氯离子和重金属离子含量均很低的渗滤液,有利于有机物的氧化去除;在pH=9的条件下电解处理氯离子和重金属离子浓度均较高的渗滤液,其COD的电解去除效果最好;在pH=2或pH=12的条件下电解处理氯离子浓度高而重金属离子浓度低的渗滤液,能促进有机物的氧化分解。在一定浓度范围内,渗滤液中无机变价离子的组成不同,电解处理垃圾渗滤液的最佳pH值也不同。 相似文献
266.
垃圾渗滤液处理工艺中有机污染物的三维荧光光谱 总被引:8,自引:2,他引:6
利用荧光发射和三维荧光光谱研究了三峡库区某垃圾堆场的渗滤液及其处理工艺出水溶解性有机质(DOM)的荧光光谱特性。堆场渗滤液的DOM含有类酪氨酸、色氨酸及紫外区类富里酸,特征荧光峰中心位于Ex/Em=275 nm/305 nm,为高激发波长类酪氨酸,与前人的研究结果并不一致,这可能与垃圾的堆放期有关。渗滤液和各处理工艺出水的荧光指数f450/500均大于1.9,表明腐殖质主要为微生物源。渗滤液在处理前后荧光峰特征和强度均发生明显改变,类蛋白荧光强度与DOC值变化趋势基本一致。生化处理工艺中,类蛋白荧光强度降低了66.4%~95.5%,紫外区类富里酸荧光强度只降低了28.8%,显示类蛋白质具有良好的可生化性,而类富里酸相对较难生化降解。三维荧光光谱能反映渗滤液处理过程中污染物的种类、性质和数量等变化信息,能快速地进行定性分析、定量评价。 相似文献
267.
鸟粪石结晶法回收垃圾渗滤液氨氮研究 总被引:7,自引:3,他引:4
采用MgSO4·7H2O和Na2HPO4·12H2O使NH3-N生成MgNH4PO4·6H2O(鸟粪石)结晶沉淀法回收渗滤液中NH3-N。考察了pH值、反应时间、药剂配比对NH3-N去除率的影响。结果表明,鸟粪石结晶回收NH3-N反应的适宜pH值为9~9.5之间,过高的pH会破坏鸟粪石晶体结构,导致固定氨从MgNH4PO4中游离出来,不利于氨氮的去除。在pH值为9.5、反应时间为25 min、Mg2+∶NH+4∶PO3-4=1.5∶1∶1.5的最佳条件下,渗滤液中NH3-N浓度由初始3 500 mg/L,经结晶沉淀后降低至175 mg/L,去除率达95%。鸟粪石结晶沉淀过程中几乎不吸收重金属,同时回收了氨氮,其沉淀产物鸟粪石是一种优良的缓释肥原料。 相似文献
268.
Anaerobic ammonium oxidation (ANAMMOX) technology has potential technical superiority and economical efficiency for the nitrogen removal from landfill leachate, which contains high-strength ammonium nitrogen (NH4 -N) and refractory organics. To complete the ANAMMOX process, a preceding partial nitritation step to produce the appropriate ratio of nitrite/ammonium is a key stage. The objective of this study was to determine the optimal conditions to acquire constant partial nitritation for landfill leachate treatment, and a bench scale fixed bed bio-film reactor was used in this study to investigate the effects of the running factors on the partial nitritation. The results showed that both the dissolved oxygen (DO) concentration and the ammonium volumetric loading rate (Nv) had effects on the partial nitritation. In the controlling conditions with a temperature of 30±1℃, Nv of 0.2-1.0 kg NH4 -N/(m3d), and DO concentration of 0.8-2.3 mg/L, the steady partial nitritation was achieved as follows: more than 94% partial nitritation efficiency (nitrite as the main product), 60%-74% NH4 -N removal efficiency, and NO2--N/NH4 -N ratio (concentration ratio) of 1.0-1.4 in the effluent. The impact of temperature was related to iVv at certain DO concentration, and the temperature range of 25-30癈 was suitable for treating high strength ammonium leachate. Ammonium-oxidizing bacteria could be acclimated to higher FA (free ammonium) in the range of 122-224 mg/L. According to the denaturing gradient gel electrophoresis analysis result of the bio-film in the reactor, there were 25 kinds of 16S rRNA gene fragments, which indicated that abundant microbial communities existed in the bio-film, although high concentrations of ammonium and FA may inhibit the growth of the nitrite-oxidizing bacteria and other microorganisms in the reactor. 相似文献
269.
Background, Aim and Scope
Acid deposition has become a concern in south China in recent years. This phenomenon has increased to a dramatic extent with
the large use of cars and coal- fueled power plants. As a consequence, soils are becoming acidified and their element dynamics
will change. A decrease in the nutrient availability will lead to slower plant growth and maybe to a change in the forest
type with current species being replaced by new ones with less nutrient requirements. Because of these reasons, it is important
to understand how the dynamics of elements will change and what mechanism is part of the process. This knowledge is important
for modeling the acidification process and either finding ways to counter it or to predict its consequences. The primary purpose
of this study was to provide information about how the dynamics of K, Na, Ca, Mg and P are affected by acid deposition in
a typical forest in southern China.
Materials and Methods:
Experimental soils and saplings were collected directly from the monsoon evergreen broad-leaved forest in Dinghushan. All
saplings were transplanted individually into ceramic pots in August 2000 and placed in an open area near their origin site.
Pot soils were treated weekly from October, 2000 to July, 2002 with an acidic solution at pH 3.05, pH 3.52, pH 4.00 or pH
4.40, or with tap water as a control. The concentrations of SO42-, NO3-, K+, Na+, Ca2+, Mg2+ and available P and the pH were
measured in soil and leachate samples taken at different times. The sapling leaves were collected and their element concentrations
were measured at the end of the experiment.
Results:
Concentrations of soil exchangeable Ca and Mg decreased quickly over time, although only Ca showed changes with the acidic
solution treatment and soil exchangeable K was stable because of soil weathering. Leaching of K, Mg and Ca was dependent upon
the treatment acidity. Soil available P decreased slowly without any correlation with the acidity of the treatment. All the
NO3- added by the treatment was taken up by the plants, but the SO42- added accumulated in the soil.
Discussion:
Amongst the plant species, Schima superba was little affected by the treatment, the leaf P content was affected in Acmena
acuminatissima plants and Cryptocarya concinna was the most susceptible species to soil acidification, with a marked decrease
of the leaf K, Ca and Mg concentrations when the treatment acidity increased.
Conclusions:
Simulated acid deposition affected the dynamics of K, Ca and Mg in the monsoon evergreen broad-leaved forest. The dynamics
of Ca in the soil and of K, Mg and Ca in the soil leachates were affected by the acidic solution treatment. If such a soil
acidification occurs, Cryptocarya concinna will be amongst the first affected species, but Schima superba will be able to
sustain a good growth and mineral nutrition.
Recommendations and Perspectives:
Acid deposition will lead to imbalance the nutrient elements in the evergreen broad-leaved forest because of accelerated leaching
losses of soil exchangeable Ca and Mg. Measures should be developed to slow down soil acidification or nutrient decrease. 相似文献
270.
短程硝化反硝化工艺处理低C/N垃圾渗滤液 总被引:1,自引:1,他引:0
针对本试验垃圾渗滤液的水质特点和传统生物脱氮工艺存在的问题,结合目前国内外在该方向的研究现状,提出短程硝化反硝化处理垃圾渗滤液的新工艺。通过控制曝气池内溶解氧浓度平均在2.0 mg/L,温度(30±2)℃,实现了稳定的亚硝氮积累和较高的氨氮去除率,亚硝化率和氨氮去除率分别维持在83%和85%左右。试验结果表明,该工艺与传统生物脱氮工艺相比,污泥负荷明显增加,耗氧量和反硝化所需碳源减少,反硝化效率和速率明显提高,从而总氮去除率也显著提高。 相似文献