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141.
通过对北京市市区内大于10 000 m2的10个湖泊上空0.5 m处甲烷浓度的季度观测,研究了北京市城市湖泊上空甲烷的浓度水平,并对其中4个典型的湖泊进行了每月1~2次的观测,分析了城市湖泊上空甲烷浓度的连续变化特征。结果表明湖泊上空甲烷浓度年平均值为2.337±0.431 mL/m3,高于全球均值和其他相关研究人员对北京市上空监测的结果。湖泊上空甲烷浓度季节之间的差异性显著(P<0.01),夏季的甲烷浓度较高(2.758±0.516mL/m3),秋季和春季相对较低。4个典型湖泊上空甲烷浓度连续变化具有一定的规律,大都在7-8月份达到甲烷浓度的高峰期,3月初融冰时都会有小幅增加;位于市中心的什刹海上空甲烷浓度相对较高。这表明了北京市内湖泊是甲烷排放的一个重要源头,同时也反映了北京作为一特大城市,其湖泊上空甲烷浓度受人类活动影响的特征。  相似文献   
142.
单嘧磺隆正辛醇-水分配系数的测定   总被引:1,自引:0,他引:1  
本文建立了水中微量单嘧磺隆的测定方法 ,方法的平均添加回收率为 97 6%—1 0 1 93%,变异系数为 0 47%— 3 96%,单嘧磺隆的最小检出量为 2× 1 0 - 9g ,最小检出浓度为 0 0 2 μg·ml- 1 .摇瓶法对单嘧磺隆正辛醇 水分配系数的测定结果表明 ,单嘧磺隆在二次蒸馏水和pH 7 0缓冲液中的Kow分别为 3 90± 0 1 4和 2 1 9± 0 1 4 ,lgKow分别为 0 5 9± 0 0 3和 0 34± 0 0 6,在双蒸水中的测定结果与EPIWIN程序的预测结果一致  相似文献   
143.
The removal capacity of different wastewater treatment plant (WWTP) technologies adopted in rural areas for phthalate was investigated in the Eastern Cape, South Africa. Wastewater samples collected from three selected WWTPs which use activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were extracted using the solid-phase extraction method followed by gas chromatography-mass spectrometry (GC-MS) analysis. The six selected phthalate esters (PAEs) dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were detected in all the samples collected from the WWTPs. DBP was the most abundant compound in the influent, effluent, and sludge samples with a maximum detection of 2497 μgL?1, 24.2 μgL?1, and 1249 μg/g dW, respectively, followed by DEHP and BBP. There was a relatively high removal capacity achieved by AS in Alice, TF in Berlin, and OP in Bedford with a removal efficiency that varied between 77 and 99%, 76 and 98%, and 61 and 98%, respectively. A high significant correlation of PAE removal with total suspended solids (TSS) and turbidity suggests that the removal performance proceeded more through adsorption on settling particles and sludge than on biodegradation. However, the concentrations of PAEs detected in the final effluent and sludge samples exceeded acceptable levels allowed internationally for a safe aquatic environment. AS may have exhibited a more stable and better performance across the different seasons; however, pollution source control still deserves a special attention to prevent the risk posed by these micropollutants.  相似文献   
144.
In this study, samples from a sewage treatment lagoon and those from a receiving stream were analyzed for their phthalate esters content. Knowledge of the distribution of ubiquitous phthalate esters in the sewage lagoon and the receiving stream was necessary because of the reports of their subtle toxicity to aquatic biota and humans. Liquid–liquid extraction, Clean-up experiment and High Performance Liquid Chromatography (HPLC) were the methods employed for the quantitative determination of the Phthalates. A study of uncontaminated water was done to establish blank levels. The sewage lagoon and the receiving stream were grossly polluted as several phthalate ester plasticizers: DMP, DEP, DPhP, DBP, DEHP, DOP and DINP were found present at monthly mean levels of between 24.02 mg/L and 139.25 mg/L in the sewage treatment lagoon and 10.41 mg/L and 80.53 mg/L in the receiving stream. The results showed higher levels of phthalate esters in the sewage lagoon compared to the receiving stream. The sewage lagoon was identified as a pollution point source into the receiving stream. Levels of phthalates obtained from the receiving stream are much higher than the water criteria of 3 μg/L phthalates recommended by the United States Environmental Protection Agency (USEPA) for the protection of fish and other aquatic life in water and the Suggested No-Adverse Effect Levels (SNAEL) of 7.5–38.5 μg/L for drinking water. This should give cause for great environmental concern. Peoples’ health downstream is at stake and so is the ‘health’ of the ecosystem.  相似文献   
145.
旋流折板厌氧反应器处理城市污水试验研究   总被引:1,自引:0,他引:1  
为了探讨高效低耗的城市污水处理技术,对厌氧反应器处理城市污水进行了试验研究。试验结果表明:设有回流装置的异波折板穿孔旋流厌氧反应器对COD的去除率高于不设回流装置的异波折板跳跃式厌氧反应器10%以上;通过使出水回流到第5室,回流比为100%时,COD平均去除率为52%;通过调节第3、7室的pH值,可以抑制反应器内有机酸的积累,使出水COD的去除率可达70%。  相似文献   
146.
We assessed the incidence of faecal-indicator bacteria in Tyume River over a 12-month period between August 2010 and July 2011. Total coliforms, faecal coliforms and enterococci were determined by the membrane filtration method. Total coliforms were detected in counts ranging from 2.1?×?102 to 3.4?×?104?CFU/100 ml. Faecal coliform counts ranged from 1?×?102 to 1.6?×?104?CFU/100 ml while enterococci counts were in the range of 3.3?×?101 to 5.1?×?103?CFU/100 ml. Indicator bacteria counts increased from upstream to downstream sampling sites. Counts of indicator bacteria at all sites were significantly affected by seasonal changes. The bacteriological qualities of the river water were poor, exceeding the guideline of 200 CFU/100 ml and 33 CFU/100 ml for faecal coliforms and enterococci, respectively, for recreational water. Faecal coliform counts also exceeded the 1,000 CFU/100 ml guideline for water used in fresh produce irrigation. Microbial source tracking results showed that faecal pollution was predominantly of human origin during spring at all sampling sites. During other seasons, human faecal pollution was largely confined to midstream and downstream sampling sites. Generally, the presence of faecal-indicator bacteria in the river water samples suggests faecal pollution of this freshwater resource, raising the possibility of the presence of pathogenic microorganisms in the water and a threat to public health.  相似文献   
147.
The physicochemical characteristics of the Buffalo River in the Eastern Cape Province of South Africa were evaluated using standard methods. The assessment was carried out with total of 72 water samples collected from six sites over a 12-month period, from August 2010 to July 2011. Water temperature ranged from 11 to 28 °C, while pH varied from 6.6 to 10.7 and turbidity from 1.7 to 133 NTU. Electrical conductivity, total dissolved solids (TDS) and salinity showed drastic variations (42.3–46,693 μS/cm, 20.3–23,350 mg/l and 0.02–33.8 PSU, respectively) and the significantly (P?<?0.05) higher mean values of these parameters recorded at Parkside reflect the influence of seawater at the Buffalo River estuary. The concentrations of other parameters ranged as follows: chloride (3.7–168 mg/l), DO (6.9–11.1), BOD (0.6–9.4), COD (3.7–45.9), nitrite–nitrogen (0.02–0.21), nitrate–nitrogen (1–4.47) and orthophosphate (0.01–1.72). There was a significant positive correlation between water temperature and DO (r?=?0.200; P?<?0.01). Significant (P?<?0.01) positive correlations also existed between TDS and salinity (r?=?0.921), COD and each of salinity (r?=?0.398), TDS (r?=?0.375) and chloride (r?=?0.330), nitrate and phosphate (r?=?0.323) and BOD and turbidity (r?=?0.290). Significant (p?<?0.01) inverse relationships existed between DO and each of phosphate (r?=??0.295) and nitrate (r?=??0.168). We conclude that the Buffalo River water quality deteriorated in the plains, compared with the upper reaches. Urgent measures are needed to safeguard the river in view of the potential health concerns as many households rely solely on the untreated river water.  相似文献   
148.
灰水的处理与回用是保障受控生态生命保障系统(CELSS)中水循环的关键,研究中采用厌氧膜生物反应器(AnMBR)处理尿液源分离后的CELSS灰水,考察了废水处理效能及微生物群落演替特征.结果发现,废水中溶解性有机物(DOM)主要为类色氨酸、表面活性剂类和类腐殖质,COD去除率可达65%~75%,阴离子表面活性剂去除率高达80%以上,有效解决了表面活性剂积累问题,但高温和低水力停留时间(HRT)条件会降低处理效能.高通量测序研究表明,表面活性剂降解相关菌群是保障污泥降解性能的关键,Synergistes、Citrobacter为关键降解细菌;但高温和低HRT条件会抑制降解,导致表面活性剂积累和有机物去除率下降.表面活性剂的累积会引起反应器中微生物群落演替,关键菌群由接种污泥中的Methanosarcina、Syntrophomonas、Keratinibaculum等嗜热产甲烷类菌属逐步演替为Proteiniclasticum、Pseudomonas、Aminobacterium、Citrobacter、Desulfovibrio等菌属,产甲烷菌特别是Methanosarcina受到显著...  相似文献   
149.
在饲料中添加8%、12%、15%的鸽粪对生长猪进行了为期1个月的对比试验,结果表明,与对照组相比较,生长速度分别降低1.37%、2.74%、10.96%;料重比分别减少5.14%、9.5%、3.94%;每头猪盈利提高9.96%、12.58%、-10.29%,这说明在生长猪饲料中添加8-12%的鸽粪,可获得理想的经济效益。  相似文献   
150.
为了揭示三峡水库不同藻类对水流速度的响应,2008年8月,利用香溪河库湾原水进行了人工控制条件下水流速度对浮游植物生长和群落组成影响的研究。结果表明,在水温、光照及营养盐相同的条件下,水流条件对藻类的细胞密度和组成会产生显著的影响。单因素方差分析的S N K多重比较结果表明,在实验设定的流速范围内针杆藻(Synedra sp.)在高流速(0139 m/s)下的细胞密度显著高于其他流速组(p<005),相对密度最高;盘星藻(Pediastrumspp.)在中流速(0075 m/s)下的细胞密度显著高于其他各处理组(p<005);微囊藻(Microcystisspp.)各实验组间细胞密度无显著差异(p>005),但在低流速(0046 m/s)下的细胞密度和相对密度均高于其他各组;小环藻(Cyclotella sp.)细胞密度在水流动组间无显著差异(p>005),但都显著高于0 m/s实验组的细胞密度(p<005  相似文献   
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