C/N和pH值对高温好氧反硝化菌产N2O的影响研究

以50℃高温、好氧条件下能进行高效好氧反硝化的菌株TAD1为研究对象,在不同C/N和pH值培养条件下,对其24 h的反硝化效率和反硝化过程中N2O的逸出量进行了研究。结果显示,C/N和pH值对菌株TAD1的反硝化效率和N2O产生量有明显影响.菌株TAD1最适宜的C/N为9,pH值为7,此时反硝化效率达到99.12%,N2O产生量仅为3.35×10-2 mg/L,N2 O转化率为0.045%,反硝化产物以氮气为主。另外,菌株TAD1不适宜在酸性条件下生长,pH值为6时反硝化效率为83.18%,N2O产生量为13.88×10-2 mg/L,是pH值为7时的4.14倍,是pH值为8时的5.07倍。     

碳源类型及进水量分配对CMICAO工艺脱氮除磷的影响

研究了分别以葡萄糖和乙酸钠为碳源时多点交替进水阶式A2/O(CMICAO)工艺氮磷的去除效果,以及在不同进水C/N比时各进水量分配对脱氮除磷效果的影响.结果表明,在相同的进水COD浓度下,乙酸钠比葡萄糖更适合作为碳源,更能提高脱氮除磷效率.以葡萄糖为碳源时,COD为200 mg/L、C/N比为5、缺氧池与厌氧池进水配比为1∶2时,出水COD、TN、氨氮和TP浓度分别为28.5、10.8、2.1和0.5 mg/L,均达到国家一级A排放标准.若采用葡萄糖作为碳源,投加量以使进水C/N比为5～7.5为宜,外加碳源时缺氧池与厌氧池进水分配比可统一采用1∶1.     

脱硫石膏粒径分布与脱水性能实验研究

脱硫石膏粒径分布是影响脱硫石膏浆液脱水性能的重要因素之一，以干法、湿法筛分和研磨破碎获得不同粒径分布的脱硫石膏，在相同的过滤条件下，对不同粒径分布脱硫石膏浆液脱水性能进行了研究，实验结果表明，当脱硫石膏粒径d50大于50μm且（d90-d10）小于100μm，真空过滤最大真空度不低于0．098MPa，过滤时间不少于2．5min，滤饼厚度不超过20mm时，石膏滤饼含水率可以降低到12％以下（最低可达10％）；d50在17μm为脱硫石膏在相同的过滤条件下能够实现真空脱水干燥的转折点；d50和（d90-d10）共同影响石膏脱水性能，d50小于20μm时，仅表现为d50的影响。     

微曝气Fenton氧化法处理模拟双酚A废水的效果及其生物验证

研究了微曝气Fenton氧化法关键工艺参数对模拟双酚A（BPA）废水处理效果的影响，并从活性污泥性质和污染物去除率两方面，采用膜生物反应器(membrane bioreactor, MBR)对微曝气Fenton氧化法的处理效果进行了实验验证，为实现BPA废水的生物处理奠定基础。结果表明，初始pH值、反应时间、H₂O₂/COD(质量浓度比)、H₂O₂/Fe²⁺ (摩尔浓度比)、反应温度及曝气量均对预处理效果有较大影响，在最佳条件下，COD去除率可达70%，BOD/COD值则由原废水的0.02提高到0.50以上。MBR处理上述出水的结果表明，经微曝气Fenton氧化处理BPA的废水，可较好地适应后续的生化处理。     

Spatial distribution of uranium and thorium in the surface soil around proposed uranium mining site at Lambapur and its vertical profile in the Nagarjuna Sagar Dam

The understanding and evaluation of the possible interactions of various naturally occurring radionuclides in the world's third largest man-made dam, Nagarjuna Sagar located in Andhra Pradesh, India and built on river Krishna assumed significance with the finding of uranium deposits in locations near the dam. For the present work, surface soil samples from the mineralized area of Lambapur, Mallapuram, Peddagattu and sediment core samples from the Nagarjuna Sagar dam were analyzed for naturally occurring radionuclides namely uranium and thorium using gamma spectrometric technique. Also toxic elements lead and chromium were analysed by the Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF) technique. Surface soil samples show a variation from 25 to 291 Bq/kg (2.02–23.5 mg/kg) for ²³⁸U and 32–311 Bq/kg (7.9–76.9 mg/kg) for ²³²Th. U/Th concentration ratio in surface soil samples ranged from 0.19 to 0.31 and was found comparable with the nation wise average of 0.26. The study of sediment core samples reflected higher U/Th concentration ratio of 0.30–0.33 in the bottom section of the core as compared to 0.22–0.25 in the upper section. The concentration ratio in the upper section of the core was similar to the ratio 0.23 found in the western Deccan Basalt region through which the river originates. A higher concentration of lead and chromium was observed in the upper section of the core compared to bottom section indicating the impact of river input on the geochemical character of dam sediment.     

Decreased Runoff Response to Precipitation,Little Missouri River Basin,Northern Great Plains,USA

High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri River Basin and identified differences in the runoff response to precipitation for the period 1976‐2012 compared to 1939‐1975 (n = 37 years in both cases). Computed mean values for the second half of the record showed little change (<5%) in annual or growing season precipitation, but average annual runoff at the basin outlet decreased by 22%, with 66% of the reduction in flow occurring during the growing season. Our results show a statistically significant (p < 0.10) 27% decrease in the annual runoff response to precipitation (runoff ratio). Surface‐water withdrawals for various uses appear to account for <12% of the reduction in average annual flow volume, and we found no published or reported evidence of substantial flow reduction caused by groundwater pumping in this basin. Results of our analysis suggest that increases in monthly average maximum and minimum temperatures, including >1°C increases in January through March, are the dominant driver of the observed decrease in runoff response to precipitation in the Little Missouri River Basin.     

Detection of tritium sorption on four soil materials

In order to measure groundwater age and design nuclear waste disposal sites, it is important to understand the sorption behavior of tritium on soils. In this study, batch tests were carried out using four soils from China: silty clays from An County and Jiangyou County in Sichuan Province, both of which could be considered candidate sites for Very Low Level Waste disposal; silty sand from Beijing; and loess from Yuci County in Shanxi Province, a typical Chinese loess region. The experimental results indicated that in these soil media, the distribution coefficient of tritium is slightly influenced by adsorption time, water/solid ratio, initial tritium specific activity, pH, and the content of humic and fulvic acids. The average distribution coefficient from all of these influencing factors was about 0.1-0.2 mL/g for the four types of soil samples. This relatively modest sorption of tritium in soils needs to be considered in fate and transport studies of tritium in the environment.     

M3法测定土壤有效态Cd、Cr、Pb和Ni

通过M3法对耕地土壤重金属的联合测定,为土壤重金属污染监测应用提供快速联合测定的方法。用M3法测定北方耕地土壤的有效Cd、Cr、Pb和Ni,通过对M3法与其他方法进行有效重金属测定值差异性及其相关性比较,与全量的浸出率分析等探讨M3法对耕地土壤有效重金属测定的特征。结果表明,M3法在《土壤环境质量标准》(GB 15618—1995)的土壤重金属含量范围内可以测定土壤有效态重金属Cd、Cr、Pb和Ni,且呈线性极显著相关。M3法与其他方法有效Cd、Cr、Pb和Ni有较好的相关性,与DTPA法呈极显著相关;与NaNO₃法除有效Pb外,呈极显著和显著相关;与HCl法除褐土和潮土的有效Pb外,也呈极显著和显著相关。M3法的有效态Cd、Cr、Pb和Ni的测定值均为最大。M3法对4种耕地土壤有效Cd、Cr、Pb和Ni的浸出率,因土壤类型不同,有效重金属含量所占比率不同,但利用M3法测定的有效态Cd、Cr、Pb和Ni的浸出率最大。     

液固比对含重金属水泥熟料制品中重金属释放的影响

通过模拟煅烧试验制取水泥熟料，参照JGJ 55-2000（《普通混凝土配比设计规程》）制取混凝土样品，参考SR003.1和NEN 7375浸出试验，分别研究液固比对粒状及块状混凝土样品中重金属（Cr、Ni和As）释放的影响。结果表明，在不同液固比条件下粒状混凝土中的重金属浸出浓度为Cr>Ni>As，Cr、As浸出浓度基本保持不变，分别为2 500 μg/L左右和5～6 μg/L，Ni在液固比（L∶S）<6时，浸出浓度随着液固比的增加而降低，在L∶S>6时，浸出浓度较稳定，为35.7～41.5 μg/L；浸出量均随着液固比的增加而增大。液固比（L∶S）<10时，块状混凝土中重金属累积释放量及扩散系数均随液固比的增加而增大，当L∶S>10时两者基本保持不变。     

提高油田伴生气回收率的研究与应用

文章阐述了陆梁油田在开发过程中采用油气混输技术、天然气发电机橇技术、锅炉烧湿气等技术,将伴生气回收率提高至92.10%;油气混输技术能够实现边缘区块油气全密闭输送;集中处理站锅炉燃烧湿气技术可增加处理站天然气外输气量,降低运行成本;小型活动天然气发电机橇的应用,可以充分利用富裕天然气降低生产成本,同时减少富裕天然气火炬放空燃烧量,收到了良好的经济效益和环境效益。