管道内瓦斯爆炸温度与压力峰值试验研究

为分析瓦斯爆炸的火焰温度及压力峰值在管道中的传播规律,采用瓦斯管网爆炸测试系统进行试验,通过爆炸压力和爆炸火焰温度采集系统采集数据。在相同点火能量和点火位置的条件下,分析了体积分数对瓦斯爆炸的温度峰值和压力峰值的影响,及温度峰值和压力峰值随管道距离的变化规律。结果表明:当瓦斯体积分数低于9.5%时,温度峰值和压力峰值随瓦斯体积分数增大而增大;同一体积分数下,温度峰值最大值出现在最接近爆源的位置,并呈逐渐下降的趋势,接近爆源的温度峰值下降较明显,随管道延长,温度峰值的下降减慢且趋于平缓;温度峰值与传播距离近似呈三次函数关系;冲击波压力峰值随管道传播呈先上升后下降再上升的波动性变化。     

超低空航拍技术在输变电环评工作中的应用研究

分析了环评工作中收集的影像资料存在的问题,提出了超低空航拍的解决方法。通过对比分析,选择了多旋翼无人机作为超低空航拍平台。该设备具有携带方便,飞行稳性的优点。从实际应用效果来看,基于该技术获得的影像信息含量全面、工作效率高、评价结果更客观可信,为提高环评工作质量提供了一个可靠的技术方案。     

干法烟气同时脱硫脱硝技术的应用及进展

综述了目前国内外干法烟气同时脱硫、脱硝技术．详细介绍了各种技术的机理、研究现状及最新进展,并分析了这些技术的优点和缺点,最后对其发展前景作了展望。     

煤制乙二醇废水预处理装置的工业化调试

针对煤制乙二醇废水含高浓度硝酸盐氮的特点,设计了缺氧膨胀床(AEB)反应器预处理装置,并进行了工业化启动和调试运行,考察了其在反硝化连续流运行条件下的处理效果及工艺参数变化。结果表明,AEB反应器启动后,填料层生物膜挂膜快速且生长稳定。反应器在工业化调试阶段运行稳定,COD和TN的去除率和去除负荷较为稳定。在受到来水冲击后,AEB反应器处理效果稳定,出水可在短期内恢复正常。该技术的系统操控参数范围较广,易于工业化操控运行,在煤制乙二醇废水和其他含高浓度硝酸盐氮废水的处理中具有较大的推广价值。     

利用Landsat7反演的亮温与土地覆盖类型相关性分析

随着城市人口的急剧增加,城市建筑规模迅速膨胀,大量热源集中排放,产生了城市内部温度明显高于郊区的特殊城市气候现象,即“热岛效应”.以安徽省芜湖市为研究区域,采用GIS叠加分析方法、缓冲区分析方法进行地表辐射亮温与土地覆盖类型的相关性研究.研究结果表明,辐射亮温与地表类型有明显的相关关系,建筑与辐射亮温的相关系数为0.87,植被、水体与辐射亮温的相关系数分别为0.59、0.78.人工建筑因素是产生热岛效应的主要原因之一,加大植被、水体在城市土地用地中的比重,是控制城市热岛效应行之有效的方法,而且利用辐射亮温图可很好地指示城市土地覆盖类型在时间上和空间上的变化.     

可持续雨水管理与海绵城市构建的美国经验

随着中国经济的快速发展,越来越多的水环境问题开始涌现。海绵城市的提出正是立足于当下中国城市内涝及相关环境问题。基于此,本文简要分析了中国城市内涝的原因及海绵城市相关构建思路,重点阐述了美国可持续雨水管理经验与守护水资源上的实际做法,并给出了美国雨水管理实例,以期为中国海绵城市建设提供参考。     

Calibration and Verification of SWMM for Low Impact Development

The Storm Water Management Model was used to simulate runoff and nutrient export from a low impact development (LID) watershed and a watershed using traditional runoff controls. Predictions were compared to observed values. Uncalibrated simulations underpredicted weekly runoff volume and average peak flow rates from the multiple subcatchment LID watershed by over 80%; the single subcatchment traditional watershed had better predictions. Saturated hydraulic conductivity, Manning's n for swales, and initial soil moisture deficit were sensitive parameters. After calibration, prediction of total weekly runoff volume for the LID and traditional watersheds improved to within 12 and 5% of observed values, respectively. For the validation period, predicted total weekly runoff volumes for the LID and traditional watersheds were within 6 and 2% of observed values, respectively. Water quality simulation was less successful, Nash–Sutcliffe coefficients >0.5 for both calibration and validation periods were only achieved for prediction of total nitrogen export from the LID watershed. Simulation of a 100‐year, 24‐h storm resulted in a runoff coefficient of 0.46 for the LID watershed and 0.59 for the traditional watershed. Results suggest either calibration is needed to improve predictions for LID watersheds or expanded look‐up tables for Green–Ampt infiltration parameter values that account for compaction of urban soil and antecedent conditions are needed.     

Hydrologic Controls on Nitrogen and Phosphorous Dynamics in Relict Oxbow Wetlands Adjacent to an Urban Restored Stream

Although wetlands are known to be sinks for nitrogen (N) and phosphorus (P), their function in urban watersheds remains unclear. We analyzed water and nitrate (NO₃^?) and phosphate (PO₄^3?) dynamics during precipitation events in two oxbow wetlands that were created during geomorphic stream restoration in Baltimore County, Maryland that varied in the nature and extent of connectivity to the adjacent stream. Oxbow 1 (Ox1) received 1.6‐4.2% and Oxbow 2 (Ox2) received 4.2‐7.4% of cumulative streamflow during storm events from subsurface seepage (Ox1) and surface flow (Ox2). The retention time of incoming stormwater ranged from 0.2 to 6.7 days in Ox1 and 1.8 to 4.3 days in Ox2. Retention rates in the wetlands ranged from 0.25 to 2.74 g N/m²/day in Ox1 and 0.29 to 1.94 g N/m²/day in Ox2. Percent retention of the NO₃^?‐N load that entered the wetlands during the storm events ranged from 64 to 87% and 23 to 26%, in Ox1 and Ox2, respectively. During all four storm events, Ox1 and Ox2 were a small net source of dissolved PO₄^3? to the adjacent stream (i.e., more P exited than entered the wetland), releasing P at a rate of 0.23‐20.83 mg P/m²/day and 3.43‐24.84 mg P/m²/day, respectively. N and P removal efficiency of the oxbows were regulated by hydrologic connectivity, hydraulic loading, and retention time. Incidental oxbow wetlands have potential to receive urban stream and storm flow and to be significant N sinks, but they may be sources of P in urban watersheds.     

制药废水硝化-反硝化除氮研究

含高浓度氮的制药废水经好氧生化处理后,虽然出水的ＣＯＤ,ＢＯＤ５均可达到行业排放标准,但ＴＮ仍高达约１７０ｍｇ／Ｌ。本研究在曝气池中设置填料,利用生物膜外层好氧,内层缺氧厌氧的条件,使硝化－反硝化脱氮在同一构筑物内进行,ＮＨ３－Ｎ和ＴＮ去除率分别可达约９０％和７０％。在本试验条件范围内,温度越高,负荷越低,硝化和反硝化作用越完全,ＮＨ３－Ｎ和ＴＮ去除率越高。     

生物膜法A/O系统处理己内酰胺废水

采用缺氧-好氧淹没式生物膜系统处理己内酰胺废水,着重探讨了碳源对硝化、反硝化的影响.研究结果表明:缺氧池进水中可生物降解COD与NO x-N的质量比必须大于3,好氧池COD负荷应小于0.98kg/(m3.d),系统才能有效地同时脱氮和去除COD.