平原型农村适用的小型污水处理技术研究

通过对集成式污水处理装置工艺和运行参数进行优化,选择水力停留时间为32 h、回流比为100％、好氧区D0 2 mg/L为最佳运行工况.并在此基础上,研制出一体化处理设施——净化槽,在北京市大兴区庞各庄镇梨花村对其进行了示范应用,结果表明净化槽具有一定的耐冲击负荷的能力,出水水质稳定,对于推动北京平原地区农村生活污水达标排放具有重要意义.     

甘肃公婆泉铜矿区生物地球化学异常特征及找矿预测模式

对比研究公婆泉铜矿生物地球化学异常与原生异常后发现 :产生生物地球化学异常的元素通常是那些在原生异常中强度高且浓度系数较大的元素 ,植物本身对元素的生理吸收特性对元素异常的形成也有重要影响。二者异常组合分带的共同特点是在矿化中心都存在Cu、(Pb)、Au、Ag异常 ,向外都存在Ba、B、As、(Sb)异常 ,最外带则都有Ti、V等异常。比较花岗闪长斑岩和英安斑岩铜矿体的生物地球化学异常 ,前者元素的种类多 ,且内带出现原生晕的中下部或尾晕元素Sn、W等 ,反映其为浅偏中等剥蚀 ;后者元素的种类少 ,内带未出现中下部或尾晕元素 ,反映其为浅剥蚀。建立的铜矿床 (体 )生物地球化学找矿预测模式能为定位预测戈壁覆盖层下的隐伏矿床 (体 )并推断其剥蚀程度和矿体规模提供重要的科学依据。     

降雨径流连续模拟参数全局灵敏性分析

长期连续模拟是客观评价城市排水系统性能、雨洪控制措施效果的重要方法之一.运用普适似然度法(Generalized Likelihood Uncertainty Estimation,简称GLUE),综合分析了暴雨管理模型(Storm Water Management Model,简称SWMM)在不同间隔降雨情景下的水量...     

黄河河南段水体中正构烷烃的分布特征与来源解析

本研究于2010年8月采集黄河河南段26个表层水及悬浮颗粒物样品,采用气相色谱-质谱联用仪(GC-MS)测定22种正构烷烃(C_(14)~C_(36))的含量,分析其组成特征,并利用特征参数解析其来源.结果表明,黄河河南段水相中正构烷烃浓度为521~5 843 ng·L~(-1),平均浓度为1 409 ng·L~(-1),组成特征以C_(25)为主峰碳的高碳单峰型.悬浮颗粒相中正构烷烃浓度范围为463~11 142 ng·L~(-1),平均浓度为1 951 ng·L~(-1),组成特征表现为双峰型,C_(25)为主峰碳的高碳烃占优势,同时存在低碳峰.多特征参数OEP、CPI、%Wax C_n以及TAR表明,黄河河南段水相及悬浮颗粒物中正构烷烃主要来源于化石燃料的燃烧,同时存在陆生植物来源.     

煤岩混合型粉尘云最低着火温度试验研究

为研究半煤岩巷道中岩粉质量分数和煤的挥发分与煤岩混合型粉尘云最低着火温度的关系,选取挥发分差异较大的5种煤样以相同比例配制煤岩混合型粉尘,利用粉尘云最小点火温度测定仪进行煤岩混合型粉尘试验。结果表明,当煤岩混合型粉尘中岩粉质量分数低于40%时,岩粉的混合会导致混合型粉尘云最低着火温度发生小幅度波动;当岩粉质量分数高于40%时,煤岩混合型粉尘最低着火温度会随岩粉质量分数的增加而大幅度升高;挥发分质量分数越小的煤粉,其混合型粉尘云最低着火温度越容易受岩粉质量分数的影响。     

The effects of drug and alcohol consumption on driver injury severities in single-vehicle crashes

Objective: It is well known that alcohol and drugs influence driving behavior by affecting the central nervous system, awareness, vision, and perception/reaction times, but the resulting effect on driver injuries in car crashes is not fully understood. The purpose of this study was to identify factors affecting the injury severities of unimpaired, alcohol-impaired, and drug-impaired drivers.

Method: The current article applies a random parameters logit model to study the differences in injury severities among unimpaired, alcohol-impaired, and drug-impaired drivers. Using data from single-vehicle crashes in Cook County, Illinois, over a 9-year period from January 1, 2004, to December 31, 2012, separate models for unimpaired, alcohol-impaired, and drug-impaired drivers were estimated. A wide range of variables potentially affecting driver injury severity was considered, including roadway and environmental conditions, driver attributes, time and location of the crash, and crash-specific factors.

Results: The estimation results show significant differences in the determinants of driver injury severities across groups of unimpaired, alcohol-impaired, and drug-impaired drivers. The findings also show that unimpaired drivers are understandably more responsive to variations in lighting, adverse weather, and road conditions, but these drivers also tend to have much more heterogeneity in their behavioral responses to these conditions, relative to impaired drivers. In addition, age and gender were found to be important determinants of injury severity, but the effects varied significantly across all drivers, particularly among alcohol-impaired drivers.

Conclusions: The model estimation results show that statistically significant differences exist in driver injury severities among the unimpaired, alcohol-impaired, and drug-impaired driver groups considered. Specifically, we find that unimpaired drivers tend to have more heterogeneity in their injury outcomes in the presence potentially adverse weather and road surface conditions. This makes sense because one would expect unimpaired drivers to apply their full knowledge/judgment range to deal with these conditions, and the variability of this range across the driver population (with different driving experiences, etc.) should be great. In contrast, we find, for the most part, that alcohol-impaired and drug-impaired drivers have far less heterogeneity in the factors that affect injury severity, suggesting an equalizing effect resulting from the decision-impairing substance.     

IC反应器处理废纸造纸废水的运行参数

通过自制IC反应器处理废纸造纸废水,研究其运行过程中的主要影响因素. 重点考察了进水量、外回流量和pH等运行参数的影响,并在此基础上研究了COD_Cr去除量与内循环水量和产气量的关系,最后说明了进水中硫酸盐和钙离子对IC反应器的影响. 结果表明:在其他因素不变的条件下,当进水量为2.0 L/h(HRT为5.5 h),外回流量为0 L/h,pH为7.0时,ρ(COD_Cr)可从2 000～2 500 mg/L降至340～425 mg/L,COD_Cr去除率在83%左右. 每去除1 kg COD_Cr可产生0.318～0.452 m3气体,当COD_Cr容积负荷在1.1 kg/(m3·d)时,内循环水量等于进水量. 硫酸盐和钙离子均对IC有一定的影响,在运行中应给予一定的控制.      

味精生产流程中氨的污染特征及影响因素分析

对味精生产整个流程中氨的污染特征进行了定量观测,并对密切相关的因素进行回归分析.结果表明,味精生产流程中各环节都有氨的释放,其年通量达521kg,但不同工艺过程差异较大,在发酵车间氨的释放量最高,平均达880mg·(L·.min)^-1;而在制糖车间,氨的释放量最小,仅为0.07mg·(L·min)^-1.整个味精生产流程中氨的释放通量,与铵态氮浓度之间存在极为显著的直线正相关关系,而与硝态氮(包括亚硝态氮)浓度之间呈显著的指数相关关系;氨的释放通量尽管与其pH变化之间不存在显著的直线相关关系,但味精废水处理过程中却与其溶液中的pH变化之间存在着极为显著的直线相关关系.     

滦河冲洪积扇地下水脆弱性评价体系研究

根据滦河冲洪积扇的主要环境地质问题,选择包气带岩性、厚度等7个参数作为评价指标,建立该区地下水脆弱性评价体系,认为只有评价参数选择正确、适当,地下水脆弱性评价才能为地下水管理、保护和规划提供决策参考。     

鸡粪高效降解菌群对堆肥的影响

为明确自行筛选开发的高效降解菌对鸡粪发酵的影响,分析研究了其堆肥的主要腐熟指标。结果表明,加入高效降解菌剂的堆肥处理方法温度相对较高,脱水快,pH值适宜,C／N调整较好,种子发芽指数高,堆肥后营养养分含量高,且大肠菌群数量少,堆肥效果较好。