溶气吹脱法处理钽铌生产氨氮废水

用溶气吹脱法对某公司钽铌生产废水进行处理,分析了pH值、温度、时间和通气量等因素对氨氮去除率的影响。在实验条件为pH=9、温度为50℃、时间为45min、通气量为2.5L/min时,氨氮的去除率达到90%以上。     

Evidence of persistent,recurring summertime hypoxia in Green Bay,Lake Michigan

Six years (2009–2015) of temperature and dissolved oxygen profile data show hypoxic conditions are common in the bottom waters of southern Green Bay, Lake Michigan during the summer. Depleted oxygen concentrations (<5?mg?L^?1) affect nearly 70% of the 38 stations sampled representing an area of ~500–600?km². Stratification typically lasts 2+?months, from late June to early September, and some stations exhibit bottom water hypoxia (<2?mg?L^?1) at a frequency of nearly 25% when sampled during this period. A monitoring program initiated in 1986 by the Green Bay Metropolitan Sewerage District has provided a 23?year, recreational season record (May–September) of continuous (15?min interval) in situ bottom water oxygen and temperature measurements at the Entrance Light station of the Green Bay navigational channel. The duration of the hypoxic season ranges from 2?weeks to over 3?months at this shallow 7?m offshore site. This variability likely results from a combination of thermal stratification, oxygen consumption in deeper waters of the bay, and physical forcing mechanisms that drive cool, oxygen depleted, bottom waters on a southerly trajectory across this sensor. These data suggest the duration of hypoxic conditions may have increased during the stratified season in recent years. Hypoxia in the bay would also appear to be sensitive to relatively small changes in these forces, particularly changes in organic carbon loading and the duration of stratification.     

基于氢氧同位素的平原湖荡地表水与地下水转化研究

地表水与地下水间的相互转化以及量化地下水补给量是湖泊水循环研究的重要内容。本文采集了元荡湖区域湖水、地下水样品,测试了其氢氧稳定同位素组成和水化学组成,运用Piper三线图分析其水化学类型、通过钻孔实测的地下水埋深绘制元荡湖区域旱季(2022年12月)和雨季(2023年6月)的地下水水位等值线图,结合电导率(EC)和溶解性总固体(TDS)定性分析地表水-地下水之间的转化关系,利用同位素水量平衡方程、线性端元混合模型定量评价了湖水、地下水、河水和降水之间的转化量。结果表明,研究区湖水和地下水的水化学类型均为HCO₃^-·SO₄^2-·Ca²⁺·Na⁺·Mg²⁺,旱季和雨季湖水均受到地下水的补给,拟合得到的湖水旱季、雨季氢氧稳定同位素线性回归方程表明雨季斜率较小,蒸发更为强烈。湖水主要由河水、地下水和降水补给,其三者在旱季的补给比例分别为59%、26%和15%,在雨季的补给比例分别为23%、39%和38%。本文成果为元荡湖区域以及太湖流域的综合治理提供了科学依据。     

含沙量对水体耗氧有机污染物降解耗氧影响

在泥沙存在情况下,水体中的耗氧有机污染物的降解耗氧规律与清水中有很大的差异。从水体耗氧有机物降解反应动力学和溶解氧反应动力学方程出发,考虑泥沙对耗氧有机污染物降解的影响,得出了耗氧有机物降解过程耗氧量随时间变化表达式。通过室内实验研究了含沙量对耗氧有机污染物的耗氧规律的影响,利用耗氧量随时间表达式对实验数据进行分析,得出了泥沙影响下的耗氧有机污染物耗氧速率常数与含沙量的一般规律。结果表明,泥沙对耗氧有机污染物降解耗氧过程符合一级动力学反应,且耗氧速率常数随含沙量的增大而增大,由泥沙存在引起的溶解氧衰减速率常数与含沙量之间存在非线线的函数关系。     

医用分子筛中心制氧系统管理的相关法律法规应用探讨

本文从医用分子筛中心制氧系统的原理、特殊性和风险性的角度出发,阐述了医用分子筛中心制氧系统依法管理的重要性,概述了医用分子筛中心制氧系统管理相关的各类法律法规,并论述了其与医疗设备全过程管理各阶段的重点相关部分。     

比重瓶法测验低含沙量误差分析

在河流水文测验、河工模型试验、水质评价及工农业取水中,通常采用比重瓶法测验含沙量。在含沙量较小时,因水中溶解质含量较大,用比重瓶法测验得到的含沙量往往大于实际含沙量,但测验者常常怀疑测验过程或测验仪器出现误差,而忽略其真正原因。通过某城市供水沉沙池试验的含沙量测验发现,影响低含沙量测验误差的潜在原因就是浑水中溶解质含量,它对含沙量的影响远远大于水体自身含沙量;此外,温度测验误差对含沙量的影响较大,并且含沙量越小,温度测验误差对含沙量的影响越大。基于此,提出了比重瓶法测验低含沙量的改进方法,得到了与烘干法基本一致的测验结果,为低含沙量测验提供了一些借鉴和参考。     

A new approach to estimate concentrations of alcohol ethoxylate in rivers in Japan for screening-level risk assessment

Alcohol ethoxylate (AE) is a widely used household detergent that is ubiquitous in aquatic environments. To assess and manage the risk of AE, its environmental exposure concentrations must be evaluated in rivers nationwide; however, very few AE monitoring data are currently available. Furthermore, developing a rigorous exposure model that would cover rivers nationwide would require a great deal of time, human resources, and money. We developed a new approach to estimate AE concentrations in rivers throughout Japan for screening-level risk assessment. In this approach, five-day biochemical oxygen demand (BOD₅) data were used as a surrogate indicator of the AE concentration in river water. The Tama and Nikko Rivers were ranked according to their BOD₅ data, and the AE concentrations of the Nikko River were then estimated using the Standardized Hydrology-based Assessment tool for chemical Exposure Load (AIST-SHANEL) model. For each river, the concentrations of AE in its waters were projected based on that river’s reported BOD₅ values, its ranking, the approximation formula for AE and BOD₅, and estimated AE concentrations in water of the Nikko River from the model. The accuracy of the projected values was validated by comparing the projected AE concentrations in water from the Tama River with its monitoring data. There are various technical uncertainties associated with this approach; however, our results suggest that this new approach can be applied in screening-level exposure assessment of other chemical substances that have properties similar to AE.     

矿用阻燃、抗静电聚丙烯防护网配方的研制

着重介绍矿用聚丙烯防护网的研制过程。通过添加溴系阻燃剂和抗静电剂对聚丙烯进行共混改性。实验结果表明 ,八溴联苯醚与 Sb2 O3 互配体系的氧指数可达 2 7以上 ;非离子型抗静电剂配以辅助抗静电剂 ,可使材料的表面电阻降至 3× 1 0 8Ω 以下     

低温储罐失效分析及对策

本文介绍了50m3低温液氧储罐泄漏事故的概况,对事故发生的原因进行了全面分析和论证,并从设计、制造、检验、使用及维护等方面提出了避免类似事故发生的预防措施。     

污水生化处理技术在涠洲终端的应用研究

中海油湛江分公司涠洲终端处理厂与桂林工学院合作研究,采用"厌氧+好氧+过滤"组合工艺对终端厂含油污水进行处理。从根本上解决了终端厂旧有污水处理设施处理量不足的问题,使终端厂污水排放指标达到了国家和当地环保部门的要求,取得了很好的经济和环保效益。