COD测定仪法测定不同水样COD消解时间的差异性

通过实验证实COD测定仪法具有较好的精密度和准确性,与标准回流法的分析结果比较,相对误差为-3.37%~1.41%,具有替代标准回流法的可行性。由于水样性质不同,所需最佳消解时间不同,通过比较不同消解时间下COD测定的结果,得到COD测定仪法测定水中COD所需的最佳消解时间分别为:工业废水60 min,生活污水和地表水90 min。     

活性炭预涂动态膜处理船舶含油废水过程中溶解性有机物的分子组成特征

动态膜技术以其高效、低成本等优点,在船舶含油废水深度处理领域展现出重要的应用潜力。然而船舶含油废水中有机物组成极其复杂,其在动态膜处理过程中的分子特征及变化尚需进一步研究。采用超高分辨质谱研究船舶含油废水中溶解性有机物(DOM)在动态膜过滤过程处理不同时间的分子组成特征。结果表明,船舶含油废水经动态膜处理前有超过2 200 种DOM分子式,其主要由CHOS、CHONP等含杂原子类物质组成。动态膜处理过程中,前10 min由于活性炭的较强的吸附能力,对大部分有机物显示出良好的去除率,废水的COD和DOC去除率均在80%以上,此阶段对大分子质量、不饱和氧化性DOM去除效果较好。随后活性炭吸附能力下降,动态膜对COD和DOC的去除率逐渐衰减,60 min时均下降至50%左右。60 min后船舶含油废水中DOM的分子组成未观察到明显变化。本研究揭示了船舶含油废水在动态膜处理过程中DOM分子层面的组成和变化特征,为动态膜技术高效处理难去除船舶含油废水提供一定的工艺参考。     

Retrieval of total suspended matter (TSM) and chlorophyll-a (Chl-a) concentration from remote-sensing data for drinking water resources

The concentrations of chlorophyll-a (Chl-a) and total suspended matter (TSM) are major water quality parameters that can be retrieved using remotely sensed data. Water sampling works were conducted on 15 July 2007 and 13 September 2008 concurrent with the Indian Remote-Sensing Satellite (IRS-P6) overpass of the Shitoukoumen Reservoir. Both empirical regression and back-propagation artificial neural network (ANN) models were established to estimate Chl-a and TSM concentration with both in situ and satellite-received radiances signals. It was found that empirical models performed well on the TSM concentration estimation with better accuracy (R ² = 0.94, 0.91) than their performance on Chl-a concentration (R ² = 0.62, 0.75) with IRS-P6 imagery data, and the models accuracy marginally improved with in situ spectra data. Our results indicated that the ANN model performed better for both Chl-a (R ² = 0.91, 0.82) and TSM (R ² = 0.98, 0.94) concentration estimation through in situ collected spectra; the same trend followed for IRS-P6 imagery data (R ² = 0.75 and 0.90 for Chl-a; R ² = 0.97 and 0.95 for TSM). The relative root mean square errors (RMSEs) from the empirical model for TSM (Chl-a) were less than 15% (respectively 27.2%) with both in situ and IRS-P6 imagery data, while the RMSEs were less than 7.5% (respectively 18.4%) from the ANN model. Future work still needs to be undertaken to derive the dynamic characteristic of Shitoukoumen Reservoir water quality with remotely sensed IRS-P6 or Landsat-TM data. The algorithms developed in this study will also need to be tested and refined with more imagery data acquisitions combined with in situ spectra data.     

Spatial distribution,pollution characteristics,and health risks of antibiotic resistance genes in China: a review

Environmental Chemistry Letters - With the extensive production and use of antibiotics for medicinal and veterinary purposes, antibiotics and genes that code for antibiotic resistance are now...     

Association of sleep problems with urinary concentrations of personal care and consumer product chemicals: a nationally representative,population-based study

Environmental Science and Pollution Research - Sleep problems are common in modern society and may be related to environmental chemicals. The objective of this study is to investigate the...     

超越增长的极限

无论是发达国家还是发展中国家。渴望增长似乎是不争的共识。前者要进一步增加本国国民的生活舒适度，而后者则致力于摆脱贫困，尽快过上体面的生活。但是，地球资源尤其是维持现代经济增长的石油、天然气等不可再生资源的供应能力、全球环境容量以及地球生态系统的服务功能却是有限的。随着世界经济规模的不断扩大，这种有限性日益明显。6月底，原油期货价格不可思议地攀升至超过143美元／桶的历史新高。尽管疲软的美元、地缘形势不稳、投机者的兴风作浪等有可能助推油价再攀新高，     

傣族传统民居技术更新的可持续性研究——以西双版纳城子寨的新民居更新为例

以往的民居改建、更新理论和原则或是从美学的角度出发，或是从功能的角度探讨问题，本文旨在可持续发展思想的指导下，在保留和继承部分民居传统技术的同时，融入现代技术的思想和方法，从技术角度实现对西双版纳城子寨傣族传统民居的积极保护与有序更新，走出技术适宜更新的可持续发展之路。     

二氧化碳灭火系统误喷事故分析及预防措施探讨

根据二氧化碳灭火系统在工程中的实际应用,系统分析灭火系统误喷事故原因,建立引起二氧化碳灭火系统误喷事故树。通过事故树计算各基本事件的结构重要度,确定基本事件对误喷事故产生的影响程度,最后为防止误喷事故发生制定了预防措施。     

生物滴滤塔的固定化技术研究

为降低微生物烟气脱硫的成本,以氧化亚铁硫杆菌为对象,研究更优的固定化技术。以2 mol/L的FeCl₃溶液为改性剂,对陶粒进行高温灼烧,改变其表面物理化学性质。采用塔内和塔外相结合的方式,用经微波照射90 s后的突变菌对改性陶粒进行挂膜。结果显示,微波处理后的突变菌活性更高,陶粒改性后比表面积和表面粗糙度增加,塔内外结合挂膜方式能有效缩短挂膜时间,提高挂膜质量。     

自动在线监测系统利用软件数据质控有效性研究

自动在线监测设备对排放的污染物进行实时监测,获取真实有效的监测数据。研究自动在线监测设备监测数据质量保证系统是污染源自动在线监控系统科学判断和分析环境问题的前提。软件系统是数据采集、记录和存储、传输、统计分析、自我识别、形成报表和报告的集成,也是监测数据质量保证的有效手段,通过设定“阈值”和“条件”．实现了监测数的自动甄别、纠错和报警。