Spectroscopic study on transformations of dissolved organic matter in coal-to-liquids wastewater under integrated chemical oxidation and biological treatment process

A large amount of wastewater containing various toxic organic contaminants is produced during coal-to-liquids process. In this study, several spectroscopic methods were used to monitor the transformation of organic pollutants during an integrated chemical oxidation and biological process. The results showed that the hydrophobic acid fraction increased after Fenton oxidation, which was likely due to the production of small-molecule organic acids. Soluble microbial products were generated during biological treatment processes,which were degraded after ozonation; meanwhile, the hydrophilic base and acid components increased. Ultraviolet-visible spectroscopic analysis indicated that peaks at the absorption wavelengths of 280 and 254 nm, which are associated with aromatic substances, were detected in the raw water. The aromatic substances were gradually removed, becoming undetectable after biological aeration filter(BAF) treatment. Fourier transform infrared spectroscopy analysis revealed that the functional groups of phenols;benzene, toluene, ethylbenzene, and xylene(BTEX); aromatic hydrocarbons; aliphatic acids;aldehydes; and esters were present in raw wastewater. The organic substances were oxidized into small molecules after Fenton treatment. Aromatic hydrocarbons were effectively removed through bioadsorption and biodegradation after BAF process.Biodegradable organic matter was reduced and finally became undetectable after anoxic–oxic treatment in combination with a membrane bioreactor. Four fluorescent components were fractionated and obtained via excitation–emission matrix parallel factor analysis(EEM-PARAFAC). Dissolved organic matter fractionation in conjunction with EEM-PARAFAC was able to monitor more precisely the evolution of characteristic organic contaminants.     

炼钢厂1号—3号转炉煤气回收实践

针对提钒炼钢厂建设于20世纪70年代初的1号—3号转炉实施煤气回收的可能性进行了论证,对影响煤气回收的问题提出了相应的完善措施,在此基础上成功实施了1号—3号转炉煤气回收改造,改进后年回收转炉煤气达2 127 138GJ以上,可发电59 124 kW.h,减少CO2排放量近20万t,对降低生产能耗及减少温室气体排放起到了较好作用。     

Can haze warning policy reduce traffic accidents: evidence from China

Environmental Science and Pollution Research - Haze pollution may decrease drivers’ driving performance by worsening their physical and psychological states. This paper explores the effects...     

固定式钢制内压容器的耐压试验压力系数

考虑设计变量的不确定性,应用随机-模糊概率模型,定量分析固定式钢制内压容器初始静强度在耐压试验时的可靠度,研究耐压试验压力系数与超压限制系数、可靠度系数和安全系数之间的关系,解决了把可靠性方法应用于压力容器工程设计的理论基础问题.     

Achieving nitritation at low temperatures using free ammonia inhibition on Nitrobacter and real-time control in an SBR treating landfill leachate

Free ammonia(FA) inhibition on nitrite-oxidized bacteria(NOB) and real-time control are used to achieve nitrogen removal from landfill leachate via nitrite pathway at low temperatures in sequencing batch reactor. The inhibition of FA on NOB activity during the aerobic period was prolonged using real-time control. The degree of nitrite accumulation was monitored along with variations of the ammonia-oxidizing bacteria and NOB population using fluorescence in situ hybridization techniques. It is demonstrated that the end-point of ammonia oxidization is detected from the on-line measured dissolved oxygen,oxidization–reduction potential, and p H signals, which could avoid the loss the FA inhibition on NOB caused by excess aeration. At low temperature(13.0–17.6°C), the level of nitrite pathway rapidly increased from 19.8% to 90%, suggesting that nitritation was successfully started up at low temperature by applying syntrophic association of the FA inhibition and real-time control, and then this high level of nitrite pathway was stably maintained for as long as 233 days. Mechanism analysis shows that the establishment of nitritation was primarily the result of predominant ammonia-oxidizing bacteria developed in the nitrifying bacteria population compared to NOB. This was mainly due to a gradual reduction of nitrite amount that is available to provide energy for the growth of NOB,eventually leading to the elimination of NOB from the bacterial clusters in sequencing batch reactor sludge system.     

繁茂膜海绵对海参养殖水体中病原菌净化作用

研究繁茂膜海绵净化海参围堰养殖池水体中病原菌的效果。将繁茂膜海绵悬吊入海参围堰养殖池水体中,监测分析水体中粪大肠菌群、致病性弧菌和总细菌数量。研究发现,在43 d试验期内,繁茂膜海绵对水体中粪大肠菌群净化率为(59.45±8.18)%,对致病性弧菌净化率为(52.99±19.33)%,对总细菌净化率为(55.79±15.64)%。试验过程中,繁茂膜海绵持续保持健康状态。结果表明,繁茂膜海绵能够有效净化海参养殖水体中病原菌。     

齐齐哈尔市土地利用变化及其对地下水水质的影响

为了探究齐齐哈尔市土地利用变化及其对地下水水质的影响,利用1995年、2003年、2011年遥感影像解译结果,比照地下水水质长期监测数据开展相关研究。结果表明,研究区土地利用类型以旱田、湿地和建设用地为主,其中旱田面积最大,占45%以上;近20a来,湿地面积持续减少,减少面积达112.38km2,主要转变为旱田、水田和建设用地,而建设用地的增加主要来自于开发旱田;1995~2003年、2003~2011年2个时期的综合土地利用动态度分别为0.97%、0.60%,研究区2003年之前总体土地利用变化程度明显高于后期。地下水中NO-3-N、SO2-4、Cl-和总硬度浓度变化趋势,与建设用地和旱田间的相互转变密切相关。城镇化建设快速发展及工矿用地土地资源的长期开发,成为对该地区地下水水质产生直接影响的主要土地利用方式。     

济南城市热岛动态变化遥感定量监测及其驱动因素分析研究

城市热岛是城市发展过程中遇到的难题,对人居环境造成较大影响.定量分析研究城市时空演变特征,探究热岛驱动因素,有助于为城市热岛动态变化分析提供技术支撑.论文以济南市为研究对象,采用2000年-2009年间7-8月份MODIS LST数据,分析10年间热岛变化特征.结果表明,10年间,济南城区温度明显高于郊区,热岛效应显著,并且,热核区、特高温区等区域呈现周期性扩张与收缩规律;通过提取2000年及2009年济南市人工表面与植被面积,发现2009年比2000年人工表面面积扩张33.33％,植被减少6.76％,且人工表面扩张与植被减少的区域大部分重合,这对城市热岛形成产生了一定促进作用.另一方面,通过统计分析2000年与2009年人口数量、机动车保有量、烟尘排放量数据,分析济南城市热岛驱动因素,结合城市规划建设,为缓解济南城市热岛提出参考性建议.