催化臭氧化反应动力学研究及机理探讨

以粉煤灰作为载体负载活性组分Mn O2催化臭氧氧化处理印染废水,对催化臭氧氧化反应动力学过程采用一级、二级方程进行拟合,并探讨其作用机理。结果表明,粉煤灰基催化剂催化臭氧化过程更符合一级反应动力学模型,方程为ln C=4.770-0.016 7t,线性相关系数R2=0.998 4;用邻二氮菲-Fe(Ⅱ)光度法间接测定单独臭氧体系和催化臭氧体系的·OH的表观生成率,分别为0.170 mmol/L和0.225 mmol/L,说明催化剂的引入能促进臭氧分解产生更多的·OH,提高了反应体系的氧化能力及臭氧的利用率。     

地下水饮用水源地分级分区防控对策研究

地下水饮用水源的污染严重,对人类的各方面造成严重的影响。加大地下水环境防控力度,对解决中国地下水环境和人类生存问题具有现实的指导意义。分析地下水主要环境问题及目前防控政策现状,弥补当前地下水分级分区防控措施的缺点,改善划分方法,提出了利用层次分析法与主成分分析法相结合的方法对地下水饮用水源地进行污染源风险等级评价,根据风险等级形成三级防控体系,以及对地下水饮用水源地进行三级防护区划分的建议与构想。     

The distribution and sea–air transfer of volatile mercury in waste post-desulfurization seawater discharged from a coal-fired power plant

The waste seawater discharged in coastal areas from coal-fired power plants equipped with a seawater desulfurization system might carry pollutants such as mercury from the flue gas into the adjacent seas. However, only very limited impact studies have been carried out. Taking a typical plant in Xiamen as an example, the present study targeted the distribution and sea–air transfer flux of volatile mercury in seawater, in order to trace the fate of the discharged mercury other than into the sediments. Samples from 28 sampling sites were collected in the sea area around two discharge outlets of the plant, daily and seasonally. Total mercury, dissolved gaseous mercury and dissolved total mercury in the seawater, as well as gaseous elemental mercury above the sea surface, were investigated. Mean concentrations of dissolved gaseous mercury and gaseous elemental mercury in the area were 183 and 4.48 ng m^?3 in summer and 116 and 3.92 ng m^?3 in winter, which were significantly higher than those at a reference site. Based on the flux calculation, the transfer of volatile mercury was from the sea surface into the atmosphere, and more than 4.4 kg mercury, accounting for at least 2.2 % of the total discharge amount of the coal-fired power plant in the sampling area (1 km²), was emitted to the air annually. This study strongly suggested that besides being deposited into the sediment and diluted with seawater, emission into the atmosphere was an important fate for the mercury from the waste seawater from coal-fired power plants.     

印染废水综合利用探讨

分析了印染生产工艺和废水水质,论述了印染废水的用于洗煤的可行性.指出印染企业选址于建有热电厂和洗煤厂的矿区比较合理,实现经济可持续性发展.     

降低负荷以提高反硝化颗粒污泥的稳定性

在上流式污泥床反应器（USB）内,接种好氧活性污泥,以甲醇为碳源,NO-3为电子受体,经过40多d培养,得到良好的反硝化颗粒污泥,粒径2～3 mm,MLSS为36 g/L,氮去除速率和COD去除速率分别在0.15 g NO₃-N/(g VSS·d)和0.8 g COD/(g VSS·d)。当负荷提高至6.44 g NO₃-N/(L·d)继续运行1周后,观察到反应器内颗粒污泥出现上浮,浓度降低,颗粒粒径多数在3～5 mm,外观呈乳白色。为恢复反应器稳定运行,当负荷降至3.86 g NO₃-N/(L·d)时,上浮现象减轻,当负荷降至2.57 g NO₃-N/(L·d)时,上浮现象消失,颗粒污泥密度由不稳定时的1.0018 g/cm³提高到1.0126 g/cm³,颗粒粘连现象基本消失,污泥氮去除速率在0.19 g NO₃-N/(g VSS·d),连续运行30 d,系统保持稳定。分析认为,颗粒污泥表面微生物生长速度过快是导致不稳定的主要因素,较长的泥龄有利于系统稳定。     

A dynamic contaminant fate model of organic compound: a case study of Nitrobenzene pollution in Songhua River, China

A one-dimensional dynamic contaminant fate model, coupling kinematic wave flow option with advection-dispersion-reaction equation, has been applied to predict Nitrobenzene pollution emergency in Songhua River, China that occurred on November 13, 2005. The model includes kinetic processes including volatilization, photolysis and biodegradation, and diffusive mass exchange between water column and sediment layer as a function of particles settling and resuspension. Four kinds of quantitative statistical tests, namely Nash-Sutcliffe efficiency, percent bias, ratio of root-mean-square to the standard deviation of monitoring data and Theil’s inequality coefficient, are adopted to evaluate model performance. The results generally show that the modeled and detected concentrations exhibit good consistency. Flow velocity in the river is most sensitive parameter to Nitrobenzene concentration in water column based on sensitivity analysis of input parameters. It indicates flow velocity has important impact on both distribution and variance of contaminant concentration. The model performs satisfactory for prediction of organic pollutant fate in Songhua River, with the ability to supply necessary information for pollution event control and early warning, which could be applied to similar long natural rivers.     

广西综合环境质量结构与功能属性构建及其关系耦合优化

用主分量分类分析方法对广西2001—2015年各要素环境质量监测指标与自然、经济、人口、能源和污染物排放等年鉴统计指标构成的综合环境质量结构与功能属性关系进行耦合。结果表明:广西综合环境质量在省域层次上呈现明显的年、季、月等时间尺度变化规律。在市域层次上,年际时空交互变化规律分异明显;月份的时空交互变化规律在城市空间格局上有明显分异,但时间序列的分异规律不明显;季度的时空交互变化规律在空间与时间上均无明显分异。研究可为经济发展、国土空间优化、能源利用、环境保护等决策管理与判别提供参考。     

复合菌剂强化处理高盐废水脱氮效果

将耐盐脱氮复合菌剂投加到序批式生物反应器中,构建生物强化高盐废水处理系统(SBR1),以未投加复合菌剂系统(SBR2)作为对照,分析典型周期中氮素和溶解氧的变化趋势以及盐度冲击对脱氮效果的影响.实验表明,在曝气时间为6h时,生物强化系统脱氮率可稳定在96％以上,出水总氮浓度为3.8 mg/L左右.反应中始终无硝氮、亚硝氮积累,生物强化系统具有同步硝化好氧反硝化能力.当受到5％和7％较高盐度冲击时,生物强化系统表现出优于对照系统的抗盐度冲击能力,能够快速恢复原有活性,且出水总氮低于15 mg/L;当受到0％盐度的淡水冲击时,对照系统中耐盐污泥失活且无法恢复,而生物强化系统只需投加少量(3％)耐盐脱氮复合菌剂,即可快速恢复活性,出水总氮低于15 mg/L.本研究能够为生物强化高盐废水脱氮系统的构建和运行提供技术支持.     

pH对厌氧氨氧化反应脱氮效能的影响

采用具有恒定pH功能的SBR接种厌氧氨氧化颗粒污泥,研究了pH对厌氧氨氧化菌脱氮效能的影响。实验结果表明:在进水ρ(氨氮)和ρ(亚硝酸盐氮)分别为58.00 mg/L和79.28 mg/L、TN容积负荷为0.82 kg/(m3·d)、不控制反应pH的条件下,随着反应的进行,pH不断升高,当pH=8.02时,菌种的去除效能最高;在进水ρ(氨氮)和ρ(亚硝酸盐氮)分别为120.00 mg/L和159.33 mg/L、TN容积负荷为1.62 kg/(m3·d)、恒定反应pH为8.00的条件下,反应4.0 h时的容积基质氮去除速率(NRR)达到1.42 kg/(m3·d),氨氮去除率达98.39%,亚硝酸盐氮去除率达99.48%;拟合曲线推导的最适pH的理论值为7.85,反应4.0 h时的NRR理论最大值达1.52 kg/(m3·d)。     

中国挥发性有机物污染防治政策及对监测技术的管理需求

本文通过梳理现行的挥发性有机物污染防治政策法规和方法标准,结合国外经验,提出了现阶段挥发性有机物污染防治政策体系。尽管起步较晚,但陆续实施的挥发性有机物排污收费和总量控制机制,已经对污染物监测提出了明确的管理需求。虽然离线检测技术具有良好的灵敏度和响应度,但使用FID和NDIR法的在线和便携仪器响应时间短、数据连续,可以实现对挥发性有机物污染的实时追踪,更好地满足污染预警、应急执法等环境管理新需求。