单环硝基芳香化合物好氧生物降解及其遗传学研究进展

硝基芳香化合物是环境中难降解的有机污染物之一 ,对环境的污染日益严重 ,利用生物技术对这类有机物进行降解是行之有效的新途径。针对几种单环硝基芳香化合物好氧降解的微生物、降解途径以及降解过程中的主要酶、降解性质粒、基因定位等分子遗传学的研究进展进行了综述     

水力负荷对厌氧氨氧化反应器运行影响的研究

采用一套有效容积为4.46 L的UASB-ANAMMOX反应器,通过对水力负荷进行3个阶段的调节,研究水力停留时间对ANAMMOX反应器处理效果的影响.3个阶段的水力负荷分别为0.20～0.25、0.38～0.43、0.16～0.20 L/(Ld).在试验过程中,水力负荷的冲击对NH 4-N、NO-2-N的去除率影响明显.其中水力负荷为0.20～0.25 L/(L·d)时,NH 4-N、NO-2-N去除率都能达到99%以上;当水力负荷为0.38～0.43 L/(L·d)时,NH 4-N、NO-2-N去除率分别降至64%和62%;当水力负荷为0.16～0.20 L/(L·d)时,NH 4-N、NO-2-N去除率立刻分别回升至94%和97%.ANAMMOX反应过程中,NO-2-N和NH 4-N的去除量比值基本在1.3∶1.0左右变化,ANAMMOX反应的优势菌种代谢在运行过程中会将一部分NO-2-N转化为NO-3-N,水力负荷的改变对NO-3-N的出水浓度影响不大;但NO-3-N日生成量与水力负荷的大小成正比.试验表明,UASB-ANAMMOX反应器对水力负荷冲击有较强的抵抗力,但是仍会造成一定量的ANAMMOX反应的优势菌流失,使该反应器在短时间内不能恢复最佳的去除效果.     

UASB反应器厌氧氨氧化菌的脱氮特性研究

研究UASB厌氧氨氧化（ANAMMOX）反应器运行情况,采用普通城市污水厂活性污泥接种,人工合成废水,pH值在7.4～7.8之间,温度控制在(32±1)℃。在反应器稳定运行270～450 d之间的180 d中,对NH⁺₄-N和NO^-₂-N去除率均达到99.9％以上,总氮去除率保持在90％以上,NO^-₃-N产生量在20～30 mg/L之间波动。研究表明,UASB厌氧氨氧化反应器处理废水效果明显,对NH⁺₄-N、NO^-₂-N和TN去除率高,NO^-₂-N和NH⁺₄-N比值可以指示厌氧氨氧化反应器性能的演变。UASB反应器稳定运行阶段容积负荷的影响较小,ANAMMOX菌对合成废水适应性强,反应器抗冲击能力较强,受冲击后恢复迅速。出水pH值稳定在8.5附近,pH值变化情况可作为反应器运行状况的指示。关键词硝化厌氧氨氧化上流式厌氧污泥床生物脱氮     

垃圾焚烧炉渣对电镀废水中Cu的吸附特性

以垃圾焚烧炉渣作吸附剂,对电镀废水中Cu的吸附特性进行了研究,包括吸附速率、解吸速率、吸附等温线和连续柱吸附实验等。结果表明,炉渣对电镀废水中Cu的吸附平衡时间和解吸平衡时间均为8 h。炉渣对Cu的吸附等温线为直线型,可用Henry型方程进行拟合。连续柱吸附实验结果表明,炉渣对电镀废水在连续吸附55 h后吸附能力逐渐丧失,累计最大吸附量为921 μg/g,而炉渣对人工配水在连续吸附80 h后吸附能力完全丧失,累计最大吸附量为2 687 μg/g。     

磺胺嘧啶对纯膜MBBR氨氧化性能及氨氧化菌群的影响

通过向NH₄⁺-N质量浓度为30 mg·L⁻¹的合成废水中投加不同剂量磺胺嘧啶(SDZ)(0、1、3、5、7和10 mg·L^–1),比较了SDZ浓度对一台60 L单级纯膜移动床生物膜反应器(pure MBBR)的氨氧化速率、amoA基因丰度和氨氧化细菌(AOB)种群结构的影响,揭示了磺胺嘧啶对纯膜MBBR系统中氨氧化作用的影响机制。结果表明：1~3 mg·L^–1的SDZ显著提升了纯膜MBBR系统的氨氧化速率(P<0.05),出水${\rm{NH}}_4^{+} $-N质量浓度可降低至(0.19±0.10) mg·L^–1;5~10 mg·L^–1的SDZ仍能促进${\rm{NH}}_4^{+} $-N去除,但氨氧化速率变化相对平缓。相比于氨氧化古菌(AOA),AOB为纯膜MBBR氨氧化的主导者,AOB amoA基因丰度是AOA amoA基因丰度的12.2~168.5倍。1~10 mg·L^–1的磺胺嘧啶暴露显著抑制了AOB amoA基因丰度(P<0.05),但能有效刺激AOA amoA基因丰度上调(P<0.05)。高通量测序结果表明,添加磺胺嘧啶改变了AOB的种群多样性及结构,且1~3 mg·L^–1的SDZ能显著促进AOB种群多样化和亚硝化螺菌属(Nitrosospira)生长(P<0.05)。SDZ对氮源的补充、对AOB与AOA丰度占比的改变、对微生物耐药性的促进以及对AOB种群结构的干扰是其影响纯膜MBBR氨氧化过程的主要机制。     

Treatment of fluorine-containing pharmaceutical wastewater by VUV/UV process

Environmental Science and Pollution Research - As an advanced oxidation process, vacuum ultraviolet/ultraviolet (VUV/UV) has been intensively studied for drinking water treatment, but assessment of...     

Assessing economic sustainability and ecological efficiency with genuine progress indicator: a case study of the Yangtze River Delta from 2000 to 2018

To achieve urban sustainability, it is critical to enhance the environment, economy, and society simultaneously. This study adopted the revised genuine progress indicator (GPI) and ecological footprint (EF) to evaluate the ecological efficiency and economic sustainability of the Yangtze River Delta from 2000 to 2018. Spatial analysis was utilized to identify spatial autocorrelation. A total of 27 cities were then partitioned through k-means cluster analysis. The results showed that GPI and ecological efficiency improved rapidly, but economic sustainability showed a downward trend. GPI and GDP had a high degree of spatial correlation, especially in Suzhou-Wuxi-Changzhou Metropolitan Area. However, no spatial correlation existed between GPI and EF. The city with high GEE can reach 3000 $/gha, indicating the city consumed 1 global hectare to create $3000 of genuine economic growth. Shanghai, Hangzhou, and Taizhou were cities with the highest level of economic sustainability and ecological efficiency. The spatiotemporal characteristics of economic sustainability and ecological efficiency revealed in this study will provide theoretical guidance for alleviating ecological pressure and promoting economic sustainable development.

     

Impact of air pollutants on hospital visits for pediatric asthma in Fuzhou city,southeast China

Environmental Science and Pollution Research - Rapid social development in China has resulted in severe air pollution and adverse impacts on people’s health. Although studies have been...     

SDG-oriented multi-scenario sustainable land-use simulation under the background of urban expansion

Environmental Science and Pollution Research - With the continuous improvement of urbanization level and the continuous expansion of city scale, there are some unreasonable land development and...     

An insight into the drag effect of water,land, and energy on economic growth across space and time: the application of improved Solow growth model

Environmental Science and Pollution Research - Economies that depend on natural resources can experience a resource drag effect when economic growth is limited by constraints on the availability of...