Ellenberg Indicator Values (EIVs) in Different Plant Communities in Subalpine Grasslands of the Giresun Mountains (Turkey)

Russian Journal of Ecology - In this paper, Ellenberg’s indicator values were estimated in order to soil nitrogen (N), pH (R) and soil moisture (M) in different subalpine grassland...     

Transparent exopolymer particles (TEPs)-associated protobiofilm: A neglected contributor to biofouling during membrane filtration

• Bacteria could easily and quickly attached onto TEP to form protobiofilms. • TEP-protobiofilm facilitate the transport of bacteria to membrane surface. • More significant flux decline was observed in the presence of TEP-protobiofilms. • Membrane fouling shows higher sensitivity to protobiofilm not to bacteria level. Transparent exopolymer particles (TEPs) are a class of transparent gel-like polysaccharides, which have been widely detected in almost every kind of feed water to membrane systems, including freshwater, seawater and wastewater. Although TEP have been thought to be related to the membrane fouling, little information is currently available for their influential mechanisms and the pertinence to biofouling development. The present study, thus, aims to explore the impact of TEPs on biofouling development during ultrafiltration. TEP samples were inoculated with bacteria for several hours before filtration and the formation of “protobiofilm” (pre-colonized TEP by bacteria) was examined and its influence on biofouling was determined. It was observed that the bacteria can easily and quickly attach onto TEPs and form protobiofilms. Ultrafiltration experiments further revealed that TEP-protobiofilms served as carriers which facilitated and accelerated transport of bacteria to membrane surface, leading to rapid development of biofouling on the ultrafiltration membrane surfaces. Moreover, compared to the feed water containing independent bacteria and TEPs, more flux decline was observed with TEP-protobiofilms. Consequently, it appeared from this study that TEP-protobiofilms play a vital role in the development of membrane biofouling, but unfortunately, this phenomenon has been often overlooked in the literature. Obviously, these findings in turn may also challenge the current understanding of organic fouling and biofouling as membrane fouling caused by TEP-protobiofilm is a combination of both. It is expected that this study might promote further research in general membrane fouling mechanisms and the development of an effective mitigation strategy.     

A combined radical and non-radical oxidation processes for efficient degradation of Acid Orange 7 in the homogeneous Cu(II)/PMS system: important role of chloride

Environmental Science and Pollution Research - Trace copper ion (Cu(II)) in water and wastewater can trigger peroxymonosulfate (PMS) activation to oxidize organic compounds, but it only works under...     

Analysis of the Shifts of Phenological Events in Birds as Indicators of Climatogenic Changes

Russian Journal of Ecology - A new method for assessing the response of biota to climatic changes in the ecosystem has been tested. In the Central Forest Natural Biosphere Reserve, the average...     

Prospects and challenges of conservation agriculture in Bangladesh for sustainable sugarcane cultivation

Environment, Development and Sustainability - Sugarcane is an industrial crop globally used for producing biofuels and bioproducts and is the only source of white sugar in Bangladesh. However,...     

Sublethal,sex-specific,osmotic, and metabolic impairments in embryonic and adult round stingrays from a location exposed to environmental contamination in southern California,USA

Environmental Science and Pollution Research - Organic contaminants are known to affect a suite of physiological processes across vertebrate clades. However, despite their ancient lineage and...     

武汉地区夏季和秋冬季大气污染的天气概念模型

利用2013～2019年武汉市生态环境局监测数据、L波段雷达探空资料、NCEP/NCAR逐日再分析资料,对夏季和秋冬季武汉地区污染日的大气污染特征、边界层结构、环流形势、物理量场进行研究,建立了武汉地区大气污染的天气概念模型.主要结论如下:(1)武汉市空气质量具有季节性变化特征,大气污染程度四季分布表现为冬＞秋＞春＞夏.夏季首要污染物是臭氧,冬季首要污染物是PM2.5.(2)比较挑选出的夏季清洁日和污染日的气象要素特征,污染日逆温的平均强度约为清洁日的一倍,逆温底高一般在600 m以下,空气质量一般为轻度-中度污染;静风频率(37.1％)明显高于清洁日的静风频率(2.9％);污染日平均风速小(0.8 m/s),边界层内相对湿度较低.同样比较秋冬季两类天气的气象要素特征,污染日逆温底高低、厚度小,不及清洁日的一半,不利于污染物的扩散,易出现重度污染天气.静风频率(20％)高于清洁日的静风频率(7.5％),风速小(1.6 m/s),污染日边界层内呈明显上千下湿的格局.(3)建立了夏季大气污染的天气概念模型,污染日副高偏弱位置偏东,长江流域易少雨干旱;地面我国东部大范围地区处于均压场中,武汉地区为偏东北异常小风,不利于大气污染物的扩散.(4)建立了秋冬季大气污染的天气概念模型,长江流域环流平直少波动,配合地面弱低压的天气形势和较强的逆温使得大气污染物聚集在近地面.蒙古冷高压强度偏弱,使得入侵我国的冷空气强度偏弱;武汉地区为偏北小风,对雾霾的移除和稀释扩散作用差.该研究结论可供大气污染预测预警研究和环境管理部门大气污染的联防联控参考.     

The performance of nitrate-reducing Fe(II) oxidation processes under variable initial Fe/N ratios: The fate of nitrogen and iron species

•Bacterially-mediated coupled N and Fe processes examined in incubation experiments. •NO₃⁻ reduction was considerably inhibited as initial Fe/N ratio increased. •The maximum production of N₂ occurred at an initial Fe/N molar ratio of 6. •Fe minerals produced at Fe/N ratios of 1–2 were mainly easily reducible oxides. The Fe/N ratio is an important control on nitrate-reducing Fe(II) oxidation processes that occur both in the aquatic environment and in wastewater treatment systems. The response of nitrate reduction, Fe oxidation, and mineral production to different initial Fe/N molar ratios in the presence of Paracoccus denitrificans was investigated in 132 h incubation experiments. A decrease in the nitrate reduction rate at 12 h occurred as the Fe/N ratio increased. Accumulated nitrite concentration at Fe/N ratios of 2–10 peaked at 12–84 h, and then decreased continuously to less than 0.1 mmol/L at the end of incubation. N₂O emission was promoted by high Fe/N ratios. Maximum production of N₂ occurred at a Fe/N ratio of 6, in parallel with the highest mole proportion of N₂ resulting from the reduction of nitrate (81.2%). XRD analysis and sequential extraction demonstrated that the main Fe minerals obtained from Fe(II) oxidation were easily reducible oxides such as ferrihydrite (at Fe/N ratios of 1–2), and easily reducible oxides and reducible oxides (at Fe/N ratios of 3–10). The results suggest that Fe/N ratio potentially plays a critical role in regulating N₂, N₂O emissions and Fe mineral formation in nitrate-reducing Fe(II) oxidation processes.     

The role of traditional knowledge policies in Egypt: the case of Wadi Allaqi

Environment, Development and Sustainability - Globally, traditional knowledge is at stake, notwithstanding intentions recorded in international policy conventions. Egypt has accepted and ratified...