The characteristics of nitrate removal by the psychrotolerant denitrifying bacterium Acinetobacter johnonii DBP-3, isolated from a low-temperature eutrophic body of water

A psychrotolerant denitrifying bacterial strain, DBP-3, was isolated from a eutrophic body of water by low-temperature-oriented acclimation culture. Based on its morphologicalandbiochemicalcharacteristics and 16S rDNA gene sequence, the bacterium was identified as belonging to the genus Acinetobacter and closely related to A. johnonii. The satisfactory growth of DBP-3 was observed at 10–30°C and pH 7–9. Strain DBP-3 was able to utilize three types of carbon sources (sodium acetate > sodium citrate > glucose) to support growth and denitrification. DBP-3 grew faster, but with lower nitrate removal efficiency and higher nitrite accumulation, under aerobic conditions than under anoxic conditions. DBP-3 was extremely susceptible to tetracycline and rifampicine and less sensitive to ampicillin and penicillin. The growth of DBP-3 was significantly affected by Hg (II), Cr (VI), Pb (II), Cd (II), and As (III) at 0.32, 0.63, 1.25, 2.5, and 25.0 mg L^?1, respectively. Interestingly, chromium (VI) significantly promoted DBP-3 growth at concentrations lower than 0.32 mg L^?1. These data may be helpful to support the use of strain DBP-3 in the purification of eutrophic water bodies at low temperatures.     

Ambient Air Benzene Concentrations in Canada (1989-1993): Seasonal and Day of Week Variations,Trends, and Source Influences

Abstract

Since 1987, the Pollution Measurement Division of the Environmental Protection Service, Environment Canada, has operated a field program for measuring benzene in ambient air. With the cooperation of provincial and municipal environmental agencies, samples have been collected at over 30 urban and rural monitoring sites across the country. Samples are collected in evacuated canisters and analyzed by gas chromatography with a mass-selective detector. Using data from all sites, the composite average benzene concentration for Canada over the years 1989 to 1993 was 3.6 μg/m³ and the composite median was found to be 2.6 μ/m³. Benzene concentrations are highest at urban sites near major streets and at sites influenced by industrial sources. For eighteen urban and suburban trend sites (those with no nearby industrial sources), composite annual median benzene concentrations decreased by 20% between 1989 and 1993. For the same period, median benzene concentrations decreased by 33% at four trend sites with nearby industries. At most monitoring sites the parameters for benzene and CO are highly correlated; supporting the inventory estimate that most emissions of benzene are due to vehicle exhaust. For sites with nearby industrial sources of benzene, the industries are estimated to account for 35 to 70% of the benzene dose experienced at the sites. These site specific contributions are much more significant than the estimated national emissions assigned to industrial sources.     

Insight into metal binding properties of biochar-derived DOM using EEM-PARAFAC and differential absorption spectra combined with two-dimensional correlation spectroscopy

Environmental Science and Pollution Research - A large amount of biochar-derived dissolved organic matter (BDOM) will be released into the environment with biochars application into repairing...     

Simultaneous adsorption and immobilization of As and Cd by birnessite-loaded biochar in water and soil

Environmental Science and Pollution Research - A novel biochar was prepared by loading birnessite to improve its capability to simultaneously adsorb As(III), As(V), and Cd(II) in water and soil....     

Identification of priority pharmaceuticals in the water environment of China

In recent years, increasing attention has been paid to the trace-level contamination of pharmaceuticals in the water environment all over the world. Considering a large number of pharmaceuticals used, it is crucial to establish a priority list of pharmaceuticals that should be monitored and/or treated first. In the present study, we developed a ranking system based on the pharmaceutical consumption, removal performance in the wastewater treatment plants (WWTPs) and potential ecological effects, and applied to the situation of China. 39 pharmaceuticals, which had available consumption data and also been reported previously in the WWTPs of China, were selected as candidate pharmaceuticals. Among them, seventeen pharmaceuticals were considered as priority pharmaceuticals, out of which, erythromycin, diclofenac acid and ibuprofen, had the high priority. Compared with other literatures, we found that some pharmaceuticals given concerns to globally should also be included in the priority list in China; while some pharmaceuticals, not mentioned in other literatures, such as cefalexin, ketoconazole, should be also given prior consideration in China. Among all the therapeutic classes, antibiotics, which were grossly abused in China, contributed the most to the priority pharmaceuticals. However, priority antibiotics accounted for only 32% of candidate antibiotics, while 71% and 100% of the candidate anti-inflammatory and antilipidemic respectively were identified as the priority pharmaceuticals, indicating that antibiotics might be overanxiously considered in the previous studies on their behaviors in the WWTPs of China.     

Catalytic activity of Ru/Al2O3 for ozonation of dimethyl phthalate in aqueous solution

With dimethyl phthalate as the model pollutant and Ru/Al(2)O(3) as catalyst, this paper systemically investigates the removal of total organic carbon (TOC) of system. Our results have confirmed that Ru/Al(2)O(3) can significantly increase the effect of ozonation. TOC removal in 120 min can reach 72% while only 24% with ozone alone. The optimal catalyst preparing condition was 0.1 wt% Ru content, 600 degrees C calcination temperature, 0.5-1.0mm particle diameter, which is characterized by a high surface area and a large population of surface active sites. The contrasting experiments of ozone alone, catalyst adsorption after ozonation, and catalytic ozonation confirmed that catalytic reaction was the most important process to TOC removal in system with Ru/Al(2)O(3) as catalyst.     

Electrocatalytic oxidation of ciprofloxacin by Co-Ce-Zr/γ-Al2O3 three-dimensional particle electrode

Environmental Science and Pollution Research - In this work, Co-Ce-Zr/γ-Al2O33 particle electrodes were prepared for the efficient degradation of ciprofloxacin (CIP). Co-Ce-Zr/γ-Al2O3...     

Occurrence and distribution of antibiotics in coastal water of the Taizhou Bay,China: impacts of industrial activities and marine aquaculture

Environmental Science and Pollution Research - The occurrence, spatial distribution, and source analysis of antibiotics in global coastal waters and estuaries are not well documented or understood....     

Simultaneous compartmentalization of lead and arsenic in co-hyperaccumulator Viola principis H. de Boiss.: an application of SRXRF microprobe

The cellular distributions of Pb and As in the leaves of co-hyperaccumulator Viola principis H. de Boiss. were inspected by synchrotron X-ray fluorescence spectroscopy (SRXRF). The results revealed that Pb and As had similar compartmentalization patterns in the leaves. Both elements were enriched in the bundle sheath and the palisade mesophyll. In comparison with the sheath and the mesophyll, the vascular bundle and the epidermis contained lower levels of Pb and As. The palisade enrichment of Pb and As indicated that V. principis H. de Boiss. may have a special mechanism on detoxification of toxic metals within the mesophyll cells. Relative concentrations of both Pb and As in trichome bases were higher than those in trichome rays. The results of hierarchical cluster analysis and correlation analysis confirmed that the distribution of Pb was similar to that of As in the leaves, and their distribution patterns were different from the nutrient elements, such as K, Ca, Mn, Fe, Ni, Cu and Zn. In vivo cellular localization of Pb and As in the leaves provides insight into the physiological mechanisms of metal tolerance and hyperaccumulation in the hyperaccumulators.     

双循环多级水幕脱硫塔的设计和性能测试

双循环多级水幕脱硫塔是在常规两段式湿法脱硫塔基础上加以改进而成的新型脱硫塔,其双循环浆液采用不同pH控制,低pH促进CaCO2溶解,高pH提高SO2吸收效果;同时,多级水幕强化气液流态,增加气液接触面积和传质动力,促进对SO2的吸收.实验利用SPSSV13.0软件进行正交实验设计,通过数据分析得出两个不同的优化运行方案,再利用多指标分析法中的综合平衡法进行单因素实验,得出最优运行方案.在最优运行方案条件下,即烟气流量为100 m3/h,上循环浆液pH为6.0,下循环浆液pH为4.8,上、下循环液气比均为20 L/m3,人口 SO2质量浓度为1 000mg/m3时,脱硫效率达97.8%,CaCO3利用率为95.2%,钙硫质量比约为1.03.双循环多级水幕脱硫塔具有良好的应用前景,实验结果对现场脱硫系统的调试和运行有很好的参考价值.