Vertical response of microbial community and degrading genes to petroleum hydrocarbon contamination in saline alkaline soil

A column microcosm was conducted by amending crude oil into Dagang Oilfield soil to simulate the bioremediation process. The dynamic change of microbial communities and metabolic genes in vertical depth soil from 0 to 80 cm were characterized to evaluate the petroleum degradation potential of indigenous microorganism. The influence of environmental variables on the microbial responds to petroleum contamination were analyzed. Degradation extent of 42.45% of n-alkanes(C8–C40) and 34.61% of 16ΣPAH were reached after 22 weeks. Relative abundance of alkB, nah, and phe gene showed about 10-fold increment in different depth of soil layers. Result of HTS profiles demonstrated that Pseudomonas, Marinobacter and Lactococcus were the major petroleum-degrading bacteria in0–30 and 30–60 cm depth of soils. Fusarium and Aspergillus were the dominant oil-degrading fungi in the 0–60 cm depth of soils. In 60–80 cm deep soil, anaerobic bacteria such as Bacteroidetes, Lactococcus, and Alcanivorax played important roles in petroleum degradation.Redundancy analysis(RDA) and correlation analysis demonstrated that petroleum hydrocarbons(PHs) as well as soil salinity, clay content, and anaerobic conditions were the dominant effect factors on microbial community compositions in 0–30, 30–60, and 60–80 cm depth of soils, respectively.     

Applications of magnetic nanoparticles in surface-enhanced Raman scattering (SERS) detection of environmental pollutants

Environmental pollution, a major problem worldwide, poses considerable threat to human health and ecological environment. Efficient and reliable detection technologies, which focus on the appearance of emerging environmental and trace pollutants, are urgently needed. Surface-enhanced Raman scattering(SERS) has become an attractive analytical tool for sensing trace targets in environmental field because of its inherent molecular fingerprint specificity and high sensitivity. In this review, we focused on the recent developments in the integration of magnetic nanoparticles(MNPs) with SERS for facilitating sensitive detection of environmental pollutants. An overview and classification of different types of MNPs for SERS detection were initially provided, enabling us to categorize the huge amount of literature that was available in the interdisciplinary research field of MNPs based SERS technology. Then, the basic working principles and applications of MNPs in SERS detection were presented. Subsequently, the detection technologies integrating MNPs with SERS that eventually were used for the detection of various environmental pollutions were reviewed. Finally, the advantages of MNP-basedSERS detection technology for environmental pollutants were concluded, and the current challenges and future outlook of this technology in practical applications were highlighted. The application of the MNPsbasedSERS techniques for environmental analysis will be significantly advanced with the great progresses of the nanotechnologies, optics, and materials.     

Trametes sp.LS-10C产漆酶发酵培养基优化及其漆酶对偶氮染料的脱色性能

为了提高菌株Trametes sp.LS-10C的漆酶产量并初步研究该酶对偶氮染料的脱色性能,本文通过单因素实验及均匀设计对菌株Trametes sp.LS-10C产漆酶培养基进行了优化,获得最优培养基配方为:葡萄糖14.4 g·L~(-1)、豆渣10.1 g·L~(-1)、麸皮100 g·L~(-1)、NH_4Cl_3g·L~(-1)、KH2PO41.4g·L~(-1)、CuSO_4’5H2O 1 g·L~(-1)、NaCl 1 g·L~(-1)、MgSO_40.8 g·L~(-1)、CaCl_20.5 g·L~(-1).菌株发酵至8 d时漆酶产量为595.15 U·m L~(-1),约是优化前的35.66倍.进一步研究表明,该漆酶-介体系统对酸性红GR、酸性蓝40和酸性铬蓝K等3种偶氮染料脱色10 h后脱色率分别高达96.86%、91.28%和86.31%.相比公开发表的文献,本研究所报道的Trametes sp.LS-10C利用优化培养基发酵产漆酶达到了较高水平,具有酶活力高和发酵时间短等特征,且该漆酶在处理偶氮染料废水脱色领域中具有进一步研发和应用价值.     

Simultaneous elimination of cyanotoxins and PCBs via mechanical collection of cyanobacterial blooms: An application of “green-bioadsorption concept”

In this study, the distribution, transfer and fate of both polychlorinated biphenyls (PCBs) and cyanotoxins via phytoplankton routes were systematically investigated in two Chinese lakes. Results indicated that PCB adsorption/bioaccumulation dynamics has significantly positive correlations with the biomass of green alga and diatoms. Total lipid content of phytoplankton is the major factor that influences PCB adsorption/bioaccumulation. Cyanobacterial blooms with relatively lower lipid content could also absorb high amount of PCBs due to their high cell density in the water columns, and this process was proposed as major route for the transfer of PCBs in Chinese eutrophic freshwater. According to these findings, a novel route on fates of PCBs via phytoplankton and a green bioadsorption concept were proposed and confirmed. In the practice of mechanical collections of bloom biomass from Lake Taihu, cyanotoxin/cyanobacteria and PCBs were found to be removed simultaneously very efficiently followed this theory.     

Challenges to quantitative applications of Landsat observations for the urban thermal environment

Since the launch of its first satellite in 1972, the Landsat program has operated continuously for more than forty years. A large data archive collected by the Landsat program sig-nificantly benefits both the academic community and society. Thermal imagery from Landsat sensors, provided with relatively high spatial resolution, is suitable for monitoring urban thermal environment. Growing use of Landsat data in monitoring urban thermal environment is demonstrated by increasing publications on this subject, especially over the last decade. Urban thermal environment is usually delineated by land surface temperature (LST). However, the quantitative and accurate estimation of LST from Landsat data is still a challenge, especially for urban areas. This paper will discuss the main challenges for urban LST retrieval, including urban surface emissivity, atmospheric correction, radiometric calibration, and validation. In addition, we will discuss general challenges confronting the continuity of quantitative applications of Landsat observations. These challenges arise mainly from the scan line corrector failure of the Landsat 7 ETM + and channel differences among sensors. Based on these investigations, the concerns are to: (1) show general users the limitation and possible uncertainty of the retrieved urban LST from the single thermal channel of Landsat sensors; (2) emphasize efforts which should be done for the quantitative applications of Landsat data; and (3) understand the potential challenges for the continuity of Landsat observation (i.e., thermal infrared) for global change monitoring, while several climate data record programs being in progress.     

On-line batch production of ferrate with an chemical method and its potential application for greywater recycling with Al(III) salt

Ferrate(VI) salt is an oxidant and coagulant for water and wastewater treatment. It is considered as a possible alternative method in greywater treatment. However, challenges have existed in putting ferrate(VI) technology into full-scale practice in water and wastewater treatment due to the instability of ferrate solution and high production cost of solid ferrate products. This study demonstrated a new approach of greywater treatment with on-line batch production of Fe(VI) to which Fe(III) salt was oxidized at a weak acidity solution. A series of experiments were conducted to investigate the effect of Fe(VI) on light greywater (total organic carbon (TOC) = 19.5 mg/L) and dark greywater (TOC = 55 mg/L) treatment under different conditions with varying pH and Fe(VI) doses. In addition, the combination use of Fe(VI) and Al(III) salts was proved to be more efficient than using the Fe(VI) salts alone at greywater recycling. The optimum dosage of Fe(VI)/Al(III) salts was 25/25 mg/L for light greywater, 90/60 mg/L for dark greywater, respectively. The TOC values of both light greywater and dark greywater were reduced to less than 3 mg/L with the dosages. The cost for treating greywater was 0.06–0.2 $/ton at ferrate(VI) dosage of 25–90 mg/L and 0.008–0.024 $/ton at AlCl₃ dosage of 25–60 mg/L. The full operating cost needs further assessment before the Fe(VI)/Al(III) technology could be implemented in greywater treatment.     

Study on the mechanism of copper–ammonia complex decomposition in struvite formation process and enhanced ammonia and copper removal

Heavy metals and ammonia are difficult to remove from wastewater, as they easily combine into refractory complexes. The struvite formation method (SFM) was applied for the complex decomposition and simultaneous removal of heavy metal and ammonia. The results indicated that ammonia deprivation by SFM was the key factor leading to the decomposition of the copper–ammonia complex ion. Ammonia was separated from solution as crystalline struvite, and the copper mainly co-precipitated as copper hydroxide together with struvite. Hydrogen bonding and electrostatic attraction were considered to be the main surface interactions between struvite and copper hydroxide. Hydrogen bonding was concluded to be the key factor leading to the co-precipitation. In addition, incorporation of copper ions into the struvite crystal also occurred during the treatment process.     

Purification, characterization and application of dual coagulants containing chitosan and different Al species in coagulation and ultrafiltration process

The objective of this study was to investigate the effect of different Al species and chitosan (CS) dosages on coagulation performance, floc characteristics (floc sizes, strength and regrowth ability and fractal dimension) and membrane resistance in a coagulation–ultrafiltration hybrid process. Results showed that different Al species combined with humic acid in diverse ways. Al_a had better removal efficiency, as determined by UV₂₅₄ and dissolved organic carbon, which could be further improved by the addition of CS. In addition, the optimal dosage of different Al species was determined to be 4.0 mg/L with the CS concentration of 1.0 mg/L, by orthogonal coagulation experiments. Combining Al_a/Al_b/Al_c with CS resulted in larger flocs, higher recovery, and higher fractal dimension values corresponding to denser flocs; in particular, the floc size at the steady state stage was four times larger than that obtained with Al species coagulants alone. The results of ultrafiltration experiments indicated that the external fouling percentage was significantly higher than that of internal fouling, at around 85% and 15%, respectively. In addition, the total membrane resistance was significantly decreased due to CS addition.     

关于建设项目生态补偿的思考

作为一种解决环境保护与经济社会发展矛盾的重要经济手段,生态补偿越来越受到人们关注。建设项目生态补偿是生态补偿的一个重要领域,但相对于其他领域而言,理论和实践研究均相对较少。结合实际案例研究,文章初次提出了建设项目生态补偿概念、原则及应注意的问题。最后,建议加强两方面研究,建设项目生态补偿内涵和范畴确定;建设项目生态补偿方式及标准确定。     

人工替代栖息地对长江口湿地的补充作用研究

利用恢复生态学和景观生态学原理构建人工替代栖息地是恢复和重建生物栖息地环境的重要手段之一,是用于滨海河口区修复或重建滩涂湿地等栖息地的一种替代方法。人工替代栖息地构建出了接近自然原貌的人工系统,创造一种湿地植被和湿地动物可以协调共存的生境,不仅可以为鸟类资源和渔业资源提供良好的栖息环境,其中多样化组合的植被群落在滨水景观、水质净化等方面也起到了重要的作用,对长江口自然湿地的恢复和自然保护区的动态管理具有不可忽视的补充作用。在迁徙鸟类重要中转驿站,珍稀或者经济鱼类的洄游通道,特殊价值的重要湿地景观格局以及水资源战略储备区域中布局人工替代栖息地,可以发挥其对长江口湿地的补充作用,使高度开放而又极为敏感的长江河口地区循着生态健康道路发展。