遥感及GIS技术在城市生态环境调查中的应用

为全面了解和掌握马鞍山市生态环境现状,马鞍山市环保局利用遥感技术和GIS技术对全市的生态环境现状进行调查。本次遥感调查以美国陆地资源卫星Landsat5TM2001年数据和同期法国SPOT卫星数据为主。通过调查得到马鞍山市城市2001年生态环境现状和1986年至2001年的动态变化,分析得出近年来马鞍山市城市土地利用结构特点、变化趋势等。     

Characteristics and sources of WSI in North China Plain: A simultaneous measurement at the summit and foot of Mount Tai

To better understand the characteristics and sources of water soluble ions (WSI) in North China Plain (NCP), fine particles (PM_2.5) were simultaneously sampled at the summit (SM) and foot (FT) of Mount Tai during May 12th to June 24th, 2017. Ion chromatography analysis showed that concentration of WSI was lower at SM (22.26 ± 16.53 μg/m³) than that at FT (31.02 ± 21.92 μg/m³). The concentration and proportion of SO₄^2? in total WSI were both lower than the values reported in previous studies. Daytime WSI concentrations were higher than that at nighttime at SM, while the opposite results were obtained at FT, possibly associated with more anthropogenic activities and higher boundary layer height (BLH) during daytimes. A severe pollution event occurred during June 14th – June 16th was documented at both FT and SM. Regional transport and topography-forced vertical transport along the slope of the mountain could explain the higher concentrations of pollutants at SM. The analyses also indicated that NH₄⁺ existed mainly in the form of NH₄HSO₄ and NH₄NO₃, but (NH₄)₂SO₄ could also exist, especially when emissions of NH₄⁺ and NH₃ were increased during daytime at FT. The results of principal component analysis (PCA) illustrated that secondary aerosols, coal/biomass burnings, sea-salts and crustal/soil dusts were the main sources at SM, and secondary aerosols and crustal/soil dusts contributed most at FT. Backward air-mass trajectories were classified into four clusters, of which air masses with the highest frequency and WSI concentrations were originated from the southwest with secondary ions (SO₄^2-, NO₃^- and NH₄⁺) as major pollutants.     

Bioaugmentation and quorum sensing disruption as solutions to increase nitrate removal in sequencing batch reactors treating nitrate-rich wastewater

Bioaugmentation of denitrifying bacteria can serve as a promising technique to improve nutrient removal during wastewater treatment. While denitrification inhibition by bacterial quorum sensing (QS) in Pseudomonas aeruginosa has been indicated, the application of bacterial QS disruption to improve nitrate removal from wastewater has not been investigated. In this study, the effect of bioaugmentation of P. aeruginosa SD-1 on nitrate removal in sequencing batch reactors that treat nitrate rich wastewater was assessed. Additionally, the potential of a quorum sensing inhibitor (QSI) to improve denitrification following bacterial bioaugmentation was evaluated. Curcumin, a natural plant extract, was used as a QSI. The chemical oxygen demand (COD) and initial nitrate concentration of the influent were 700±20 mg/L and 200±10 mg/L respectively, and their respective concentrations in the effluent were 56.9±3.2 mg/L and 9.0±3.2 mg/L. Thus, the results revealed that bioaugmentation of P. aeruginosa SD-1 resulted in an increased nitrate removal to 82%±1%. Further, nitrate was almost completely removed following the addition of the QSI, and activities of nitrate reductase and nitrite reductase increased by 88%±2% and 74%±2% respectively. The nitrogen mass balance indicated that aerobic denitrification was employed as the main pathway for nitrogen removal in the reactors. The results imply that bioaugmentation and modulation of QS in denitrifying bacteria, through the use of a QSI, can enhance nitrate removal during wastewater treatment.     

Water quality induced corrosion of stainless steel valves during long-term service in a reverse osmosis system

The current study analyzes the contribution of 10 water quality parameters (including pH, turbidity, conductivity, total dissolved solids (TDS), hardness, total organic carbon (TOC), alkalinity, calcium ions, chlorides and sulfates) to corrosion extent of stainless steel valves taken from different locations in a reverse osmosis system of a reclaimed water plant. The valves were in service for 5 years. Raman spectroscopy and X-ray photoelectron spectroscopy analyses are conducted to quantify corrosion products on different valves under various water quality conditions. On that basis, bivariate and multivariate regression analyses between the 10 water quality parameters and the corrosion extent of valve specimens (represented by metal loss percentage (MLP) values) are carried out to check the contribution of those water quality parameters to MLP. The results indicate that the proportions of metal oxides as corrosion products vary according to the corrosion extent of the valves. Although no linear correlation is found, all 10 water quality parameters except for pH show a significant positive correlation with the MLP values of the valve specimens. Moreover, results of multivariate regression suggest that the variation of MLP can be explained by turbidity, TDS, TOC and sulfates. A positive contribution of turbidity, TDS and TOC to MLP is observed, whereas the contribution of sulfates is negative. The results from the current work help to identify the reasons for water quality-induced failure of stainless steel equipment in RO systems.     

氯嘧磺隆降解菌的筛选及对污染土壤的生物修复

采用富集培养方法从江苏某激素研究所污水处理池排污口污泥中分离得到1株氯嘧磺隆降解菌,经菌株形态学特征和26S rDNA序列分析,鉴定为胶红酵母菌（Rhodotorula mucilaginosa ）.经降解条件优化,菌株对含100mg/L氯嘧磺隆的无机盐培养基中氯嘧磺隆的最佳降解条件为：接种量2.5%,培养温度28℃,pH 6.0,培养5d后降解率为87.33%;在氯嘧磺隆初始浓度为10mg/kg（干土）的模拟污染土壤中,菌株最佳降解条件为：接种量2.5%,温度25℃,pH 6.0,土壤含水量30%,静息培养30d后降解率为90.74%.土壤修复实验结果表明,施加胶红酵母菌后减轻了氯嘧磺隆对小麦幼苗的药害,在氯嘧磺隆浓度为10mg/kg的土壤中投加降解菌后,小麦的出苗率、株高、根长及鲜重均明显高于未投加降解菌的对照组（P < 0.05）.     

包覆型纳米零价铁的制备及其对染料溶液的脱色性能

采用一步法合成了SiO_2包覆型纳米零价铁(SiO_2-NZVI),并采用TEM,XRD,FTIR及EDS方法对其进行了表征,考察了SiO_2-NZVI对偶氮、蒽醌、三苯甲烷3种不同类型的染料溶液的脱色能力。表征结果表明:SiO_2-NZVI平均粒径为15~22 nm,SiO_2薄膜厚度均一,约为10 nm;SiO_2-NZVI中所含元素主要为Fe和Si,质量比为90.6∶9.4。实验结果表明:SiO_2-NZVI对3种染料溶液均具有脱色能力,在染料溶液质量浓度为100 mg/L、SiO_2-NZVI加入量为2 g/L、反应时间为35 min的条件下,对甲基橙、孔雀石绿、洋红溶液的脱色率分别为86.04%,97.50%,82.13%;SiO_2-NZVI相对于NZVI有更强的抗氧化能力,且酸性环境有利于SiO_2-NZVI对染料溶液的脱色。     

Stainless steel corrosion scale formed in reclaimed water: Characteristics, model for scale growth and metal element release

Stainless steels generally have extremely good corrosion resistance, but are still susceptible to pitting corrosion. As a result, corrosion scales can form on the surface of stainless steel after extended exposure to aggressive aqueous environments. Corrosion scales play an important role in affecting water quality. These research results showed that interior regions of stainless steel corrosion scales have a high percentage of chromium phases. We reveal the morphology, micro-structure and physicochemical characteristics of stainless steel corrosion scales. Stainless steel corrosion scale is identified as a podiform chromite deposit according to these characteristics, which is unlike deposit formed during iron corrosion. A conceptual model to explain the formation and growth of stainless steel corrosion scale is proposed based on its composition and structure. The scale growth process involves pitting corrosion on the stainless steel surface and the consecutive generation and homogeneous deposition of corrosion products, which is governed by a series of chemical and electrochemical reactions. This model shows the role of corrosion scales in the mechanism of iron and chromium release from pitting corroded stainless steel materials. The formation of corrosion scale is strongly related to water quality parameters. The presence of HClO results in higher ferric content inside the scales. Cl⁻ and SO₄^2 − ions in reclaimed water play an important role in corrosion pitting of stainless steel and promote the formation of scales.     

固定化微生物技术在废水处理中的研究进展

介绍了固定化微生物的载体和制备方法，综述了固定化微生物技术近年来在废水处理中的应用现状，并提出今后的研究方向和发展前景。     

石油贮罐硫自燃的化学机理和控制技术

根据硫化学、电化学和热化学原理 ,系统地分析研究了石油贮罐硫化物的形成和硫自燃的化学机理 ,探讨石油贮罐硫自燃控制技术 ,并提出了新的自然控制思路。笔者认为 ,化学反应、放热、热量积蓄是自燃条件 ,硫氧化、聚热、升温、着火为自燃的主要过程 ;控制硫自燃的主要技术有防止硫腐蚀、减少硫化物的氧化反应、加快散热和降低温度 ,而最有效的方法是电化学控制技术。     

1993年世界重要地震灾情与地震活动特征

１９９３年全世界重要灾害地震２７条（其中中国１０条），因地震死亡者１１３３２人（中国６人），受伤者３１０６０人（中国１３２人），造成房屋破坏、财产损失而无家可归者９０００人。遭毁坏与破坏的房屋至少６．３万间（中国２．９４万间），其中最严重的９次经济损失达２．５亿美元以上．全球６级以上地震１１８次（其中７级以上地震９次），６级以上深震（深度≥８０ｋｍ）３５次（其中７级以上２次），有增强的趋势，地震多发生于环太平洋地震带和青藏高原边缘地震带。对印度的大灾害地震之背景作了论述。