不同粒径的大气细颗粒物对A549细胞的毒性研究

研究了不同粒径的大气细颗粒物对人肺癌上皮细胞A549的生物学效应,探讨了大气中细颗粒物粒径与细胞毒性的关系。采集杭州市大气中不同粒径的细颗粒物,制备成不同粒径的颗粒物总悬浮液,将A549细胞暴露于该制备液24 h后,测定细胞活力(MTT法)和培养液上清液中的LDH含量;并选择最佳浓度为后续暴露剂量,测定ROS生成量,评价不同粒径大气细颗粒物对细胞损伤效应。此外,还采用RTPCR测定凋亡基因P50、BAX、BCL-2表达情况。不同粒径的细颗粒物均显著抑制A549细胞活力,LDH显著增多,并存在剂量-效应关系;最佳染毒质量浓度为10μg/m L;ROS的生成量和各个凋亡基因的mRNA表达量均高于对照组。大气中不同粒径的细颗粒物均能对A549细胞产生毒性,并且随粒径增加,颗粒物对细胞的毒性呈降低趋势。     

Performance evaluation of microbial fuel cell for landfill leachate treatment: Research updates and synergistic effects of hybrid systems

Over half of century, sanitary landfill was and is still the most economical treatment strategy for solid waste disposal, but the environmental risks associated with the leachate have brought attention of scientists for its proper treatment to avoid surface and ground water deterioration. Most of the treatment technologies are energy-negative and cost intensive processes, which are unable to meet current environmental regulations. There are continuous demands of alternatives concomitant with positive energy and high effluent quality. Microbial fuel cells (MFCs) were launched in the last two decades as a potential treatment technology with bioelectricity generation accompanied with simultaneous carbon and nutrient removal. This study reviews capability and mechanisms of carbon, nitrogen and phosphorous removal from landfill leachate through MFC technology, as well as summarizes and discusses the recent advances of standalone and hybrid MFCs performances in landfill leachate (LFL) treatment. Recent improvements and synergetic effect of hybrid MFC technology upon the increasing of power densities, organic and nutrient removal, and future challenges were discussed in details.     

Rat cardiomyocyte H9c2(2-1)-based sulforhodamine B assay as a promising in vitro method to assess the biological component of effluent toxicity

The treatment of wastewaters is crucial to maintain the ecological status of receiving waters, and thereby guarantee the protection of aquatic life and human health. Wastewater quality evaluation is conventionally based on physicochemical parameters, but increasing attention has been paid to integrate physicochemical and biological data. Nevertheless, the regulatory use of fish in biological testing methods has been subject to various ethical and cost concerns, and in vitro cell-based assays have thus become an important topic of interest. Hence, the present study intends: (a) to evaluate the efficiency of two different sample pre-concentration techniques (lyophilisation and solid phase extraction) to assess the toxicity of municipal effluents on rat cardiomyoblast H9c2(2-1) cells, and (b) maximizing the use of the effluent sample collected, to estimate the environmental condition of the receiving environment. The gathered results demonstrate that the H9c2(2-1) sulforhodamine B-based assay is an appropriate in vitro method to assess biological effluent toxicity, and the best results were attained by lyophilising the sample as pre-treatment. Due to its response, the H9c2(2-1) cell line might be a possible alternative in vitro model for fish lethal testing to assess the toxicity of municipal effluents. The physicochemical status of the sample suggests a high potential for eutrophication, and iron exceeded the permissible level for wastewater discharge, possibly due to the addition of ferric chloride for wastewater treatment. In general, the levels of carbamazepine and sulfamethoxazole are higher than those reported for other countries, and both surpassed the aquatic protective values for long-term exposure.     

高压均质对蓝藻有机质释放与厌氧发酵产酸的促进效果

为提高蓝藻在厌氧发酵过程中的资源化利用率,采用高压均质技术处理蓝藻以提高其厌氧发酵产VFAs（挥发性脂肪酸）的效率,通过对蓝藻进行不同压力和pH的高压均质处理,比较处理后蓝藻营养物质的释放情况,并确定该处理的优选运行条件;同时,对未处理蓝藻、高压均质蓝藻、热碱蓝藻进行厌氧发酵试验,评估高压均质处理对蓝藻发酵产酸效果的影响.结果表明:不同条件下高压均质的蓝藻所释放的有机质均较处理前有所提高,其中高压均质的优选条件为压力100 MPa和pH=11,该条件下ρ（SCOD）（SCOD为溶解性化学需氧量）可达22.74 g/L,比对照组提高了52.34倍.在厌氧发酵试验中,高压均质处理在促进有机质释放的同时,还可以提高底物的可生化性,进而提升产酸量.高压均质蓝藻产VFAs的质量浓度最高达8.22 g/L,是对照组的2.16倍.另外,高压均质处理蓝藻的CST（毛细吸水时间）由热碱预处理蓝藻的2 940 s降至1 940 s,减缓了有机质释放带来的脱水性能的恶化趋势.研究显示,高压均质预处理能够提高蓝藻细胞有机质释放、改善碳源可生化性、促进厌氧发酵产酸量,并且降低了分离回收碳源的难度.      

大气细颗粒物暴露干扰心肌细胞存活和炎性反应的主要毒性组分研究

鉴于PM_(2.5)组分呈现多样性和复杂性,其引起心力衰竭的主要毒性组分尚不清楚.由于采样地区、季节和污染源的不同,PM_(2.5)不同组分的占比也会有巨大差异,但不同浓度无法比较其不同组分间的毒性差异.因此,为了揭示大气PM_(2.5)引起心肌毒性作用的关键组分,分离复合型PM_(2.5)的3种主要组分(有机组分、金属组分和水溶性组分),综合两种浓度暴露方式,即实际占比浓度和与复合型PM_(2.5)相同的暴露浓度,染毒H9C2大鼠心肌细胞24 h和48 h,选择心肌细胞的细胞存活和炎症反应为主要评价指标,旨在揭示PM_(2.5)对心肌造成毒性损伤的关键性成分.CCK-8法检测存活结果显示,不同组分在实际环境比重下,对心肌细胞存活率没有造成显著影响.相同浓度暴露下,高剂量组分(30μg·cm~(-2))引起心肌细胞存活率显著降低,且有机组分毒性大于其他组分.根据细胞活力测定结果,选择低染毒浓度(10μg·cm~(-2))暴露细胞,采用qRT-PCR和ELISA试剂盒检测炎症因子变化.与对照组相比,金属组暴露后,炎症因子TNF-α和IL-1β显著升高,而有机组则显著升高TNF-α的含量.结果表明,造成心肌细胞存活毒性和炎症损伤的主要PM_(2.5)组分可能为有机组分和金属组分,而炎性反应对这两种组分的响应存在显著差异.     

高锰酸钾对牛粪微生物燃料电池长期产电性能的影响

为探讨KMnO₄用作阴极电子受体对牛粪长期发酵产电性能的影响,构建了以牛粪为主要底物的双室微生物燃料电池（Microbial fuel cell,MFC）,考察了50,200,800mg/L KMnO₄时牛粪MFC开路电势、输出电压、功率密度、有机底物变化及降解情况.结果表明：当KMnO₄为800mg/L（MFC-800）时产生的开路电势和输出电压最高,分别达到1148mV和234mV,最大功率密度达177mW/m³,库伦效率和净产能最大,分别为18%和19.5MJ/t;电池运行203d后,MFC-800的COD去除率最高,达68.1%;在电池运行过程中,MFC-800的VFA浓度增加了3.5倍,达388mmol/L;pH值从7.25下降到5.71下降了1.54;产电结束后,阳极发酵固态剩余物的成分符合《有机肥料》（NY525-2012）标准,可用于有机肥料生产.     

An innovative approach to minimize excess sludge production in sewage treatment using integrated bioreactors

The present investigation deals with an application of integrated sequential oxic and anoxic bioreactor(SOABR) and fluidized immobilized cell carbon oxidation(FICCO) reactor for the treatment of domestic wastewater with minimum sludge generation. The performance of integrated SOABR-FICCO system was evaluated on treating the domestic wastewater at hydraulic retention time(HRT) of 3 hr and 6 hr for 120 days at organic loading rate(OLR)of 191 ± 31 mg/(L·hr). The influent wastewater was characterized by chemical oxygen demand(COD) 573 ± 93 mg/L; biochemical oxygen demand(BOD5) 197 ± 35 mg/L and total suspended solids(TSS) 450 ± 136 mg/L. The integrated SOABR-FICCO reactors have established a significant removal of COD by 94% ± 1%, BOD5 by 95% ± 0.6% and TSS by 95% ± 4% with treated domestic wastewater characteristics COD 33 ± 5 mg/L; BOD59 ± 0.8 mg/L and TSS 17 ± 9 mg/L under continuous mode of operation for 120 days. The mass of dry sludge generated from SOABR-FICCO system was 22.9 g/m~3. The sludge volume index of sludge formed in the SOABR reactor was 32 mL/g and in FICCO reactor it was 46 mL/g. The sludge formed in SOABR and FICCO reactor was characterized by TGA, DSC and SEM analysis. Overall, the results demonstrated that the integrated SOABR-FICCO reactors substantially removed the pollution parameters from domestic wastewater with minimum sludge production.     

Effect of air-exposed biocathode on the performance of a Thauera-dominated membraneless single-chamber microbial fuel cell (SCMFC)

To investigate the effect of air-exposed biocathode(AEB) on the performance of singlechamber microbial fuel cell(SCMFC), wastewater quality, bioelectrochemical characteristics and the electrode biofilms were researched. It was demonstrated that exposing the biocathode to air was beneficial to nitrogen removal and current generation. In Test 1 of 95%AEB, removal rates of ammonia, total nitrogen(TN) and chemical oxygen demand(COD)reached 99.34% ± 0.11%, 99.34% ± 0.10% and 90.79% ± 0.12%, respectively. The nitrogen removal loading rates were 36.38 g N/m~3/day. Meanwhile, current density and power density obtained at 0.7 A/m3 and 104 m W/m~3 respectively. Further experiments on opencircuit(Test 2) and carbon source(Test 3) indicated that this high performance could be attributed to simultaneous biological nitrification/denitrification and aerobic denitrification, as well as bioelectrochemical denitrification. Results of community analysis demonstrated that both microbial community structures on the surface of the cathode and in the liquid of the chamber were different. The percentage of Thauera, identified as denitrifying bacteria, maintained at a high level of over 50% in water, but decreased gradually in the AEB. Moreover, the genus Nitrosomonas, Alishewanella, Arcobacter and Rheinheimera were significantly enriched in the AEB, which might contribute to both enhancement of nitrogen removal and electricity generation.     

类黄酮生物活性的研究进展

类黄酮是一大类从高等植物中提取的可食用的多酚类物质,具有抗氧化和自由基清除活性,对人体具有营养及医疗价值,如抗病毒、抗癌、保护神经系统和心血管系统等.在类黄酮体外及体内生物活性的研究中,近年又出现一种新的观点,认为类黄酮可作为细胞信号传导途径的调节因子,并能影响基因的表达.图2参28     

DNA adducts in fish following an oil spill exposure

On 12 December 1999, one third of the load of the Erika tanker, amounting to about 10,000 t crude oil flowed into sea waters close to the French Atlantic Coast. This oil contained polycyclic aromatic compounds (PAC) that are known to be genotoxic. Genotoxic effects induce DNA adducts formation, which can thus be used as pollution biomarkers. Here, we assessed the genotoxic impact of the “Erika” oil spill by DNA adducts detection in the liver of immature fishes (Solea solea) from four locations of the French Brittany coasts. Two months after the spill, a high amount of DNA adducts was found in samples from all locations, amounting to 92–290 DNA adduct per 10⁹ nucleotides. Then total DNA adduct levels decreased to reach about 50 adducts per 10⁹ nucleotides nine months after the spill. In vitro experiments using human cell cultures and fish liver microsomes evidence the genotoxicity of the Erika fuel. They also prove the formation of reactive species able to create DNA adducts. Furthermore, in vitro and in vivo DNA adducts fingerprints are similar, thus confirming that DNA adducts are a result of the oil spill.