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471.
废电池的环境污染及资源化价值分析   总被引:11,自引:0,他引:11  
分析了各类废电池的资源化,安再生利用价值由高到低顺序依次为铅酸蓄电池、镍镉、镍氢电池、普通干电池。电池中含有的主要污染物质包括重金属以及酸、碱等电解质溶液。对环境和人体健康危害较大的废电池类别主要为:(1)含汞电池,指氧化汞电池,部分汞含量较高的锌锰和碱锰干电池;(2)铅酸蓄电池;(3)含镉电池,主要是Ni-Cd电池。废电池中化学物质释放进入环境过程是在电池包壳破损后发生的,或者是电池包壳本身发生浸蚀作用。普通家用干电池中的污染物质大多呈固态,由电池内部迁移到环境中是一种缓慢的过程。文中还分析了废电池污染环境的主要途径、采用各种不同处理、处置方式管理废电池可能引起的环境污染。  相似文献   
472.
饮用水消毒过程中卤代烃的形成和控制   总被引:4,自引:0,他引:4  
研究了饮用水消毒过程中卤代烃形成的各种条件及控制技术。结果表明:加氯量多时卤代烃形成多、水温高时卤代烃生成快、加凝聚剂后因pH值下降能控制卤代烃形成、加氨氮后生成氯胺可进一步降低饮用水中的卤代烃。  相似文献   
473.
O3/GAC/UV预处理医药化工废水的研究   总被引:2,自引:0,他引:2  
以对硝基苯甲酸车间废水为试验对象,采用先进的O3/GAC/UV工艺进行预处理。结果表明:对原水CODcr浓度为10960mg/L,经预氧化处理后,CODcr去除率达53%,废水BOD5/CODcr由原来的0.1提高到0.34,极大地改善了废水的生化性能,为后续的生物降解打下了良好的基础。  相似文献   
474.
The relatively recent discovery of disinfection by-products has driven the main regulatory organisms to set maximum contaminant levels for certain substances in drinking water. Trihalomethanes can be deemed as the most important group of by-products in chlorinated surface waters. The present work has focused on trihalomethane formation in a full-scale water treatment plant. We studied the effect of several factors, including ozonation, on trihalomethane levels in chlorinated treated water. The treatment scheme also includes an ozonation step. Electronic Publication  相似文献   
475.
The deactivation of catalyst is a significant reason for its limited application during the catalytic fast pyrolysis (CFP) process. To reduce the coke formation, binary compound impregnation (BCI) and chemical liquid deposition (CLD) were used to modify HZSM-5 catalysts. At the same time, the self-designed microwave reactor separated the pyrolysis of bamboo and catalytic upgrading of primary vapor, which made the catalytic effect more thorough. Experimental results indicated that CLD used TiO2 deposition to cover external acid sites, while BCI by phosphorus-nickel could cover and partly destroy superficial acid sites through two different ways. Within the scope of the loaded amount studied, the yield of aromatic hydrocarbons in the oil phase increased at first and then decreased, while the coke formation reduced continuously. BTX (benzene, toluene and xylene), the most valuable product in bio-oil, drastically increased by 39.1% and 22.6% respectively over the CLD and BCI modified catalysts. Considering the catalytic performance as well as cost, CLD over HZSM-5 has more advantages in the CFP process to upgrade bio-oil.  相似文献   
476.
To manage potential microbial risks and meet increasingly strict drinking water health standards, UV treatment has attracted increasing attention for use in drinking water systems in China. However, the effects of UV treatment on microbial control and disinfection by-products (DBPs) formation in real municipal drinking water systems are poorly understood. Here, we collected water samples from three real drinking water systems in Beijing and Tianjin to investigate the impacts of UV treatment on microbial control and DBP formation. We employed heterotrophic plate count (HPC), flow cytometry (FCM), quantitative PCR analysis, and high-throughput sequencing to measure microorganisms in the samples. Different trends were observed between HPC and total cell count (measured by FCM), indicating that a single indicator could not reflect the real degree of biological re-growth in drinking water distribution systems (DWDSs). A significant increase in the 16S rRNA gene concentration was observed when the UV system was stopped. Besides, the bacterial community composition was similar at the phylum level but differed markedly at the genera level among the three DWDSs. Some chlorine-resistant bacteria, including potential pathogens (e.g., Acinetobacter) showed a high relative abundance when the UV system was turned off. It can be concluded that UV treatment can mitigate microbial re-growth to some extent. Finally, UV treatment had a limited influence on the formation of DBPs, including trihalomethanes, haloacetic acids, and nitrogenated DBPs. The findings of this study may help to understand the performance of UV treatment in real drinking water systems.  相似文献   
477.
The photodegradation of anthracene(AN) and benzo[a]pyrene(BaP),two priority polycyclic aromatic hydrocarbons(PAHs),was examined at ultra-trace levels in surface water to elucidate their behaviour under several irradiance values and types of radiation.The emitting flux and the spectrum of the lamps were found to develop a crucial role in AN and BaP degradation since removal efficiencies of the target contaminants higher than 99%were found after 15 min of irradiation under an ultraviolet C(UVC) irradiance of 0.63 mW/cm~2,corresponding to a fluence of 560.25 mJ/cm~2.On the other hand,although ultraviolet A(UVA) lamps exhibited a higher irradiance compared to that of UVC lamps,they were not efficient for degrading the target PAHs.The removal kinetic studies corroborated these findings,being the AN elimination rate in surface water higher than that in deionized water at optimal operating conditions.Disinfection potential was also measured.A rapid microbial load inactivation,in terms of total coliforms naturally contained in the water matrix studied,was evidenced within 15 min of treatment for the fluence referred.However,after 24 hr in the dark,a regrowth was observed.Additionally,photolysis products more toxic than the parent compounds were found,which were not removed even by extending the treatment time.In this regard,it can be concluded that the individual action of UVC light for removing AN and BaP with disinfection purposes is not an efficient treatment;therefore,the use of radiation in combination with other kinds of treatments is required.  相似文献   
478.
Ship auxiliary engines contribute large amounts of air pollutants when at berth.Biodiesel,including that from waste cooking oil(WCO),can favor a reduction in the emission of primary pollutant when used with internal combustion engines.This study investigated the emissions of gaseous intermediate-volatile organic compounds(IVOCs) between WCO biodiesel and marine gas oil(MGO) to further understand the differences in secondary organic aerosol(SOA) production of exhausts.Results revealed that WCO exhaust exhibited similar IVOC composition and volatility distribution to MGO exhaust,despite the differences between fuel contents.While WCO biodiesel could reduce IVOC emissions by 50% as compared to MGO,and thus reduced the SOA production from IVOCs.The compositions and volatility distributions of exhaust IVOCs varied to those of their fuels,implying that fuel-component-based SOA predicting model should be used with more cautions when assessing SOA production of WCO and MGO exhausts.WCO biodiesel is a cleaner fuel comparing to conventional MGO on ship auxiliary engines with regard to the reductions in gaseous IVOC emissions and corresponding SOA productions.Although the tests were conducted on test bench,the results could be considered as representative due to the widely applications of the test engine and MGO fuel on real-world ships.  相似文献   
479.
Introduction. Paramedics are at risk of occupational blood exposure, increased by the immediacy of provided treatment. However, the issue has not been acknowledged to date by any research in Europe. Methods. This research aimed at assessing occupational blood exposure among paramedics in Poland. Respondents represented 21 Polish medical institutions. Their participation was voluntary and anonymous. Paramedics were provided with a self-directed job-specific questionnaire adapted to Polish conditions from an original US version. Results. 118 paramedics participated in the study from institutions constituting the National Emergency Medical System in Poland; including ambulance crews, Helicopter Emergency Medical Services and emergency department employees. Occupational exposure was reported by 18.64% of respondents and the main route of exposure was needlestick events. Conclusions. There is a further need to improve education among paramedics concerning the threat of being infected with blood-borne pathogens through all existing routes. Our findings point to the problem as being hidden and considered a shameful issue.  相似文献   
480.
The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2+and Zn2+in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients(above 0.99 for both metal ions) and insignificant lack of fit(p = 0.0838 and 0.0782 for Pb2+and Zn2+, respectively). Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation(between –NH2,-CN and metal ions) and ion-exchange(between –COOH and metal ions). The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions.  相似文献   
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