首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
随着国民经济的日益发展,工业现代化的规模不断扩大,城市垃圾,工业废水等各种废物将会日积月累,越来越多,如不及时处理,必然会影响城市建设,制约工业化的步伐,甚至污染水质,恶化环境,危害人民.怎样处理好广大城镇的各种废弃物,是实现工业现代化所必须解决的重要课题.根据我国及西方国家,近几年的经验证明,运  相似文献   

2.
步骤将样品于60℃烘干2小时,粉碎,研磨,通过0.25毫米筛孔。贮于广口瓶中备用。准确称取0.5克(视钼含量而定)试样,置150毫升锥形瓶中,加浓硝酸5毫升,放置过夜。然后将装有样液的锥形瓶放在用调压器控温的电热板上加热,起初低温,逐步提高温度,维持微沸状态,待剧烈反应完毕,取下锥形瓶,冷却后,沿着瓶壁加入5毫升硝酸一高氯酸混合酸(2∶1)继续加热分解,直至瓶内冒高氯酸的白烟,样液接近透明无色,继续加热赶走残留高氯酸,当样液很少时,可适当降低温度,蒸至近干,取下冷却,加少量蒸馏水并加热使盐类溶解,冷却,移入25毫升容量瓶中,用蒸馏水洗涤锥形  相似文献   

3.
一、对来稿的总体要求 来稿首先必须属本刊刊登范畴(参见本刊简介中的栏目设置),其次,应主题明确,重点突出,论据充分,数据可靠,文字精练,图表清晰。每篇论文篇幅尽量不超过8页。来稿应包括(按以下顺序):题名,作者姓名、工作单位(需全称,大学应到院系一级)、所在城市、邮编,摘要,关键词(3~8个),中图分类号,英文题名,作者姓名汉语拼音,作者单位英文名称,英文摘要,英文关键词(与中文关键词相对应),正文以及参考文献。  相似文献   

4.
一、对来稿的总体要求 来稿首先必须属本刊刊登范畴(参见本刊简介中的栏目设置),其次,应主题明确,重点突出,论据充分,数据可靠,文字精练,图表清晰。每篇论文篇幅尽量不超过8页。来稿应包括(按以下顺序):题名,作者姓名、工作单位(需全称,大学应到院系一级)、所在城市、邮编,摘要,关键词(3~8个),中图分类号,英文题名,作者姓名汉语拼音,作者单位英文名称,英文摘要,英文关键词(与中文关键词相对应),正文以及参考文献。  相似文献   

5.
一、对来稿的总体要求 来稿首先必须属本刊刊登范畴(参见本刊简介中的栏目设置),其次,应主题明确,重点突出,论据充分,数据叮靠,文字精练,图表清晰。每篇论文篇幅尽量不超过8页。来稿应包括(按以下顺序):题名,作者姓名、工作单位(需全称,大学应到院系一级)、所在城市、邮编,摘要,关键词(3~8个),中图分类号,英文题粥,作者姓铝汉语拼音,作者单位英文名称,英文摘要,英文关键词(与中文关键词相对应),正文以及参考文献。  相似文献   

6.
绍兴县位于宁绍平原西部,全县总面积1377.9平方千米,总人口94.28万人。党的十一后三中全会以来,绍兴的经济发展很快,特别是近几年来,绍兴县工业产值以每年14.5%至38.6%之间的速度向前发展,到1992年末,实现工业总产值147.48亿元,比1989年增长153.1%,绍兴县的工业体系以轻纺工业为主体,尤其是印染业,发展迅速,遐迩闻名。全县一百二十余家印染厂加工各种印染布160754万米,比1991年增加64.06%,是经济发展的重要支柱。但是,印染业的发展给水质带来消极影响也是不容低估的,在一定程度上威胁着酒缸的发展。由于印染厂点多面广,废水排放量大,面绍兴县是一个水网地带,河网纵横,水环境污染问题显得尤为突出。因此,给环境管理带来了诸多不便。要关闭这么多印染厂,不可能。因为没有印染行业,将制约绍兴的经济发展,实行经济处罚,也不可能全面地铲除污染问题;若进行治理,就目前环保部门自身力量去管理,也难以发挥治理设备应有的作用。因此,根据绍兴县的实际情况,如何对印染行业的污染防治和监督管理,特将该县福全、漓诸,兰亭等三个镇实行环保工作新机制的做法介绍及探讨如下。 1992年,绍兴县环保局根据县人大常委会建立印染废水治理工作新机制,实行印染企业“治产分流”的建议,于1992年3月先在福全镇试点,然  相似文献   

7.
3AMBR工艺在昆明第四污水处理厂的应用   总被引:1,自引:0,他引:1  
昆明第四污水处理厂3AMBR工艺于2010年投入使用,排放标准为国家一级A标,运行状况良好,目前是国内最大的处理生活污水的MBR工艺污水处理厂,设计日处理量为6万m3生活污水,2012年年实际处理量2 071万m3污水,吨水耗电量约0.61度/吨,吨水耗絮凝剂量约0.51 g,深度处理部分吨水耗硫酸亚铁量约19 g。通过对工艺沿程参数数据的分析(DO,ORP,TN,TP,NH3-N,NO3-N,MLSS,COD),深入探讨了3AMBR工艺运行的原理、现状及存在的问题,研究发现,该工艺存在出水水质好,运行稳定,产泥量少等优点,同时系统也存在过量曝气、污泥龄过长和进水碳源严重不足等现象。  相似文献   

8.
新修订的《水污染防治法》,通篇洋溢着时代的气息和创新精神,为消除政府、市场“双失灵”的不良倾向,努力克服“地方保护主义”,引导市场客观地反映环境成本,宽严相济,刚柔并用,突出制度创新和机制创新,强调政府责任,主张公民权利,大幅度地提高了违法成本,强力推进了市场主体的外部不经济性内部化,旨在实现社会主义市场经济条件下的公平与和谐。当前,在“两高一低”(守法成本高,执法成本高,违法成本低)的态势之下,无疑必须严格执法,方能彰显公平,追求和谐。在严格执法的同时,应十分注重拓宽守法空间,拓宽创新空间,拓宽法律实施的有效空间,进一步强化政府责任,强化公众参与,调动方方面面保护环境的内在动力,以推动社会经济的全面、协调、可持续发展。  相似文献   

9.
汽车排出气中的氮氧化物净化研究   总被引:1,自引:0,他引:1  
在汽车排出气中包含着多种成分,因发动机的种类及运转条件的不同而变化。一般说可以分为两类,一类是N_2,O_2,H_2,CO_2,H_2O等无害成分;另一类是NO_2,HC,CO,SO_2微粒,臭气等对人体有害成分。世界各国,尤  相似文献   

10.
黑白胶片显影废液主要成份为对苯二酚,米吐尔,亚硫酸钠,碳酸钠,溴化钾,其中对苯二酚,米吐尔属有毒物质。胶片在显影过程中少量显影剂被氧化生成醌类化合物,同时,由于胶片上溴化银中银的还原,显影液中溴离子不断积增,而溴离子对显影有抑制作用,使得显影液失效。这些含显影剂废液的排放,即污染环  相似文献   

11.
黄程兰  陈滢  刘敏 《环境工程学报》2012,6(11):3894-3898
污泥膨胀是活性污泥工艺运行中经常遇到的最棘手的问题之一。本实验以人工合成污水为底物,采用序机式活性污泥法(SBR);研究投加无机混凝剂氯化钙控制污泥膨胀的情况,同时研究丝状菌和菌胶团的变化。研究发现,投加氯化钙后,丝状菌数量明显减少;形成较多大而密实规则的菌胶团,污泥膨胀得到控制。污泥容积指数(SVI)由最初的309.5 mL/g降到67.1 mL/g,污泥沉降性能改善。停止投加氯化钙后又运行了18周期,活性污泥没有发生再次膨胀。投加氯化钙对COD去除率没有明显影响。研究结果表明,投加氯化钙是一种有效的污泥膨胀应急控制措施。  相似文献   

12.
Combustion experiments in a laboratory-scale fluidized-bed reactor have been performed to clarify the effects of copper chloride as a catalyst on polychlorinated dibenzofurans (PCDFs) formation in municipal waste incineration. We used model wastes with and without copper chloride (CuCl2 x 2H2O) as a catalyst, both of which contained polyvinyl chloride (PVC) as a chlorine source. Combustion temperature was set to 900 degrees C, and the amount of air supplied was twice as much as the theoretical amount. The experimental setup had been carefully planned to ensure avoidance of the influences of previous experiments. Results of these present experiments revealed that copper chloride in the waste increased the amount of PCDFs formed and made the homologue profile shifted towards the highly chlorinated species. Copper chloride contributes to PCDFs formation by promoting chlorination via catalytic reactions, whereby the reaction could be important in that organic matters are chlorinated directly by chlorinated compounds related to Deacon reaction such as copper chloride. It was elucidated that characteristic isomer distribution patterns appeared in case the waste contained copper chloride. It is probable in our experiment with copper chloride that PCDFs are mainly formed via catalytic reactions of copper compounds and carbon.  相似文献   

13.
以自制的二氧化铅粉末多孔电极为阳极,不锈钢为阴极,探讨了投加Cl-对氨氮电化学氧化反应速率、途径及产物等的影响。结果表明,投加Cl-能显著提高氨氮的电化学氧化速率;有氯离子存在的条件下,氨氮的去除主要靠电催化过程中产生的强氧化性物质.OH,HClO的作用,其去除率随着电流密度的增大呈增高的趋势,随初始pH的增大而增大;投加氯离子后,NO3--N的生成量增加,但氧化产物主要是以N2为主的含氮气体。  相似文献   

14.
There are about 5 Tg of methyl chloride in the Earth’s atmosphere making it one of the largest reservoirs of gas-phase chlorine. We discuss the time series of global measurements taken over the last 16 yr at seven locations distributed among the polar, middle, and tropical latitudes of both hemispheres (1981–1997). Measurements were also taken at 20 more sites between 1987 and 1989. The vertical distribution was measured during campaign experiments in the Arctic, Western Atlantic, and over Brazil. Small, mostly decreasing trends are observed, showing that on average, there was 4% less methyl chloride during the last three years (1994–1996) than there was in the first three years (1985–1987) of the experiment. The latitudinal variation is marked by highest concentrations in the tropics and lowest in the polar regions. Sites representing inland locations show higher concentrations, suggesting continental sources, mostly confined to the tropics. There are seasonal variations at various latitudes that can be explained mostly by the cycles of OH radicals, which are the dominant removal process for methyl chloride in the atmosphere. Based on these data, the expected emissions can be calculated at the polar, middle, and tropical latitudes represented by the six long-term primary sites. Using a photochemical model of OH, we estimate that a global source of about 3.7 Tg yr-1 of methyl chloride is needed to explain the observed concentrations. Other removal processes have been identified that may add to this estimate of the global annual emissions. The results further establish that some 85% of the emissions must come from the half of the earth’s surface between 30°S and 30°N, representing tropical and sub-tropical latitudes. Small emissions are estimated for the middle latitudes, and no emissions are expected from the polar regions.  相似文献   

15.
Microbial inhibitors such as mercuric chloride are frequently used to sterilize soil or soil-water slurries in experimental studies on the fate of xenobiotics in the environment. This study examined the influence of mercuric chloride additions to soil-water slurries on the sorptive behaviour of a phenoxy herbicide (2,4-D) in soil. The results demonstrated that mercuric chloride strongly decreased the capacity of the soil to retain herbicides, and that the interference of mercuric chloride with herbicide sorption increased with increasing soil organic carbon contents. Because of the competitive sorption between mercuric chloride and the phenoxy herbicide, we conclude that mercuric chloride may not be a good soil sterilization procedure for use in xenobiotic fate studies.  相似文献   

16.
通过水溶液聚合法制备了聚丙烯酸水凝胶(polyacrylic acid,PAA),研究了溶液酸碱度和温度对聚丙烯酸水凝胶吸附氯化1-丁基3-甲基咪唑离子液体的影响。结果表明,水凝胶对氯化1-丁基3-甲基咪唑离子液体的吸附量随溶液pH值增大而逐渐增大,pH=2~4时增幅明显,而pH大于4时变化趋于缓慢;随温度的升高而逐渐降低。该等温吸附行为基本符合Langmuir吸附等温式,由二级吸附动力学模型获得的吸附过程活化能(Ea=52.470 kJ/mol)可以看出,PAA对氯化1-丁基3-甲基咪唑的吸附属于化学吸附范畴。  相似文献   

17.
Methyl chloride (CH3Cl) is the most abundant natural chlorine containing compound in the atmosphere, and responsible for a significant fraction of stratospheric ozone destruction. Understanding the global CH3Cl budget is therefore of great importance. However, the strength of the individual sources and sinks is still uncertain. Leaf litter is a potentially important source of methyl chloride, but factors controlling the emissions are unclear. This study investigated CH3Cl emissions from leaf litter of twelve halophyte species. The emissions were not due to biological activity, and emission rates varied between halophyte species up to two orders of magnitude. For all species, the CH3Cl emission rates increased with temperature following the Arrhenius relation. Activation energies were similar for all investigated plant species, indicating that even though emissions vary largely between plant species, their response to changing temperatures is similar. The chloride and methoxyl group contents of the leaf litter samples were determined, but those parameters were not significantly correlated to the CH3Cl emission rate.  相似文献   

18.
Spatial patterns of organic chlorine and chloride in Swedish forest soil   总被引:7,自引:0,他引:7  
The concentration of organic carbon, organic chlorine and chloride was determined in Swedish forest soil in the southern part of Sweden and the spatial distribution of the variables were studied. The concentration of organically bound chlorine was positively correlated to the organic carbon content, which is in line with previous studies. However, the spatial distribution patterns strongly indicate that some other variable adds structure to the spatial distribution of organic chlorine. The distribution patterns for chloride strongly resembled the distribution of organic chlorine. The spatial distribution of chloride in soil depends on the deposition pattern which in turn depends on prevailing wind-direction, amount of precipitation and the distance from the sea. This suggests that the occurrence of organic chlorine in soil is influenced by the deposition of chloride or some variable that co-varies with chloride. Two clearly confined strata were found in the area: the concentrations of organic chlorine and chloride in the western area were significantly higher than in the eastern area. No such difference among the two areas was seen regarding the carbon content.  相似文献   

19.
Using thermodynamic data, the equilibrium constant for dissociation of solid ammonium chloride aerosol into gaseous hydrogen chloride and ammonia has been calculated. The existence of solid ammonium chloride aerosols is thermodynamically possible at temperatures and concentrations observed in the troposphere, but significant gas phase concentrations of hydrogen chloride and ammonia will also be present.  相似文献   

20.
在研究氢氧化镁混凝特性的基础上,复配氯化镁和硫酸铝作为混凝剂,以高岭土配水水样为研究对象,运用iPDA在线监测技术对混凝过程絮体形成进行监测,探讨了单独使用氯化镁和硫酸铝以及二者复配使用的混凝效果和絮体特性,确定复配使用的各种条件。结果表明,对于浊度20 NTU,pH 11.5的高岭土配水水样,氯化镁、硫酸铝最佳投加量分别为7.2 mg/L(Mg2+计)和3 mg/L(Al3+计);硫酸铝跟氯化镁复配使用时,先投加硫酸铝,间隔30 s后投加氯化镁,混凝效果较好;在镁离子最佳投加量7.2 mg/L时,铝和镁最佳质量比在1∶3~1∶2之间;镁铝复配时其FI值明显大于单独作用时,即絮体尺寸大小:二者复配硫酸铝氯化镁,而且复配条件下Zeta电位值在零电势左右浮动,浮动范围小,更利于聚集沉淀;镁铝复配时发生了协同效应,弥补了单独使用氯化镁混凝过程的不足。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号