市政污泥深度脱水滤液水质特性研究

以武汉市五座污水处理厂剩余污泥经Ⅰ、Ⅱ、Ⅲ三种污泥调理方法调理及脱水的污泥深度脱水滤液为研究对象,分析测定了水样的常规水质指标。结果表明,配方Ⅰ所得脱水滤液pH为12.8左右,呈强碱性,配方Ⅱ、Ⅲ所得脱水滤液pH=3.0~6.2,呈酸性。污泥深度脱水滤液的水质随脱水污泥的来源、污泥调理方法不同而异,稳定、氧化程度高的污泥其深度脱水滤液水质较好。经调理后的深度脱水滤液ρ(COD)为180~1200 mg/L,为中低浓度有机废水;BOD5/COD=0.49~0.66,可生化性良好;氨氮浓度为20~200 mg/L,差异较大,但普遍较高,C/N在2.2~13.4,属低C/N比废水;TP在0.4~5.5 mg/L,C∶N∶P对微生物生长来说并不协调。污泥调理剂中的破胞试剂对污泥脱水滤液水质影响较大,配方Ⅱ、Ⅲ调理剂中含破胞试剂,调理后的污泥深度脱水滤液COD和氨氮值较大。最后,建议对氨氮负荷过高而不适合回流的深度脱水滤液采用高效的生物脱氮工艺进行处理。     

Effect of a high strength chemical industry wastewater on microbial community dynamics and mesophilic methane generation

A high strength chemical industry wastewater was assessed for its impact on anaerobic microbial com- munity dynamics and consequently mesophilic methane generation. Cumulative methane production was 251 mL/g total chemical oxygen demand removed at standard temperature and pressure at the end of 30 days experimental period with a highest recorded methane percentage of 80.6% of total biogas volume. Volatile fatty acids （VFAs） analysis revealed that acetic acid was the major intermediate VFAs produced with propionic acid accumulating over the experimental period. Quantitative analysis of microbial communities in the test and control groups with quantitative real time polymerase chain reaction highlighted that in the test group, Eubacteria （96.3%） was dominant in comparison with methanogens （3.7%）. The latter were dominated by Methanomicrobiales and Methanobacteriales while in test groups increased over the experimental period, reaching a maximum on day 30. Denaturing gradient gel electrophoresis profile was performed, targeting the 16S rRNA gene of Eubacteria and Archaea, with the DNA samples extracted at 3 different time points from the test groups. A phylogenetic tree was constructed for the sequences using the neighborhood joining method. The analysis revealed that the presence of organisms resembling Syntrophomonadaceae could have contributed to increased production of acetic and propionic acid intermediates while decrease of organisms resembling Pelotomaculum sp. could have most likely contributed to accumulation of propionic acid. This study suggested that the degradation of organic components within the high strength industrial wastewater is closely linked with the activity of certain niche microbial communities within eubacteria and methanogens.     

Community structure and elevational diversity patterns of soil Acidobacteria

Acidobacteria is one of the most dominant and abundant phyla in soil,and was believed to have a wide range of metabolic and genetic functions. Relatively little is known about its community structure and elevational diversity patterns. We selected four elevation gradients from 1000 to 2800 m with typical vegetation types of the northern slope of Shennongjia Mountain in central China. The vegetation types were evergreen broadleaved forest,deciduous broadleaved forest,coniferous forest and sub-alpine shrubs. We analyzed the soil acidobacterial community composition,elevational patterns and the relationship between Acidobacteria subdivisions and soil enzyme activities by using the 16 S rRNA meta-sequencing technique and multivariate statistical analysis. The result found that 19 known subdivisions as well as an unclassified phylotype were presented in these forest sites,and Subdivision 6 has the highest number of detectable operational taxonomic units(OTUs). A significant single peak distribution pattern(P 0.05) between the OTU number and the elevation was observed. The Jaccard and Bray–Curtis index analysis showed that the soil Acidobacteria compositional similarity significantly decreased(P 0.01) with the increase in elevation distance. Mantel test analysis showed the most of the soil Acidobacteria subdivisions had the significant relationship(P 0.01) with different soil enzymes. Therefore,soil Acidobacteria may be involved in different ecosystem functions in global elemental cycles. Partial Mantel tests and CCA analysis showed that soil pH,soil temperature and plant diversity may be the key factors in shaping the soil Acidobacterial community structure.     

速读

<正>给大笨钟穿上太阳能电池板为了争取达到2020年温室气体减排34%这个雄伟目标,英国国会正寻求议会关于房地产的意见,打算给大笨钟穿上一层太阳能电池板,以此来减少碳排放并提高能源效率。大笨钟建于1859年,安装在西敏寺桥北议会大厦东侧高96米的钟楼上,钟楼四面的圆形钟盘,直径为6.7米,是伦敦的传统地标。2012年,国会将其更名为伊丽莎白塔。     

低碳氮比条件下膜生物反应器处理高氨氮废水时稳定亚硝化过程的建立

以人工配制高氨氮低碳氮比(C/N)废水为进水,采用膜生物工艺,通过控制亚硝化池内温度为28~30℃,溶解氧浓度为0.5 mg/L,水力停留时间为12 h,pH为7.8~8.0,进水氨氮浓度为200 mg/L、CODCr为40 mg/L,在亚硝化池中成功实现了C/N为1∶5条件下废水的亚硝化。经过14 d的运行时间,污泥龄控制在100 d,在膜生物反应器(MBR反应器)中得到了稳定的亚硝酸盐氮积累。将氨氮浓度分别提高至400和800 mg/L的情况下,其亚硝化菌的耐受浓度负荷冲击能力均较强。     

低碳高氮污水处理应用技术研究

针对碳氮比小于7的污水,其碳源不能满足硝化与反硝化的要求这一问题,通过改变SBR工艺的运行方式、调解工艺参数等技术手段,使其能够达标处理此类工业废水,并通过某淀粉厂的工程实例进行了验证:采用改良的SBR工艺可以对低碳高氮污水进行有效的处理。     

未来10大高风险高回报的新技术

世界经济论坛全球事务理事会发布了一份关于信息技术的新报告,其中提到了10项有可能对全社会造成重大影响的新技术。这10项新技术涵盖了科学、医学、能源、制造、交通和电子等众多领域,理事会的报告简要说明了那些新技术将如何影响和改变我们的生活。     

高水压载荷下软硬原煤瓦斯渗流试验研究

采用二次成型法成功地制作同一煤矿的硬煤和软煤原煤样,并在高水压加载前后使用自行设计的瓦斯渗流试验装置对两种典型原煤煤样的瓦斯渗透率的变化规律进行研究。结果表明:高水压加载前后,两种原煤样的瓦斯渗透率的变化规律差异较大,硬煤原煤样在高水压作用下,煤体内部发生脆性变形,其裂隙得到充分扩张、衍生,形成贯通裂隙网,有效孔隙度增加,煤样瓦斯渗透率较加载前大幅提高;相反,软煤原煤样在高水压作用下,煤体内部发生塑性变形,煤体被水压实,其原生裂隙也被堵塞,瓦斯的流动性更进一步弱化,煤样瓦斯渗透率较加载前大大降低。     

高陡岩质边坡植被修复的立地条件研究——以洛阳市宜阳锦屏山为例

以洛阳市宜阳锦屏山采石场高陡岩质边坡为例,通过对锦屏山高陡岩质边坡岩壁裂隙发育情况、裂隙的温湿度和裂隙内土壤肥力等植物立地条件的调查与分析,认为岩壁发育的裂隙可为植物提供充足的水分和根系发育空间,裂隙内留存的土壤肥力高可为植物生长提供养分,裂隙内的温湿度条件适宜植物的正常生长,因此若能对这些岩壁条件合理利用,并加以适当的人工改造,可实现高陡岩质边坡的快速覆绿,对废弃采石场陡壁小生境生态恢复重建具有重要的意义。     

DGGE及T-RFLP分析光照下电位对细菌群落的影响

电位和光照能影响生物电化学系统中产电光合微生物的富集和生长,为了明确电位对细菌多样性的影响,采用变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)和末端限制性片段长度多态性(terminal restriction fragment length polymorphism,T-RFLP)两种方法分析光照条件下电位对电极生物膜细菌群落多样性的影响,实验设置0、0.2、0.4、0.6 V(vs.Ag/AgCl)4个电位.结果表明,0.6 V(vs.Ag/AgCl)下电极生物膜细菌DGGE条带数量较其他处理明显降低,对条带的测序结果显示不同电位下电极生物膜细菌主要属于α-变形菌纲(α-Proteobacteria)、β-变形菌纲(β-Proteobacteria)和梭菌纲(Clostridia).而0.2 V(vs.Ag/AgCl)处理下末端限制性片段(terminal restriction fragment,T-RF)的数量最高,片段数量随电压进一步升高呈现降低趋势.虽然DGGE和T-RFLP两种方法分析结果有一定差异,但都能反映电位对电极生物膜细菌群落多样性影响显著,高电位降低了细菌多样性.