水中亚硝化细菌和硝化细菌检测方法的探讨

介绍了亚硝化细菌和硝化细菌的培养方法,并用MPN法计数亚硝化细菌和硝化细菌.对判断培养物中亚硝酸盐和硝酸盐存在的显色反应进行了对比试验.结果表明, 在NO-3的显色反应中,可用氨基磺酸铵溶液作为NO-2的抑制剂,并且要先加入二苯胺,再滴加浓硫酸,这样更便于结果观察.指出硝化细菌培养基对于显色反应没有影响,NO-2显色的质量浓度为0.15 mg/L.     

城市生活污泥和矿化垃圾中氮磷淋失的模拟研究

通过模拟土柱实验,分析了城市生活污泥和矿化垃圾中氮磷的迁移对地下水的影响以及矿化垃圾对氮磷的去除特性.测定项目包括总磷、总氮、硝态氮、pH和电导率(EC).结果表明:施用污泥和矿化垃圾后淋滤液的pH呈下降趋势;EC和总氮都有显著增加;硝态氮增加特别明显,容易造成地下水污染;总磷变化不大,污染地下水的可能性较小.矿化垃圾对氮的去除作用不明显,反而增加了淋滤液中的氮素含量,但对磷的去除效果明显.因此,在利用矿化垃圾取代土壤时,应注意矿化垃圾中氮特别是硝态氮的污染.     

改进倒置A2/O工艺处理生活污水试验研究

对倒置A2/O工艺进行了缺氧池生物挂膜实验,结果表明,在化粪池出水COD有一定波动情况下,缺氧池COD去除率不仅较高且较稳定,有利于后续硝化反应的进行,提高系统的脱氮效果.同时研究了C/N在缺氧池中对脱氮效果的影响,C/N(质量比)     

夏季潮滩对上海老港垃圾填埋场渗滤液氮、磷净化效果研究

垃圾填埋产生的渗滤液造成的环境污染问题El益严重。采用自然湿地对垃圾渗滤液净化有诸多优点,而相关的研究较少。根据渗滤液的不同浓度和不同滞留时间的净化效果不同,采用实验室模拟和培养的方法来研究老港垃圾填埋场附近潮滩对垃圾渗滤液营养盐N、P的净化效果。研究发现：夏季老港中、低潮滩在较短滞留时间（6h）内对各浓度渗滤液中N、P的净化效果不明显,而在较长滞留时间内（96h）中、低潮滩对各浓度渗滤液净化效果明显,净化后污水中N、P含量可达到排放标准;垃圾渗滤液质量分数为5％时,潮滩对N、P的净化效果最为明显。     

粪便与生活垃圾混合堆肥氮转化与腐熟度

采用静态仓强制通风进行粪便和生活垃圾混合堆肥,以玉米秸和石灰为调理剂,考察堆肥过程的氮转化与腐熟度。试验结果表明:堆肥中氮的损失量为26%～49%,堆体高温期持续时间长,导致氮的损失增加。添加石灰使堆肥前期的氮损失率增加,但加快了堆肥过程,总氮的损失没有加大。水溶性氨氮含量在堆肥升温期出现峰值5.61mg/gdw,堆肥结束时氨氮含量小于0.34mg/gdw;堆肥中硝态氮主要在降温期和腐熟期形成,达到1.84～4.05mg/gdw。氨氮和硝态氮之比小于0.16和水溶态有机碳与总氮之比小于1.10,较适合作为粪便与垃圾的混合堆肥腐熟指标。     

Nitrogen dynamics in the sediments of a wetland coastal ecosystem of southern India

The study area, Kuttanad Waters is a part of the Cochin estuarine system on the west coast of India. Kuttanad is well known for its agricultural activity and so the major contribution to the inorganic ions of nitrogen will be from fertilisers applied in agriculture. Based on observed salinity the stations have been divided into three zones. The fresh water zones had higher quantities of silt and clay whereas the estuarine zone was more sandy. The chemical speciation scheme applied here distinguishes three forms of ammoniacal nitrogen species: exchangeable, fixed, and organic ammoniacal nitrogen. No significant trends were observed in the seasonal distribution of total, exchangeable, fixed and organic nitrogen. A significant concentration of exchangeable ammonia was observed in the sediment due to their predominantly reducing environment, which restricts nitrification. High NH₄-N concentrations in the pore waters, along with the sedimentary composition leads to a significantly high quantity of fixed NH₄-N. The low values for N org is due to high mineralisation or deamination of organic nitrogen     

镉胁迫对龙葵幼苗氮代谢及其相关酶活性的影响

采用营养液培养方法,研究了系列镉浓度处理对龙葵（Solanum nigrumL）幼苗氮代谢的影响。结果表明：龙葵根系可溶性蛋白质较叶片受Cd影响更大。龙葵植株叶片和根系NO3--N含量、硝酸还原酶（NR）、谷氨酰胺合成酶（GS）活性均随镉浓度提高而先增后降,且随处理时间的延长而逐渐下降。叶片NO3--N含量和NR活性均在25μm镉处理8d后达到峰值,而根系NO3--N则在50μm镉处理8d后最高。叶片NO3--N含量受镉处理影响较根系稍大。然而,龙葵叶片中NH4＋-N含量随镉浓度升高和时间延长逐渐升高,100μm镉处理16d后最高,表明镉胁迫下龙葵叶片铵态氮富集效应明显。龙葵叶片和根系中谷氨酸脱氢酶（GDH）活性随镉处理浓度提高和处理时间延长而逐渐升高,100μm镉处理16d后达到峰值。     

碳氮比对悬浮填料生物反应器氮去除效果的影响

文章研究了C/N对悬浮填料生物反应器脱氮效果的影响。出水中NH4+-N、NO2--N和NO3--N浓度以及pH值变化均受C/N的影响,实验得到的最佳C/N质量比为12∶1,TN去除率平均在85%。     

福建泉州市东、西湖水体中氮的空间分布研究

初步探讨了东湖和西湖水体中氯的空间分布特征以及3种不同形态的氮与溶解氧的相关性.结果表明,(1)泉州东湖、西湖水体中总氮的平均含量分别为3.396、3.929mg/L,氨氮的平均含量分别为1.927、2.182mg/L,硝酸盐氮的平均含量分别为1.061、1.236mg/L,亚硝酸盐氮的平均含量分别为0.084、0.059 mg/L,东湖和西湖水体的主要氮素形式均是氨氮.(2)东湖出水口和位于动物园附近的采样点总氮、氨氮和亚硝酸盐氮浓度较其它采样点高,入水口、湖区北部及湖心区采样点的氨氤和硝酸盐氮的分布趋势基本一致.西湖东南部采样点总氮、氨氯、硝酸盐氯和亚硝酸盐氮的含量都较其它采样点高.(3)东湖水体的DO浓度与氨氛、硝酸盐氮和亚硝酸盐氯的含量都不具有相关性,而西湖水体的DO浓度与这3种形态氮显著相关.     

Testing differences in methods of preparing moss samples

The main objective of this research was to estimate the total mass of nitrogen discharged from various sources in Korea using the mass balance approach. Three different nitrogen mass balances were presented: (1) agricultural activities including raising crops and animal husbandry; (2) domestic activities, and (3) activities in forest and urban areas. These nitrogen balances were combined to estimate riverine discharge of nitrogen to the ocean in national scale. Nitrogen inputs include atmospheric deposition, biological nitrogen fixation, application of inorganic fertilizers/manures, animal feed/imported foodstuffs, and meat/fish. Nitrogen outputs include ammonia volatilization, denitrification, human/animal waste generation, crop/meat production, and riverine discharge to the ocean. The estimated total nitrogen input in Korea was 1,194.5 × 10³ tons N/year. Nitrogen discharged into rivers was estimated as 408–422 × 10³ tons N/year, of which 66–71% was diffuse in origin. The estimated diffuse discharges for land uses were estimated as 82 × 10³ tons N/year from agricultural areas, 7 × 10³ tons N/year from forestry and 75 × 10³ tons N/year from urban and industrial areas.