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Urea hydrolysis and recovery of nitrogen and phosphorous as MAP from stale human urine

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Journal of Environmental Sciences 2008年第8期20卷 1018-1024页

作者： lee duujong Department of Chemical Engineering "National"Taiwan UniversityTaipeiTaiwan 10617China

Laboratory-scale tests for magnesium ammonium phosphate（MAP）precipitation following urea hydrolysis of human urine were conducted using orthogonal experiment *** effects of initial pH,temperature and the volumetric ratios of stale urine to fresh urine,on urea hydrolysis in urine were studied to determine the final hydrolysis time to recover most nitrogen from separated human urine by *** a volumetric ratio of stale to fresh urine>10% and at temperature≥20℃,urea hydrolysis could be completed in two *** pH inhibited urea hydrolysis *** final pH values were all around 9.0 following urine hydrolysis,while the suspension pH might act as an indicator to detect the start and extent of urea *** 95% of ammonium nitrogen and over 85% of phosphorus from hydrolyzed urine as MAP precipitate were obtained using MgCl;·6H;O and Na;HPO;·12H;O as precipitation agents at pH 8.5,molar ratio of Mg;:NH;-N:PO;-P at（1.2-1.3）:1:1,mixing speed of 120 r/min,and precipitation time and reaction time of 3 h and 15 min,*** precipitate has a structure resembling pure MAP crystal.

关键词： urea hydrolysis human urine magnesium ammomum phosphate(MAP) ammonium-nitrogen(NH_4^+-N) phosphorus

Minimizing N_20 fluxes from full-scale municipal solid waste landfill with properly selected cover soil

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Journal of Environmental Sciences 2008年第2期20卷 189-194页

作者： ZHANG Houhu HE Pinjing SHAO Liming QU Xian lee duujong State Key Laboratory of Pollution Control and Resources Reuse Tongji University Shanghai 200092 China Chemical Engineering Department ＂National＂ Taiwan University Taipei 10617 Taiwan China

Municipal solid waste landfills emit nitrous oxide （N2O） gas. Assuming that the soil cover is the primary N2O source from landfills, this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux.

关键词： municipal solid waste landfill N2O flux cover soil leachate nitrification/denitrification environmental factors

Convective Drying of Sludge Cake

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Journal of Thermal Science 2002年第3期11卷 277-282页

作者： Jianbo Chen Xiaofeng Peng Yuan Xue duujong lee Chingping Chu Thermal Engineering Department Tsinghua University100084 BeijingChina Department of Chemical Engineering National Taiwan UniversityTaipeiTaiwanChina

This paper presented an experimental study on convective drying of waste water sludge collected from Beijing GaoBeiDian Sewage Treatment Plant, particularly on the correlation between the observed shrinkage dynamics of sludge cake and the drying curve. During the initial stage of drying the process resembles to that of a particulate bed, in which moisture diffuses and evaporates at the upper surface. Conventional drying theory assuming a diffusion-evaporating front interprets this period of drying. Consequently, owing to the very large shrinkage ratio of the dried cake, cracks emerges and propagates on and within the cake body, whence inducing evaporating channel that facilitates the water removal. This occurrence compensates the reduction of surface area for evaporation, whence extending the constant-rate period during the test. Afterwards, the cracks meet with each other and form isolated cake piles, while the subsequent drying occur mainly within these piles and the conventional theory fails. The

关键词： sludge convective drying visualization.

Current status and developing trends of the contents of heavy metals in sewage sludges in China

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Frontiers of Environmental Science & Engineering 2014年第5期8卷 719-728页

作者： Jun YANG Mei LEI Tongbin CHEN Ding GAO Guodi ZHENG Guanghui GUO duujong lee Center for Environmental Remediation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Chemical Engineering Taiwan University Taipei 106 China

It is essential to determine the heavy metal concentrations in sewage sludge to select appropriate disposal methods. We conducted a national survey of heavy metal concentrations of sewage sludge samples from 107 municipal sewage treatment plants located in 48 cities covering the 31 provinces and autonomous regions, as well as Hong Kong, Macao and Taiwan by Xinjiang Production and Construction Corps in 2006, and identified the temporal trends of heavy metal contents in sewage sludge by comparison with surveys conducted in 1994-2001. In 2006, the average concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in sewage sludge were 20.2, 1.97, 93.1, 218.8, 2.13, 48.7, 72.3, and ***-1, respectively. Because of the decreased discharge of heavy metals into industrial wastewater in China and the increasingly stringent regulations governing the content of industrial wastes entering sewers, the average concentrations of Cd, Cr, Cu, Hg, Ni, Pb, and Zn have decreased by 32.3%, 49.7%, 54.9%, 25.0%, 37.2%, 44.8%, and 27.0%, respectively, during the past 12 years. The concentrations of Cd, Cr, Cu, Ni, and Zn in the samples exceeded the heavy metal limits of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant in China （GB 18918-2002） by 6.5%, 3.7%, 6.5%, 6.5%, and 11.2%, respectively. From these results, 85 of the 107 municipal sludges analyzed would be considered suitable for land application.

关键词： sewage sludge heavy metals temporal variation national survey environmental policies

不同曝气位点对微氧强化硫酸盐还原-反硝化脱硫效果及群落结构的影响

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环境科学学报 2019年第10期39卷 3302-3309页

作者：王雪廷陈川徐熙俊王爱杰李笃中哈尔滨工业大学环境学院城市水资源与水环境国家重点实验室哈尔滨150090 台湾大学化工学院中国台北106 台湾科技大学化工学院中国台北106

微氧强化硫酸盐还原-反硝化脱硫(SR-DSR)工艺因具有同步处理废水中COD、NO-3、SO4^2-生成S0且运行成本低、流程短的优势而受到关注.但因不同曝气方式而在反应器中形成的不同微氧区的位置对反应器运行效能、S0转化率和群落结构的影响尚... 详细信息

微氧强化硫酸盐还原-反硝化脱硫(SR-DSR)工艺因具有同步处理废水中COD、NO-3、SO4^2-生成S0且运行成本低、流程短的优势而受到关注.但因不同曝气方式而在反应器中形成的不同微氧区的位置对反应器运行效能、S0转化率和群落结构的影响尚不明确.因此,本文以5 mL·min^-1·L^-1曝气速率、10.4 mmol·L^-1硫酸钠、31 mmol·L^-1乳酸钠和8 mmol·L^-1硝酸钾连续运行膨胀颗粒污泥床(EGSB)反应器,对比研究了回流槽中(底部)曝气(微氧区位于反应器下部)和反应区上部曝气(微氧区分别位于反应器上部和下部但DO更低)运行稳定后,反应器的运行效能、S0转化率和功能微生物的演替规律.结果表明,上部曝气时乳酸盐去除率为100%,出水中乙酸盐浓度为9.1 mmol·L^-1,丙酸盐浓度为3.7 mmol·L^-1,NO-3去除率为100%,出水中NO2^-浓度为0.35 mmol·L^-1,SO4^2-去除率为84%,出水中S2-浓度为2.6 mmol·L^-1,S0转化率为59%.与底部曝气相比,上部曝气时出水中乙酸盐和丙酸盐浓度分别升高2.2和1.9 mmol·L^-1,NO2^-浓度下降0.15 mmol·L^-1,S^2-浓度降低0.5 mmol·L^-1,SO4^2-去除率和S0转化率分别下降6%和1%.上部曝气时,反应器下部和上部均存在相对减弱的微氧环境,使得反应器中硫酸盐还原菌(SRB)Desulfomicrobium和Desulfobulbus的总丰度分别增加9%和5%,硫氧化反硝化菌(soNRB)Halothiobacillaceae和Sulfurovum的丰度均减小3.1%,异养反硝化菌(hNRB)Comamonas的丰度升高0.2%,互营菌Synergistaceae的丰度减少37%.其中,反应器下部的SRB和soNRB总丰度分别升高28%和3%,为SO4^2-还原和S0转化提供了充分条件,而反应器上部的微氧环境又减弱了SO4^2-还原过程,从而降低了反应器出水中的S2-.因此,在碳源充足的条件下,可以采取反应器上部曝气的方式创造微氧环境,既可以保证较高的S0转化率,又可以减少出水中S^2-和NO2^-的浓度.

关键词：硫酸盐还原-反硝化脱硫微氧曝气位点运行效能群落演替

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同步代谢戊糖、己糖产絮菌的选育

哈尔滨工业大学学报 2015年第6期47卷 50-53页

作者：王丽苏欣颖刘丽红马放王爱杰李笃中任南琪哈尔滨工业大学市政环境工程学院哈尔滨150090 哈尔滨师范大学生命科学与技术学院哈尔滨150025 哈尔滨商业大学食品学院哈尔滨150028

以玉米秸秆为廉价基质,可以有效降低生物絮凝剂合成成本.用1.7%的稀硫酸水解玉米秸秆,获得含有戊糖木糖、己糖葡萄糖的水解液,戊糖很难被微生物代谢.获得能同步代谢戊糖、己糖的产絮菌,是玉米秸秆高效转化为生物絮凝剂的关键.本研究以... 详细信息

以玉米秸秆为廉价基质,可以有效降低生物絮凝剂合成成本.用1.7%的稀硫酸水解玉米秸秆,获得含有戊糖木糖、己糖葡萄糖的水解液,戊糖很难被微生物代谢.获得能同步代谢戊糖、己糖的产絮菌,是玉米秸秆高效转化为生物絮凝剂的关键.本研究以玉米秸秆水解液为基质选育出产絮菌W4,探讨该菌株同步代谢戊糖、己糖的能力.结果显示,菌株W4经16S r DNA鉴定为枯草芽孢杆菌Bacills subtilis,其代谢葡萄糖速率(0.27 g·L-1·h-1)大于代谢木糖速率(0.14 g·L-1·h-1),表明菌株W4能够同步代谢木糖、葡萄糖.菌株W4在木糖和葡萄糖培养基中合成生物絮凝剂的絮凝率分别为96%和97%.经红外光谱分析W4生物絮凝剂的主要成分为多糖和蛋白.

关键词：生物絮凝剂枯草芽孢杆菌同步代谢戊糖己糖