Removal of ammonia nitrogen in wastewater by microwave radiation.

Ammonia nitrogen contaminated wastewater has posed great threat on the safety of water resources. In this study, a novel process, microwave (MW) radiation, was developed for the removal of ammonia nitrogen from wastewater. The effects of pH, radiation time, aeration and initial ammonia concentration on the removal were investigated. pH and radiation time showed significant influence on the removal of ammonia nitrogen. The largest removal was obtained at pH 11 in 3 min. Initial ammonia concentration and aeration had minute influence. The mechanism of ammonia removal was proposed as the formation of molecular ammonia (NH(3)) and the subsequent evaporation of NH(3) by MW radiation. Compared with conventional heating (CH) mode, MW radiation led to higher ammonia removal. Both thermal and non-thermal effects were responsible for the removal, but the contribution of thermal effect was more significant. In the end, coke-plant wastewater containing high concentration of ammonia nitrogen was treated by MW radiation. With the initial ammonia concentration of 5000 mg/L at pH 11, ammonia was reduced to 350 mg/L at 750 W by 10 min MW radiation. It could be proposed that MW radiation was an effective method for the removal of ammonia nitrogen from wastewater.

[1]  A. Bianco Prevot,et al.  Microwave-assisted extraction of polycyclic aromatic hydrocarbons from marine sediments using nonionic surfactant solutions. , 2001, Analytical chemistry.

[2]  Z. Kawala,et al.  Microwave-enhanced thermal decontamination of soil , 1998 .

[3]  Tsu-Wei Chou,et al.  Microwave processing: fundamentals and applications , 1999 .

[4]  X. Hao,et al.  Ammonium removal from landfill leachate by chemical precipitation , 1999 .

[5]  R. Hoff,et al.  Influence of eutrophication on air-water exchange, vertical fluxes, and phytoplankton concentrations of persistent organic pollutants. , 2000 .

[6]  S. Yuan,et al.  Microwave remediation of soil contaminated with hexachlorobenzene. , 2006, Journal of hazardous materials.

[7]  S Banik,et al.  Bioeffects of microwave--a brief review. , 2003, Bioresource technology.

[8]  In-Tae Kim,et al.  Electrochemical conversion characteristics of ammonia to nitrogen. , 2006, Water research.

[9]  Wei Liu,et al.  Water eutrophication in China and the combating strategies , 2007 .

[10]  J. J. Pis,et al.  Microwave-induced pyrolysis of sewage sludge. , 2002, Water research.

[11]  Hang-Sik Shin,et al.  Enhanced ammonia nitrogen removal using consistent biological regeneration and ammonium exchange of zeolite in modified SBR process. , 2004, Water research.

[12]  Peng Wang,et al.  Microwave Irradiation: A Novel Method for Rapid Synthesis of D,L‐Lactide , 2007 .

[13]  K. C. Cheung,et al.  Ammonia stripping as a pretreatment for landfill leachate , 1997 .

[14]  August Bonmatí,et al.  Air stripping of ammonia from pig slurry: characterisation and feasibility as a pre- or post-treatment to mesophilic anaerobic digestion. , 2003, Waste Management.

[15]  Miguel A. Porras,et al.  ULTRASHORT PULSED GAUSSIAN LIGHT BEAMS , 1998 .

[16]  M. de Rosa,et al.  Non‐thermal effects of microwaves on proteins: thermophilic enzymes as model system , 1997, FEBS letters.

[17]  P. Hering,et al.  Investigations of OH–N- and NH–O-type hydrogen-bonded clusters by UV laser spectroscopy , 1998 .

[18]  A. Shazman,et al.  Examining for possible non-thermal effects during heating in a microwave oven , 2007 .

[19]  C. Lan,et al.  Use of ammoniacal nitrogen tolerant microalgae in landfill leachate treatment. , 2007, Waste management.

[20]  Min Yang,et al.  Ammonia removal in bubble column by ozonation in the presence of bromide , 1999 .

[21]  Thomas Welander,et al.  Biological nitrogen removal from municipal landfill leachate in a pilot scale suspended carrier biofilm process , 1998 .

[22]  N. Wu,et al.  Microwave-assisted solution synthesis of SnO nanocrystallites , 2002 .

[23]  H. Tai,et al.  Application of granulated activated carbon packed-bed reactor in microwave radiation field to treat BTX , 1998 .

[24]  S. Haswell,et al.  Perturbation of a solid phase separation process by a non-thermal microwave effect , 1999 .

[25]  R. Maoz,et al.  Specific Nonthermal Chemical Structural Transformation Induced by Microwaves in a Single Amphiphilic Bilayer Self-Assembled on Silicon , 1998 .

[26]  Q. Gan.  A case study of microwave processing of metal hydroxide sediment sludge from printed circuit board manufacturing wash water , 2000 .

[27]  Thomas Welander,et al.  Nitrification of landfill leachate using suspended-carrier biofilm technology , 1997 .

[28]  Mohamed Hamoda,et al.  Athermal microwave effects for enhancing digestibility of waste activated sludge. , 2007, Water research.

[29]  Kwang Victor Lo,et al.  Removal of nitrogen from swine manure wastewaters by ammonia stripping , 1995 .

[30]  R. Abramovitch,et al.  In situ decomposition of PAHs in soil and desorption of organic solvents using microwave energy , 1999 .

[31]  Shuo Chen,et al.  Regeneration of acid orange 7-exhausted granular activated carbons with microwave irradiation. , 2004, Water research.

[32]  G. González,et al.  Emulsion polymerization in a microwave reactor , 1998 .

[33]  S. Zang,et al.  Investigation on the rapid degradation of congo red catalyzed by activated carbon powder under microwave irradiation. , 2007, Journal of hazardous materials.

[34]  Erik Jeppesen,et al.  Anthropogenic impacts on lake and stream ecosystems, and approaches to restoration , 2007 .

[35]  D. Archer,et al.  Microwave radiation can alter protein conformation without bulk heating , 2003, FEBS letters.