Removal of ammonia nitrogen in wastewater by microwave radiation: A pilot-scale study

Determination of ammonia removal from aqueous solution and volumetric mass transfer coefficient by microwave-assisted air stripping

“…In 2009, Lin et al reported in two studies that MW radiation heating is a promising way for ammonia removal from wastewater. Compared with the conventional heating with 60 % ammonia removal efficiency, they obtained *95 and 80 % ammonia removal efficiency in laboratory-scale (Lin et al 2009b) and pilot-scale (Lin et al 2009a) experiments, respectively. In laboratory-scale experiments, Lin et al tested the effect of pH, aeration, radiation time, and initial ammonia concentration.…”

“…Industrial wastewaters, such as coke plant, tannery, textile, landfill leachate, and fertilizer wastewaters, contain ammonia in high concentration (Lin et al 2009a;Yu et al 1997;Tchobanoglous and Burton 1991). Since the presence of even small amounts of ammonia has serious negative effects on ecology and human health and it can be used as a raw material, the importance of researches on ammonia recovery increases.…”

“…Since the presence of even small amounts of ammonia has serious negative effects on ecology and human health and it can be used as a raw material, the importance of researches on ammonia recovery increases. The recovery or/and removal of ammonia with low concentration and its compounds from wastewaters can be achieved by biological, physical, and chemical processes (Lin et al 2009a, b) or by a combination of these processes, such as adsorption, chemical precipitation, membrane filtration, reverse osmosis, ion exchange, air stripping, breakpoint chlorination, and biological nitrification (Lin et al 2009a). The recovery of industrial wastewaters by biological systems (Yu et al 1997), chemical precipitation (Uludag-Demirer et al 2005), supercritical water oxidation (Bermejo et al 2008;Segond et al 2002), and steam stripping (Ghose 2002;Yang et al 1999) is not satisfied due to the following disadvantages: (1) Biological processes are usually difficult to treat ammonia containing wastewaters due to their toxic nature and the certain C/N ratio requirement (Qian et al 1994;Lin et al 2009b), (2) chemical precipitation needs additional reagents leading to the formation of the new pollutants to the water sources (Uludag-Demirer et al 2005), (3) supercritical water oxidation requires high temperatures and pressures (Bermejo et al 2008), and (4) steam-stripping method uses a large stripping tower which consumes a large amount of energy, and ammonia concentration in effluent is often very high (Yang et al 1999).…”

“…Ammonia removal efficiency increases with increasing pH and microwave radiation time, while aeration and initial ammonia concentration do not affect the process significantly (Lin et al 2009b). After the bench-scale experiments, Lin et al carried out the MW-assisted ammonia removal in the pilot-scale experiments (Lin et al 2009a). They indicated that MW-assisted heating process can be applied effectively to remove ammonia in high concentration from the coke plant wastewater.…”

Progress of the technique of coal microwave desulfurization

“…As a energy field, Microwave can heat substance fastly, uniformly and selectively. It has been used widely in many fields including mineral leaching (AlHarahsheh and Kingman 2004;Chen et al 2011), wastewater treatment (Lin et al 2009;Remya and Lin 2011), environmental engineering and oil sand and petroleum upgrading (Jones et al 2002;Mutyala et al 2010). With the increasing emphasis on environmental issues, the application of microwave technology in the field of clean coal technology has attracted attention of experts (Zavitsanos and Blriler 1978;Meikap et al 2005;Kalra 2006; Lester et al 2006;Sahoo et al 2011;Royaei et al 2012;Ge et al 2013;Xia et al 2013).…”