Characteristics of Heavy Metals Emitted from a Heavy Oil-Fueled Power Plant in Northern Taiwan

To explore the feasibility of simultaneous carbon reduction and energy saving/recycling during wastewater decolorization, this study used naturally-occurring microbes (e.g., Aeromonas and Klebsiella sp.) for dye decolorization as well as energy and materials recycling. These microbes were tested for capabilities of bioelectricity generation in parallel with dye treatment for simultaneous energy recovery. The supplementation of electron-shuttling mediators (e.g., aminophenols) significantly increased the electron-transfer efficiency of electrochemically-active microorganisms. Moreover, the presence of decolorized intermediate(s) might repress intracellular accumulation of the biodegradable polyhydroxyalkanoates (PHAs), likely due to toxicity of aromatic amines. Microbial fuel cells (MFCs) appear to be feasible for use in the reduction of CO 2 emitted (ca. 40-60 Faraday efficiency) during the generation of bioenergy (e.g., bioelectricity) and biomaterials (e.g., PHAs) in wastewater treatment, thus aiding the development of cradle-to-cradle sustainable designs.

Section: Introductionmentioning

confidence: 94%

Reduction of Carbon Dioxide Emission by Using Microbial Fuel Cells during Wastewater Treatment

Chen

Liu

Hung

et al. 2013

“…The natural sources of arsenic compounds are mainly released from volcanic activity, since they are widely distributed in the earth's crust (2 mg/kg) (Wedepohl, 1991). Throughout the related high temperature processes, some arsenic compounds are adsorbed on volcanic ash and deposited to the ground, while the others remain in atmospheric aerosols, and these are then subject to longrange transportation in the troposphere (Thomaidis et al, 2003;Wang et al, 2010;Chen et al, 2012;Fang et al, 2012a). However, human activities account for three times more emissions of arsenic compounds to the environment than volcanic activity, and these mostly come from mining, municipal solid waste incineration, fossil fuel combustion processes, metallurgical facilities, and vehicles (Wang and Mulligan, 2006;Contreras et al, 2009;Boamponsem et al, 2010;Lee and Nguyen Thi, 2011;Ny and Lee, 2011;Tian et al, 2011;Chen et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Atmospheric Arsenic Deposition in Chiayi County in Southern Taiwan

Lin

et al. 2013

Self Cite

Although arsenic contamination of underground water in southern Taiwan is well known, few studies examine atmospheric arsenic deposition in this area, which might be the major source of such pollution to the soil, water, and even underground water. This research focused on the atmospheric arsenic concentration, dry and wet depositions, and the As distribution around Chiayi County, located in the south of Taiwan. Eight sampling sites are used, both upwind and downwind of an area with heavy industrial and human activities. All samples were collected by a PS-1 high volume sampler at each site, pretreated by a digestion process, and further analyzed with an ICP-MS. The results show that the arsenic deposition flux ranged from 65.0 to 473 μg/m 2 -month in Chiayi County. This deposition flux has no significant seasonal variation, based on the multiple trend results obtained from pooling the dry and wet deposition data. The average dry deposition flux of As ranged from 34 to 161 μg/m 2 -month during the sampling year, and had the opposite trend to the wind speed. Additionally, the correlations between atmospheric arsenic concentration and PM levels were significant, supported by the low p-value (< 0.01) at a 99% confidence level. Meanwhile, the highly linear correlation between As and PM concentrations was also evaluated. The amount of precipitation was statistically correlated to the wet deposition flux (11.3-414 μg/m 2 -month with a p-value = 2 × 10 -7 and r-value = 0.9306. Furthermore, the composition of the As mass concentrations in ambient air were dominated by As (V) in both fall (66.4%) and winter (68.9%). According to the GIS spatial analysis of the As concentration in the dry season, from October to March, the As contribution of local emissions were not significant. Consequently, this study indicates that the atmospheric As around Chiayi County might be sourced from the upwind northern area, and mainly deposited through wet scavenging.

“…Combustion sources possess highbred concentrations, huge flow rates of stack flue gases and in great numbers, revealing that they are not only major PCDD/F emission sources, but also important PBDE emitters to the atmosphere . But not like PCDD/Fs, comprehensive research have been conducted into their important sources, such as waste incinerators (Wang et al, 2003b;Lin et al, 2010a;Wang et al, 2010d), iron ore sintering (Wang et al, 2003c;Wang et al, 2008b), power plants (Lin et al, 2007;Lin et al, 2010b;Wang et al, 2010e;Wu et al, 2010), boilers (Chen et al, 2011), electric arc furnaces (EAFs) (Lee et al, 2004;Lee et al, 2005;Wang et al, 2010c;Chiu et al, 2011), secondary aluminum smelters (ALS) (Lee et al, 2005;, crematories (Wang et al, 2003a), vehicles (Chuang et al, 2010a;Chuang et al, 2010b), and the open burning of rice straw (Lin et al, 2007) and wood (McNamara et al, 2011). Furthermore, intensive studies have conducted to identify the formation mechanisms of PCDD/Fs that occur within the combustion system.…”

Section: Introductionmentioning

confidence: 99%

Thermal Formation of Polybrominated Diphenyl Ethers in Raw and Water-Washed Fly Ash

Artha

Wang

et al. 2011

Self Cite

To the best of our knowledge, the formation mechanisms of PBDEs in the combustion system, fly ash, as well as their relation with temperature, have never been investigated. In this study, the formation mechanisms of PBDE soccurring in the processes of heating fly ash have been investigated using a laboratory furnaceand graphite crucibles in order to clarify the effects of temperature. A dramatic increase in total PBDE content in the heated water-washed fly ash (3.33 ng/g) occurred, 17.7 times higher than that of the unheated one (0.188 ng/g), when the heating temperature reached 400°C. We speculate that at this temperature, PBDEs form through de novo synthesis as well as heterogeneous solid-phase reactions of the precursor mechanisms. Another dramatic increase in PBDE content in the water-washed fly ash occurred in the range 650°C-850°C, due to the enormous amounts of brominated aromatic precursors that are formed, and then condensed or are adsorbed onto the surface of the fly ash during the cooling down to 400°C, where PBDEs form through de novo synthesis and precursor mechanisms. The raw fly ash contains more alkaline compounds such as sodium and calcium compounds than the water-washed fly ash, which are inhibitors for the formation of precursors and PBDEs. Consequently, the water-washed fly ash has much greater PBDE formation potential than the raw fly ash.