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Assessment of Luffa cylindrica as Support in Biofilms Reactors for the Biological Treatment of Domestic Wastewater
2009
Ruiz-Marín, Alejandro | Campos-Garcia, Silvia | Zavala-Loría, José | Solana, Fernando | Canedo-López, Yunuen
A simultaneous treatment of BOD, phosphorous and ammonia in artificial wastewater was carried out in biofilm reactors with Luffa cylíndrica as organic support and compared with PVC's support under variations of dissolved oxygen of 1.5 a 3.0 mg l⁻¹ in the same reactor. During semicontinous treatment, the removal of BOD (92.5%) with Luffa cilíndrica was higher than PVC support (80%). Nitrification only existed at levels of oxygen of 3 mg l⁻¹, showed in the effluent a final concentration of ammonium of 17 and 19 mg l⁻¹ for Luffa cilíndrica and PVC support, respectively. In reactors with Luffa cilíndrica a higher percentage of P removal (40%) was reached, while no elimination in reactors with PVC was observed. The formation of anaerobic-aerobic zones inside the natural support probably allowed the increase in the efficiency of removal of phosphorous. Oxidation of organic matter, P removal and nitrification can be achieved with the variation of oxygen inside of the same biofilm reactor using L. cylindrical as support material.
Show more [+] Less [-]Nitrogen Budget and Ammonia Volatilization in Paddy Fields Fertilized With Liquid Cattle Waste
2009
Zhou, Sheng | Nishiyama, Kotoha | Watanabe, Yoichi | Hosomi, Masaaki
A study was conducted to determine nitrogen budget and ammonia volatilization in Japanese paddy fields supplemented with liquid cattle waste (LCW). A series of four, 2 x 10 m experimental plots was established in a paddy field with silty clay soil planted with forage rice (Oryza sativa L.). In addition to 195 kg N ha⁻¹ of chemical or compost-based basal fertilizer, LCW was applied as an additional fertilizer at total nitrogen rates of 0, 255, 255, and 405 kg N ha⁻¹ to the four plots C195, T450-1, T450-2, and T600, respectively. The mass balance showed that after application of LCW, 32-39% of total input nitrogen was assimilated into aboveground parts of rice plants, 11-15% leached downward, 2.5-4.0% was lost via ammonia volatilization, 1.6-5.1% was retained in roots or was adsorbed onto soil, and approximately 30-40% was lost via denitrification. Compared to animal waste slurries applied to unsaturated soils, nitrogen loss via ammonia volatilization was relatively lower, probably due to the dilution effect of floodwater. Nitrogen loss via denitrification was markedly higher in areas where LCW was applied compared to areas without LCW application. On the other hand, nitrogen leaching downwards represented a substantial loss and may be an environmental concern. However, after LCW application only, the ammonium ion was detected, at a maximum nitrogen concentration of 11.4 mg L⁻¹. In this system, therefore, nitrogen has a different fate to that in animal waste slurries applied to unsaturated soil. In that situation, the major nitrogen form in leaching water is nitrate nitrogen, which moves readily into groundwater.
Show more [+] Less [-]Trends of Livestock-related NH₃, CH₄, N₂O and PM Emissions in Greece
2009
Sidiropoulos, Christos | Tsilingiridis, George
It is well established that the livestock sector is a major contributor to greenhouse gases (GHG) and ammonia (NH₃) emissions. In this paper, the evolution of livestock NH₃, methane (CH₄), nitrous oxide (N₂O) and particulate matter (PM) emissions is presented for the period 1960-2005 in Greece and the factors influencing the emission fluxes (such as livestock population changes, manure management systems in use) are examined and analyzed. Emission estimates are based on the updated EMEP/CORINAIR methodology together with the revised IPCC guidelines; newly published, Greece-specific emission factors are used. The emissions level from livestock is evaluated and compared with the corresponding emissions from other anthropogenic sources in Greece. Geographical analysis concerning the distribution of animals and the subsequent NH₃ emissions is performed. Main results indicate high levels of emissions from 1960 to 1995, while emissions from 1995 to 2005 show a stabilizing trend.
Show more [+] Less [-]Ammonia Emission from a Young Larch Ecosystem Afforested after Clear-Cutting of a Pristine Forest in Northernmost Japan
2009
Hayashi, Kentaro | Takagi, Kentaro | Noguchi, Izumi | Fukuzawa, Karibu | Takahashi, Hiroyuki | Fukazawa, Tatsuya | Shibata, Hideaki | Fujinuma, Yasumi
The present study aimed to elucidate the atmosphere-forest exchange of ammoniacal nitrogen (NHX-N) at a young larch ecosystem. NHX-N exchanges were measured at a remote site in northernmost Japan where 4-year-old larches were growing after a pristine forest had been clear-cut and subsequent dense dwarf bamboo (Sasa) had been strip-cut. The site was a clean area for atmospheric ammonia with mean concentrations of 0.38 and 0.11 μg N m⁻³ in snowless and snow seasons, respectively. However, there was a general net emission of NHX-N. The annual estimated emission of NHX-N of 4.8 kg N ha⁻¹ year⁻¹ exceeded the annual wet deposition of 2.4 kg N ha⁻¹ year⁻¹, but the weekly exchange fluxes may have been underestimated by 28-60%. The main cause of the ammonia loss from the young larch ecosystem was probably enhanced nitrogen supply stimulated by the cutting of the pristine forest and Sasa, in particular, the Sasa.
Show more [+] Less [-]Simultaneous SO₂ Removal by Wastewater with NH₃
2009
Ipek, Ubeyde | Ekinci, Mehtap | Arslan, E Isıl | Cuci, Yakup | Hasar, Halil
Sulfur dioxide (SO₂) is basically resulted from emission of fossil fuel. The ammonia washing is of methods used to remove SO₂ from fuel gas. Several wastewaters contain high ammonia concentrations causing the various problems at wastewater treatment or receiving environment. The synthetic wastewater containing NH₃ was sprayed down as flue gas moved up in the scrubber so that it could be a reaction between SO₂ and NH₃. The effect of NH₃ concentration and pH on SO₂ removal was determined. SO₂ was decreased from about 1,000 to 0, 36, 49 and 66 ppm at NH₃ concentrations of 328, 88, 32 and 9 mg l⁻¹, respectively. While SO₂ of 1,000 ppm was completely treated at 328 mg NH₃ l⁻¹, pH was around 7.16 at the end of process. Consequently, it was recognized that this process could be used for both the SO₂ removal and the wastewater neutralization.
Show more [+] Less [-]Reduction of nitrogen loss and Cu and Zn mobility during sludge composting with bamboo charcoal amendment
2009
Hua, Li | Wu, Weixiang | Liu, Yuxue | McBride, Murray B. | Chen, Yingxu
Background, aim, and scope Composting is an effective treatment process to realize sludge land application. However, nitrogen loss could result in the reduction of nutrient value of the compost products and the stabilization effect of composting on heavy metal concentration and mobility in sludge has been shown to be very limited. Materials and methods Laboratory-scale experiments were carried out to investigate the effects of bamboo charcoal (BC) on nitrogen conservation and mobility of Cu and Zn during sludge composting. Results The result indicated that the incorporation of BC into the sludge composting material could significantly reduce nitrogen loss. With 9% BC amendment, total nitrogen loss at the end of composting decreased 64.1% compared with no BC amendment (control treatment). Mobility of Cu and Zn in the sludge may also have been lessened, based on the decline in diethylenetriaminepentaacetic acid-extractable Cu and Zn contents of composted sludge by 44.4% and 19.3%, respectively, compared to metal extractability in the original material. Discussion Ammonia adsorption capability of BC might be the main reason for the retention of nitrogen in sludge composting materials. Decrease of extractable Cu²⁺ and Zn²⁺ in the composting material mainly resulted from the adsorption of both metals by BC. Conclusions Incorporation of BC into composting material could significantly lessen the total nitrogen loss during sludge composting. Mobility of heavy metals in the sludge composting material could also be reduced by the addition of BC. Recommendations and perspectives Bamboo charcoal could be an effective amendment for nitrogen conservation and heavy metal stabilization in sludge composts. Further research into the effect of BC-amended sludge compost material on soil properties, bioavailability of heavy metals, and nutrient turnover in soil needs to be carried out prior to the application of BC-sludge compost in agriculture.
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