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Autotrophic Biological Denitrification for Complete Removal of Nitrogen from Septic System Wastewater
2006
Sengupta, Sukalyan | Ergas, Sarina J | Lopez-Luna, Erika | Sahu, Asish K | Palaniswamy, Kumaravel
The overall objective of this research was to develop a reliable, robust, and maintenance-free passive system for biological denitrification in on-site wastewater treatment systems. The process relies on sulfur oxidizing denitrifying bacteria in upflow packed bioreactors. Since this process consumes alkalinity, it is necessary to add a solid-phase buffer that can scavenge the H⁺ as it is generated by the biologically-mediated reaction and arrest the drop in the pH value. This study investigated the use of limestone, marble chips and crushed oyster shell as solid-phase buffers that provide alkalinity. Two bench-scale upflow column reactors and two field-scale bioreactors were constructed and packed with sulfur pellets and an alkalinity source. The pilot scale bioreactors (~200 L each) were installed at the Massachusetts Alternative Septic System Test Center (MASSTC) in Sandwich, MA. The pilot-scale bioreactors performed better when oyster shell was used as the solid-phase buffer vis-à-vis marble chips. In both (pilot-scale and laboratory-scale) systems, denitrification rates were high with the effluent NO₃ - --N concentration consistently below 8 mg/L.
Show more [+] Less [-]Algological research of the Slatina and the Pecena Slatina near Opovo (Vojvodina) [Serbia]
2006
Subakov-Simic, G. (Univerzitet u Beogradu, Beograd (Serbia). Bioloski fakultet), E-mail: gsubak@bfbot.bg.ac.yu | Karadzic, V. (Institut za zastitu zdravlja Republike Srbije Dr Milan Jovanovic Batut, Beograd (Serbia)) | Fuzinato, S. (Univerzitet u Beogradu, Beograd (Serbia). Bioloski fakultet) | Fodora, A. (Univerzitet u Beogradu, Beograd (Serbia). Bioloski fakultet) | Cvijan, M. (Univerzitet u Beogradu, Beograd (Serbia). Bioloski fakultet)
The puddles Slatina and Pecena Slatina are the old meanders of the river Tamis. These ecosystems are periodicity fill with moderate salt and high alkaline water. The paper gives a review of qualitative and quantitative analysis of the algal compositions. Cyanoprokaryota and Euglenophyta are more common. All investigated parameters like compositions of lagal communities, their abundace, biomass and chlorphyll-a showed a high level of nature eutriphication in these ecosystems.
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