RESUMEN
A biotrickling filter was focused on treatment of odorous NH(3) gas, along with volatile organic compounds (VOCs) and other odorous gases during cattle manure composting. The biotrickling filter could treat NH(3), the main composition, with removal efficiencies of close to 100% because NH(4)(+) was bio-oxidized in the biofilm to NO(3)(-) resulting final NO(3)(-) concentrations of about 1000 mg/L. Results of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) revealed that ammonia-oxidizing bacteria, Nitrosospira sp, and nitrite-oxidizing bacteria, Nitrococcus mobilis, coexisted in the biofilm. There were 23 kinds of VOCs detected in the exhaust gas. A significant observation was that the biofilm itself of the biotrickling biofilter released VOCs. The odor concentrations of inlet and outlet gases were 1425 and 110, respectively, with removal efficiency of 92.2%, suggesting that the biotrickling filter was effective for treatment of odorous gases during composting.
Asunto(s)
Amoníaco/aislamiento & purificación , Bacterias/genética , Bacterias/metabolismo , Filtración/métodos , Biología Molecular , Odorantes , Suelo/química , Amoníaco/química , Amoníaco/metabolismo , Animales , Biodegradación Ambiental , Bovinos , ADN Bacteriano/genética , Concentración de Iones de Hidrógeno , Nitrificación , Nitrógeno/química , Reacción en Cadena de la Polimerasa , Compuestos Orgánicos Volátiles/aislamiento & purificación , Compuestos Orgánicos Volátiles/metabolismoRESUMEN
A pilot biotrickling filter (BTF) packed with ZX02 fibrous balls as packing material was tested for the treatment of ammonia (NH(3)) released from a composting plant of dairy manure. In order to investigate the effects of three compost aeration modes (mode Co-I, Co-II and In-II) on the NH(3) removal efficiency, a field experiment was continuously carried out for more than eight months. The results demonstrated that under the intermittent aeration mode (In-II), the NH(3) removal efficiency reached 99.2±0.1% when the inlet NH(3) concentration was 7.5-32.3mg m(-3) (9.8-42.5ppmv). The maximum and critical elimination capacity of the biotrickling filter was 22.6 and 4.9g NH(3)m(-3)h(-1), respectively. The effluent concentration of NH(3) was lower than 1.0mg m(-3), which meets the first class discharge standards of GB14554-93. When the concentration of free ammonia in the trickling liquid was varied from 0.1 to 0.4mg L(-1), the nitrification yield was between 47.9% and 103.8%. In addition, the optimum liquid tricking velocity (LTV) of the biotrickling filter was 0.5m(3)m(-2)h(-1) for low inlet concentrations and 2.2m(3)m(-2)h(-1) for high inlet concentrations. Therefore, the use of the biotrickling filter for the compost under the third aeration mode (In-II) yielded an effective optimum NH(3) removal and reduced the nitrogen loss in the compost.