Elimination of NH3 and odor from composting by biotrickling filter and preliminary exploration on molecular biology

Abstract

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.

Treatment of real high-concentration dyeing wastewater using a coagulation-hydrolysis acidification-multilevel contact oxidation system

“…Coagulation was the main physicochemical process in our system. In coagulation, ammonia was mainly adsorbed on the surface or at the internal structure of the flocs, and then removed from the water phase as the flocs settled down [18]. Ammonia removal during biological treatment was important in meeting the discharge standards [20].…”

“…Modification of existing processes to achieve higher pollutant removal efficiency is also significant. Contact oxidation process, which is widely used in China for its ability to remove large amount of COD and ammonia , is a kind of activated sludge process modification. In addition, contact oxidation process is easily implemented by adding different suspended or fixed carriers into the activated sludge reactor to improve pollutant removal efficiency.…”

Waste Gas Biofiltration: Advances and Limitations of Current Approaches in Microbiology

“…As in other environmental biotechnologies, the use of fingerprinting techniques such as DGGE, complemented by clone libraries and sequencing, is common to explore the composition, phylogeny and spatial distribution of microbial communities ,,,− that often degrade single-compound and, infrequently, mixed , waste gas streams. The study of increasingly mixed feeds, which are more likely to be treated with greater efficacy by complex microbial communities, will mandate the application of more sophisticated and powerful tools.…”

Effective utilisation of trickling liquid discharged from a bio-trickling filter as a moisture conditioning agent for composting

“…Secondly, given that nitrifying bacterial activity is inhibited at >40 C ambient temperature, the negative impact of this activity caused by the high temperature of exhausting compost odour can be reduced by the recirculation and intermittent discharge of TL . Therefore, studies on the treatment of NH 3 in air streams by bio-trickling filters have increased (Xue, Wang, Wu, Zhang, & Xie, 2010;Xue, Wang, Wu, Zhao, & Xie, 2011). However, the accumulation of nitrogen-containing metabolites and nitrogen species in the TL following long-term operation may result in negative effects on nitrifying bacteria and diminish the efficiency of a bioreactor (Baquerizo et al, 2005;Chen, Yin, & Wang, 2005;Smet, Van, & Maes, 2000;).…”