Odorous Compound Removal Performance and Water Properties of a Biotrickling Filter Installed in a Piggery

Highlights We evaluated the performance of a two-stage biotrickling filter in a pig facility. A short empty bed residence time lowered the secondary filter removal efficiency for many odorous compounds. The removal efficiency of some compounds increased when the pH in the secondary water tank decreased. Low-odor-threshold compounds such as MT, n-BA, n-PA, and p-cresol were indicated as targets for optimization. Abstract . Odor is a major problem in pig production, and it is important to minimize odor emissions. To determine the factors influencing variations in odor removal efficiency, we analyzed the performance of a biotrickling filter installed in growing-finishing pig rooms on a commercial farm. Over 16 months, we conducted measurements of representative odorous compounds, namely sulfur compounds (hydrogen sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide), volatile fatty acids (propanoic acid, 2-methylpropanoic acid, butanoic acid, 3-methylbutanoic acid, and pentanoic acid), and ammonia. The average removal efficiencies of methanethiol, dimethyl disulfide, volatile fatty acids, and ammonia were 83% to 89%, with 50% for hydrogen sulfide and 18% for dimethyl sulfide. For many, but not all, odorous compounds, removal efficiency declined significantly with decreasing empty bed residence time (EBRT). From an analysis of the correlations of odorous compounds’ removal efficiency with the properties of the trickling water, we hypothesized that water properties such as pH, free ammonia, free nitrous acid, ionic species (Na+, Ca2+) concentrations, temperature, electrical conductivity, and biological oxygen demand, in addition to EBRT, were associated with fluctuations in removal efficiency during full-scale operation. The pH in the secondary water tank was negatively correlated with the removal efficiencies of methanethiol, dimethyl sulfide, butanoic acid, 3-methylbutanoic acid, pentanoic acid, and ammonia. Our identification of key odorous compounds indicates the importance of the secondary filter in odor treatment. Biotrickling filters for air in pig facilities could be further optimized by targeting low-odor-threshold compounds such as methanethiol, butanoic acid, pentanoic acid, and p-cresol, in addition to ammonia. Keywords: Ammonia, Biotrickling filter, Pig facility odor, Sulfur compound, Trickling water, Volatile fatty acid.

Preparation and Evaluation of a Composite Filler Micro-Embedded with Pseudomonas putida for the Biodegradation of Toluene : Preparation of composite filler with high toluene removal efficiency

The main objective of this study was to evaluate the performance of a self-developed filler micro-embedded with Pseudomonas putida (P. putida) for toluene removal in a biofilter under various loading rates. The results show that the biofilter could reach 85% removal efficiency (RE) on the eighth day and remain above 90% RE when the empty bed residence time (EBRT) was 18 s and the inlet loading was not higher than 41.4 g m−3 h−1. Moreover, the biofilter could tolerate substantial transient shock loadings. After two shut-down experiments, the removal efficiency could be restored to above 80% after a recovery period of three days and six days, respectively. Sequence analysis of the 16S rRNA gene of fillers in four operating periods revealed that the highly efficient bacterial colonies in fillers mainly included Firmicutes, Actinobacteria and Proteobacteria and that the abundance of Bacteroidetes increased significantly during the re-start period.

Effects of n-butanol presence, inlet loading, empty bed residence time and starvation periods on the performance of a biotrickling filter removing cyclohexane vapors from air

This paper presents the results of investigations on the removal of cyclohexane vapors from air using a peat-perlite packed biotrickling filter. Effects of basic process parameters i.e. inlet loading and empty bed residence time as well as introduction of n-butanol to the treated air stream and starvation periods on the process performance were evaluated. The results show that the introduction of hydrophilic n-butanol results in an enhanced removal of hydrophobic cyclohexane comparing to the experiments where only cyclohexane was treated. Additionally, the biotrickling filter performance after the starvation events is regained to more extent for mixed system than for the single cyclohexane. A novel and interesting element of the paper is the application of an electronic nose for the process monitoring. Obtained results are discussed in the perspective of an influence of the presence of a compound with different affinity to aqueous phase on the removal efficiency of the compound with opposite chemical properties.

Bacterial community diversity in a full scale biofilter treating wastewater odor

Constantly, the odors coming from sewage plants are considered a problem by the population. The purpose of this study was to evaluate the microbial community present in a full scale biofilter used for odor treatment. The filter was packed with peat. The main gas treated was hydrogen sulphide (H2S). The removal efficiency reached 99%, with an empty bed residence time of 30 seconds. Molecular analysis can enhance our understanding of the microbial communities in biofilters treating wastewater odor. The analysis made to characterize microbial community was High-throughput 16S rRNA sequencing analysis MiSeq® Illumina. The sampling, carried out in the year 2015, was seasonal (summer and winter) and spatial (depth and position in the biofilter). In this study, a total of 206,174 raw sequence reads for six samples were analyzed using Mothur software (v 1.33.3) based on MiSeq SOP protocol. After Mothur analysis, the results of the bacterial community were explored at the Phylum and Genus levels. In this study, the efficiency removal of hydrogen sulfide reached values greater than 99% during the monitoring, and the main bacterial genera found were Acidotermus, Telmatobacter, Methylovirgula and Bryobacter representing the bacterial community active in the transformation of H2S into a system with long operating time.

ADSORPTION OF FLUORIDE FROM INDUSTRIAL WASTEWATER IN FIXED BED COLUMN USING JAVA PLUM (SYZYGIUM CUMINI)

ABSTRACTObjective: The quality of drinking water is important for public safety and quality of life. Thus, providing every person on earth safe drinking waterseems to be the biggest challenge in front of mankind. For this purpose, here we have investigated the fluoride removal capacity of java plum.Methods: In this study, removal of fluoride from industrial wastewater using fixed-bed reactor adsorption techniques by java plum seed (Syzygiumcumini) was investigated. Fixed-bed column experiments were carried out for different bed depths, influent fluoride concentrations, and various flowrates. The Thomas model and bed depth service time model were applied to the experimental results. Both model predictions verify the experimentaldata for all the process parameters studied, indicating that the models were suitable for java plum (S. cumini) seeds (Biosorbent) fix-bed columndesign.Results: The empty bed residence time (EBRT) model optimizes the EBRT, and the Thomas model showed that the adsorption capacity is stronglydependent on the flow rate, initial fluoride concentration, and bed depth and is greater under conditions of a lower concentration of fluoride, lowerflow rate, and higher bed depth.Conclusion: The experimental results were encouraging and indicate that java plum (S. cumini) seed is a feasible option to use as a biosorbent toremove fluoride in a fixed bed adsorption process.Keywords: Adsorption, Column experiment, Thomas model, Empty bed residence time, Java plum.

TREATMENT OF FLUORIDE BEARING CONTAMINATED WATER USING SIMULTANEOUS ADSORPTION AND BIODEGRADATION IN A LABORATORY SCALE UP: FLOW BIO-COLUMN REACTOR BY JAVA PLUM SEED

ABSTRACTObjective: Here, we aimed for the treatment of fluoride bearing contaminated water using simultaneous adsorption and biodegradation in a biocolumnreactor by using java plum seed.Methods: We immobilized Acinetobacter baumannii bacteria on the java plum seed in the bio-column reactor. The water used contained a sample offluoride with concentration of 20 mg/L. The bed depth service time design model and empty bed residence time were used to analyze the performance thebio-column. We examined and observed closely the effect of different operating parameters such as flow rate of bed depth and initial concentration on thissimplified bio-column reactor design model. Desorption experiment was conducted to evaluate the possibilities of regeneration and to reutilize of media.Results: We observed that the bio-column reactor is capable to reduce the concentration of the pollutants in the effluent water below their permissiblelimit. Reduction in DO along the bed height of the reactor was also observed, which supports the aerobic nature of the bacteria.Conclusion: The experimental results were encouraging and indicate that java plum (Syzygium cumini) seed is a feasible option to use as a biosorbentto remove fluoride in the bio-column reactor.Keywords: Bio-reactor, Simultaneous adsorption and biodegradation, Flow rate, Acinetobacter baumannii MTCC 11451, Physicochemical adsorption,Bed depth service time, Empty bed residence time.

Styrene Removal from Polluted Air in Biotrickling Filter with Pyrocarbon-Sawdust and Ceramic-Raschig-Rings-Sawdust Packings

In this paper, a mixed microbial population biotrickling filter (BTF) was investigated for styrene removal with two different packings at different empty bed residence times and gas-liquid ratio(GLR). The two biotrickling filters inoculated with a Pyrocarbon-sawdust and ceramic-raschig-rings-sawdust mixed packings were filled respectively in two identical laboratory-scale biotrickling filters which were operated in parallel. The results showed that the BTF filling with pyrocarbon-sawdust packings had higher rate of bio-film formation and removal efficiency of styrene than that of ceramic-raschig-rings-sawdust packings. When an inlet gas concentration of 50 to 450 mg/m³, an Empty Bed Residence Time (EBRT) of 21.6 to 43.2 s, and a gas-liquid ratio (GLR) of 110.7 to 55.3, a maximum styrene removal load is up to 153.1 g/(m³·h). During shock-load experiments with shutdown, the styrene removal efficiency of the BTF could gradually reach 92 % to 100 % by 14 h.

Performance and biofilm characteristics of a gas biofilter for n-hexane removal at various operational conditions

The effects of operational parameters including nitrate concentration,n-hexane inlet concentration and gas empty bed residence time (EBRT) on long-term removal performance ofn-hexane were discussed.

Removal of Ethanethiol Gas by Iron Oxide Porous Ceramsite Biotrickling Filter

The performance of ethanethiol removal in biotrickling filter was investigated by microorganisms fixed on iron oxide-based porous ceramsite (IPC) under different operating parameters conditions. Ethanethiol removal efficiency was examined as a function of inlet concentration, empty bed residence time (EBRT), and spray density of nutrient solution. The results showed that the optimized operation conditions and operation characteristics of biotrickling filter for this study were at the inlet concentration of less than 250 mg·m−3, the spray density of 0.24 m3·m−2 h−1, and the EBRT of 68.7 s. The variation of the EBRT of about 100 s and the spray density of about 0.24 m3·m−2 h−1did not change the ethanethiol removal efficiencies at certain ethanethiol concentrations of less than about 300 mg/m3, respectively. The main metabolic product was sulfate such asSO42-under continuous long-running regime in filter. The ethanethiol desulfurization process better meets the Michaelis-Menien model with calculated kinetic degradation parametersKs=7.96 mg·m−3andVm=221.73 g·m−3 h−1.

Treatment of Chlorobenzene-Contaminated Gas Stream in a Biotrickling Filter Inoculated with Ralstonnia pickettii L2

Biotrickling filter (BTF) inoculated with Ralstonniapickettii L2 was established to treat waste gas containing chlorobenzene (CB). Results revealed BTF could achieve more than 80% removal efficiency of CB under the conditions of <0.6 g·m-3inlet concentration and >30 s empty bed residence time (EBRT). The mass ratio of carbon dioxide produced to the mixture of benzene, toluene, and oxylene (BTo-X) removed was approximately 2.10, indicating that 89.5% mineralization of the incoming CB vapor. The degradation of CB in the BTF followed Michaelis-Menten kinetic model, and the maximum specific degradation rate (rmax) was 76.3g·m-3·h-1. AWCD values indicated that the microganisms in the BTF showed the high microbial metabolic activities. Real-time PCR indicated that Ralstoniapickettii L2 could still maintain its stability andactivity in the BTF under different conditions.