Nanh Lovanh

The effect of stratification and seasonal variability on the profile of an anaerobic swine waste treatment lagoon.

In this study, the characterization of an anaerobic swine waste treatment lagoon from a farrowing operation (approximately 2000 sows) was carried out to examine the dynamics of the system due to stratification and seasonal variability. Swine waste samples were taken at different depths with a pulley system equipped with a special sampler that allows for sampling exclusively at certain depth. Chemicals and microbial dynamics were monitored throughout a one-year-period. Results showed that nutrient (C, N, P, S) concentrations varied according to stratified lagoon layers and season. Trace minerals (Al, Ca, Fe, and Mg), on the other hand, appeared to be affected more by stratification than seasonal variability. Molecular analysis also showed that microbial community structure appeared to be affected by the stratification and seasonal variability. Based on these data, it is important to consider the effect of stratification and seasonal variability in managing these open lagoons.

Determination of ammonia and greenhouse gas emissions from land application of swine slurry: A comparison of three application methods

In this study, the comparison and monitoring of the initial greenhouse gas (GHG) emissions using a flux chamber and gas analyzer from three different liquid manure application methods at a swine farm in Kentucky were carried out. Swine slurry was applied to farmland by row injection, surface spray, and Aerway injection. Ammonia and GHG concentrations were monitored immediately after application, 72 and 216h after application. The results showed that the initial ammonia flux ranged from 5.80 mg m(-2)h(-1) for the surface spray method to 1.80 mg m(-2)h(-1) for the row injection method. The initial fluxes of methane ranged from 8.75 mg m(-2)h(-1) for surface spray to 2.27 mg m(-2)h(-1) for Aerway injection, carbon dioxide ranged from 4357 mg m(-2)h(-1) for surface spray to 60 mg m(-2)h(-1) for row injection, and nitrous oxide ranged from 0.89 mg m(-2)h(-1) for surface spray to 0.22 mg m(-2)h(-1) for row injection. However, the Aerway injection method seemed to create the highest gas (GHG) concentrations inside the monitoring chambers at the initial application and produced the highest gas fluxes at subsequent sampling time (e.g., 72h after application). Nevertheless, the surface spray method appeared to produce the highest gas fluxes, and the row injection method appeared to emit the least amount of greenhouse gases into the atmosphere. Gas fluxes decreased over time and did not depend on the initial headspace concentration in the monitoring flux chambers.

Equilibrium Sampling Used to Monitor Malodors in a Swine Waste Lagoon

The concentrations of malodorous compounds in a 0.4-ha anaerobic lagoon that received waste from approximately 2000 sows were monitored during the late summer to late fall of 2006 to gain insight into the factors influencing their concentrations. Selected malodorous compounds were measured by the use of equilibrium samplers consisting of submersible stir plates and stir bar sorbtive sampling with polydimethylsiloxane-coated magnetic stir bars. During the same period, air and water temperatures, suspended solids, total organic carbon and nitrogen content, and wastewater pH were recorded. Concentrations of malodorous compounds were higher at the surface of the lagoon than at the middle or bottom of the lagoon. Skatole concentration, for instance, averaged 54, 24, and 38 microg L(-1) near the surface, in the middle, and at the lowest sampling depths, respectively. While the lagoon was being pumped down during field application of wastewater, concentrations of malodorous compounds fluctuated widely, increased 16-fold as compared with the sampling period before pumping, and continued to increase as fall progressed and temperatures cooled. Suspended solids, volatile suspended solids, and total organic carbon increased near the bottom of the lagoon during this same period. The increases in the concentrations of malodorous compounds in the wastewater during the fall could have been due to a combination of several factors. These factors include reduced degradation by lagoon bacteria, less wind stripping of volatile compounds from the lagoon surface due to lowering of the lagoon surface after crop application, and/or reduced evaporation of malodorous compounds due to falling temperatures.

Development of a Quantitative Real-Time Polymerase Chain Reaction Assay to Target a Novel Group of Ammonia-Producing Bacteria Found in Poultry Litter

Ammonia production in poultry houses has serious implications for flock health and performance, nutrient value of poultry litter, and energy costs for running poultry operations. In poultry litter, the conversion of organic N (uric acid and urea) to NH(4)-N is a microbially mediated process. The urease enzyme is responsible for the final step in the conversion of urea to NH(4)-N. Cloning and analysis of 168 urease sequences from extracted genomic DNA from poultry litter samples revealed the presence of a novel, dominant group of ureolytic microbes (representing 90% of the urease clone library). Specific primers and a probe were designed to target this novel poultry litter urease producer (PLUP) group, and a new quantitative real-time PCR assay was developed. The assay allowed for the detection of 10(2) copies of target urease sequences per PCR reaction (approximately 1 x 10(4) cells per gram of poultry litter), and the reaction was linear over 8 orders of magnitude. Our PLUP group was present only in poultry litter and was not present in environmental samples from diverse agricultural settings. This novel PLUP group represented between 0.1 to 3.1% of the total microbial populations (6.0 x 10(6) to 2.4 x 10(8) PLUP cells per gram of litter) from diverse poultry litter types. The PLUP cell concentrations were directly correlated to the total cell concentrations in the poultry litter and were found to be influenced by the physical parameters of the litters (bedding material, moisture content, pH), as well as the NH(4)-N content of the litters, based on principal component analysis. Chemical parameters (organic N, total N, total C) were not found to be influential in the concentrations of our PLUP group in the diverse poultry litters Future applications of this assay could include determining the efficacy of current NH(4)-N-reducing litter amendments or in designing more efficient treatment protocols.

Evaluation of nitrogen retention and microbial populations in poultry litter treated with chemical, biological or adsorbent amendments

Poultry litter is a valuable nutrient source for crop production. Successful management to reduce ammonia and its harmful side-effects on poultry and the environment can be aided by the use of litter amendments. In this study, three acidifiers, two biological treatments, one chemical urease inhibitor and two adsorber amendments were added to poultry litter. Chemical, physical and microbiological properties of the litters were assessed at the beginning and the end of the experiment. Application of litter amendments consistently reduced organic N loss (0-15%) as compared to unamended litter (20%). Acidifiers reduced nitrogen loss through both chemical and microbiological processes. Adsorbent amendments (water treatment residuals and chitosan) reduced nitrogen loss and concentrations of ammonia-producing bacteria and fungi. The use of efficient, cost-effective litter amendments to maximum agronomic, environmental and financial benefits is essential for the future of sustainable poultry production.

Evaluation of second-generation multistage wastewater treatment system for the removal of malodors from liquid swine waste.

Wastewater quality and malodors in a second generation implementation of environmentally superior technology (EST) were monitored over three cycles of pig (Sus scrofa) production and 15 mo. The wastewater treatment system consisted of three modules: solids separation, biological N removal, and P recovery/wastewater disinfection. While approximately more than 90% of the wastewater suspended solids were removed in the first stage of treatment, little reduction in malodorous compounds occurred, indicating that malodors largely remained with the liquid waste stream. The greatest improvements in wastewater quality occurred in the N treatment module where ammonium was removed through nitrification/denitrification processes: there was more than 99% reduction in aromatic malodorous compounds (e.g., p-cresol, skatole) and almost 90% reduction in volatile fatty acids (e.g., propanoate and butanoate) in N module effluent as compared to raw flushed manure. The system performed consistently well in wastewater odor removal, even during the first cycle of livestock production when system performance was being optimized. These findings showed that the combination of the processes of solids removal and biological N treatment into a practical treatment system can be very effective in reducing malodors from livestock wastewater.

Ammonia and Greenhouse Gases Emission from Land Application of Swine Slurry: A Comparison of Three Application Methods

In this study, we monitored the initial greenhouse gas emissions from three different liquid manure application methods using a flux chamber and gas analyzer at a farm in Larue County, KY. Swine slurry was applied to farm land (100 m by 300 m) that was divided into subplots. Row injection, surface spray, and aerway injection were utilized to apply the slurry. Flux chambers (38 x 102 x 10 cm) were deployed at different application plots. Ammonia and greenhouse gas (GHG) concentrations, such as methane, nitrous oxide, and carbon dioxide, were monitored using a photoacoustic gas analyzer (CAI, CA). Ammonia and GHG concentrations were monitored after application and 72 hours after application. The concentrations were measured every half an hour (broken down into 10-minute periods) with half an hour allocation for equilibrium with the atmospheric conditions. Two fans were used in the flux chamber for thorough mixing of gases before and during sampling. Gas fluxes were calculated based on Fickian diffusion. Comparison of linear and non-linear regression of calculating gas fluxes was carried out. Linear regression resulted in smaller fluxes. The results showed that the initial ammonia flux ranged from 5.80 mg/m2hr for the surface spray method to 1.80 mg/m2hr for the row injection method. The initial fluxes of methane ranged from 8.57 mg/m2hr for aerway injection to 2.10 mg/m2hr for row injection, carbon dioxide ranged from 4,337 g/m2hr for aerway injection to 55 g/m2hr for row injection, and nitrous oxide ranged from 0.89 mg/m2hr for aerway injection to 0.23 mg/m2hr for row injection. Thus the aerway injection method seemed to create the highest gas concentrations inside the monitored chambers. However, surface spray method appeared to produce the highest gas fluxes, and row injection method appeared to emit the least amount of greenhouse gases into the atmosphere. Gas fluxes decreased over time and did not depend on the initial headspace concentration in the monitoring flux chambers.

A simple device for the collection of water and dissolved gases at defined depths.

A device, consisting of a jar fitted with an inlet comprised of a gas-tight check valve and two-way ball valve outlet connected via tubing to a portable peristaltic pump, was constructed to collect water samples without atmospheric contamination or loss of dissolved gases. A headspace void for dissolved gas analysis was created by enclosing silicone tubing sealed with rubber stoppers within the jar. The device was deployed in a 0.4-ha lagoon that served as the primary waste recipient of a 2,000-sow farrowing operation as well as a 4,000-ha impoundment reservoir. Water samples were analyzed for dissolved methane and common indices of water quality such as pH, suspended solids, various ions, and metals concentration. In addition, lagoon wastewater samples were analyzed for malodorous compounds. For reservoir samples, methane concentrations at the bottom of the lake of 60 µg L-1 were about three orders of magnitude higher than at the upper levels of the lake while ammonium levels increased from 0.03 mg L-1 at the surface to 1.67 mg L-1 in bottom samples. pH steadily decreased from 8.58 near the surface to 7.47 at the bottom. Other water quality parameters such as dissolved metals were similar at each depth. For lagoon samples, ammonium concentration and malodorous compounds declined markedly as temperatures warmed. Results for both reservoir and lagoon sampling indicate that this device affords an inexpensive yet effective means of water collection for subsequent analysis of both water quality and dissolved gas concentration.

A System for Estimating Bowen Ratio and Evaporation from Waste Lagoons

A low-cost system was deployed above a swine waste lagoon to obtain estimates of Bowen ratios and characterize lagoon temperatures. The system consisted of humidity and temperature sensors and anemometers deployed above the lagoon, water temperature sensors, and a meteorological station located by the lagoon. To evaluate the system, data was analyzed from the 25th through 28th June 2007. Bowen ratios showed diurnal behavior near the lagoon surface characterized by negative values during day and positive ones at night. Latent (evaporation) and sensible heat fluxes were towards the atmosphere and the lagoon, respectively for most of the day. A diurnal cycle in atmospheric and lagoon temperatures was also observed. Furthermore, wind speeds above the lagoon were highest in the afternoon. These variations were linked to lagoon temperature stratifications which became more pronounced as wind speeds increased. Temperature stratification at the lagoon indicated increased heat exchange at the lagoons interface with the atmosphere. During the night, the stratification disappeared and temperatures in the water column were almost identical down to about 60 cm. This behavior is similar to that observed in other shallow water bodies that are fetch-limited. Lagoon heating was driven by the diurnal cycle of solar radiation and net radiation. This suggests that Bowen ratios had an inverse relationship with lagoon heating and its thermal stratification. This also indicates that there was an increase in latent heat flux and evaporation during the daytime. These results are important for characterizing the thermal behavior of the lagoon leading to a better representation of processes responsible for emissions.

Simultaneous utilization of soju industrial waste for silica production and its residue ash as effective cationic dye adsorbent

Abstract Soju industrial waste is an important biomass resource. The present study aimed to utilize soju industrial waste for silica extraction, and residual ash (RA) as a low cost adsorbent for the removal of methylene blue (MB) from aqueous solution. A high percentage of pure amorphous nanosilica was obtained from soju industrial waste ash by the acid dissolution-precipitation process. The synthesized nanosilica and the RA were characterized well using various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), and field-emission electron microscopy with energy dispersive spectroscopy (EDS). The amorphous nature of nanosilica and its 99% purity were confirmed by XRD and EDS profiles, respectively. Transmission electron microscopy (TEM) micrographs show the nano range (14–18 nm) of synthesized silica. The adsorption capacity of RA was evaluated as a function of initial dye concentration, pH, and contact time. The sorption equilibrium data were modeled with isotherms; the Langmuir isotherm model fits well with maximum monolayer adsorption capacity of 232.5 mg/g at 30°C. The adsorption kinetics was best fitted with the pseudo-second-order model, suggesting that chemisorption plays a significant role in the adsorption process. The results showed that soju industrial waste is a potential waste for silica extraction and that its byproducts are effective adsorbents.