• Journal of Environmental Health Sciences
• /
• v.33 no.4
• /
• pp.338-343
• /
• 2007

Chlorine inhibition on the denitrifing activity of activated sludge treating dairy wastewater was investigated in this study. Filamentous bulking was caused artificially by a sudden load of feed and monitored by measuring sludge volume index. In cases of the activated sludge and bulking sludge which were contacted with chlorine as $7.5\;mgCl_2/gVSS/day$ for bulking control, the decreases of specific denitrification of $32.2{\sim}40.4%\;and\;43.5{\sim}46.5%$ were shown in comparison to the control group which was not reacted with chlorine, respectively. In continuous operation, it was observed that the removal efficiency of total nitrogen was more susceptible to chlorine than the removal efficiency of total phosphorus.

• Membrane and Water Treatment
• /
• v.9 no.3
• /
• pp.163-172
• /
• 2018

This study investigated the effect of organic matter on the precipitation of struvite and calcium phosphate for phosphorus recovery from synthetic dairy wastewater. Batch precipitation experiments were performed to precipitate phosphorus from solutions containing $PO_4{^{3-}}$ and $NH_4{^+}$ by the addition of $Mg^{2+}$ and $Ca^{2+}$, separately, at varying pH, Mg/P and Ca/P molar ratios, and organic matter concentrations. Soluble total organic solids exhibited more inhibition to precipitation due to potential interaction with other dissolved ionic species involved in phosphorus precipitation. Xylan with low total acidity only exhibited significant inhibition at very high concentrations in synthetic wastewater (at up to 100 g/L). No significant inhibition was observed for Mg and Ca precipitation at relatively lower concentrations (at up to 1.2 g/L). MINTEQ simulations show that dissolved organic matter (DOM) as humic substances (HS) can cause significant inhibition even at relatively low concentrations of 0.165 g/L fulvic acid. However, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis suggested that xylan altered the crystal structure of both precipitates and had caused the formation of smaller sized struvite crystals with slightly rougher surfaces This could be due to xylan molecules adhering on the surface of the crystal potentially blocking active sites and limit further crystal growth. Smaller particle sizes will have negative practical impact because of poorer settleability.

• Korean Chemical Engineering Research
• /
• v.60 no.3
• /
• pp.423-432
• /
• 2022

Magnetic biochar produced from pyrolysis of dairy cattle manure was used to develop an effective sorbent for arsenic purification from aqueous solution. Biomass and magnetized biomass were pyrolyzed in a tube furnace with 10 ℃/min heating rate at 450 ℃ under nitrogen flow of 100 cm³/min for 2 h. Biochars were characterized by SEM-EDX, BET, XDR, FTIR, TGA, zeta potential analysis. The resultant biochar and magnetic biochar were opposed to 50-100-500 ppm As(V) laden aqueous solution. Adsorption experiments were performed by using ASTM 4646-03 batch method. The effects of concentration, pH, temperature and stirring rate on adsorption were evaluated. As(V) was successfully removed from aqueous solution by magnetic biochar due to its highly porous structure, high aromaticity and polarity. The results suggest dairy cattle manure pyrolysis is a promising route for managing animal manure and producing a cost effective biosorbent for efficient immobilization of arsenic in aqueous solutions.

• Journal of Animal Environmental Science
• /
• v.14 no.3
• /
• pp.149-158
• /
• 2008

The purpose of this study was to determine the effect of milking system type on milking center effluent production through the four seasons. Four different types of milking systems (Bucket, Pipeline, Tandem and Herringbone) were estimated, in duplicate, through the different seasons. The following conclusions can be drawn from this study. 1. The quantity of wastewater produced from Tandem and Herringbone milking systems were significantly larger than Bucket milking system (p<0.05). 2. The main wastewater production was from the washing of milking apparatus. Tandem and Herringbone milking systems produced 398.8 and $407.7{\ell}$/day of wastewater, respectively, for apparatus washing. These values were significantly higher than the other milking systems during the summer (p<0.05). 3. The average wastewater production from the various milking systems was $15.4{\ell}$/head/day. The quantity of wastewater production during summer ($16.4{\ell}$/head/day) season was higher than of the other seasons. 4. The highest level of $BOD_5$ ($906.4mg/\ell$) was produced from the washing of the parlor floor and the lowest level of $BOD_5$ ($212.4mg/\ell$) was produced from the washing of the udders of the cows. 5. The pH of dairy wastewater was in the range of $7.3{\sim}8.2$ and the average levels of $BOD_5$, COD, SS, T-N, and T-P were 731.2, 479.0, 751.6, 79.1, $14.7mg/\ell$, respectively. Following conclusions can be drawn from this experiment. The quantities of wastewater production from Bucket, Pipeline, Tandem and Herringbone milking system were 143.9, 487.9, 914.0, and $856.7{\ell}$, respectively. The average wastewater produced from the milking systems was $15.4{\ell}$/head per day. In order to effectively manage on the wastewater from milking systems, dairy farms need to consider the milking system type and farm size when determining the optimum wastewater treatment system.

• Journal of Dairy Science and Biotechnology
• /
• v.35 no.4
• /
• pp.244-248
• /
• 2017

The effects of ultrasonic (1.2~1.7 kJ/g TS) pretreatment on the solubilization of dairy and livestock sludge were separately evaluated to investigate the possibility of recycling dairy sludge as a potential source of organic carbon. Compared to other industrial wastewater and sewage sludge, dairy sludge has higher organic matter content and no toxic materials. The solubilization rates of dairy and livestock sludge, at a specific energy input of 1.7 kJ/g TS, were 14.5% and 10.6%, respectively. After the 90-minute ultrasonic treatment, the soluble COD (chemical oxygen demand) increased about 7.1 times that of the initial SCOD, at an increase rate of $0.022m^{-1}$. In comparison, the increase in soluble nitrogen, which was ~3.4 times that of the initial soluble nitrogen concentration, was much smaller than the increase in SCOD; thus, the C/N ratio increased from 4.0 to 8.7.

• Journal of Korean Society of Water and Wastewater
• /
• v.14 no.1
• /
• pp.37-44
• /
• 2000

Laboratory experiments were conducted to investigate the performances of anaerobic filters packed with ceramic tube and pall-ring media treating a dairy waste. The media packing volume was 65% of effective volume of anaerobic filter. Organics removals of anaerobic filters were maintained above 80% even at an organics loading rate of $10kgCOD/m^3/d$, and this was comparable to aerobic treatment of organic wastes. Organics removals of the ceramic tube anaerobic filters were always lower than those of the pall-ring anaerobic filters due to intrinsic physical property of ceramic tube, especially lower void space which caused to clogging and entrapment of biogas, substrate transfer limitation, and irregular evolution of biogas leading to loss of solids and biomass. This was clearly observed in higher concentration of TSS in the effluent from the ceramic tube anaerobic filter despite of higher retention capacity of TSS compared with pall-ring media. Vertical distribution of organics and solids in the filters showed above 90% of organics and solids in influent were removed below 20% of reactor height, and 50% of remaining organics and solids were removed though media packing zone. Effluent quality from the anaerobic filter was heavily depended on media itself as well as suspended biomass formed below media. It is therefore concluded that the type of media played an important role in biomass accumulation arid gas-liquid-solid separation efficiency. Type of media did not affect the start-up behaviors of the anaerobic filter, and supernatant from anaerobic digested sludge showed a good performance as a seeding materials.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.1
• /
• pp.179-186
• /
• 2010

In biological wastewater treatment, high lipid concentrations can inhibit the activity of microorganisms critical to the treatment process and cause undesirable biomass flotation. To reduce the inhibitory effects of high lipid concentrations, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor in series, was applied to synthetic dairy wastewater treatment. During 153 days of operation, the two-phase system showed stable performance in lipid degradation. In the ASBR, a 13% lipid removal efficiency and 10% double-bond removal efficiency were maintained. In the UASB, the chemical oxygen demand (COD), lipid, and volatile fatty acid (VFA) removal efficiencies were greater than 80%, 70%, and 95%, respectively, up to an organic loading rate of 6.5 g COD/l/day. No serious operational problems, such as significant scum formation or sludge washout, were observed. Protein degradation was found to occur prior to degradation during acidogenesis.

• Journal of Animal Environmental Science
• /
• v.11 no.1
• /
• pp.17-24
• /
• 2005

Aerobic sequencing batch reactor (SBR) was used to treat screened dairy wastewaters. The study examined the production of volatile organic compounds (VOCs) and volatile fatty acids (VFAs) in the aerobic SBR and raw manure effluent storage over 35 days. The reduction of total VFAs in the aerobic SBR was over $59\%$ removal than that of the raw manure. Acetic acid production in the aerobic SBR and the raw manure effluent storage were kept 138 and 286 mg/L. The propionic acid in the aerobic SBR was 1.9 mg/L, while the raw manure effluent storage was 68 mg/L, respectively. The concentrations of VOCs in the aerobic SBR reactor and effluent fill down remarkably than the raw manure storage. The results confirmed that the aerobic biological treatment is an essential requirement for minimizing odor problems.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.5
• /
• pp.155-163
• /
• 2004

The objectives of this study were to characterize the wastewater flow through the VFS, and relate this to the P removal in the VFS. A total of 68 subsurface wells (20∼40 cm below the soil surface) and 35 surface wells (0~5 cm), and the application of chloride tracer were used to investigate flow paths and soluble reactive P (SRP) removal from the 21 m wide and 33 m long VFS receiving dairy milkhouse waste. The early chloride breakthroughs in wells in the center of the VFS showed that the milkhouse waste flows preferentially down in the center of the hillslope. The locally saturated area created near the discharge pipe in the center of the VFS accelerates surface flow that contributed to rapid transport of P to the down slope area. Although VFS of 33m long eventually reduced SRP to lower than 0.2 mg/L in most cases, SRP is less effectively removed in the areas where soil saturation occurred. It is suggested that the effort to distribute the wastewater uniformly to avoid soil saturation and reduce the flow velocity need to be considered in new designs.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.4
• /
• pp.343-348
• /
• 1994

Enterobacter sp. producing -$\beta$-galactosidase with high transgalactosylation activity was isolated from dairy wastewater. The isolate had common biochemical features to E. aerogenes and E. cloacae. Enzyme production increased as the cell mass increased with optimum enzyme activity of 0.21 Unit/mg-protein (o-nitro-phenyl-$\beta$ -D-galactoside (ONPG) as substrate) until 8 hr of culture. Whole cells permeabilized by toluene were used to produce galacto-oligosaccharide. Optimum toluene concentration, temperature and pH for -$\beta$-galactosidase activity of permeabilized whole cells were 10% (v/v), $50^{\circ}C$ and 6.0, respectively. A maximum of 38% (w/w) of galacto-oligosaccharide was obtained with lactose concentration of 20% (w/w) at $40^\{\circ}C$ and pH 6.0.