• Journal of Environmental Health Sciences
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• v.19 no.3
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• pp.1-16
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• 1993

This paper describes an investigation to determine whether the activated sludge (AS) process could be used for the treatment of wastewater at the Union Carbide Coporation (UCC) plant in Seadrift, Texas. This plant presently utilizes a waste stabilization pond (WSP) system for treatment of the wastewater. The treatment system consists of an in-plant primary WSP and two off-plant WSPs (secondary and tertiary WSPs), run in series. The total hydraulic detention time of the WSP system is approximately 150 days. Several laboratory-based treatability studies have been conducted to evaluate the performace of the WSP system and the degradability of specific chemical compounds. From an additional study, it was determined that the WSP system was stressed and occasionally operating near the limit of its treatment capacity. The existing primary WSP plays an important role in the overall treatmemt system, because it not only functions as a pH and organic-strength equalization basin, but also serves as a "preconditioning" basin by fermenting high strength organic wastes to volatile organic acids for subsequent degradation in the escondary WSP. However, in view of pending RCRA legislatin conerning the "proposed organic toxicity characteristics limits" (40 CFR Part261: Federal Register, July, 1988), it is possible that the primary WSP will have to be abandoned in favor of alternative treatment options. Therefore the main purpose of this study was to perform activated sludge treatability evaluations for the development of an alternative to the existing primary WSP treatment ststem. In addition, another purpose was to determine the degradability of bis(2-chloroethyl)ether (Chlorex or CX) and benzene(BZ) in the activated sludge process. The presence of these two chemicals in the wastewater of the plant prompted the question of whatedether they could be degraded in an activated sludge system.

• Journal of the Korean GEO-environmental Society
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• v.9 no.2
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• pp.23-29
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• 2008

It has been mentioned that CSTR (Completely Stirred Tank Reactor) and UASB (Upflow Anaerobic Sludge Blanket) processes, the existing anaerobic processes, have problems in the treatment of highly concentrated particulate organic wastewater (HCPOW). Therefore, this paper discusses the treatment possibility of distillery wastewater which is a typical HCPOW using ADEPT (anaerobic Digestion Elutriated Phased Treatment) process. In the comparison of CSTR and ADEPT, ADEPT produced much higher gas than that of CSTR removing more organic matters and suspended solids in ADEPT process, ADEPT had no effect on the decrease in pH by volatile fatty acids and showed steady pH in spite of relatively short HRT. In the results of removal rate according to recycle ratios between 6Qin and 2Qin in ADEPT, 6Qin showed high removal rate during the operation time. Therefore it appears that ADEPT had an applicability for the treatment of distillery wastewater. ADEPT could be a economical process, due to the short HRT, the energy recovery by the methane production, and the utilization for carbon source of produced organic acid from the ADEPT-acid reactor.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.365-372
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• 2016

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.151-157
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• 2002

Landfill leachate is one of highly contaminated and heterogeneous wastewater. The leachate from initial landfill can be treated by anaerobic process because it contains biodegradable matters, particularly, volatile fatty acids (VFAs). However, the anaerobic treatment of leachate is generally required longer hydraulic retention time (HRT) than aerobic process and another treatment process to satisfy effluent concentration. Therefore the modification of conventional anaerobic treatment is needed. Two phase anaerobic membrane process (TPAMP) is an integrated membrane process to be able to separate anaerobic metabolism into two phase which are acidogenesis and methanogenesis for improvement of anaerobic treatment efficiency. In this study, the efficiency of TPAMP and conventional anaerobic treatment were compared in terms of HRT, effluent SCOD, VFAs Membrane used in TPAMP was the UF of capillary type with the surface area of $0.048m^2$. The average effluent SCOD of conventional anaerobic treatment was 1352 mg/L and the removal was 96 % at HRT 60 days, while in TPAMP, 927 mg/L and 98% at HRT 30 days.

• Journal of Animal Environmental Science
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• v.9 no.1
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• pp.45-56
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• 2003

$TAO^{TM}$ System is an auto-heated thermophilic aerated digestion process using a proprietary microbe called as a Phototropic Bacteria (PTB). High metabolic activity results in heat generation, which enables to produce a pathogen-free and digested liquid fertilizer at short retention times. TAO$^{TM}$ system has been developed to reduce a manure volume and convert into the liquid fertilizer using swine manure since 1992. About 100 units have been installed and operated in Korean swine farms so far. TAO$^{TM}$ system consists of a reactor vessel and ejector-type aeration pumps and foam removers. The swine slurry manure enters into vessel with PTB and is mixed and aerated. The process is operated at detention times from 2 to 4 days and temperature of 55 to $65^{\circ}C$. Foams are occurred and broken down by foam removers to evaporate water contents. Generally, at least 30% of water content is evaporated, 99% of volatile fatty acids caused an odor are removed and pathogen destruction is excellent with fecal coliform, rotavirus and salmonella below detection limits. The effluent from TAO$^{TM}$ system, called as the "TAO EFFLUX", is screened and has superb properties as a fertilizer. Normally N-P-K contents of screened TAO Efflux are 4.7 g/L, 0.375 g/L and 2.8 g/L respectively. The fertilizer effect of TAO EFFLUX compared to chemical fertilizer has been demonstrated and studied with various crops such as rice, potato, cabbage, pumpkin, green pepper, parsley, cucumber and apple. Generally it has better fertilizer effects and excellent soil fertility improvement effects. Moreover, the TAO EFFLUX is concentrated through membrane technology without fouling problems for a cost saving of long distance transportation and a commercialization (crop nutrient commodity) to a gardening market, for example.

• Food Science and Preservation
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• v.6 no.4
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• pp.469-474
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• 1999

The chemical components of Hovenia dulcis leaf and fruit stalk naturally growing in Korea, were determined. Crude protein of leaf and total sugar of fruit stalk was 7.30 and 51.64%, respectively. The major mineral components were K, Ca, Mg, Na and Mn in that order. The content of vitamin C was 4.8 mg% for leaf and 3.8 mg% for fruit stalk and that of free sugar was 1.37% of fructose for leaf and 8.83% of sucrose for fruit stalk. The highest organic acid in leaf and fruit stalk was malic acid and its content was 1,715.21 mg% and 439.18 mg%, respectively. The highest component of total amino acids in leaf and fruit stalk was glutamic acid(497.99mg%) and proline(751.78mg%), respectively. The highest lady acid in leaf and fruit stalk was 43.54% of linolenic acid and 23.15% of palmitic acid, respectively. trans-Geraniol(124.36 ppm) and isobutyric acid(292.67 ppm) were predominant volatile compounds in leaf and fruit stalk, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.1
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• pp.102-108
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• 2011

Characteristics of hydrogen production from various food wastes in anaerobic batch reactors were evaluated to assess the energy potential of organic wastes. Organic wastes which were used in this study were scallion as vegetable, apple as fruit, rice as grain and pork as meat. Ultimate hydrogen yield of scallion, apple, rice and pork were 0.46, 0.47, 0.62 and $0.05mol\;H_2/mol\;hexose$, respectively. On the other hand, hydrogen production rates of scallion, apple, rice and pork were 0.013, 0.021, 0.014 and $0.005mol\;H_2/mol\;hexose/h$, respectively. These results indicated that anaerobic hydrogen fermentation from food waste except for meat was effective in removing organic material as well as producing renewable energy. Volatile fatty acids increased as hydraulic retention time was increased. In the hydrogen fermentation, acidification degree of rice was measured as the highest rate of 75.8% whereas pork was found as the lowest rate of 35.2%.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.1
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• pp.103-109
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• 2019

Objective: Ensiling of tannin-rich fruit byproducts (FB) involves quantitative and qualitative changes in the tannins, which would consequently change the rumen fermentation characteristics. This study aimed to evaluate whether ensiled FBs are effective in mitigating methane emission from ruminants by conducting in vitro assessments. Methods: Fruit byproducts (grape pomace, wild grape pomace, and persimmon skin) were collected and subjected to four-week ensiling by Lactobacillus buchneri inoculant. A defined feed component with or without FB samples (both fresh and ensiled material) were subjected to in vitro anaerobic culturing using rumen fluid sampled from beef cattle, and the fermentation parameters and microbial populations were monitored. Results: Reduced methane production and a proportional change in total volatile fatty acids (especially enhanced propionate proportion) was noted in bottles containing the FBs compared with that in the control (without FB). In addition, we found lower gene copy number of archaeal 16S rRNA and considerably higher levels of one of the major fibrolytic bacteria (Fibrobacter succinogenes) in the bottles containing FBs than in the control, particularly, when it was included in a forage-based feed. However, in the following cultivation experiment, we observed that FBs failed to exhibit a significant difference in methane production with or without polyethylene glycol, implying that tannins in the FBs may not be responsible for the mitigation of methane generation. Conclusion: The results of the in vitro cultivation experiments indicated that not only the composition but also ensiling of FBs affected rumen fermentation patterns and the degree of methane generation. This is primarily because of the compositional changes in the fibrous fraction during ensiling as well as the presence of readily fermented substrates, whereas tannins in these FBs seemed to have little effect on the ruminal fermentation kinetics.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.741-748
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• 2018

This study was conducted to evaluate the nutritional value of total mixed rations (TMR) containing rice grain in an in vitro rumen fermentation system. Three types of grains (corn, wheat, and rice), timothy, and soybean meal (SBM) were used to prepare the experimental TMR: Corn TMR, Wheat TMR, and Rice TMR. The rumen fermentation characteristics of all the experimental TMRs were evaluated by an in vitro anaerobic system using rumen fluid for 24 and 48 h. The digestibility of the nutrients (dry matter [DM], crude protein [CP], and neutral detergent fiber [NDF]), pH, ammonia ($NH_3-N$), and volatile fatty acids (VFA) were determined. Rice TMR showed a higher DM digestibility than that of the Corn TMR at 48 h (p < 0.05). In all treatments, the CP digestibility was more than 80% at 48 h, but no significant differences were observed among the treatments. The NDF digestibility tended to be the lowest in the Wheat TMR (p = 0.06), and the pH tended to be the lowest in the Rice TMR (p = 0.09) among the treatments for the 48 h incubation. The Wheat TMR had the highest $NH_3-N$ concentration among the treatments (p < 0.01). Rice TMR had a lowest total VFA concentration among the treatments (p = 0.05) at 24 h, but no significant differences were observed at 48 h. Based on this in vitro result, it was considered that a rice grain has the potential to replace conventional grain ingredients when the TMR was formulated.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.233-240
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• 2019

Objective: This study was to investigate the effects of dietary cotton stalk on nitrogen and free gossypol in sheep. Methods: Treatments included 25% cotton stalk (Treat 1), 50% cotton stalk (Treat 2), and a control (no cotton stalk). Six Xinjiang daolang wethers were cannulated at the rumen and duodenum and fed one of these diets. The effects of these diets on nitrogen and free gossypol absorption and metabolism were determined. Fifteen healthy Xinjiang daolang wethers were assessed for daily gain, tissue lesions, and free gossypol accumulation. Results: Dry matter intake decreased with increasing dietary cotton stalk. Total tract dry matter digestibility did not significantly differ among treatments. Dietary cotton stalk significantly decreased volatile fatty acids and increased ammonium nitrogen in the rumen. Nitrogen intake was significantly higher in Treat 2 than in the control or Treat 1. Nitrogen retention and free gossypol intake increased with dietary cotton stalk. Duodenal free gossypol flow did not increase, and free gossypol almost disappeared from the rumen. The free gossypol content of plasma and tissue was increased with dietary cotton stalk with liver free gossypol>muscle free gossypol>kidney free gossypol. Elevated dietary free gossypol decreased platelets, hemoglobin, and serum iron. Aspartate aminotransferase and ${\gamma}$-glutamyltransferase increased in Treat 2. With high long-term dietary cotton stalk intake, liver cells were swollen, and their nuclei dissolved. Renal cells were necrotic and the interstitia were enlarged. Conclusion: With short-term cotton stalk administration, only a small amount of free gossypol is retained in the body. In response to long-term or high free gossypol cotton stalk feeding, however, free gossypol accumulates in, and damages the liver and kidneys.