• 한국수산과학회지
• /
• 제48권4호
• /
• pp.555-563
• /
• 2015

Organic matter and trace metals were investigated in surface sediments of Gomso Bay, where there is dense Manila clam Ruditapes philippinarum farming activity, to evaluate contamination of sediments in intertidal shellfish farming area. We measured mean grain size (Mz), chemical oxygen demand (COD), ignition loss (IL), acid volatile sulfide (AVS), total organic carbon (TOC), and total nitrogen (TN), and trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb and Zn) in intertidal and sublittoral sediments. The intertidal sediments were mainly composed of coarser sediments (sand, silty sand, and sandy silt), with Mz values ranging from 2.61 to 4.79 Ø. Mz and the content of organic matter in sediments were lower in the intertidal zone than in the sublittoral zone. The mean metal concentrations in surface sediments decreased in the order Fe > Mn > Zn > Cr > Pb > Cu > As > Cd > Hg. The metal concentrations in surface sediments showed a significant positive correlation with Mz and organic matter content, indicating that metal concentrations in the surface sediments of Gomso Bay are controlled by Mz and organic matter. The concentrations of organic matter and trace metals in the study region were lower than or similar to those in other intertidal zones in western coast and much lower than those reported in other shellfish farming areas in Korea. Our results suggest that intertidal Manila clam farming sediments from Gomso Bay are not contaminated by organic matter and trace metals.

• 한국환경보건학회지
• /
• 제28권5호
• /
• pp.86-92
• /
• 2002

This study was performed to assets the operating characteristics of food waste composting and co-composting (food waste + sewage sludge) at a compelling facility. The facility was being operated successfully without being affected by kind of composting feed materials. Partial anaerobic condition was detected during food waste composting and co-com-posting, but these two composting systems were proven to be operated successfully under aerobic condition from the monitoring results of $O_2$, volatile solids reduction rate, temperature, and other parameters. The conductivity and chloride concentrations of compost were gradually increased during two composting periods, but the conductivity and chloride concentrations of co-compelling indicated lower values than those of food waste composting at final point(40 m). As a result, co-composting was turned out to be more desirable than food waste composting, considering salt problem. High correlations ($R^2$= 0.9265 for food waste composting and $R^2$= 0.9685 for co-composting) between CEC and volatile organic matter were found. Quality of composts produced from two composting process satisfied Korean heavy metal standard.

• Asian-Australasian Journal of Animal Sciences
• /
• 제11권3호
• /
• pp.217-233
• /
• 1998

Milk yield and its composition is governed by level of nutrition and the composition of diet. Higher concentrate input improves milk yield, whereas its input at moderate levels improves yield of milk fat. High level of dietary protein improves dry matter intake and milk production, however, CP content above 14% has less advantage. Milk yield is enhanced by the feeding of cottonseed and soyabean meal, whereas milk fat increases by the supplementation of cottonseed. Dietary fat increases energy intake, production of milk and milk fat. Quality and quantity of feeds consumed affect fermentation patterns in rumen. Among the rumen metabolites, volatile fatty acids (VFA) content and propionate proportion have been related positively with milk yield, whereas proportion of acetate and butyrate have been related positively with milk fat content. Dietary carbohydrates through the source of sugar, starch, roughage and fibre affect VFA concentration in rumen. Therefore, concentration of volatile fatty acids could be altered to the advantage of consumer through judicious manipulation of diet.

• 한국환경보건학회지
• /
• 제31권4호
• /
• pp.294-300
• /
• 2005

Food waste can be a valuable carbon source in biological nutrient removal (BNR) systems because of high C/N and C/P ratios. However, food waste should be pretreated to promote its hydrolysis rate because hydrolysis reaction would be a rate-limiting step. This study investigates the influence of the enzymatic pretreatment on acid fermentation of food waste. Solubilization of particulate matter in food waste by using commercial enzymes was examined. The acidification efficiency and the volatile fatty acids (VFAs) production potential of enzymatically pretreated food waste were also examined. The highest volatile suspended solids (VSS) reduction was obtained with an enzyme mixture ratio of 1:2:1 of carbohydrase:protease:lipase. An optimum enzyme dosage for solubilization of food waste was $0.1\%$(V/V) with the enzyme mixture ratio of 1:2:1. In the acid fermentation of enzymatically pretreated food waste, $0.1\%$(V/V) enzyme mixture dosage for pretreatment result in the maximum VFAs production and the best VFAs fraction in soluble COD(SCOD). The VFAs production at this addition level was 3.3 times higher than that of no-enzyme added fermenter. The dominant VFAs present was n-butyrate followed by acetate.

• 상하수도학회지
• /
• 제13권1호
• /
• pp.72-80
• /
• 1999

Separation of VOCs(Volatile Organic Compounds) in Water Using Activated Carbon is known to be effective. Activated Carbon has been and will be employed in many water treatment plants. Simplified plug flow homogeneous surface diffusion model(PFHSDM) has been used to predict adsorption of organic matter. Finite Element Method(FEM) was used to analyze the model. Out of water quality control substances, benzene, toluene and tetrachloroethylene were used in the small column test. Film diffusion coefficients and surface diffusion coefficients were obtained from the column test, and were compared with the modeling results. Mc Cune, Williamson, William and Kataoka model, were compared with film diffusion coefficients obtained in the test. McCune model was fitted best for those VOCs used in this experiment. Film diffusion coefficients of VOCs obtained were benzene 0.265 cm/min, toluene 0.348 cm/min and tetrachloroethylene 0.298 cm/min. Surface diffusion coefficients of VOCs obtained were benzene $6.36{\times}10^{-8}cm^2/min$, toluene $3.20{\times}10-8cm2/min$, and tetrachloruethylene $4.94{\times}10^{-8}cm^2/min$.

• 환경생물
• /
• 제20권2호
• /
• pp.101-108
• /
• 2002

Benthic organisms dwell in sediment-water interface that contains significant amount of organic and inorganic contaminants. Their feeding behavior is highly related with sediment itself and pore water in the sediments, especially in ease of deposit feeder (i.e. polychaete, amphipod). The acid volatile sulfide (AVS) is one of the important binding phases of sediment-bound metals in addition to organic matter and Fe and Mn oxide fractions in sediments, particularly in anoxic sediments. The AVS model is a powerful tool to predict metal bioavailability and bioaccumulation in benthic organisms considering SEM/AVS mole ratios in surficial sediments. However, several biogeochemical factors must be considered to use AVS model in the sediment-bound metal bioavailability.

• 한국물환경학회지
• /
• 제23권5호
• /
• pp.781-788
• /
• 2007

The Carbon source to enhance the denitrification is essential matter in the advanced sewage treatment. For the high level of nutrient removal, external carbons such as ethanol, methanol, volatile fatty acids and so on should be needed. In this study, the methods to increase the sludge solubilization and acidification rate were compared with waste activated sludges and food waste leachate. Ultrasonication and acids were used for the pretreatment of organic particles in sludges. As a results, the optimal temperature and HRT were $60^{\circ}C$ and 5 days, respectively. HAc, HPr, HBr, and other VFAs for acid fermentations reduced up to 22, 16, 14, and 48% with HRT reduction. For the increase of solubilization, 28% of solids destruction rate was shown at 0.3 watts/mL.

• 농업생명과학연구
• /
• 제43권6호
• /
• pp.67-75
• /
• 2009

본 연구는 한약재 (결명자, 계피, 산초, 감초) 추출물의 반추위내 발효와 미생물 활성에 대한 효과를 구명하기 위하여 수행되었다. In vitro 건물소화율은 계피와 산초 추출물 첨가구에서는 0시간대, 감초 추출물 첨가구에서는 3시간대에 대조구에 비해 현저히 (P<0.05) 낮았다. 한약재 추출물 첨가에 따른 발효 시간대별 휘발성 지방산 조성의 변화는 3시간대에서만 처리간 유의성이 인정되었는데, acetate 비율은 대조구가 천연 추출물 첨가구보다 유의적으로 높았으나, butyrate, isobutyrate, isovalerate 및 valerate은 대조구에서 가장 낮았다 (P<0.05). 미생물 성장율은 발효 3시간대에서 결명자 첨가구를 제외한 한약재 첨가구에서 대조구에 비해 유의적 (P<0.05)으로 높았으나 다른 발효 시간대에서는 차이가 없었다. 이상의 결과로부터 한약재로 사용되고 있는 계피, 산초 및 감초 추출물을 in vitro 반추위 배양액에 첨가하였을 때, 발효초기에 반추위 미생물의 활성을 억제하는 경향은 있었으나 미생물 성장에 대한 억제 효과는 없는 것으로 나타났다.

• 한국수산과학회지
• /
• 제46권6호
• /
• pp.930-940
• /
• 2013

We evaluated contamination with organic matter and trace metals by analyzing grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Ni, Cr, Mn, Hg, and As) in surface sediments at 28 stations around the Geum River estuary in July 2008. The surface sediments in the estuary were mainly composed of coarse sediment (sand and muddy sand), with mean grain size (Mz) ranging between $2-4{\O}$. The high concentrations of IL, COD, and trace metals were mainly found at stations in front of the Gusan outer port and industrial complex, and near the Seocheon coast with relatively fine sediments. In addition, the concentrations of IL and all trace metals, except Pb and As, showed good positive correlations with Mz, indicating that the concentrations of organic matter and trace metals were mainly dependent on sediment grain size. The concentrations of COD, AVS, and trace metals in most sediments did not exceed the sediment quality guideline (SQGs). Although the sediments in the study region are not polluted with organic matter and trace metals, there are many point sources of pollutants, such as Gusan port and industrial complex, Janghang refinery, and a thermoelectric power plant around the Geum River estuary. Thus, the management of coastal environments through periodic monitoring of organic matter and trace metals is required in the future.

• Asian-Australasian Journal of Animal Sciences
• /
• 제2권1호
• /
• pp.43-49
• /
• 1989

In spite of the well confirmed advantages of wilting on the fermentation quality, wilting silages are difficult to make at optimum dry matter content. The prolonged wilting, especially in humid condition, result in lower water soluble carbohydrate (WSC) contents, extensive protein breakdown and sometimes higher total volatile fatty acid (VFA) during wilting an ensilage. Apart from difficulty of controlling moisture content, another problem associated with wilted silages is different evaluation on the potential productivity. In temperature climate of Asia, therefore further researches on the effects of wilting on the silage fermentation and potential productivity seen to be necessary.