• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.52-62
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• 2023

This study focused on determining the specific causes and prevention methods of mass fish deaths occurred in five reservoirs (Gagugi, Neupgokgi, Danggokgi, Sagokji, and Hangokji) in Andong-si. For this purpose, a survey of agricultural land and livestock in the upper part of the reservoirs and analysis of water quality in the reservoir irrespective of whether it rains or not were conducted. We attempted to examine the changes in dissolved oxygen (DO) in the surface and bottom layers of reservoirs and changes in DO depending on the amount of livestock compost and time. Based on the above investigations, treatment plans were established to efficiently control the inflow of contaminated water into reservoirs. The rainfall and farmland areas in the upper part of the reservoir were investigated using Google and aviation data provided by the Ministry of Land, Infrastructure, and Transport. The current status of livestock farms distributed around the reservoirs was also examined because compost from these farms can flow into the reservoir when it rains. Various water quality parameters, such as phosphate phosphorus (PO₄-P) and ammonium nitrogen (NH₃-N), were analyzed and compared for each reservoir during the rainy season. Changes in the DO concentration and electrical conductivity (EC) were also observed at the inlet of the reservoir during raining using an automated instrument. In addition, DO was measured until the concentration reached 0 ppm in 10 min by adding livestock compost at various concentrations (0.05%, 0.1%, 0.3%, and 0.5% by wt.), where the concentration of the livestock compost represents the relative weight of rainwater. The DO concentration in the surface layer of reservoirs was 3.7 to 5.3 ppm, which is sufficient for fish survival. However, the fish could not survive at the bottom layer with DO concentration of 0.0-2.1 ppm. When the livestock compost was 0.3%, DO required 10-19 h to reach 0 ppm. Considering these results, it was confirmed that the DO in the bottom layer of the reservoir could easily change to an anaerobic state within 24 h when the livestock compost in the rainwater exceeds 0.3%. The results show that the direct cause of fish mortality is the inflow of excessive livestock compost into reservoirs during the first rainfall in spring. All the surveyed reservoirs had relatively good topographical features for the inflow of compost generated from livestock farms. This keeps the bottom layer of the reservoir free of oxygen. Therefore, to prevent fish death due to insufficient DO in the reservoir, measures should be undertaken to limit the amount of livestock compost flowing into the reservoir within 0.3%, which has been experimentally determined. As a basic countermeasure, minerals such as limestone, dolomite, and magnesia containing calcium and magnesium should be added to the compost of livestock farms around the reservoir. These minerals have excellent pollutant removal capabilities when sprayed onto the compost. In addition, measures should be taken to prevent fish death according to the characteristics of each reservoir.

• Journal of Animal Environmental Science
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• v.10 no.1
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• pp.11-22
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• 2004

This work was carried out to measure volatile fatty acids emissions from different manure (poultry, swine, cattle) incubated at $10^{\circ}C$, $25^{\circ}C$, and $37^{\circ}C$ for 6 days under anaerobic condition. Following are summary of these tests results. 1. Amounts of Acetic acid generated were 1,128.05mg/kg, 628.21mg/kg and 592.50mg/kg for swine, poultry, and cattle manure, respectively, during the period of incubation. In the case of swine and cattle manure, 83.87%(946.10mg/kg) and 57.49%(340.63mg/kg) from all the temperature treatments were produced in the $25^{\circ}C$, respectively. 83.57% in swine and 78.79% in cattle manure were intensively emerged from 3 day, 4 day and 5 day of the $25^{\circ}C$ treatment. In the case of poultry manure, 45.36%(284.93mg/kg) and 45.36%(284.93mg/kg) in the $25^{\circ}C$ and in the $37^{\circ}C$, respectively, were produced. Accordingly, acetic acid generated from poultry manure was characteristic of being mainly produced in more than $25^{\circ}C$. 2. Amounts of propionic acid generated were 238.56mg/kg, 162.14mg/kg and 155.49mg/kg for swine, poultry, and cattle manure, respectively, during the period of incubation. In the case of swine manure, 78.52%(187.32mg/kg) of propionate emitted from all the temperature treatments was produced in the $25^{\circ}C$ and 79.1% of them was intensively emerged from 3day, 4day and 5day of the $25^{\circ}C$ treatment. In the case of poultry manure, 35.12%(56.95mg/kg) and 45.89%(74.40mg/kg) of the propionate amounts were produced in the $25^{\circ}C$ and in the $37^{\circ}C$, respectively. In the case of cattle manure, 28.21% (43.86mg/kg) and 49.30% (76.66mg/kg) of the propionate amounts were produced in the $10^{\circ}C$ and in the $25^{\circ}C$, respectively. Accordingly, propionate evolved from poultry manure was characteristic of being mainly produced in more than $25^{\circ}C$ and from cattle manure, in less than $25^{\circ}C$, respectively. 3. Amount of butyric acid generated were 1,463.87mg/kg, 96.72mg/kg and 129.18mg/kg for swine, poultry, and cattle manure, respectively, during the period of incubation. The time intensively emerged from the period of incubation was differently generated from the incubation temperature and animal feces. 4. Amounts of iso-valeric acid generated were 6,885.99mg/kg, 399.28mg/kg and 307.47mg/kg for swine, cattle and poultry manure, respectively, during the period of incubation. In the case of swine and cattle manure, 28.22%(1,943.52mg/kg) and 48.56%(193.90mg/kg) in the $25^{\circ}C$, 68.76%(4,734.90mg/kg) and 46.93%(187.40mg/kg) in the $37^{\circ}C$, respectively, were occupied. Accordingly, iso-valeric acid evolved from swine and cattle manure was characteristic of being mainly produced in more than $25^{\circ}C$. In the case of poultry manure, 59.89%(184.13mg/kg) of iso-valeric acid generated from all the temperature treatments was produced in the $37^{\circ}C$ and 100% of them was intensively emerged from 2 day and 3 day of the $37^{\circ}C$ treatment.