보고서 정보
주관연구기관 |
부산대학교 Busan National University |
보고서유형 | 최종보고서 |
발행국가 | 대한민국 |
언어 |
한국어
|
발행년월 | 2002-05 |
주관부처 |
농림부 Ministry of Agriculture and Forestry |
등록번호 |
TRKO201400024055 |
DB 구축일자 |
2014-11-14
|
초록
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Ⅳ. 연구개발 결과 및 활용에 대한 건의
3년간의 연구를 통해 SBR을 이용한 가축분뇨 고도처리 기술, 탈색 기술, 악취 제어 기술, 혐기소화 기술, 유기산화 기술, 그리고 난분해성 유기물의 고도산화를 이용한 처리법등이 개발되었다. 그러나, 질소인 회수기술 개발에 있어 질소, 인 회수를 위한 물리적 조작은 후속처리인 생물학적 처리에 치명적인 영향을 줄 수 있었고, 방류수 처리 기준을 맞추기 위한 후처리 개발에서는 막대한 비용이 드는 막분리를 이용하지 않고서는 그 기준을 만족시킬 수가 없었다. 고도 산화 등을 거친 유출수 내에는
Ⅳ. 연구개발 결과 및 활용에 대한 건의
3년간의 연구를 통해 SBR을 이용한 가축분뇨 고도처리 기술, 탈색 기술, 악취 제어 기술, 혐기소화 기술, 유기산화 기술, 그리고 난분해성 유기물의 고도산화를 이용한 처리법등이 개발되었다. 그러나, 질소인 회수기술 개발에 있어 질소, 인 회수를 위한 물리적 조작은 후속처리인 생물학적 처리에 치명적인 영향을 줄 수 있었고, 방류수 처리 기준을 맞추기 위한 후처리 개발에서는 막대한 비용이 드는 막분리를 이용하지 않고서는 그 기준을 만족시킬 수가 없었다. 고도 산화 등을 거친 유출수 내에는 대부분이 난분해성 유기물만이 함유되어 있어 환경에 대한 영향이 적으므로 좀 더 현실적인 관계법 개정이 요구된다.
본 연구의 효율적 활용을 위해서는 가축분뇨가 가지는 특성인 다양성으로 인해 몇몇 처리장에 본 기술을 적용시키고, 이후 확대 적용을 실시할 수 있도록 해야할 것으로 판단된다.
Abstract
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Ⅰ. TITLE
Development of advanced swine waste treatment and recovery of resource for environment preservation
Ⅱ. OBJECTIVES AND IMPORTANCE
A livestock density in Korea is ranked to the third among the OECD countries and even though the relatively few discharge amount, the contribution fracti
Ⅰ. TITLE
Development of advanced swine waste treatment and recovery of resource for environment preservation
Ⅱ. OBJECTIVES AND IMPORTANCE
A livestock density in Korea is ranked to the third among the OECD countries and even though the relatively few discharge amount, the contribution fraction of pollution to the whole water system was reached to 8% by it's extremely high organic concentration. In addition, because the most of large scale stalls are located at the upper stream of the pumping point of drinking water and scattered with the broad area throughout the country, their effective management and control have been actually difficult.
For these reasons, much efforts has been provided to solve the livestock waste including wastewater problems, especially piggery wastewater, through the resource like fertilization. However, because the amount and concentration of nutrients in wastewater exceeded the receptive capacity, additional wastewater treatment to avoid environmental obstruction was desired essentially.
The management of livestock wastewater is not so simple. Amount and nature of livestock wastewater are quite different by the kinds of livestock, feeding materials and clean methods of stalls. Most of all, the wastewater can be characterized by the scraper or slurry type : scraper type, where the feces were separated with urine during the collection by the mechanical device and having relatively low organic concentration; and slurry type, where the feces were mixed with urine and cleaning water and organic carbon concentrations are about 2 times higher than scraper type. Except for organic substrate, the concentrations of nitrogen and phosphate in slurry are narrowly higher than scraper type wastewater.
The aim of this study is to develop Korea type integrated management system for complex scale livestock wastewater.
Ⅲ. SCOPE AND CONTENT
This study has been conducted by a link of the first sub-institution for development of treatment and recovery of N, P in wastewater, the second sub-institution for development of deodor system from livestock or manure, the first cooperative institution for development of anaerobic fermenter and the second cooperative institution for development of VFA's formation and removal of non-biodegradable substrates. This study has been conducted for 3 years. The detailed research contents can be summarized as followings;
1. Development of treatment and recovery of nitrogen and phosphorus in manure
1) Recovery of nitrogen and phosphorus for fertilizer production
To achieve high recovery efficiency of N, P, decarbonation and pH adjusting at the range of 4-10 were essentially required. No adjusting, few amount of N, P was recovered. Moreover, after the adjusting, the application of effluent from recovery reactor was impossible by extremely low or high pH. Therefore the application of recovery technique for fertilizer production can not be recommended.
2) Advanced treatment of N, P with SBR
A pilot scale SBR (effective volume, 20m3) for the treatment of piggery wastewater treatment was performed with three different kinds of wastewater; fermenter effluent, scraper type and slurry type. The react phase in SBR was performed by sub-cycle operation consisting of repeated short cycle of anoxic-aerobic step. The fermenter effluent was characterized by the rapid nitrification and NOx-N accumulation due to depletion of organic matter in wastewater. The scraper type wastewater showed appropriate nitrogen removal efficiency, however, a poor response capacity for high loading rate often resulted in increased nitrogen concentration in effluent. Moreover, severe P release was the most serious problem in scraper type wastewater. SBR treated slurry type wastewater with high nitrogen removal efficiency to satisfy effluent quality requirement. It was thought that high concentration of organic matter in slurry made it possible to uptake P during SBR operation, where P concentration of 140mgP/l was decreased to 8mgP/l. As results, SBR was suitable to treat slurry type wastewater which has been discharged to the ocean till now.
The effective feeding method of the external carbon source(ECS) to complete denitrification in SBR based on the anoxic/aerobic sub-cycle for the piggery wastewater treatment was investigated. Generally, the wastewater quality of manure is strongly dependent on the collection, separation method and storage period. The wastewater discharged from scraper type barns is characterized by comparetively lower organic substrate concentration and readily biodegradable organic matter(Ss), then NOx-N becomes accumulated during the repeating of sub-cycle operation. In batch test, when only influent was fed, NOx-N was removed with the rate of 57mgN/hr, and then reached to the complete denitrification after 1 hr. On the other hand, when the influent was adjusted to C/N ratio of 8 with acetic acid, the removal rate of NOx-N was increased to 156mgN/hr, accomplished the denitrification within 30 minutes. These proper addition was very effective to increase the denitrification rate. The simultaneous reaction of denitrification and P-release during 30 minutes could be evaluated as specific advantage of ECS feeding. In final step ECS feeding method, the maximum nitrogen removal rate was limited to 0.22kgN/m3/d under conventional sub-cycle operation by the large amount of ECS feeding for the high concentration of NH4-N in final step and the denitrification inihibition by the pH drop. At the influent loading condition of over 0.22kgN/m3/d, the final step feeding caused the NOx-N accumulation and the removal loading rate was reduced. To overcome these limitation and achieve higher nitrogen removal rate, the ECS feeding method was changed from conventional final step feeding to every anoxic step feeding. When acetic acid was added in each anoxic step, sub-cycle numbers per one day were increased from five times to seven times. In case of every anoxic step (intermittent) feeding, the removal rate was increased to 0.45kgN/m3/d without NOx-N accumulation. The denitrification rate in ECS addition was 2.5 times higher to 135.5mgN/hr than that of 53.3mgN/hr in no addition. By the difference of the denitrification rate, NOx-N concentration in effluent showed quite different quality of 260mgN/l and 23mgN/l, respectively. Over these influent loading, the nitrification was not completed under given fixed time sequence, and ammonium ion was accumulated. From these results, it was found that the nitrogen removal loading rate with intermittent feeding was superior about 2 times as higher as with the final feeding. For the more enhanced performance of SBR, the control of nitrification end point and the control system is desired to optimize the external carbon feeding.
A pilot-scale SBR (effective volume, 20m3) treating piggery wastewater was operated with real wastewater in situ. The operation mode of intermittent feeding of raw water and subcycle with repeating anoxic-aeration conditions were adapted to avoid the high-stregth nitrogen inihibition. During the subcycle operation, the controls of each phase and on/off pumps, mixer, blower were performed using only ORP meter. ORP profiles were very dependent on influent loading rates, however, the developed control strategy was proved to be useful for the stable control throughout wide operation conditions. Differing to prior control studies such as ammonia valley in pH or bending point in ORP, dORP/dt values with range of 0∼1 corresponding to the end of ammonia oxidation and make it possible to actually stable operation regardless of influent variation. With the ORP Characteristics of rapid and sensitive response towards microbial status within reactor, operation diagnosis such as abnormal feeding of raw water by some mechanical trouble was possible. It was found that the increased nitrogen removal loading rate from 0.24 kgN/m3/d to 0.31 kgN/m3/d was somehow related with the optimized aeration time corresponding to loading rate and improve microbial activity which results of shorten subcycles. As results, the ORP was effective control criteria for the stable SBR operation for the piggery wastewater treatment and increased the nitrogen removal loading rate and improve operation stability through the rapid dianosis towards immediate influent disturbances.
With the ORP Characteristics of rapid and sensitive response towards microbial status within reactor, operation diagnosis such as abnormal feeding of raw water by some mechanical trouble was possible. It was found that the increased nitrogen removal loading rate from 0.24kgN/m3/d to 0.31kgN/m3/d was somehow related with the optimized aeration time corresponding to loading rate and improve microbial activity which results of shorten subcycles. As results, the ORP was effective control criteria for the stable SBR operation for the piggery wastewater treatment and increased the nitrogen removal loading rate and improve operation stability through the rapid diagnosis towards immediate influent disturbances.
2. Development of deodoring technique
By the development of media and air distribution system, the operation performance was improved with high removal efficiency of H2S, R-NH2, NH3.
3. Development of anaerobic fermenter for formation of organic acids
In fermenter, concentration of organic acids increased rapidly until HRT of 3 days, after that slowly decreased. The production of organic acid was 7 times as much as initial concentrations. cross flow media AFB with pilot plant influent showed optimized HRT of 0.5 - 1 day, and UB test indicated that quite amount of 30% in manure was revealed to non-biodegradable organic substrates.
4. Development of biological removal of nitrogen and phosphorus using SCFA's and advanced oxidation of non-biodegradable substrates in concentrated effluent from RO membrane filtration.
Phosphorus release rates were significantly affected by type of substrate added at anaerobic condition. Those observed with acetate and fermented swine wastewater(F.S.W) were 4-5 times greater than those with propionate, methanol and domestic wastewater. Also, biological phosphorus release was greatly affected by concentration of NOx-N in anaerobic condition. In the cases supplied with acetate, propionate and F.S.W, PO43--P release rates were less influenced by a NOx-N concentration during PO43--P relese period than those with methanol and domestic wastewater. The activation energy of phosphorus release was determined in temperature of 9 to 30℃. This value of acetate, propionate, glucose and domestic wastewater was 49.83, 55.82, 54.61 and 45.44 KJ/mol, respectively. Corresponding temperature correction coefficient was 1.0844, 1.0799, 1.0882, and 1.0618, respectively.
With sludge adapted with acetate, activation energy value and temperature correction were 44.94 KJ/mol and 1.0706, respectively. These values were relatively smaller than those obtained from unadapted sludge. In addition, we investigated the effect of fermented swine wastes on biological nutrient removal in SBR. In this research, fermented swine waste was used as an electron donor in SBR system. SBR system was operated in fill-aerobic-anoxic-reaeration-settle-draw mode, corresponding operation period was 0.1, 13, 7, 3, 0.83 and 0.07hr, respectively. Three sets of SBR system was operated. Each of two system were added acetate or fermented swine waste as an electron donor and the rest was operated without electron donor addition.
All system was operated at SRT of 20day and HRT of 24hr. Electron donor was added at anoxic mode. When electron donor was not used, T-N and T-P removal efficiency were 77 and 15%, respectively, whereas addition of external electron donor of acetate or fermented swine waste in SBR system enhance nutrient removal efficiency. T-N removal efficiency is 90.6 and 90%, respectively, and T-P removal efficiency is both 87%.
Alternative sources of fermented swine wastewater organics were compared to acetate and methanol as electron donor for denitrification. Results of this research indicated that fermented swine sludge was observed to be an excellent electron donor for denitrification. Corresponding denitrification rate was 1.4803mgNO3-N/gVSS-h which was 1.42 times of denitrification rate obtained with methanol as an external electron donor. In addition, effect of the three methods of feeding fermented food waste such as continuous, step and temporary feeding on phosphorus release in EBPR was studied.
Initial C/N ratio(as SCOD/NO3--N) was varied from 5 to 25. In case of temporary feeding, the terminal PO43--P(mg PO43--P/g MLVSS) released from activated sludge for 4.5 hr were 0.34(C/N=7.5), 1.31(C/N=10), 3.01(C/N=15), 5.14(C/N=20) and 7.18(C/N=25).
In case of step feeding, the terminal PO43--P conentrations(mg PO4 3--P/g MLVSS) released from activated sludge for 4.5 hr were 0.37(C/N=7.5), 2.55(C/N=10), 3.53(C/N=15), 5.49(C/N=20) and 7.38(C/N=25). In case of continuous feeding, the terminal PO43--P concentrations(mg PO43--P/g MLVSS) released from activated sludge for 4.5 hr were 2.04(C/N=7.5), 3.05(C/N=10), 3.47(C/N=15), 4.58(C/N=20) and 7.18(C/N=25). At the lower SCOD/NO3--N ratio, the continuous feeding can be recommended as the more efficient method because the magnitude of SCFAs played a crucial role in determining phosphorus release. However, at the higher SCOD/NO3--N ratio, the temporary feeding can be regarded as the more efficient method because the length of retardation time spent on denitrification was limiting factor for phosphorus release. Overall, it appears that step feeding was thought as the most efficient method because the denitrification rate in the step feeding was more increased than in the continuous feeding and also the more SCFAs was present in the step feeding than in the temporary feeding after denitrification ended up. In conclusion, based on the experimental results obtained from this study, it is likely that the fermented food waste may be possible good electron donor for BNR process and step feeding to optimize EBPR.
Study on removal of nonbiodegradable organic matter using coagulation and AOP precesses was conducted. In conclusion, order of TCOD removal efficiency was Fenton(77%)>Alum/O3(74%)>Alum/UV/H2O2(69%) and order of UV-254 removal efficiency was Alum/UV/H2O2(97%)>Alum/O3(89%)>Fenton(83%). The interesting fact is that relationship of removal efficiency of TCOD and UV-254 is in inverse. In addition, biodegradability after treatment of coagulation and AOP is nearly zero. Toxicity test using INT showed toxicity of raw wastewater was higher than application results of coagulation and AOP process.
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