• 한국지하수토양환경학회지:지하수토양환경
• /
• 제28권5호
• /
• pp.36-50
• /
• 2023

Soil health can deteriorate through both contamination and remediation. Accordingly, revitalization processes are needed to reuse or recycle the remediated soil. The study was conducted to assess the changes in soil health parameters of heavy metals-contaminated soil during soil washing process. In addition, unit processes were proposed to improve the quality of the remediated soil relevant to its reclamation purposes, such as agricultural and forest lands. A total of 21 indicators were used to determine whether the soil health was degraded or recovered. The performance of 6 amendments in improving soil health was quantitatively evaluated according to their dosage and application duration. Finally, the experimental results were assessed by simple regression analyses to determine the statistical significance and relative performance of each amendment. The results indicated that 18 health indicators out of 21 deteriorated through the soil washing process. Based on the results, it is recommended that several effective amendments be complementarily combined and applied in real applications because use of single amendment does not likely improve the quality of remediated soils.

• 한국농공학회논문집
• /
• 제53권4호
• /
• pp.67-74
• /
• 2011

The objectives of this study were to assess the rice yields and evaluate fertilizer reduction effect of reclaimed wastewater irrigation in paddy fields using the Decision Support System for Agrotechnology Transfer (DSSAT) v4.5 model. The experimental plots were designed, which was located near the Suwon wastewater treatment plant in Gyeonggi-do, Korea. The rice yield, irrigation amount, irrigation water quality and soil data were monitored and collected between 2006 and 2009. The DSSAT model was calibrated and validated with observed data. The methods that were used to evaluate this model were the root mean square error (RMSE), normalized root mean square error (nRMSE), and index of agreement (d). The values of RMSE, nRMSE, and d ranged from 145 to $789\;kg\;ha^{-1}$, 3.0 to 13.3 %, and 0.90 to 0.95 for the calibration period, respectively and represented from 91 to $538\;kg\;ha^{-1}$, 2.0 to 10.4 %, 0.94 to 0.98 for the validation period, respectively. Overall, this model showed good agreement with observed data of rice yields irrigated with reclaimed wastewater. The fertilizer reduction effect in paddy field of reclaimed wastewater irrigation was assessed about 60 % in 2008 and 40 % in 2009.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제28권5호
• /
• pp.51-58
• /
• 2023

In this study, an empirical experiment was conducted to assess the feasibility of replacing groundwater with rainwater in melon cultivation using a smart rainwater harvesting system. The rainwater harvesting efficiency was calculated under three different melon cultivation scenarios. After cultivation, the quality of the fruits grown with rainwater and groundwater was compared by examining the weight, degree of sweetness, and flesh hardness of the products. The results revealed that the water quality of the smart rainwater harvesting device was suitable for melon cultivation to provide better hardness and chloride levels than groundwater. It was also estimated that about 40% of the total water demand for full growth of the melon could be supplied by rainwater. The fruit weight and sweetness were equivalent or slightly better for the melons cultivated with rainwater than those cultivated with groundwater. In particular, the flesh hardness was significantly improved by rainwater cultivation. These results collectively suggest that rainwater can be used as a substitute for groundwater to preserve groundwater resources without compromizing the produced fruit quality.

• 농업생명과학연구
• /
• 제52권6호
• /
• pp.73-79
• /
• 2018

본 연구에서는 고수분 음식물 및 농업 폐기물을 재활용한 고형연료 제조에 필요한 열분해장치를 개발하고 실험을 통해 그 성능을 확인하고자 하였다. 연구를 위해 건조용량 50kg/hr인 실험실용 열분해장치를 제작하였다. 건조 처리된 농업폐기물과 음식물 폐기물을 열분해처리용 실험 원료로 사용하였다. 원료종류, 열분해 온도, 열분해 시간에 따른 농업폐기물과 음식물 폐기물의 열분해 특성을 파악하였다. 농업폐기물 건조물의 열분해 처리 결과, 열분해 처리능력은 평균 55.35kg/hr, 저위발열량은 평균 3,333kcal/kg으로 측정되었다. 열분해처리 하지 않은 농업폐기물의 고위발열량은 3,400kcal/kg, 저위발열량은 3,090kcal/kg으로 측정되어 열분해처리로 발열량이 향상됨을 알 수 있었다. 음식물 폐기물 건조물의 열분해 처리 결과, 열분해 처리능력은 평균 88.27kg/hr, 저위발열량은 평균 4,016kcal/kg으로 측정되었다. 열분해처리 하지 않은 음식물 폐기물의 고위발열량은 4,040kcal/kg, 저위발열량은 3,686kcal/kg으로 측정되어 열분해처리로 발열량이 역시 향상됨을 알 수 있다. 열분해 처리능력은 연구목표치인 50kg/hr보다 높게 나타났으며, 저위발열량은 연구목표치인 4,000kcal/kg 보다 다소 높게 나타났다. 다만 저위발열량 측정 기준 함수율이 습량기준으로 약 10%로 추정되는 바 5%로 조절하고, 열분해 열풍온도를 상승시키면 발열량이 더욱 향상될 것으로 판단되었다.

• 한국버섯학회지
• /
• 제16권3호
• /
• pp.225-230
• /
• 2018

본 연구는 느타리버섯 수확후배지를 배지자원으로 재사용하기 위하여 미생물처리에 의한 수확후 배지의 총질소함량 증진효과를 조사하였다. Bacillus sp. GM20-4 와 Rhodobacter sphaeroides(RS) 배양액 30%를 함께 접종하여 5일간 상온에서 배양 시 총질소 함량이 가장 크게 증가하였다. 농가의 수확후배지 조성에 따른 GM20-4와 RS처리에 의한 T-N함량 변화를 조사하기 위하여 경기 지역 버섯재배농가 세 곳의 수확후배지(spent mushroom substrates, SMS A, B, C)를 수집하여 GM20-4 와 RS 배양액 30%를 처리한 결과, 무처리구에 비해 건조 SMS B에서 T-N함량이 20%p로 가장 크게 증가하였고, 건조 SMS A는 17%, C는 12% 증가하였다. 반면에 생수확후 배지에서는 미생물 처리에 의한 T-N 함량 증가 효과가 크지 않았다. 또한 아미노산 조성별 함량 변화는 건조된 SMS A, B, C 모두 GM20-4와 RS 처리로 aspatic acid와 glutamic acid가 상대적으로 높게 증가한 결과를 보였고, 특히 건조 SMS B의 처리구에서 두 아미노산의 함량이 무처리구보다 2.9배 증가를 보임으로서 미생물처리가 수확후배지의 총질소 및 아미노산 함량의 증진효과를 확인하였다.

• 복식문화연구
• /
• 제11권3호
• /
• pp.416-422
• /
• 2003

Agricultural drainage salt generated during irrigation of crops in San Joaquin Valley, California, exceeds 600,000 tons annually and cumulates in the field in a rapid rate. As a result, the waste is taking out more farmlands for salt storage and disposal, imposing serious concerns to environment and local agricultural industry. In searching for a potential solution to reduce or eliminate the waste, this research explored feasibility of producing a value-added product, sodium sulfate, from the waste and utilizing the product in textile dyeing. The results indicated that sodium sulfate could be produced from the salt and could be purified by a recrystalization method in a temperature range within the highest and lowest daily temperatures in summer in the valley. The recovered sodium sulfate samples, with purities ranging from 67% to 99.91, were compared with commercially available sodium sulfate in the dyeing of levelling dyes with nylon/wool fabrics. In nylon/wool fabrics, C.I. Acid Yellow 23 had similar exhaustions among Na₂SO₄ I, Na₂SO₄ II, Na₂SO₄ III and Na₂SO₄ Ⅴ which had similar ratios of sodium sulfate and sodium chloride in recovered salts. Na₂SO₄ Ⅳ had low exhaustion which had low ratios of sodium sulfate and sodium chloride. In nylon/wool fabrics, C.I. Acid Blue 158 had similar exhaustions among Na₂SO₄ I, Na₂SO₄ II, Na2₂SO₄ III, Na₂SO₄ IV and Na₂SO₄ Ⅴ despite of Na₂SO₄ Ⅳ had low ratios of sodium sulfate and sodium chloride Generally, the dyeing of levelling dyes using recovered salts from farm drainage has similar or low exhaustion than the dyeing of levelling dyes using commercial sodium sulfate.

• 한국물환경학회지
• /
• 제32권6호
• /
• pp.528-536
• /
• 2016

The purpose of Total Pollution Load Control at Tributary is to obtain maximum improvement effect of water quality through finding the most impaired section of water-body and establishing the proper control measure of pollutant load. This study was implemented to determine the optimal management of reach, period, condition, watershed, and pollution source and propose appropriate reduction practices using the Load duration curve (LDC) and field monitoring data. With the data of measurement, LDC analysis shows that the most impaired condition is reach V (G4~G5), E group (flow exceedance percentile 90~100%) and winter season. For this reason, winter season and low flow condition should be preferentially considered to restore water quality. The result of pollution analysis for the priority reach and period shows that agricultural nonpoint source loads from onion and garlic culture are most polluting. Therefore, it is concluded that agricultural reuse of surface effluent (storm-water runoff with non-point sources) and low impact farming that includes reducing fertilization and controlling the height of drainage outlet are efficient water quality management for this study watershed.

• 한국농공학회지
• /
• 제45권4호
• /
• pp.55-65
• /
• 2003

Pilot study was conducted to examine the effects of ponded-water depth and reclaimed wastewater irrigation on paddy rice culture. For the ponded-water depth effect, three treatments of shallow, traditional, and deep water depths were applied, and each treatment was triplicated. The irrigation water for the treatment pots was an effluent from constructed wetland system for sewage treatment, while the control pot was irrigated with tap water kept traditional ponded-water depth. Irrigation water quantity varied with ponded-water depth as expected and drainage water quantity also varied similarly, which implies that shallow irrigation might save irrigation water and also reduce environmental impacts on downstream water quality. Rice growth and production were not significantly affected by ponded-water depth within the experimental condition, instead there was an indication of increased production in shallow and deep ponded-water depths compared to the traditional practice. Raising drainage outlet to the adequate height in paddy dike might be beneficial to save water resources within the paddy field. There was no adverse effect observed in reclaimed wastewater irrigation on the rice production, and mean yield was even greater than the control pots with tap water irrigation although statistically not significant. Water-saving irrigation by shallow ponded-water depth, raising the outlet height in diked rice paddy fields, minimizing forced surface drainage by well-planned irrigation, and reclaimed wastewater irrigation are suggested to save water and protect water quality. However, deviation from traditional farming practices might affect rice growth in long term, and therefore, further investigations are recommended before full scale application.

• 농업과학연구
• /
• 제10권1호
• /
• pp.156-165
• /
• 1983

태양열(太陽熱)을 이용(利用)한 silica gel의 활용(活用)에 대(對)한 기초자료(基礎資料)를 얻고자, silica gel을 이용(利用)한 양파의 건조특성(乾燥特性)과, 공기(空氣)의 제습효과(除濕效果)를 구명(究明)하고, 건조제(乾燥劑)로서의 재사용(再使用)을 위(爲)하여 실험(實驗)한바, 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 외기온도(外氣溫度) $30^{\circ}C$, 상대습도(相對濕度) 55% 내외(內外)에서 포화(飽和)silica gel을 수분함량(水分含量) 8%까지 재생(再生)시키는데 14시간(時間) 소요(所要)되었다. 2. 집열기(集熱器)를 재순환(再循環)시켜 건조(乾燥)한 결과(結果), 노천건조(露天乾燥)보다 1/2정도(程度) 시간(時間)이 단축(短縮)되었다. 3. 실험기간중(實驗期間中) 집열기(集熱器)의 평균효율(平均效率)은 25%였다. 4. 건조실(乾燥室)을 이용(利用)한 송풍건조시(送風乾燥時), 갈변도(褐變度)가 1/2로 감소(減少)되었다.

• 한국토양비료학회지
• /
• 제36권1호
• /
• pp.24-31
• /
• 2003

벼 재배에 있어 이앙기 가뭄시 대체 용수원을 개발하고자 공장폐수처리장(이하 공장폐수 처리수)와 하수종말처리장 방류수(이하 하수처리수)를 관개한 다음 지하 침투수 수질 및 벼생육 변화를 구명하기 위해 본 시험을 수행하였다. 대체 관개 용수원으로서 공장폐수 처리수의 COD, $NH_4{^+}-N$, $Mn^{2+}$, 및 $Ni^+$ 농도와 하수처리수중의 SS및 $PO_4-P$농도는 여러 국가들의 관개 재활용 수질 기준보다 높은 것으로 나타났다. 하수처리수의 초장은 공장폐수 처리수 10일간 관개구를 제외하고 지하수 관개구 보다 약 2 cm 정도 짧았으나, 지하수 및 하수처리수 관개구의 경수는 관개기간에 관개 없이 유의차가 없는 것으로 나타났다. 그리고 하수처리수 및 공장폐수 처리수 20일 관개구의 수확지수는 유의차가 없었지만, 공장폐수 처리수 30일 관개구의 수확지수는 토성에 관계없이 하수처리수 관개구 보다 약간 높은 것으로 나타났다. 공장폐수 처리수 관개구의 토양 침출수중의 SAR값은 하수처리수 관개구보다 2배 이상 높았지만, 하수처리수 관개구는 지하수 관개구와 비교하여 유의차가 없는 것으로 나타났다. 이앙 30일 후 공장폐수 및 하수종말처리수 관개구의 토양침출수중 평균 전기전도도(EC1) 값은 각각 식양토에서 4.7과 $3.4dS\;m^{-1}$ 그리고 사양토에서 3.5 및 $2.5dS\;m^{-1}$로 나타났다. 전생육 기간 및 토성에 따른 공장폐수 처리수 관개구의 토양 침출수중 $EC_i$값이 하수처리수 관개구 보다 2배 이상 높게 나타났지만, 이앙 30일 후부터 급격히 감소하는 경향을 보였다. 그렇지만 하수종말 처리수 관개구의 토양 침출수 중 $EC_i$ 값은 지하수 관개구와 비교하여 유의차가 없는 것으로 나타났다. 이상의 결과로 보아 벼 재배시 하수종말 처리수는 가뭄으로 인한 농업용수가 부족한 경우 대체수자원으로서 잠정적 활용이 가능한 것으로 생각된다.