사고 누출 황산의 국내 지질매체 반응 특성

이윤호,현성필,문희선,신도연,이은희,유재영 한국광물학회 2019 광물과 암석 (J.Miner.Soc.Korea) Vol.32 No.4

Acid spill accidents are frequently occurring in Korea with increasing production, use, storage, and transport of acids, accompanying industrialization and economic growth. The acids introduced to the subsurface environments would eventually be neutralized by reactions with geomedia. However, the spatial and temporal extent to which the spilled acids would affect will be dependent on the characteristics of the geomedia exposed to the acids. In this work, sulfuric acid, the most used acid in Korea, was reacted with a set of model geomedia representative of the geology of Korea. The buffering capacity of the model geomedia was determined through batch-type experiments using pH changes as an indicator. X-ray diffraction was used to identify the mineral phases contributing to the acid neutralization. The results showed that sandstone had the largest acid neutralization capacity among the tested geomedia, while kaolinite had the smallest. The findings of this study would contribute to quantitatively assessing the impact of spilled acids on geomedia and hence to predicting the vulnerability of geomedia to the spilled acid. 산업화와 경제 발전에 따라 생산량, 사용량, 보관량, 운반량이 늘어난 산 물질들의 누출 사고가빈발하고 있다. 지중 환경으로 유입된 누출 산은 지질매체와의 반응에 의해 궁극적으로 중화될 것으로 예상된다. 하지만 누출 산이 영향을 주는 공간적 및 시간적 범위는 산에 노출된 지질매체의 특성에따라 달라질 것으로 예측된다. 본 연구에서는 국내에서 가장 사용량이 많은 황산을 한국의 지질을 대표할 수 있는 모델 지질매체들과 반응시켰다. 용액의 pH 변화를 지시자로 회분식 실험을 통해 모델지질매체들의 산 완충능을 평가하였다. 그리고 산 중화에 기여하는 광물성분을 X-선회절분석을 통해확인하였다. 실험 결과는 평가한 지질매체 중 사암이 가장 큰 중화능을 가졌으며, 캐올리나이트가 가장 낮은 중화능을 가졌음을 보여준다. 이 연구 결과는 지질매체에 대한 누출 산의 영향을 정량화하고따라서 누출 산에 대한 지질매체들의 취약성을 예측하는데 기여할 것으로 기대된다.

Effects of Soil Buffering Capacity and Citric Acid in Electrolyte on Electrokinetic Remediation of Mine Tailing Soils

이기세,이효상,김상식,고성환 한국공업화학회 2003 Journal of Industrial and Engineering Chemistry Vol.9 No.4

Electrokinetic remediation was applied to the removal of heavy metals from mine tailing soils sampled from the piles at two abandoned mines (K and O) in which major contaminants were Cu, Pb, Cd, As and Zn. Experimental results on metal removal characteristics, tendency of electroosmosis, established soil pH profile and the role of citric acid as an electrolyte component were presented and discussed concerning to the buffering capacity and zeta potential of the soils. Since both tailing soils had positive zeta potential, electroosmotic flow formed toward anode and thus about 15-34% of removed metals were found in anode chamber, implying that the mechanisms of metal removal were by electromigration mostly and by electroosmosis in minor. The use of citric acid as an electrolyte component enabled us to maintain an acidic pH for the soil with a low buffering capacity (K soil), resulting in increased electroosmotic flow rate and 35-40% higher metal removal efficiency. Without the addition of citric acid, a steep pH gradient was developed in K soil and the electroosmotic flow rate was greatly diminished. For the soil with a high buffering capacity (O soil), there were no significant differences in pH gradient, eletroosmotic flow rate and metal removal, regardless the use of citric acid. Overall 37-41% of metals were removed for 2 weeks under the 2 conditions of 0.25 mA/cm(2) of current density and using electrolytes with 2.5 mS/cm conductivity.

산 완충능력과 토양 성분이 동전기-펜톤 공정에 의한 phenanthrene 오염토양 정화에 미치는 영향

김정환,나소정,박주양,변영덕,Kim, Jung Hwan,Na, So Jeong,Park, Joo Yang,Byun, Young Deog 한국지하수토양환경학회 2013 지하수토양환경 Vol.18 No.1

This research was conducted to investigate effects of acid buffering capacity and soil component in treatment of phenanthrene using electrokinetic-Fenton process. In Hadong clay of high acid buffering and low iron oxide content, it was difficult to oxidize phenanthrene due to shortage of iron catalyst and scavenger effect of carbonate minerals. The desorbed phenanthrene conductive to Fenton oxidation was transported toward cathode by electroosmotic flow. However, in Youngdong illitic clay, oxidation of phenanthrene near anode readily occurred compared to Hadong clay due to high iron content and low acid buffering capacity.

산성강하물이 지표수의 산성화에 미치는 영향 Ⅱ: 컬럼연구 및 현장조사

김영관,우경식 江原大學校 附設 環境硏究所 1997 環境硏究 Vol.14 No.-

토양층과 모암층에서의 산성우에 대한 중화능력을 평가하기 위하여 인공강우를 이용한 컬럼실험을 실시하였으며 토양을 이루고 있는 모암 특성의 차이에 의한 산성강하물의 환충효과를 비교하기 위하여 연구지역내의 모암의 조성광물에 차이가 있는 두 개의 골짜기를 선정하고 골짜기에 흐르는 지표수의 pH를 1996년 5월부터 1996년 10월까지 측정하였다. 컬럼실험에서 사용한 인공강우는 증류수에 황산과 질산을 적절히 첨가하여 pH를 각각 3,4, 및 5로 조절하였으며 컬럼유출수의 주요 양이온과 음이온을 측정하였다. A층위와 B층위의 양이온 교환용량(CEC)은 각각 9.68 meq/100g과 6.16 meq/100g 이었으며 인공강우의 살포시 컬럼유출수의 pH는 중간층토양에서보다 양이온 교환용량이 큰 표층토양에서 더 크게 나타났다. 컬럼유출수에서의 Ca^(2+), Mg^(2+), Na^(+)의 합이 점차로 감소하여 지속적인 산성우는 토양의 양이온 교환용량을 감소시키는 것으로 나타났다. 현장조사결과에 따르면 골짜기의 하류로 내려옴에 따라 지표수의 pH는 계속 증가하여 하류로 흐르는 과정에서의 완충효과를 나타내었다. 이러한 완충효과는 모암의 조성광물중 kaolinite와 illite이외에도 smectite를 함유하고 있는 골짜기에서 더 크게 나타나는 것이 특징적이었다. 이 결과는 토양층 뿐만 아니라 모암이 산성우의 완충용량을 가지고 있음을 나타내었다. A column study using artificial acid rain was conducted to evaluate the buffering capacities in soil layer and host rock. In an effort to compare the effect of composition of host rock, two valleys of which compositions of host rock are different were chosen within the study area and the pHs of the water flowing in the valleys were measured from May, 1996 to October, 1996. The pHs of the artificial acid rain prepared by adding appropriate amounts of both sulfuric and nitric acids to distilled water were 3,4,and 5, and the column effluents were analyzed for major cations and anions. The cation exchange capacities(CECs) of A Horizon and the B Horizon were 9.68 and 6.16 meq/100g, respectively. Compared to the B Horizon, the pH in the column effluent of A Horizon with larder CEC was higher. The sums of Ca^(2+), Mg^(2+) and Na^(+) in the column effluents gradually decreased, indicating the loss of CEC by acid rain. The field study showed that pHs of the surface water in the valleys increased as the water flows downwards. The magnitude of this buffering capacity was greater for the valley in which smectite in addition to kaolinite and illite was a weathered product of host rocks. This also indicates that host rock as well as soil layer retains the buffering capacity.

산성강하물이 지표수의 산성화에 미치는 영향 Ⅰ: 현장 조사

김영관,이동석,김만구,우경식 江原大學校 附設 環境硏究所 1997 環境硏究 Vol.14 No.-

Effects of acid deposition on the acidification of surface water over a short period were studied during June~October, 1995. A reservoir located in Chunchon, Kangwondo was selected for this study because this reservoir had received little man-made pollutants. Geological survey within the study area was carried out and the pH of a small and shallow stream flowing from the mountain valley down to the reservoir was monitored. Rainfall was measured by using a rain gauge and the precipitation was collected by automatic precipitation sampler. During the study period, rain pH was in the range of 3.81~5.77 with an average of 4.8. The EC was in the range of 8~189㎲/cm with an average of 10.6㎲/cm. Ionic composition of the rainfall showed that, of the anions, deposition of SO₄^(2-) was highest with 3,119.7 kg/㎢, and is was NH^(4+)with 1,053.2kg/㎢ for cations. The surface water pHs were maintained neutral or weak basic, representing little evidence of acidification regardless of the acidic rainfall pH. Every time of sampling, however, the pHs exhibited increasing tendency as elevation of measuring site of the stream become lowered, which indicated the impacts of acid-base reactions by acidic or basic substances during travel of water downstream. This result suggested the necessity of further research to determine the respective buffering capacity of soil and underlying rocks. 산성강하물이 단기간에 걸쳐 지표수의 산성화에 미치는 영향을 조사하기 위하여 1995년 6월 부터 10월까지 외부오염원이 거의 없는 강원도 춘천시에 위치한 저수지를 선정하여 인구를 수행하였다. 연구지역 일대의 지질을 조사하고 산골짜기에서 저수지로 흐르는 작고 얕은 하천의 수질을 분석하였다. 강우량은 우량계를 이용하여 측정하였고 강하물은 자동포집기를 이용하여 포집하였다. 연구기간동안의 강우의 pH범위는 3.81~5-77로 평균 4.8을 나타내었으며 전기전도도(EC)sms 5~189㎲/cm로 평균 10.6㎲/cm를 나타냈다. 음이온 중에서는 SO₄^(2-)의 강하량이 3,119.7kg/㎢로 가장 많았고, 양이온 중에서는 NH^(4+)가 1,053.2kg/㎢로 가장 많았다. 지표수의 pH는 중성 또는 약염기성으로 강우의 pH가 산성이었음에도 지표수의 산성화 현상은 관찰되지 않았다. 그러나 골짜기에서 흐르는 하천수를 측정할때마다 측정지점의 고도가 낮아질수록 pH값은 증가하는 경향을 나타내어 물이 하류로 흘러가는 동안에 일어난 산성 또는 염기성물질로 인한 산염기반응의 영향을 보여주었다. 이 결과는 토양의 완충능력과 모암내에서의 중화능력을 각각 구별하여 조사할 필요성을 제시하였다.

Synthesis and Characterization of Polyester-Based Dendrimers Containing Peripheral Arginine or Mixed Amino Acids as Potential Vectors for Gene and Drug Delivery

Silvana Alfei,Sara Castellaro 한국고분자학회 2017 Macromolecular Research Vol.25 No.12

Macromolecular systems with well-defined sizes, shapes and high controlled architecture like dendrimers are of eminent interest in nanomedical applications such as drug delivery, gene transfection, and imaging. In this paper versatile protocols for the synthesis of polyester-based, hydrolysable, polycationic dendrimers have been setup. Fourth and fifth generation dendrimers equipped with several peripheral hydroxyl groups were prepared from 2, 2-bis(hydroxymethyl)propanoic acid. They were successfully esterified with arginine alone or mixed with lysine or O-methyltyrosine and with dipeptide arginine-glycine and seven polycationic dendrimers were finally obtained as hydrochlorides. Their structures and composition were confirmed by NMR analysis and by experimental molecular weight computed by volumetric titration and their buffer capacity was higher than fourth generation polyamidoamine (G4- PAMAM) derivatives taken as reference. The synthesized dendrimers harmonize a polycationic character and a buffer capacity which presuppose a good transfection efficiency with a degradable scaffold thus appearing as a promising team of new non-toxic vectors for biomedical applications.

산성우(酸性雨)에 대한 산림생태계(山林生態系)의 민감도(敏感度) 및 자정기능(自淨機能)(II) - 식생층(植生層)과 토양층(土壤層) 용탈(溶脫)이온 분석(分析)을 중심으로 -

장관순,이수욱,Chang, Kwan Soon,Lee, Soo Wook 한국산림과학회 1995 한국산림과학회지 Vol.84 No.1

산림생태계(山林生態系)의 산성우(酸性雨)에 대한 완충능(緩衝能)과 민감성(敏感性)을 분석하기 위해서 리기다소나무림(林) 굴참나무림(林)의 수관통과수(樹冠通過水), 수간류(樹幹流) 및 토양층 용탈용액(溶脫溶液)의 성분을 각각 분석하였고, GIS의 IDRISI system을 이용하여 토양도(土壤圖)와 식생도(植生圖)를 영상(映像) 변환(變換)시킨 후 중첩시켜 토양(土壤) 모암(母岩)에 따른 임상(林相)의 분포를 분석하였다. 모암(母岩) 및 토양(土壤)은 산성암(酸性岩), 퇴적암(堆積巖)으로 구분하고 산성(酸性), 중성(中性), 염기성(鹽基性), 변성잔적토(變成殘積土)로 세분하였다. 식생층(植生層)을 통과한 강우의 평균 pH는 굴참나무림(林)보다 리기다소나무림(林)에서 낮았으며, 두 수종 모두 임외강우(林外降雨)보다 수관통과수(樹冠通過水)에서는 높은 반면에 수간류(樹幹流)에서 낮았다. 식생층(植生層)을 통과한 강우(降雨)내 $SO{_4}^{2-}$, $NO_3{^-}$ 및 $Cl^-$의 양은 수관통과수(樹冠通過水)보다 수간류(樹幹流)에서 높았고, 토양으로 투입되는 $SO{_4}^{2-}$, $NO_3{^-}$ 및 $Cl^-$ 양은 임외(林外)보다 리기다소나무림(林)에서 각각 7.2, 4.3 및 2.5배, 굴참나무림(林)에서 각각 4.4, 2 및 2.5배 많았으며 굴참나무림(林)보다 리기다소나무림(林)에서 많았으나, 치환성(置換性) 양이온의 농도는 리기다소나무림(林)에서 4.1배, 굴참나무림(林)에서 4.6배로 굴참나무림(林)에서 높았다. 토양층(土壤層) 용탈용액(溶脫溶液)의 평균 pH는 수관통과수(樹冠通過水) pH보다는 낮은 반면에, 수간류(樹幹流)보다 높은 경향을 보였으며, 수종별(樹種別)로는 리기다소나무림(林) 지역에서 낮았다. 산성물질(酸性物質)에 의해서 토양층(土壤層)으로부터 용탈되는 양료(養料)와 $Al^{3+}$ 양(量)은 관엽수림(關葉樹林)보다 침엽수림(針葉樹林)이 많았고, 이들 양은 토양(土壤) 용탈용액(溶脫溶液)내 산성물질(酸性物質) 증가함에 따라 유의적으로 증가하였다. 산림생태계중(山林生態系中) 리기다소나무림(林)은 식생층 용탈용액에 $SO{_4}^{2-}$, $NO_3{^-}$ 및 $Cl^-$ 양이 많은 것으로 보아 산성물질(酸性物質)의 침적량(沈積量)과 차단량(遮斷量)이 많은 것으로 인정되는 동시에 토양으로부터 양료손실이 많았고 반면 굴참나무림(林)은 수관층(樹冠層)에서 양(陽)이온치환(置換)과 $H^+$ 소비가 많았고, 토양에서 양료손실(養料損失)이 적어 식생과 토양층의 완층력(緩衝力)이 우수했다. 대전지역의 산림토양은 산성암잔적토가 69%, 퇴적 및 변성암잔적토가 25%, 중성 및 염기성암잔적토는 6%를 차지하고 있는데, 양이온 치환용량(置換容量)이 부족한 산성암(酸性岩)에서 풍화된 토양(土壤)이 가장 많은 면적을 차지하고 있었고, 산성우(酸性雨) 대해서 가장 민감성(敏感性)을 나타내는 산성암이면서 동시에 침엽수림(針葉樹林)으로 구성된 임지는 소나무림(林)과 리기다소나무림(林)林으로 전체 면적중 50%를 차지하고 있었다. To estimate buffer capacity and sensitivity of forest ecosystem to acid rain in Taejon, ionic components of throughfall, stemflow, soil leachate, and open rain in Pinus rigida and Quercus variabilis forest were analysed. The spatial sensitivity based on parent rock and forest type was given by IDRISI of GIS which created imagery conversion from soil and vegetation map. Parent rocks and soils were classified into acidic, sedimentary, metamorphic rock and then subdivided based on $SiO_2$ content. Average pH of vegetation leachate was higher in throughfall but lower in stemflow than open rain and higher in Quercus variabilis forest than in Pinus rigida forest. The flow of $SO{_4}^{2-}$, $NO_3{^-}$ and $Cl^-$ through vegetation leaching(throughfall plus stemflow) into soil were 7.2, 4.3, and 2.5 times, respectively, higher in Pinus rigida forest and 4.4, 2, and 2.5 times, respectively, higher in Quercus variabilis forest than in open field. But the concentration of exchangeable cations was 4.1 times higher in Pinus rigida forest and 4.6 times higher in Quercus variabilis forest than in open field. Average pH of soil leachate was lower than that of throughfall, but higher than that of stemflow. The concentration of exchangeable canons and $Al^{3+}$ in soil leachate were more in Pinus rigida forest than in Quercus variabilis forest and increase signficantly with the increase of acidic deposits. Pinus forest had more deposition and canopy interception of acidic pollutants and more nutrient loss than Quercus forest, and Quercus forest had more cation exchange and proton consumption and than consequently had less nutrient loss and better buffer capacity than Pinus forest. The 69% of forest soils was distributed on acidic rock, 25% of it on metamorphic rock, and 6% of it on intermediate and basic rock. Acidic rock residuals which had low very canon exchange capacity and high sensitivity to acid rain occupied a half of total forest land in Taejon area. Therefore forests in Taejon showed high vulnerability to acid rain and will receive much more stress with the increase of acid rain precursors.

人工酸性雨가 몇 樹種의 發芽, 生長 및 土壤緩衝能의 變化에 미치는 影響

閔一植 中部大學校 農業開發硏究所 1993 農業開發硏究論文集 Vol.2 No.-

大氣汚染 및 酸性雨로 인한 森林生態 環境의 被害變化를 구명하기 위하여 人工酸性雨를 조제하여 pH水準別(pH 5.7, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5)로 분류하여 몇가지 주요 造林用 및 造景用 樹木의 種子發芽率, 苗木의 生長量 및 忠南 林葉試驗場 부근 造林植生分布地域의 土壤에 대한 緩衝能을 酸度의 變化를 中心으로 분석한 결과 다음과 같은 結論을 얻었다. 1. 人工酸性雨 處理에 의한 種子의 發芽率은 pH 5.0 處理區을 제외하고는 전체 處理區間에서 모두 針葉樹의 發芽率이 높게 나타났으며, pH 4.5 以下부터는 pH가 減少함에 따라 針葉樹 및 闊葉樹 모두 發芽率이 減少하는 경향을 보였다. 2. 針葉樹의 경우 삼나무와 落葉松을 제외하고 人工酸性雨 處理水準別로 有意性이 인정되었다. 리기테다소나무 및 잣나무는 pH 5.0 處理區에서 最大 發芽率이 나타났고, 리기다소나무는 pH 4.0 以下에서, 소나무 및 海松은 pH 3.0 以下에서, 편백나무는 pH 2.0 以下에서 有意的인 差異를 나타내었다. 闊葉樹의 경우 人工酸性雨 處理에 따른 發芽率의 反應은 느티나무 및 목백합나무는 pH 4.5 處理區에서 가장 양호하였으며, 참싸리나무는 전체 處理區間에 대한 有意性이 인정되지 않았다. 3, 人工酸性雨를 酸度別로 處理한 苗木의 生長變化는 단풍나무를 제외하고 모두 pH 處理別로 有意性이 인정되었으며, pH가 減少할수륵 樹高 및 根元徑의 生長도 減少하였다. 4. 針葉樹의 경우 잣나무 및 落葉松은 pH 4.5 處理區에서 樹高 및 根元徑의 生長이 가장 양호하였으며, 개잎갈나무의 경우 樹高는 pH 5.0 處理區에서, 根元徑은 pH 4.0 處理區에서 가장 양호하였다. 5. 闊葉樹의 경우 단풍나무를 제외하고 모두 pH 3.0부터 pH 4.5 處理區에서 樹高 및 根元徑의 生長이 양호하였으며, pH 3.0 以下에서는 生長의 減少가 有意的으로 나타났다. 6. 人工酸性雨 處理에 의한 土壤緩衝能의 酸度變化는 人工酸酸性雨의 pH가 減少함에 따라 土壤溶脫溶液의 pH도 減少하였으며, pH 3.0以下 處理區에서는 溶脫溶液의 pH가 급격히 減少하였다. 7. pH 3.0 및 pH 4.0 處理區의 경우 溶脫溶液의 酸度變化는 자작나무地域의 pH가 가장 높았고, 리기테다소나무地域이 가장 낮았다. 8. 人工酸性雨의 각 pH 水準別로 처리한 전체 1,000㎖의 投入溶液에 대한 每 250㎖씩 측정한 土壞溶脫溶液의 酸度의 變化는 無處理區의 경우 자작나무地域의 溶脫溶液 pH가 가장 높게 나타났으며, pH 3.0 處理區까지 針葉樹林地域의 pH가 闊葉樹林地域보다 낮게 나타났다. 9. 投入溶液量의 增加에 따른 變化는 無處理區는 投入溶液 1,000㎖까지도 曲線의 기울기가 다소 增加하였으며, pH 5.0 處理와 pH 4.0 處理區에서는 投入溶液 750㎖까지는 增加하였으나 그 이후부터는 增加率이 다소 減少하였다. pH 3.0 處理區는 500㎖부터 減少現象이 나타났고, pH 2.5 處理區는 溶脫溶液의 pH가 급격히 減少하는 경향이 나타났다. A research effort has been made to determine the influence of germination rate, seedling growth, and foest soil buffer capacity, near by Chungnam Forest Research Institute, treated by artificial acid precipitation (pH 5.7, 5.0, 4.5, 4.0, 3.5, 3.0, 2.5) in some tree species. The following conclusions have been drawn in response to the overall research objectives ; 1. Germination rate in coniferous species treated by artificial acid precipitation was higher in total pH levels than in deciduous, except in the level of pH 5.0. Below pH 4.5 level, germination rate in coniferous and deciduous species decreased with artificial acid precipitation pH. 2. Changes of seedling growth were significant with the pH levels of artificial acid precipitation, except in Acer. That is, low artificial acid precipitation pH induced the decrease with seedling height and root collar diameter. 3. Soil leachate pH for soil buffer capacity decreased as artificial acid precipitation decreasing. And then below the level of pH 3.0, soil leachate pH rapidly decreased. 4. Soil leachate pH treated by the pH levels in 1,000㎖ of acidic input solution was the highest in Betula. And leachate pH in coniferous species were higher than in deciduous until in pH 3.0 level. 5. Changes of increasing amount of artificial acid precipitation each pH level first increased to total 1,000㎖ in Control. Then below the level of pH 5.0 and pH 4.0, soil leachate pH increased when inputted to 750㎖, but in lower pH levels, increasing rate somewhat lessened. Below level of pH 3.0 decreasing tendency was appeared from 500㎖ in amount of input solution, especially in pH 2.5, change of leachate pH rapidly dropped.

4종 촤화류에 대한 pH 수준별 처리가 잎의 완충능력, chlorophyll 함량 및 무기성분 용출에 미치는 영향

김학윤 한국생명과학회 2001 생명과학회지 Vol.11 No.3

This study was conducted to investigate the effect of simulated acid solution(SAS) on acid buffering capacity, chlorophyll content and butrient leacking in 4 herb species(Petunia hybrida Vilm, Gomphrena globosa L. Celosia cristat L. Salvia officinallis L) . The acid buffering capacity in the leves was increased in the treatment of pH 3.0 in Celosia L., whereas it was increased at pH 4.0 in Petunia Petunia hybrida Vilm. and Gomprean globosa L.. But, the acid buffering capacity of the leaves did not work at ph 2.0 treatment in 4 herb species. With decreasing pH level, the chlorophyll content of Petunia hybrida Vilm. and Gomphrena globosa L. Was markedly decreased than that of Gelosia cristata L. and Savia officinalis L. As the pH levels decreased from 5.6 to 2.0 the nutrient leaching from leaves was significantly increased in 4 herb species. In pH 4.0 and 5.6, the concentrations of nutrient leaching from leaves were higher in Perunia hybrida Vilm. and Gomphrean globosa L. than Gelosia cristata L. and Salvia officinalis L., Based on the results, there was a great differences in response to SAS among the 4 herb species. Im general, Gelosia cristata L. and Salvia officinalis L. represented a higher tolerance to SAS Petunia hybrida Vilm, and Gomphrena globosa L..

Effects of Dietary Buffering Characteristics and Protected or Unprotected Acids on Piglet Growth, Digestibility and Characteristics of Gut Content

Bosi, P.,Jung, H.J.,Han, In K.,Perini, S.,Cacciavillani, J.A.,Casini, L.,Creston, D.,Gremokolini, C.,Mattuzzi, S. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.7

We condicted two experiments to evaluate the interaction among fumaric acid (FA), protected acids (PA), or no additional acid (NO) and two different levels of acid buffering capacity (BC) in diets for 14-d-old weaned pigs. BC was varied substituting mono-calcium phosphate and calcium sulfate for dicalcium phosphate and calcium carbonate. In the high BC diet plus PA, FA was also added. In Exp. 1, 48 gilts were raised for 31 days on the six diets, evaluating growth performance and fecal digestibility. In Exp. 2, 42 gilts were raised. With each diet three subjects were sacrificed after 19 days and four after 38 days. In addition, six subjects were sacrificed at weaning. Growth and carcass performance, ileal digestibility, bacterial populations and pH in the gut were assessed. The piglet performance and stomach, ileal and cecal pH, and empty body composition were not affected by the diets. Empty body composition other than ash content was affected by piglet age (p<0.01). The BC did not influence digestibility. The dietary inclusion of PA improved fecal digestibility of protein (p<0.05) compared to the addition of FA and NO. Ileal digestibility slightly increased with both acid additions (p<0.10), the groups receiving PA showing the higher values. Piglets fed diets with low BC had lower Lactobacillus and E. coli counts in the ileum (p=0.07) and higher Lactobacillus in the colon (p=0.08). Acidified diets tended to reduce E. coli counts in the ileum (p=0.10) and increased Lactobacillus in the colon (p=0.09). The addition in the diet of PA increased Lactobacillus in the ileum compared to the sole addition of free fumaric acid (p=0.07). The addition of protected acids, combined with free fumaric acid in the case of high BC diets, increased protein digestibility and Lactobacillus counts and reduced E.coli counts. Only some changes in the concentration of bacterial population can be expected with a diet of low BC.