• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.192-195
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• 2003

The hight density sludge process (HDS) is a process that has been developed to achieve greatly increased sludge densities compared to those resulting from conventional pH modification systems. This study was carried out to apprehend variation of sludge properties and removal of metals during recycling of the sludge. The principal neutralization and settlement took place in neutralization beaker and mass cylinder. Sludge was recycled, as a volumetric ratios of 20%, 40% and 60%. The pH was controlled in neutralization tanks near 9.5. The average lime consumption rate was about 10g per L of AMD. The increment of sludge density was correlated with the volumetric ratios of recycled sludge.

• Archives of Pharmacal Research
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• 제18권5호
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• pp.314-319
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• 1995

Antacid granules were prepared by agglomeration and powder method in high speed agitation type granulator. The copmositions of the test antacids were sodium bicarbonate nad magnesium carbonate nad a coating material was powder of polyvinylacetal diethyl-aminocacetate (AEA) and an additive material was talc powder. The dissolution characteristics of base from the antacid granules were investigated to evaluate neutralization capacity of hydrochloric profile of base and neutralization behavior, the following results were obtained : The prepared granules showed a pH-dependent dissolution pattern of a base. The dissolution profile of a base was varied with addition of talc powder as well as coating amount of AEA. The relationship between the ratio of dissolution retarded time for 20% and 10% AEA. The relationship between the ratio of dissolution retarded time for 20% AEA coated granules $\theta_{20}/\theta_{10}$ and the diameter reduction of the granules was explained by the rate process of neutralization of hydrochloric acid.

• 펄프종이기술
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• 제29권3호
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• pp.87-94
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• 1997

As the paper market becomes more and more competitive, more mills will want to switch to alkaline papermaking to take advantage of the Vowing demand. Many papermakers have tried to do this without success in the past much like the American papermakers did in the late 1970's. The Problem is that runnability Problems occur, drainage slows, Presses pick drying becomes more difficult and sheet quality suffers as a result Sheet holes and breaks occur, and runnability becomes a real operating problem. Converting to alkaline papermaking is not as simple as turning off the alum. We must be aware of the numerous factions that alum served at acid pH and provide alkaline alternatives. It is the purpose of this paper to discuss methods of deposit control via charge neutralization and system control at alkaline pH. This article explains the concept as well as the measurement and control. The resultant benefits are seen in runnability, quality and profitability for the papermaker.

• 한국축산시설환경학회지
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• 제18권sup호
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• pp.13-20
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• 2012

연구는 양돈분뇨의 액비화 처리과정 중 농지환원 직전단계인 액비 후숙처리 단계에 있어서 $SCOD_{Mn}$ 농도 및 산도(pH)의 조정이 후숙액비의 이화학적성상에 미치는 영향을 알아보고 적절한 후숙 액비화 공정을 구축하기 위하여 수행하였으며, 실험결과를 요약하면 다음과 같다. 1. $SCOD_{Mn}$ 감소율은 알칼리발효 처리구에서 평균 29.9%, 인산중성화 처리구에서는 평균 36.9%로 인산 중성화 처리구가 비교적 높은 감소율을 보였다. 2. 30일간 처리 후 $SCOD_{Mn}$의 농도가 가장 낮은 처리구는 유입농도가 가장 낮았던 인산 중성화 처리구 T-6이다. 후숙 액비의 목표수준을 $SCOD_{Mn}$ 3,000 ppm 이하로 가정할 경우 후숙 발효조의 초기 투입농도는 5,500 ppm 이하로 조정하는 것이 적합하다고 사료된다. 3. 질소의 잔존율은 알칼리발효 처리구에서 평균 29.3%, 인산중성화 처리구에서 평균 38.9%로 인산중성화 처리구가 비교적 질소의 손실이 적은 한편, T-P의 경우 인산중성화 처리구에서 높은 농도(평균 1,473 ppm)로 유지되었다. 4. 본 연구를 통해 액비 후숙처리 시 '저인산-저질소'의 형태는 "알칼리발효 처리구", '고인산-고질소'의 형태는 "인산중성화 처리구"의 조건이 유리할 것으로 기대된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.142-152
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• 2014

In this study, generic characteristics of the acid mine drainage (AMD), removal efficiency of iron, aluminium and manganese by chemical treatment, electrolysis and hybrid process using electrolysis after neutralization were evaluated. The pH of AMD was inversely proportional to the rainfall. In dry-season, the average pH of AMD was ranged from 4.5 to 5.5, showing slight variation. However, the pH of AMD was gradually decreased along with rainfall and dropped to 3.02 in September showing the greatest rainfall. Removal efficiency of heavy metals by chemical treatments using three different neutralizing agents or by electrolysis was low. However, a hybrid process performed with electrolysis after addition of neutralization shows higher removal capacity for heavy metal ions than neutralization-alone and electrolysisalone process.

• 한국환경과학회지
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• 제18권12호
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• pp.1411-1416
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• 2009

Several adsorbents were tried to remove the selenium ions from industrial wastewater and the following ascending order of the adsorption performance for the selenium at pH 9 was observed: cation exchange resin < chelate resin < zeolite < brown marine algae < granular activated carbon < anion exchange resin. Initial concentration of selenium(146 mg/L) in industrial wastewater was reduced to 63 mg/L of selenium at pH 9 by neutralization process. The maximum uptake of Se calculated from the Langmuir isotherm with anion exchange resin was 0.091 mmol/g at pH 10 and that with granular activated carbon was 0.083 mmol/g at pH 6. The affinity coefficients of Se ion towards anion exchange resin and granular activated carbon were 3.263 L/mmol at pH 10 and 0.873 L/mmol at pH 6, respectively. The sorption performance of anion exchange resin at the low concentration of Se, namely, was much better than that of granular activated carbon. The Se ions from industrial wastewater throughout neutralization process and two steps of adsorption using anion exchange resin was removed to 97.7%.

• 한국환경농학회지
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• 제19권1호
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• pp.72-74
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• 2000

우리나라 강우의 산성도 중화에 미치는 $NH_4\;^+$ 및 $Ca^{2+}$ 영향을 평가하기 위하여 '98년 5월부터 10월까지 6개월 동안 수원, 안성 및 태안지역에 내린 강우의 주요 이온들의 함량을 조사한 결과, $[H^+]+[NH_4\;^+]+[Ca^{2+}]$의 역대수값으로 계산되는 이론적 산성도는 측정된 pH값에 비해 각각 7.9, 8.7 및 6.5배 높았다. 또한 빗물의 산성도 중화에는 $NH_4\;^+$가 $Ca^{2+}$ 보다 기여도가 컸으며, 지역별 $Ca^{2+}$의 영향은 수원지역이 안성 및 태안지역에 비해 크게 나타났다.

• 자원리싸이클링
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• 제16권6호
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• pp.39-45
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• 2007

황동 전구 base 제조과정에서 발생하는 황산폐수에 함유된 구리와 아연의 농도를 저감시키기 위해 중화법에 의한 최적조건을 조사하였다. 구리와 아연이 함유된 황산용액에 대해 화학반응과 물질수지를 고려하여 용액의 pH에 따른 구리와 아연의 농도분포와 용해도를 구하였다. 구리와 아연의 수산화물이 침전되는 pH영역에서 아연의 용해도가 구리의 용해도보다 크므로, 구리에 비해 아연의 제거율이 용액의 pH에 민감하였다. 응집제로 $Al_2(SO_4)_3$를 첨가하는 경우 아연의 제거율은 응집제의 첨가형태에 영향을 받지 않았으나, 구리의 경우에는 용액으로 첨가하는 것이 고체상태로 첨가하는 것보다 제거율이 높았다.

• 콘크리트학회논문집
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• 제16권3호
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• pp.311-318
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• 2004

농업부산물인 볏짚재를 혼입한 다공성콘크리트 블록의 공학적 특성과 다공성 블록내 식생 특성을 평가하기 위하여 수행되었으며, 공극률과 중성화 처리 시점 및 양생방법에 따른 다공성콘크리트의 압축강도, 휨강도 및 pH 등을 측정하였고, 개발된 다공성 블록내 잔디, 참싸리, 비수리를 파종하여 식생 특성에 대한 연구를 수행하였다. 연구결과, 볏짚재의 혼입량이 증가함에 따라 공극률은 감소하였고, 강도는 혼입량이 증가함에 따라 증가하였으며, 재령 6일에 중성화 처리를 한 경우 의 강도가 가장 크게 나타났다. pH는 기건양생보다는 수중 생한 경우 저감효과가 우수하였으며, 수중양생과 중성화 처리를 병행할 경우 중성화처리 시점에 관계없이 높은 pH저감 효과를 나타내었다. 개발된 다공성 블록에 잔디, 참싸리, 비수리를 식생한 결과 잔디의 성장속도가 가장 우수하였으며, 참싸리와 비수리는 초기성장속도는 늦었으나, 장기적으로 성장이 우수하여 일반적인 토양에서와 비슷한 성장길이를 나타내어 블록내 식생이 가능한 것으로 나타났다. 또한, 시멘트의 일부로 볏짚재를 혼입한 다공성 콘크리트불록을 개발하였으며, 다공성 블록내 식생이 가능하여 식생블록에 대한 현장 적용이 가능할 것으로 판단된다.

• 공업화학
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• 제33권1호
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• pp.109-112
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• 2022

Lime has been used for the neutralization of acidic waste because it is cheap and available in large quantities. The resulting sludge often contains a considerable amount of unreacted lime due to alkali overdosing, even during automatic neutralization processes, which mainly arises from the poor solubility of lime. The sludge cake from lime neutralization of Ilkwang Mine also contained high percentages of calcium and magnesium. The elemental content of the sludge cake was compared with those obtained from a simulation of the lime neutralization facility installed at Ilkwang Mine. A Goldsim^® model estimated the degree of lime overdosing to be 19.1% based on the fractions of ferrous oxide. The analysis suggests that resolubilization of aluminum hydroxide could occur in the settling basin, in which pH exceeded 10 due to the continued dissolution of the overdosed lime. The present study demonstrated that chemical analysis of sludge combined with process simulation could provide a reasonable estimate of mass balance and chemistry in a neutralization facility for acid mine drainage.