• 대한토목학회논문집
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• 제26권1B호
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• pp.51-60
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• 2006

산업활동으로 인해서 발생하는 제강슬래그와 최근 선진국에서 환경개선 및 오염방지를 위한 용도로 활용하고자 활발히 연구되고 있는 제올라이트 등의 다공성 재료를 오염된 하천의 정체수역에 설치하여 저비용으로 수질을 개선시킬 수 있는 기법은 폐기물의 재이용 측면과 하천수질개선 측면에서 매우 필요하다. 현재 제철소에서 발생하는 부산물인 제강슬래그의 화학적성분은 주로 CaO, $SiO_2$, $Al_2O_3$, $Fe_2O_3$ 등으로 이루어져 있으며, 침전유발물질 및 흡착성물질이 함유되어 있다. 제강슬래그는 다공질 형태의 비표면적을 가지고 있어서 정화용 필터나 흡착재로 이용하기에 좋은 이점을 지니고 있다. 그리고 제올라이트는 양이온 교환특성, 흡착특성, 촉매특성, 탈수 및 재흡수특성 등의 이점을 지니고 있어서 축산농가의 환경개선, 도시의 생활하수의 처리, 공업폐수 처리, 음료수 수질개선, 방사성폐기물 처리 및 방사성 물질의 오염방지 등에 응용되고 있다. 그러므로 제강슬래그나 제올라이트를 Mattress/Filter의 채움재 및 수질정화용 여재로 활용함으로써 수질개선 등 효과를 동시에 얻을 수 있다. 본 연구에서는 제강슬래그와 제올라이트가 정체수역에 설치되는 Mattress/Filter시스템의 채움재로 활용할 때 공극률에 따른 수질개선효과를 파악하기 위하여 공극률을 38.6%인 P1, 45.8%인 P2 및 49.8%인 P3로 변화시켜 각각의 유입수와 유출수의 pH, DO, T-N, T-P 등을 측정하여 비교하였다. 수질개선에 사용된 Mattress/Filter시스템은 오염된 하천수가 Mattress/Filter시스템의 공극사이를 통과하면서 채움재에 형성된 다공질에 의한 여과작용과 생물막에 의한 접촉작용, 흡착작용 및 생물분해작용 등을 촉진시키는 기능을 가지고 있음을 알 수 있었다. 제강슬래그 및 제올라이트를 채움재로 사용한 Mattress/Filter 시스템은 쉽게 생물막을 형성시키고 유기물의 흡착을 촉진시켜 오염물질을 정화하는데 필요한 자정작용의 효과를 증대시키고 수질개선을 촉진시킬 수 있는 자연환경에서 하천정화에 이용될 수 있는 시스템임을 확인할 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.172-172
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• 2011

Anaerobic digestion(AD) has successfully been used for many applications that have conclusively demonstrated its ability to recycle biogenic wastes. AD has been successfully applied in industrial waste water treatment, stabilsation of sewage sludge, landfill management and recycling of biowaste and agricultural wastes as manure, energy crops. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is primarily composed of methane(CH4) and carbon dioxide(CO2) with smaller amounts of hydrogen sulfide(H2S) and ammonia(NH3), trace gases such as hydrogen(H2), nitrogen(N2), carbon monoxide(CO), oxygen(O2) and contain dust particles and siloxanes. The production and utilisation of biogas has several environmental advantages such as i)a renewable energy source, ii)reduction the release of methane to the atomsphere, iii)use as a substitute for fossil fuels. In utilisation of biogas, most of biogas produced from small scale plant e.g. farm-scale AD plant are used to provide as energy source for cooking and lighting, in most of the industrialised countries for energy recovery, environmental and safety reasons are used in combined heat and power(CHP) engines or as a supplement to natural. In particular, biogas to use as vehicle fuel or for grid injection there different biogas treatment steps are necessary, it is important to have a high energy content in biogas with biogas purification and upgrading. The energy content of biogas is in direct proportion to the methane content and by removing trace gases and carbon dioxide in the purification and upgrading process the energy content of biogas in increased. The process of purification and upgrading biogas generates new possibilities for its use since it can then replace natural gas, which is used extensively in many countries, However, those technologies add to the costs of biogas production. It is important to have an optimized purification and upgrading process in terms of low energy consumption and high efficiency giving high methane content in the upgraded gas. A number of technologies for purification and upgrading of biogas have been developed to use as a vehicle fuel or grid injection during the passed twenty years, and several technologies exist today and they are continually being improved. The biomethane which is produced from the purification and the upgrading process of biogas has gained increased attention due to rising oil and natural gas prices and increasing targets for renewable fuel quotes in many countries. New plants are continually being built and the number of biomethane plants was around 100 in 2009.

• Advances in environmental research
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• 제6권1호
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• pp.35-51
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• 2017

The use of Granular Activated Carbon (GAC) and naturally occurring silica (Sand) as filtration media in water and waste water treatment systems is very common. While GAC offers the additional functionality of being an "adsorptive" filter for dissolved organics it is also more expensive. In this paper we present an experimental evaluation of the performance of a bed of GAC for colloid removal and compare the same with that from an equivalent bed of Sand. The experiments are performed in an "intermittent" manner over extended time, to "simulate" performance over the life of the filter bed. The experiments were continued till a significant drop in water flow rate through the bed was observed. A novel "deposition" and "detachment" rate based transient mathematical model is developed. It is observed that the data from the experiments can be explained by the above model, for different aqueous phase electrolyte concentrations. The model "parameters", namely the "deposition" and "detachment" rates are evaluated for the 2 filter media studied. The model suggests that the significantly better performance of GAC in colloid filtration is probably due to significantly lower detachment of colloids from the same. While the "deposition" rates are higher for GAC, the "detachment" rates are significantly lower, which makes GAC more effective than sand for colloid removal by over an order of magnitude.

• 생명과학회지
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• 제6권1호
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• pp.14-26
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• 1996

In order to effectively utilize fish(Cod, Gadus macrocephalus) bone obtained as fish waste in fish manufactory, the preparation of the fish bone gelatin were attempted by heat extracting method from collagen protein contained in the fish bone. The methods of two kinds pretreatments (the B-type by alkali pretreatment and the E-type by enzyme pretreatment) for fish bone and the optimal extraction conditions to prepare gelatin from pretreated fish bone were investigated. Physical properties and functionalities of the two type fish bone gelatins obtained were compared with the commercial gelatin and the fish skin gelatin. The optimal extraction conditions of the B-type and the E-type gelatins were 5 folds of added water with material(w/w), pH 5.0, 3 hrs of extraction time and 60$\circ$C of extraction temperature. The yield of the B-type and the E-type gelatins were 32.6% and 28.1 %, respectively. The B-type gelatin was superior to the E-type un all physical properties. Molecular weight of the B-type was larger than that of the E-type due to its pretreatment method. Among the composition of amino acids, the amino acids such as glycine, alanine, glutamic acid and imino acids(proline and hydroxyproline) were responsible for 68$\sim$70% of the total amino acids. Functionalities of the fish bone gelatin were almost similar to commercial gelatin.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권6호
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• pp.1-9
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• 2005

토양오염으로 인해 피해가 발생하면 그 피해배상과 토양오염정화에 대한 책임을 진다. 이러한 책임은 민사상의 일반적 책임과는 다르다. 토양환경보전법상으로는 피해에 대하여 과실책임이 아닌 무과실책임을 지우고 있으며, 공동의 책임인 경우에는 연대책임(부진정연대책임)을 지우고 있다. 이것은 피해자의 구제를 용이하게 하기 위한 것이다. 그리고 토양정화책임과 그에 따른 비용책임에 대하여도 소급책임, 엄격책임, 연대책임을 지게하고 있다. 다만 천재지변과 전쟁으로 인한 경우에는 면책하고 있다. 책임당사자는 오염유발자와 토양오염시설의 소유 또는 점유자 및 운영자, 그리고 그 시설을 양수한 자 및 인수자로 규정하고 있다. 이와 관련하여 책임당사자가 불명하거나 무자력 등으로 인하여 책임을 질 수 없는 경구에 결국 국가가 책임을 짐으로써 국민의 조세부담을 가중시킬 염려가 있다 따라서 책임당사자의 범위를 확대시키거나 정화비용에 대한 기금제도의 활용이 요청된다

• International journal of advanced smart convergence
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• 제4권1호
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• pp.154-161
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• 2015

A novel process has successfully been developed by overcoming major difficulties through the elimination of number of process steps involved in the Classical Transesterification reaction during the preparation of Fatty Acid Methyl/Ethyl Ester (FAME.FAEE) called biodiesel. The Classical process with cost intensive process steps such as the utilization of excess alcohol, needing downstream distillation for the recovery and reutilization of excess alcohol/cosolvent, unrecoverable homogenous catalyst which consumes vast quantity of fresh distilled water during the purification of the product and downstream waste water treatment before its safe disposal to the surface water body. The Novel Process FAME/FAEE is produced from any vegetable oil irrespective of edible or inedible variety using sonication energy. The novelty of the finding is the use of only theoretical quantity of alcohol along with a co-solvent and reduced quantity of homogeneous catalyst. Under this condition neither the homogeneous catalyst goes to the FAME layer nor is the distillation needed. The same ester also has been prepared in high pressure high temperature reactor without using catalyst at sub critical temperature. The quality of prepared biodiesel without involving any purification step meets the ASTM standards. Blended Biodiesel with Common Diesel Fuel (CDF) and FAME is prepared, characterized and used as fuel in the Kirloskar make CI Engines. The evaluation of the engine performance result of pure CDF, B05 biodiesel, B10 biodiesel of all types of biodiesel prepared by using the feedstock of Soybean (Glycine max) and Karanja (Pongamia pinnate) oil along with their mixed oil provides useful information such as brake power, brake thermal efficiency, brake specific fuel consumption, etc, and established it as ideal fuel for unmodified CI engine.

• 상하수도학회지
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• 제26권1호
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• pp.123-129
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• 2012

A septic tank is a purification treatment system where night soil and other waste matter is converted into harmless material by the activities of bacteria. Effluent from the septic tank flows into the sewer pipe, and then this effluent affects the quality of water environment and makes foul smell. In this study, through the proper maintenance of septic tank it was tried to minimize the impact of sewer pipe on water quality and fouling smell. BOD removal rate from the septic tank's effluent which exceeded legal cleaning period was investigated for the proper maintenance. BOD Removal rate of the twelve septic tank's effluent is -62.5% to 43.9%. According to the result of BOD removal rate, septic tank cleaning should be done at least once a year. And the pathogenic coliform bacillus in the twelve septic tank's effluent is average 768,000 (MPN/$100m{\ell}$). The chlorine disinfection is needed to remove the pathogenic coliform bacillus in septic tank effluent.

• Elastomers and Composites
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• 제47권2호
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• pp.96-103
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• 2012

본 논문에서는 PET를 재활용하는 최근의 기술들을 소개한다. PET가 광범위하게 사용되고 또한 썩지 않기 때문에 환경 문제를 야기하고 또한 이 물질의 폐기 및 소각은 경제적 손실이기도 하다. PET의 화학적 재활용은 이 폐기물들을 유용한 원료물질로 전환하여 PET를 재생산하는 것이 가능하게 한다. PET의 화학적 재활용은 글리콜에 의한 글리콜리시스, 메탄올에 의한 메탄올리시스, 물에 의한 가수분해 등의 반응에 의한 PET 고분자 사슬의 분해가 이루어지고, 분리정제 과정을 거쳐 MEG, DMT, PTA와 같은 단량체 혹은 폴리에스터 올리고머로 만들어진다. 이 물질들은 폴리에스터를 합성하는 데 사용될 수 있다.

• 조명전기설비학회논문지
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• 제12권3호
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• pp.104-113
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• 1998

일반적으로 수처리시설은 상수처리장, 하수처리장 등을 포함하며, 이중에서 상수처리공정은 취수, 응집, 침전, 여파, 살균소독처리 과정으로 구성되어 있다. 그리고, 응집.침선 처리공정은 상수처리시스템에서 가장 핵심부분 으로, 탁도의 처리에 가장 크게 영향을 주게 되며, 이에 따른 응집제의 주입공정을 개선하기 위한 노력이 필요하다. 응집제 주입공정은 응집 반응과정에 관여하는 여러 외부요소들과 탁도와의 관계가 명확히 규정되어 있지 않고, 외부환경조건에 따라 다양하게 변하는 원수로부터 적절한 응집제의 양을 간단하게 결정할 수 없는 상황이다. 따라서, 전반적인 원수처리 공정의 자동화를 위해서는 응집제 주입공정 자동화와 수처과시설의 유지관리기 능을 갖춘 운용지원시스템을 관리자에게 제공하는 것이 요구되었다. 본 논문에서는 수처리시설의 설비유지관리와 응집제 주입공정을 자동화하는 운용지원시스템의 프로토타입올 구현하고자 한다. 응집제 주업공정의 자동화를 위해서 실제 수처리공정에서 1년간 수행된 웅집제 투입양과 원수 의 수질을 결정하는 여러 요소들과의 데이터를 이용하여 신경회로망을 학습시카고, 이를 이용하여 응집제 주업량을 결정하도록 하였다. 이렇게 구축된 웅집제 주입공정 자동화는 운영지원 시스템내 에서 운영되며, 운영지원 시스템은 상수처리설비의 유지분수뜰 위한 설비관리와 상태감시를 하는 환경을 구축하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.357-361
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• 2001

The possibility of producing Cr$_2$O$_3$powder from waste magnesia-chromium refractory was investigated by sulfuric acid reaction, alkali fusion, water leaching & purification and heat treatment. The effects of temperature, the amount of NaOH added and the flow rate of air on chromium extraction efficiency in an alkali fusion step were investigated. The fusion product was leached with methanol to solve free-NaOH, and then leached with water to produce a Na$_2$CrO$_4$solution. The purity of chrome(Ⅵ) oxides, prepared both from monochromate with an impurity content and monochromate purified with $CO_2$were also examined. The purified monochromate solution was reduced from Cr(Ⅵ) to Cr(III) with NaHSO$_3$solution. The reduced solution was neutralized with NaOH to produce Cr(OH)$_3$. Water washing was treated to eliminate Na$_2$SO$_4$from neutralized Cr(OH)$_3$slurry. The washed Cr(OH)$_3$was dried and thermally treated to produce Cr$_2$O$_3$powder. The properties like lightness and hue of Cr$_2$O$_3$fabricated in this study were L=47.47, a=-14.40 and b=17.21.