• 수산해양기술연구
• /
• 제50권2호
• /
• pp.185-192
• /
• 2014

The main object of this study was to investigate the collection characteristics of wet-type cyclone with wall cavity. The experiment was executed to analyze the characteristics of pressure drop and collection efficiency for the present system with the experimental parameters such as water spray, water spray type, inlet velocity etc. In results, for the present system of wet-type, the pressure drop represented 35 mm $H_2O$, while in dry-type 33 mm $H_2O$ showing lower 6% at $v_{in}=21m/s$. In case of $v_{in}=21m/s$ and water spray 200 mL/min, the collection efficiency of the present system became significantly higher as 96.8% comparing to that of the conventional wet-type scrubber. Additionally, for 200 mL/min, $SO_2$ removal efficiencies decreased with the increment of inlet velocity representing 75.0, 62.5, 50.0%, at $v_{in}=6,9,12m/s$, respectively.

• 공업화학
• /
• 제18권1호
• /
• pp.29-35
• /
• 2007

현재 국내 화력발전소에서 운영중인 일부 배연탈황설비는 건설비 절감을 위해 설계시 여유율을 축소하여 비정상상태에 대응이 어렵고, 노후화 등으로 탈황효율이 저하하는 등 일부의 문제점이 제기되고 있다. 이러한 문제점에 대응하기 위해, 본 논문에서는 흡수액의 pH, 입구 $SO_2$ 농도, 운전 단수 변경 및 liquid distribution ring (LDR) 등의 탈황설비의 운전 조건 변경에 따른 탈황율을 검토하였으며, sulfite 이온 및 Al/Fx 이온이 석회석의 blinding에 미치는 효과에 대해 실험하였다. 흡수액 재순환 펌프를 3대 운전하였을 때는 2대 운전했을 때와 비교하여 탈황율이 최대 12% 향상하였고, LDR을 설치함에 따라 탈황효은 약 2~7%가 향상하였다. Limestone blinding 현상이 발생한 흡수액에 dibasic acid (DBA)를 500, 1,000 ppm 주입하였을 때 흡수액 용존산소가 0.5 ppm 이상 증가하며, limestone blinding 현상을 완화하였다. 흡수액 중에 $Al^{3+}$, F- 이온이 공존한 경우 석회석 용해속도는 20% 감소하였다.

• 멤브레인
• /
• 제5권4호
• /
• pp.129-136
• /
• 1995

본 연구는 에멀젼 액막을 이용한 염색 폐수 내의 염료 이온 제거에 관한 연구이다. Aliquat 336을 함유한 액막과 D2EHPA를 함유한 액막으로 각각 음이온성 염료와 양이온성 염료 제거에 관한 최적 조건을 확립하였으며, 이 조건하에서 실제의 염색 폐수 처리 실험을 행하였다. 직접 염료인 Sirius Red, 반응성 염료인 Reactofix Supra Blue 및 염기성 염료인 Apollo Blue를 대상으로 하여 막상의 계면활성제(Span 80)와 담체(Aliquat 336 or D2EHPA)의 농도, 내수상의 counter ion($Na_2SO_4$) 농도, 그리고 에멀젼 투여량 등을 변화시키며 염료 제거 실험을 행하였다. 반응 5분 후에 추출 평형에 도달하였으며, 각 염료에 대하여 색소 성분의 95% 이상을 제거할 수 있었다. 제막 조건에 가장 큰 영향을 미치는 인자는 담체의 농도로서 일정량 이상의 담체는 막의 물질 전달 저항을 증가시켜 색도 제거 효과를 감소시킴을 알 수 있었다. 또한, 막상의 계면활성제의 양, 내수상의 counter ion의 양 및 투여 에멀젼의 양은 평형 도달 후의 최종 색도보다는 추출 속도에 더 큰 영향을 미침을 알 수 있었다. 실제 염색 폐수를 에멀젼 액막으로 2단계 처리한 결과 550nm에서의 흡광도를 초기 0.53에서 10분 후 0.03까지 낮출 수 있었다.

• 한국물환경학회지
• /
• 제26권6호
• /
• pp.963-968
• /
• 2010

This study has carried out to evaluate the performance of direct and indirect oxidation electrode for the purpose of decolorization of Rhodamine B (RhB) in water. Four kinds of electrodes were used for comparison: Pt and JP202 (indirect oxidation electrode), Pb and boron doping diamond (BDD, direct oxidation electrode). The effect of applied current (0.5 ~ 2.5 A), electrolyte type (NaCl, KCl, HCl, $Na_2SO_4$ and $H_2SO_4$) and electrolyte concentration (0.5 ~ 2.5 g/L), solution pH (3 ~ 11) and initial RhB concentration (25 ~ 125 mg/L) were evaluated. Experimental results showed that RhB removal efficiency were increased with increase of current, NaCl dosage and decrease of the pH. However, the effect of operating parameter on the RhB removal were different with the electrode type. JP202 electrode was the best electrode from the point of view of performance and energy consumption. The order of removed RhB concentration per energy lie in: JP202>Pt>Pb>BDD.

• 자원환경지질
• /
• 제33권1호
• /
• pp.31-40
• /
• 2000

Sorption characteristics of Pb, Cu, Cd, and Zn onto Ca- and Na-bentonites were investigated by the batch experiments in the condition of various pHs and concentrations of groundwater major anions (${So_4}^{2-}$ and ($HCO_3$), which can form a complex with heavy metals. The sorption removal of heavy metals steadily increases as pH increases. The sorption capability about heavy metals of both Ca-bentonite and Na-bentonite is in the order of Pb>Cu>Zn>Cd. The effect of pH and selectivity of heavy metals of bentonites were explained by the change of surface charge of bentonite and the speciation of heavy metals. Na-bentonite has a little higher sorption ability about heavy metals than that of Ca-bentonite. A high sorption removal of Pb in 0.1M sulfate solution may be attributed to the precipitation of $PbSo_4$(anglesite). However, sulfate has a slight effect on the sorption of CU, Cd and Zn. More than 99% of heavy metals were removed from the 0.1 M bicarbonate solution. However, the efficiency of sorption removal of heavy metals highly decreases in the bicarbonate solution of $10^{-2}$M to $10^{-4}$M. The speciation and saturation index calculated by the WATEQ4F program indicate that the sorption of anionic complexes such as ${Pb(CO_3)_2}^{2-}$, ${Cd(CO_3)_2}^{2-}$, ${Zn(CO_3)_2}^{2-}$, ${Cu(CO_3)_2}^{2-}$ and the precipitation of the solid phases such as $PbCO_3$(cerrusite), $ZnCO_3$(smithsonite), $CdCO_3$(obtavite) are involved in sorption removal of heavy metals in bicarbonate solution. The sorption capability about heavy metals of bentonites in the presence of anions shows the following order: Pb>Cu Cd>Zn.

• 한국환경보건학회지
• /
• 제29권1호
• /
• pp.34-42
• /
• 2003

The objective of this study is to investigate the waste recycling possibility, practicability, economic efficiency and acid gas sorbent use of the hard-shelled mussel. This study is to investigate the hydration/calcination reaction and fixed bed reactor. The physical-chemical characteristics of the hard-shelled mussel were analyzed by ICP SEM-EDX, BET and pore volume. Thus, the results could be summarized as follows; Hard-shelled mussel can be used as iron-manufacture and chemical sorbents considering more than 53.7% of the mussel is lime content. The SO$_2$removal efficiency of the hard-shelled mussel after calcined hydration increased thirty times as a result of the higher pore size, specific surface area and pore volume. Also, the CaO content, pore volume, pore size distribution and specific surface area greatly influenced the SO$_2$ and NOx removal reactivity. The optimum particle diameter average of hard-shelled mussel was $\pm$100 mesh, which was applied to the sorbent on the medium/small scale waste incinerator and flue gas desulfurization processes.

• 한국물환경학회지
• /
• 제29권2호
• /
• pp.170-175
• /
• 2013

Achieving very low phosphorus levels in treated wastewater will require the installation of additional treatment. Phosphorus removal experiments by chemical coagulation were carried out for the effluent of wastewater treatment plant in this study. TP (total phosphorus) or phosphate were highly related to the addition of PAC (poly aluminium chloride) which is one of the inorganic coagulants. But, organic polymer did not significantly affect the phosphorus removal efficiency. Polymer affected the flocculation of particle especially particle matter less than 10 micrometer so, the number of micro particles was decreased by polymer dose. Chlorination would not affect on chemical coagulation process and TP and turbidity could be effectively removed by the co-addition of PAC and polymer.

• 한국대기환경학회지
• /
• 제16권4호
• /
• pp.399-408
• /
• 2000

This study evaluated the SO2 adsorption characteristics using a continous moving bed system. Natural manganese oxide (NMO) reaction condition such as L/D the starting time of the NMO feed, feed rate, and flow rate of simulated flue gas, and NMO size were tested. The results showed that optimum L/D was 1.0 in this moving bed system. The higher the feeding rate was the higher the SO2 removal efficiency was and the higher the flow rate of simulated flue gas was the shorter the time to reach the euqilibirum concentration was. The final SO2 con-centration when it reaches the equilibrium concentration was not affected by the starting time of the NMO feed.

• 한국환경보건학회지
• /
• 제31권2호
• /
• pp.99-106
• /
• 2005

The removals of organic matter, nitrogen and phosphate in wastewater were investigated with Sequencing Batch Reactor (SBR). Glucose and sodium acetate were Used for organic carbon source so as to know nutrient removal efficiency in proportion to MLSS concentration. In the case of glucose, the COD removal rate was $74\%,\;41\%\;and\;66\%$ in MLSS 5000, 3000 and 1000, respectively. On equal terms, the BOD was $57\%,\;21\%\;and\;38\%$, the T-N was $24\%,\;13\%\;and\;44\%$, and the T-P was $12\%,\;21\%\;and\;33\%$. As a result, the removal rate of organic materials showed the finest remove when MLSS was 5000, but the nutrient removal rate appeared as was best when MLSS was 1000. In the case of sodium acetate, the COD removal rate was $83\%,\;81\%\;and\;86\%$ in MLSS 5000, 3000 and 1000, respectively. On equal terms, the BOD was appeared by $76\%,\;82\%\;and\;92\%$, the T-N $57\%,\;42\%\;and\;78\%$, and the T-P $48\%,\;52\%\;and\;38\%$. As a result, organic and T-N removal rates were best when MLSS was 1000. But, the T-P removal rates were best when MLSS was 3000. Glucose was shown fast removal in reaction beginning, but screened by more efficient thing though sodium acetate removes organic matter, nitrogen and phosphate. Form of floc was ideal in all reactors regardless of carbon source and MLSS concentration. And its diameter was about $200\~500{\mu}m$.

• 한국입자에어로졸학회지
• /
• 제19권2호
• /
• pp.43-53
• /
• 2023

In this study, the ventilation system of the enclosed conveyor belt for coal transportation was evaluated, and the particle removal efficiency according to the ventilation conditions was identified using computational fluid dynamics and particle behavior analysis. The most effective way to remove dust generated inside the closed conveyor belt is to adjust the position of the exhaust port of the duct so that the air is exhausted around the rear of the conveyor belt. And this method seems to work for another narrow and long spaces where air enters in one direction. In addition, when the air flow rate of the each duct was less than 300 CMM, it was efficient to increase the flow rate of the duct located at the rear of the conveyor belt, and when the flow rate of the each duct was higher than 300 CMM, it was efficient to increase the flow rate of the duct located at the front of the conveyor belt.