Recovery of sulfuric acid aqueous solution from copper-refining sulfuric acid wastewater using nanofiltration membrane process

Yun, Taeseon,Chung, Jae Woo,Kwak, Seung-Yeop Elsevier 2018 Journal of environmental management Vol.223 No.-

<P><B>Abstract</B></P> <P>We used a nanofiltration (NF) membrane process to produce purified aqueous sulfuric acid from copper-refining sulfuric acid wastewater. Wastewater generated from a copper-refining process was used to explore the membrane performances and acid stabilities of six commercial NF membranes. A combination of permeate flux, sulfate permeation, and metal ion rejection clearly showed that two polyamide membranes and a polyacrylonitrile-based membrane achieved recovery of a purified sulfuric acid solution. Acid-stability and long-term performance tests showed that the polyamide membranes were unsuitable for copper-refining wastewater treatment because of their low acid stabilities. In contrast, the polyacrylonitrile-based composite membrane showed excellent acid stability, and gave greater than 90% metal ion rejection, with the exception of calcium ions, for 430 d. We also evaluated the recovery performance in 1 ton/d pilot-scale process using wastewater from copper-refining process; 90% metal ion rejection was achieved, with the exception of calcium ions, even at 95% recovery rate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We applied NF membranes to treatment of copper-refining sulfuric acid wastewater. </LI> <LI> Purified sulfuric acid aqueous solution was recovered from sulfuric acid wastewater. </LI> <LI> We found that a non-polyamide membrane in this study showed excellent acid stability. </LI> <LI> MPS-34 was maintained metal ion rejection greater than 90%, except Ca ion, for 430 d. </LI> <LI> The sulfuric acid recovery was also achieved in 1 ton/d pilot-scale process. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

화학침전을 이용한 발효액의 젖산 회수 및 유기물 특성분석

이원태(Wontae Lee) 유기성자원학회 2018 유기물자원화 Vol.26 No.1

유기성 폐기물 소화공정의 발효액에서 젖산(lactic acid)을 회수하기 위해 화학침전법을 평가하였다. 젖산(lactic acid)의 회수율을 높이기 위하여 화학침전제 종류와 교반속도 및 침전시간 등 반응조건이 회수율 향상에 미치는 영향을 살펴보았다. 화학침전제의 종류에 관계없이 주입양이 증가할수록 젖산(lactic acid) 회수율 이 증가하는 경향을 보였으며, CaO가 Ca(OH)2와 CaCO3에 비하여 높은 회수율을 나타냈다. CaO를 사용한 반응조건 최적화 실험결과, 교반속도 180 rpm, 침전시간 24 h, ethanol 주입량 25%(v/v)에서 회수율이 48%로 가장 높게 나타났다. 본 연구에서는 발효액 내 젖산(lactic acid)의 농도만 고려하여 주입할 침전제의 양을 계산하였기 때문에 실제 적용을 위해서는 발효액의 유기산 종류 및 농도를 고려하여 침전제의 투입량을 결정해야할 것이다. 유기물의 정성적 분석(FEEM, SEC) 결과로 볼 때 침전공정은 유기산의 특성에 큰 영향을 미치지 않았다. Recovery of lactic acid from fermentation broth using chemical precipitation was investigated with various chemicals. Effects of chemical types, mixing speeds, settling duration, and solvent addition were evaluated to improve the recovery rates of lactic acid. Overall, recovery efficiencies increased as the dosage of chemicals increased. Recovery rate of lactic acid by CaO was higher than those of Ca(OH)2 and CaCO3. Recovery of lactic acid increased by 48% under the optimized reaction conditions which included a mixing speed at 180 rpm, a settling duration of 24 h, and addition of ethanol at 25%(v/v). Practical application needs to consider types and concentrations of other organic acids as well as lactic acid. Based upon the results of fluorescence excitation emission matrix (FEEM), size exclusion chromatography (SEC), characteristics of recovered lactic acid were same as that in the fermentation broth.

유증기 회수설비 유무에 따른 주유소 근로자들의 요중 trans, trans-Muconic acid, Hippuric acid에 관한 연구

최재준 ( Jaejun Choi ),원종욱 ( Jong Uk Won ),김치년 ( Chi Nyon Kim ),노재훈 ( Jaehoon Roh ) 한국산업보건학회 2014 한국산업보건학회지 Vol.24 No.2

Objectives: This study aims to investigate the excretion aspect of urinary t, t-MA and hippuric acid by measuring concentrations of urinary metabolites according to the use of gasoline vapor recovery system. Materials:In order to analyze urinary metabolites, samples from the 23 gas station workers ten gas stations in the Seoul and Gyeonggi Province area were collected once daily after work. In addition, a survey was conducted on work factors and lifestyle habits as factors affecting the concentration of urinary metabolites. Results: The average concentrations of t, t-MA and hippuric acid after work were 0.124±0.177 mg/g creatinine and 0.557±0.251 g/g creatinine among workers at gas stations where gasoline vapor recovery systems were installed. The average concentrations of t, t-MA and hippuric acid were 0.160±0.113 mg/g creatinine and 0.682±0.619 g/g creatinine among workes at gas stations where gasoline vapor recovery systems were not installed. Average concentrations were higher at gas stations where a gasoline vapor recovery system was not installed, but the differences were not statistically significant differences. Urinary t, t-MA and hippuric acid average concentrations of smokers and non-smokers were higher in the gas stations where gasoline a vapor recovery system was not installed. T, t-MA as a factor evaluation affecting the concentration of urinary metabolites was not statistically significant in all factors, while hippuric acid was statistically significant only for age(p=0.024). Conclusions: The average concentrations of urinary t, t-MA and hippuric acid were higher in gas stations where gasoline vapor recovery systems were not installed compared to gas stations where such a system was installed. There needs to be an assessment of biological monitoring according to refueling activity considering skin absorption of benzene and toluene and presence of gasoline vapor recovery system.

Fatty Acid 추출제를 사용한 용매추출법에 의한 Praseodymium과 Dysprosium의 분리

김세미 ( Se Mi Kim ),이은수 ( Eun Su Lee ),김정훈 ( Jeong Hoon Kim ),김영운 ( Young Wun Kim ),박종목 ( Jong Mok Park ),허남호 ( Nam Ho Heo ),강호철 ( Ho Cheol Kang ) 한국환경분석학회 2013 환경분석과 독성보건 Vol.16 No.2

The separation of praseodymium and dysprosium has been studied by solvent extraction using fatty acid series such as hexanoic acid, octanoic acid, 2-ethylhexanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, and oleic acid as an extractant in kerosene as a diluent. In this study, we want to know extractive trend depending on the carbon chain length and the pH of aqueous phase. The results obtained from solvent extraction of praseodymium and dysprosium using fatty acids are as follows; the pH0.5 of dysprosium is from 4.93 to 5.94, and that of praseodymium is from 4.24 to 5.34. The pH0.5 of them is increased with increasing the length of the carbon chain of the fatty acid. Using 1.5 M octanoic acid as an extractant, we can get the highest separation factor of praseodymium and dysprosium that is 49.

Experimental work on leaching of printed circuit boards

( Srikanth Srivatsa ),( Sankar Bhattacharya ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-

Ground printed circuit boards (PCB) were pyrolysed to devolatilize the plastic components to fuel oils and gas for energy recovery. The by-product is a mixture of metals which is further treated with acids to dissolve the metals into leach liquor. A significant number of experiments were conducted with three inorganic acids and three organic acids using the metallic residues after pyrolysis. The major conclusions are: · The plastics can be easily converted into oil which can be used for on-site heat generation to support the pyrolysis process. The pyrolysis process can be accomplished in around 400℃ · The inorganic acids HCl, H₂SO₄ and HNO₃ are studied for the leaching of metals from the PCB metal mixture. · Cu, Al, Li, and Co can be easily extracted using either of the three acids. · Zn and Sn leaching has very low efficiency in all the three acids · Ni and Fe are poorly extracted into the leach liquor, with HCl showing relatively better extraction. · Au and Ag is easily extracted into HCl with efficiency reduced in HNO₃. However, the use of inorganic acids has its own difficulties in handling and disposal of waste liquid to meet environmental standards. Hence as alternative organic acids were used for the leaching of metals, organic acids are environmentally benign and bio-degradable. The organic acids tested for the purpose are citric acid, lactic acid and oxalic acid. The results suggest the following - · Oxalic acid has superior activity dissolving the majority of the metals present in the PCB mixture except for Sn and Fe. · 1M oxalic acid between 50-75 ℃ and for a duration of 2-4 h is sufficient to dissolve majority of the metals in the solution. The work is currently being scaled up.

지속 혹은 분할 유산소 운동방법에 따른 에너지 소비량과 혈중 젖산 농도 비교

이형국 한국발육발달학회 2018 한국발육발달학회지 Vol.26 No.1

The aim of this study was to estimate and compare energy expenditure and blood lactic acid in a 30min continuous bout of bicycle ergometer cycling at 80% of HRmax reserve with 45 min of recovery and in 10 min intermittent bouts of exercise with equally divided into three 15min periods of recovery. Subjects were fourteen college-aged males(age: 22±1.8 years, height: 173±6.5 cm, weight: 70±13.8 kg, %body fat: 19±6.5%) volunteered to participate. Energy expenditure was measured with the POLOR(RS 800CX, Finland) & exercise record/analysis program and Lactate Tester (YSI 1500, USA), at warm up, exercise and during recovery. The 30 min continuous bouts of exercise included a 45 min recovery and each of the three 10 min bouts included 15 min of recovery. Workload was adjusted during exercise to maintain at 80% target HR. Setting of target HR was at 1/3 position of main exercise and maintaining to the end of the exercise. Differences in energy expenditure between continuous and intermittent exercise, recovery from exercise, as well as the combination of exercise an recovery were assessed with a paired t-test. And blood lactic acid concentration were analysis with independent t-test and oneway repeated measures ANOVA were employed to analyse blood lactatic acid. Significance was set a p<.05. The energy expenditure for exercise only was no significantly greater(6.3 kcal) with continuous bout of exercise than intermittent bouts of exercise. On the other hand, during recovery from exercise, they expended more energy(22.7 kcal) following intermittent exercise than following continuous exercise. The total energy expenditure for the combination of exercise and recovery was greater(16.3 kcal) than intermittent bouts of exercise, but it was not significant. And on blood lactic acid, there is significant different at point of exercise finish and at 15min of recovery(p<.01, p<.05 respectively).

하천에서 분해되는 보릿짚 유래 페놀산의 추출 및 분석법 개발

김가영(Ga Young Kim),주진철(Jin Chul Joo),이민지(Min Ji Lee),홍수인(Suin Hong),복진영(Jin Young Bock),박재로(Jae Roh Park),안창혁(Chang Hyuk Ahn),오종민(Jong Min Oh) 대한환경공학회 2018 대한환경공학회지 Vol.40 No.9

하천과 호소 내 다양한 유기/무기물질과 함께 존재하는 보릿짚 유래 페놀산의 추출·분석을 위한 전처리법(pretreatment) 과 Ultra High Performance Liquid Chromatography (UHPLC)-MS 분석법을 개발 후 페놀산의 정량/정성분석을 실시해 분석 회수율(analytical recovery), 정확도(accuracy), 정밀도(precision)를 검증하였다. 검증결과, 보릿짚으로부터 용출되는 것으로 보고된 페놀산 7종 화합물의 크로마토그램 내 peak는 Gallic acid 〉 4-Hydroxybenzoic acid 〉 Vanillic acid, Caffeic acid 〉 Syringic acid 〉 Coumaric acid 〉 Ferulic acid 순으로 상호 간섭없이 분리되었으며, 전처리 과정을 통해 추출된 Gallic acid와 Caffeic acid를 제외한 5종의 페놀산은 80.4~112.8%의 분석 회수율을 나타내었다. 실제 하천 · 호수 시료 내에 존재하는 4종의 페놀산(4-Hydroxybenzoic acid, Vanillic acid, Syringic acid, Ferulic acid)의 검량선의 직선상관성(R²)값은 0.998~1.0으로 비교적 넓은 검출범위 내에서 높은 직선성을 나타냈으며, 비교적 낮은 검출한계(LOD)와 정량한계(LOQ)로 조사되었다. 현장 하천수 내 보릿짚 유래 페놀산의 용출 농도는 검출한계와 유사한 극미량(0.095~0.273 μg/mL)이며, 유의할만한 농도의 페놀산 용출 지속 시간도 10일 이내인 것으로 조사되었다. 본 연구를 통해 개발된 전처리법과 UHPLC-MS 분석법을 통해 보릿짚 유래 페놀산의 추출 및 분석을 하천수 및 호소수와 같은 복잡한 매트릭스에서도 효과적으로 적용할 수 있는 것으로 확인되었다. Both extraction of phenolic acids eluted from barley straw in rivers/lakes and analytical method for the extracted phenolic acids using ultra high performance liquid chromatography (UHPLC)-mass spectroscopy (MS) were developed. Then, the analytical recovery, accuracy and precision of the developed analytical method were evaluated based on the quantitative/qualitative analysis. According to the chromatograms, seven phenolic acids eluted from barley straw were clearly separated in the order of Gallic acid 〉 4-Hydroxybenzoic acid 〉 Vanillic acid 〉 Caffeic acid 〉 Syringic acid 〉 Coumaric acid 〉 Ferulic acid, and five phenolic acids except Gallic acid and Caffeic acid were found to have analysis recovery of 80.4~112.8%. Four phenolic acids (4-Hydroxybenzoic acid, Vanillic acid, Syringic acid, and Ferulic acid) presented in rivers/lakes displayed high linear correlation (R²) values (i.e., 0.998~1.0) of calibration curves within the wide detection ranges, and had relatively low limit of detection (LOD) and limit of quantitation (LOQ). From the results of this study, the developed pretreatment method and analytical method were confirmed to effectively extract and analyze phenolic acid mixtures eluted from barley straw in complex environment matrix such as rivers/lakes.

Silicon wafer 에칭공정시 발생(發生)되는 폐(廢)에칭액 으로부터 초산(醋酸), 질산(窒酸) 및 불산(弗酸)의 분리.회수(分離.回收)에 관한 연구(硏究)

안재우,Ahn, Jae-Woo 한국자원리싸이클링학회 2007 資源 리싸이클링 Vol.16 No.1

실리콘 웨이퍼 제조공정 중 발생되는 초산, 질산 및 불산을 함유한 3성분계 폐혼산으로부터 개별산으로 분리하여 재활용할 목적으로 용매추출법을 적용하였다. 각 산의 분리를 위해 사용한 추출제로는 초산의 경우는 EHA(2-Ethylhexlalcohol)를 사용하였고, 질산과 불산의 경우에는 TBP(Tri-butylphosphate)를 사용하여 각 산의 분리과정에 대한 공정설계를 위한 기초 data를 얻고자 하였다. 3성분계 폐혼산에서 초산을 추출 분리하고 이후 추출여액 중 질산 및 불산을 순차적으로 추출 분리 할 수 있는 연속공정개발을 위하여 기초 실험 자료와 McCabe-Thiele해석을 통해 최적 투입유량비(O/A), 소요단수(Stage) 등을 결정하였다. 분석 결과 혼산으로부터 초산의 회수율은 90%이상 이었으며 초산 추출여액에서 질산의 회수율은 90%, 최종 추출잔류액에서 불산의 회수율은 67%이상 이었다. Recovery of acids from the waste etching solution of containing acetic, nitric and hydrofluoric acid discharged from silicon wafer manufacturing process has been attempted by using solvent extraction method. EHA(2-Ethylhexlalcohol) for acetic acid and TBP(Tri-butly Phosphate) for nitric and hydrofluoric acid as a extraction agent was used to the experiment to obtain the process design data in separation procedure. From the experimental data and McCabe-Thiele diagram analysis, we obtained the optimum conditions of phase ratio(O/A) and stages to separate each acid sequently from the mixed acids. The recovery yield was obtained above 90% for acetic acid from the acid mixtures, 90% for nitric acid from acetic acid extraction raffinate and then above 67% for hydrofluoric acid from final extraction raffinate.

Recovery of Lactic Acid by Reactive Dividing Wall Column

Youngmin Cho,Bokyung Kim,Dongpil Kim,Myungwan Han 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

Lactic acid is widely used in the food, chemical and pharmaceutical industries, and there is an increasing demand for Lactic acid as the raw material of poly lactic acid (PLA), which is a biodegradable polymer. Lactic acid production has been changing over from production by synthesis to production by fermentation, since the fermentation process is more nature friendly and economic. However, the fermentation method generates excess water and impurities with high boilers. The presence of high boilers and non volatility of lactic acid makes the separation of lactic acid very difficult job. Also, the purification-separation process requires the many investment costs and energy costs. The separation method that uses the reaction was proposed in order to overcome these problems. Esterification of lactic acid with methanol followed by hydrolysis of the separated methyl acetate was proposed as a technique to overcome these difficulties. Reactive distillation concept was also introduced for the process, giving higher selectivity and yield compared to the convention method [1]. Recently, the process consisting of evaporator, two-phase CSTR, a reactive distillation column, and distillation column was proposed for the purification of lactic acid by Kumar et al. [2-3]. We introduce a new highly integrated process, reactive diving wall column, to reduce the capital and energy cost for producing a pure lactic acid. The reactive dividing wall column combines reactive distillation and dividing wall column. The dividing wall column provides higher thermodynamic efficiency than conventional distillation sequences. We compared capital and energy cost required for the purification of lactic acid the between the proposed process and the process of Kumar et al. [2-3] and examined the effect of major process variables on the process performance.

Characterization of post-flooding recovery-responsive enzymes in soybean root and hypocotyl

Mudassar Nawaz Khan,Setsuko Komatsu 한국식물학회 2016 Journal of Plant Biology Vol.59 No.5

Soybean exhibits markedly reduced growth and yields under flooding stress. To determine the functional roles of four soybean proteins in post-flooding recovery, the organ/stress specificity and time-dependency of their enzymatic activities were analyzed. Peroxidase activity decreased in root and hypocotyl exposed to flooding and cold stresses, but increased during the post-stress recovery period. In contrast, its activity increased in both root and hypocotyl under drought stress. Acid phosphatase activity was suppressed in root treated with flooding and cold stresses, and slightly increased during the recovery period; however, the opposite profile was observed in hypocotyl. In response to drought stress, it did not change in root, but was decreased in hypocotyl. Beta-ketoacyl reductase activity did not change in root under flooding conditions, but was decreased in hypocotyl, although the activity increased slightly during the recovery period. In addition, it was decreased in both organs under drought and cold stresses, but again increased during the recovery period. Nucleotidylyl transferase activity was increased in root under flooding and drought stresses, but was decreased in hypocotyl. It was decreased in response to cold stress, but exhibited a slight increase during the recovery period. Furthermore, the treatment with jasmonate and salicylate suppressed the activities of peroxidase and acid phosphatase in root and hypocotyl under flooding stress; however, the activity of acid phosphatase increased during the recovery period. Nucleotidylyl transferase activity in root was also elevated by treatment with jasmonate, but gradually decreased during the recovery period. These results suggest that jasmonate-induced changes in nucleotidylyl transferase activity may facilitate soybean root recovery after flooding stress.