Evaluation of Carbon Uptake and Emissions by Forests in Korea During the Last Thirty Years (1973–2002)

The contribution of Korean forests to carbon sequestration for anthropogenic carbon emissions was evaluated. In addition, monitoring of carbon species released from forest fires was conducted. Despite a high carbon uptake by Korean forests, a tremendous increase in fossil fuel burning resulted in a small contribution by forests to carbon removal. The removal efficiency had a 5–31% range with an average of 12% during the period 1973–2002. In 2000, the amount of carbon released from burned trees corresponded to 1.6% of carbon uptake by forests. The distribution of surface CO concentration (ppb) derived from MOPITT (Measurement of Pollution in the Troposphere) showed high CO levels over the East/Japan Sea on April 10, 2000 when the largest forest fires occurred along the east coast of Korea. Trajectory analysis and ground CO measurements also indicated that CO levels over the East/Japan Sea were influenced by forest fires. This study suggests that continuous monitoring of carbon emissions from forest fires is needed for a more reliable estimate of carbon flux in the environment.     

4种典型纳米材料对小鼠胚胎成纤维细胞毒性的初步研究

为探讨不同种类纳米材料对原代培养小鼠胚胎成纤维细胞(Mouse embryo fibroblasts,MEF)的毒性效应及作用机制,选择4种典型的纳米材料(纳米碳、单壁碳纳米管、纳米氧化锌、纳米二氧化硅)制备颗粒悬液,设立5个剂量组(5、10、20、50、100μg·mL-1)对BALB/c小鼠MEF细胞进行24、48、72h染毒培养,利用细胞形态学观察和噻唑蓝实验(MTT比色法)检测上述4种纳米材料对MEF细胞活性的影响,同时,测定染毒24h后细胞培养液上清中乳酸脱氢酶(LDH)活性以探讨纳米颗粒对细胞膜完整性的影响.结果显示:1)4种纳米材料均能明显影响MEF细胞的生长形态.染毒24h后,MEF细胞发生不同程度的回缩变形,细胞间隙增大,排列稀疏,胞内颗粒物增多,细胞透明度下降.2)纳米碳、纳米氧化锌、纳米二氧化硅对MEF细胞增殖的抑制作用和对细胞膜完整性的损伤作用均随染毒剂量的升高而增强,具有明显的剂量-效应关系,其半数致死浓度(24h-IC50)分别为21.85、21.94、461.10μg·mL-1;碳纳米管组的剂量-效应之间不呈对数线性关系,未能得出其24h-IC50.3)在不同染毒剂量水平上,4种纳米材料的毒性对比差异显著:低剂量水平上纳米碳与碳纳米管的毒性强于纳米氧化锌和纳米二氧化硅,随着剂量的升高纳米氧化锌的细胞毒性升高最为显著.结果提示,纳米材料能够对MEF细胞造成毒性损伤,破坏细胞膜的完整性可能只是作用途径之一;纳米材料的毒性可能受粒径、形状、化学组成等许多因素的影响.     

CO2资源化利用的现状及前景

介绍了CO2分离捕集最新工艺——电化学法、膜法、化学循环燃烧法的研究进展。评述分析了CO2的各种资源化应用前景：CO2气体用作生物碳源、辅助注射成型剂及有机物（如氨基甲酸酯、表面活性剂）合成原料等;液态CO2用于人造金刚石、热泵干燥、超临界CO2萃取及固体干冰冷喷射清洗等。CO2作为一种潜在的丰富碳源,应不断研发其新的应用领域,加快其工业化应用。     

负载稀土元素活性碳纤维在微型反应器中净化NO废气

以NH3为还原剂,以活性碳纤维（ACF）、HNO,浸渍的ACF、负载CuO的ACF和负载La2O3的ACF为催化剂,在微型反应器中考察各种催化剂对NO催化还原的活性,并进行了差热-热重、扫描电镜分析。实验结果表明,ACF负载La能有效地改善催化剂的活性,且催化活性中心为非晶态的氧化物;当ACF负载20％的La2O3时具有最好的低温活性,NO的去除率最高可达92％以上。     

脱除SO2活性炭的再生方法

分别用溶剂和气体对脱除SO2后失活的活性炭进行了再生。在固定床反应器上考察了再生后活性炭的脱硫性能。实验结果表明：用溶剂再生时,质量分数为60％的HNO3溶液的再生效果最好,活性炭的再生率达到80％以上。用气体再生时,400℃左右时的再生效果最好,活性炭的再生率达到70％以上。再生后活性炭的比表面积和pH是衡量活性炭再生效果的重要参数。在实际脱硫生产中,用H2O对失活活性炭进行反复洗涤再生,是一种经济、实用的方法,活性炭的再生率达60％以上。     

纳米级铁粉脱氯降解四氯化碳

四氯化碳的生产和使用,给人类带来了较大危害.为此,采用纳米铁粉这一新方法对其进行脱氯处理.试验以纳米级铁粉对四氯化碳的脱氯率为考察指标,选用L25(56)正交试验方案,考察了降解介质的初始pH值、纳米铁粉的质量、降解温度、摇床转速和脱氯时间5个影响因素.结果表明,pH值这一因素有极显著影响;在得出的纳米铁粉对四氯化碳脱氯的最佳工艺条件下,获得了99.5%的脱氯率,为有机氯化物脱氯开辟了一条新途径.     

活性碳纤维在环境保护中的应用

由于活性碳纤维的吸附面积大,可以作为固相微萃取的纤维用于对环境污染物质的分析检测,包括含硫和含氯的一些有机化合物.同时,活性碳纤维具有良好的导电性能,可以作为电极,能有效地去除环境中城市污水、燃料废水和腐植酸的污染.     

Fish mercury increase in Lago Manso, a new hydroelectric reservoir in tropical Brazil

It has been frequently demonstrated that mercury (Hg) concentrations in fish rise in newly constructed hydroelectric reservoirs in the Northern Hemisphere. In the present work, we studied whether similar effects take place also in a tropical upland reservoir during impoundment and discuss possible causes and implications. Total Hg concentrations in fish and several soil and water parameters were determined before and after flooding at Rio Manso hydroelectric power plant in western Brazil. The Hg concentrations in soil and sediment were within the background levels in the region (22-35 ng g(-1) dry weight). There was a strong positive correlation between Hg and carbon and sulphur in sediment. Predatory fish had total Hg concentrations ranging between 70 and 210 ng g(-1) f.w. 7 years before flooding and between 72 and 755 ng g(-1) f.w. during flooding, but increased to between 216 and 938 ng g(-1) f.w. in the piscivorous and carnivorous species Pseudoplatystoma fasciatum, cachara, and Salminus brasiliensis, dourado, 3 years after flooding. At the same time, concentrations of organic carbon in the water increased and oxygen concentrations decreased, indicating increased decomposition and anoxia as contributing to the increased Hg concentrations in fish. The present fish Hg concentrations in commonly consumed piscivorous species are a threat to the health of the population dependent on fishing in the dam and downstream river for sustenance. Mercury exposure can be reduced by following fish consumption recommendations until fish Hg concentrations decrease to a safe level.     

TiO2/活性炭催化剂对4-CP的吸附和光催化活性

采用常压金属有机物化学气相沉积技术在活性炭表面沉积构成纳米TiO2催化剂,XRD分析表明,沉积在活性炭表面的TiO2为锐钛矿晶型.TEM分析表明负载量为8%(wt)时,TiO2颗粒的粒径为10-20nm;载体负载前后BET面积仅改变了6%,表明负载TiO2后对活性炭的结构影响不大.利用Langmuir-Hinshelwood动力学模型探讨了TiO2/活性炭催化剂对4-CP的吸附行为和光催化活性之间的关系,求出4-CP降解反应速率常数Kr,在紫外光照条件下催化剂对4-CP的吸附明显增强.     

电增强活性炭纤维吸附有机污染物的动力学研究

研究了在电极化条件下,几种具有代表性污染物质在活性炭纤维上的电吸附动力学特性.结果表明,各种污染物的电吸附动力学比较好地符合Lagergren一级吸附动力学,其平衡吸附量在电极化下的增加量各不相同.在400mV的极化电位下,苯酚钠的吸附量从开路时的0.008 3mmol·g^-1增加到0.18 mmol·g^-1,增加了17倍;而对硝基苯酚的吸附量从开路时的2.93mmol·g^-1降到2.65 mmol·g^-1.在-400mV的极化电位下,苯胺的吸附量从开路时的3.60 mmol·g^-1增加到3.88 mmol·g^-1;而十二烷基苯磺酸钠的吸附量从开路时的2.20 mmol·g^-1降到1.59 mmol·g^-1.说明不同取代基的苯衍生物,电吸附改变量不相同,供电子基团的单取代苯,正极化都能明显增强其吸附量;但是吸电子基团的单取代,正负极化对吸附量的影响都很小;供体-共轭桥键-受体型结构的苯衍生物,正负极化都使其吸附减弱但吸附速率加快.静电作用在离子型污染物的电吸附中表现明显.