活性炭的电解氧化再生研究

通过比较饱和吸附苯酚的活性炭的交换再生和电解再生,揭示了电解再生比交换再生有更高的再生效率。无论是单独的阳极再生还是阴极再生,其再生效率均可超过80%,但由于阳极区的氧化性,可以时苯酚在活性炭的表面聚合,从而降低了再生效率和活性炭的吸附性能。同时,在研究的体系内,200 mA认为是电解过程中最佳的电流强度,这一电流强度不但可以有效地再生活性炭,还可以有效地去除再生出来的苯酚。较小粒径的活性炭不仅有较高的吸附效率,而且也有较高的电解再生效率。     

铁碳微电解处理中活性炭吸附作用及其影响

铁炭微电解反应系统的反应机理十分复杂,除了铁碳原电池作用之外,还存在着絮凝、沉淀以及活性炭的吸附等作用,有关活性炭吸附作用及其对铁碳微电解反应系统处理效率的影响尚存在分歧.文章采用动态微电解处理工艺,以极难降解的盐酸金刚烷胺模拟医药废水为处理对象,研究活性炭的吸附作用及其对于铁碳微电解系统处理性能的影响.研究表明活性炭...     

铁炭微电解预处理ABS凝聚干燥工段废水

采用铁炭微电解系统对ABS凝聚干燥工段废水进行预处理研究,研究了不同进水pH对铁炭微电解处理效果的影响. 为了研究铁炭微电解系统分解转化有毒难降解有机污染物的电化学作用,分别建立了活性炭对照试验和海绵铁对照试验. 结果表明,铁炭微电解系统能高效分解转化废水中的有毒难降解有机污染物,使废水的ρ(BOD₅)/ρ(COD_Cr)由0.32提高到0.60以上,极大地提高了废水的可生化性;不同进水pH对铁炭微电解系统处理该废水的影响相对较小;在保障铁炭微电解高处理效率的前提下,为了降低铁屑的消耗速率,提高铁炭微电解的使用寿命,降低其运行成本,最佳进水pH为4～6.      

预涂动态膜强化超滤去除海水中有机物及其对膜污染的影响

以粉末活性炭和硅藻土为涂膜材料,在聚醚砜超滤膜表面形成预涂动态膜,考察了预涂动态膜对海水中有机物的去除效果和作用机制,通过比较分析直接超滤和预涂动态膜过滤海水前后膜表面亲疏水性、形貌结构、粗糙度及膜阻力分布的变化,探讨了活性炭和硅藻土预涂覆对超滤膜污染的影响.结果表明,预涂动态膜可提高超滤膜对海水中溶解有机碳(DOC)和UV_(254)的去除率,活性炭预涂动态膜对海水中DOC和UV_(254)的去除率较直接超滤分别提高11.2%和11.3%.硅藻土预涂膜主要利用超滤膜表面形成的硅藻土滤饼层强化海水中蛋白质类有机物的截留,活性炭对海水中小分子有机物的额外吸附导致海水过滤过程中活性炭预涂膜对有机物的去除效果优于硅藻土预涂膜.与直接超滤相比,预涂动态膜过滤海水后膜表面亲水性更好,膜表面粗糙度更低,膜过滤阻力也更小,活性炭预涂动态膜净化海水时膜过滤总阻力较直接超滤降低50.3%.利用涂膜材料在超滤膜表面形成的滤饼层将超滤膜与有机物进行了"隔离",避免了超滤膜与有机污染物直接接触,降低了小分子有机物在膜孔内的吸附堵塞,能够有效减缓超滤膜的不可逆污染.     

有机玻璃生产废水的处理

一、前言上海嘉定有机化工厂在生产有机玻璃过程中,排出化学需氧量高达1万ppm以上,含氰50—70ppm的废水,我们曾采用混凝、吸附、电解等多种物化手段进行试验,结果表明,新颖的电解氧化法—充填活性炭电解,对水量小、难降解的有机废水有显著的处理效果。为此,我们最后确定采用中和沉淀、电解氧化、生物处理的工艺流程,使废水中的氰根达到排放标准,COD去除率达90％左右。在高浓度废水经电解氧化后,将厂内的生活污水与之混合,一并进行生物处理,可达到良好的效果。二、工艺流程的确定1.探索性试验由于有机玻璃生产废水呈酸性,为此,必须进行预处理,调节pH值,沉淀过滤。然后,再采用混凝、吸附等手段进行探索,并与新颖的电解氧化法—充填活性炭电解进行比较。其结果     

吸附电解氧化法处理印染废水的研究

采用附电解氧化法对印染废水的处理进行了研究,获得适宜工艺参数：电流强度为400mA,废水停留时间为25rain,pH为6．0-7．0。试验表明：吸附电解氧化法能够使印染废水的CODcr 的去除率提高,使活性炭颗粒的再生周期延长。同时,从技术和经济上论证采用电解絮凝一吸附电解氧化法串联工艺处理印染废水的可行性,因此吸附电解氧化法在废水处理中具有一定的实用意义。     

非膜技术处理生物稳定渗滤液的效果及成本

以经厌氧-好氧处理的生物稳定渗滤液为研究对象,分别比较了其经活性炭吸附、混凝、芬顿和电解处理后的溶解性有机碳(DOC)、COD、溶解性氮(DN)和比紫外吸光度(SUV254)的变化,及去除单位COD的成本变化.研究发现,活性炭吸附、芬顿和混凝对生物稳定渗滤液的COD、DOC和DN的去除效率均随药剂投加量的增加而提高;包...     

超声-微电解耦合处理难降解污染物研究进展

超声-微电解是近年来发展起来的一项水处理复合技术,此法借助超声波的空化效应、自由基作用和机械作用强化微电解反应。超声空化效应产生的空化泡在溃陷的瞬间形成高温高压,不仅有利于铁屑表面的传质作用,还引发了自由基反应,空化效应产生的微射流和冲击波促使电极表面不断更新,同时使反应液与铁屑、活性炭充分混合接触,有效的促进了原电池反应的快速进行,实现超声和微电解对工业废水中有机污染物的协同降解,提高对废水有机污染物的降解效率。     

铁碳微电解法预处理湿法腈纶废水试验研究

采用铁碳微电解工艺对湿法腈纶废水进行预处理试验。通过单因素试验确定了铁屑、活性炭投加量及反应时间等因素对处理效果的影响。结果表明,采用铁碳微电解工艺处理初始CODCr为1 076 mgL,CN-浓度为5.50mgL的湿法腈纶废水,当铁碳微电解反应中铁屑和活性炭投加量均为35 gL,反应时间为90 min,初始pH为4.50时,废水中CODCr的去除率在36.0%以上,CN-的去除率超过90%;废水BOD5CODCr由0.39提高到0.56,废水可生化性显著提高。     

铁炭填料去除模拟矿山酸性废水中Cu~(2+)的特性

研究了多孔铁炭填料对模拟矿山酸性废水中Cu~(2+)的去除特性,并与商业活性炭的吸附性能作了比较。研究表明,铁炭填料对Cu~(2+)的去除速度快,当填料投加量为1.14 g/L时,吸附10 min后Cu~(2+)的去除率超过95%,吸附平衡后Cu~(2+)的去除率达99.96%,模拟矿山酸性废水经铁炭微电解处理后,pH值从约3.0上升到5.0~5.5,降低了其酸污染。铁炭填料和活性炭对酸性矿山废水中Cu~(2+)的去除均符合准二级吸附动力学规律和Langmuir等温吸附模型,铁炭填料和活性炭对Cu~(2+)的最大吸附量分别为714.29和9.69 mg/g,铁炭填料去除Cu~(2+)的性能远高于活性炭。铁炭微电解去除Cu~(2+)包括了吸附、金属置换、微电解和絮凝等多种作用机理。     

一种高效的硅胶中氚化水自动化解析技术

文章介绍采用温度自动控制的铸铝加热方式提取硅胶中氚化水的一种高效节能解析技术,并通过实验验证表明,该解析技术对硅胶吸附氚化水样品的最佳解析时间为15 min,此时100 g饱和硅胶样品至少能解析水7～10 mL用于液闪测量,对硅胶中氚化水的平均回收率优于99%,氚记忆效应小于万分之二。该技术与GB12375-90标准提出的氚蒸馏技术相比,具有能同时处理多个样品,可提高硅胶氚吸附样品前处理制样效率、节约能源等特点。     

Isolation and characterization of a thermophilic Bacillus shackletonii K5 from a biotrickling filter for the production of polyhydroxybutyrate

Polyhydroxyalkanoates（PHAs） are aliphatic polyesters accumulated intracellularly by both Gram-negative and Gram-positive bacteria. However, compared to the PHAs of Gramnegative bacteria, few endotoxins（lipopolysaccharides, LPS）, which would be co-purified with PHAs and cause immunogenic reactions, are found in the PHAs produced by Gram-positive bacteria. A thermophilic Gram-positive bacterium K5, which exhibited good growth and polyhydroxybutyrate（PHB）-accumulating ability, has been isolated and characterized from a biotrickling filter designed for the removal of NOx from flue gas in a coal-fired power plant in China. Based on the biochemical characterization and 16 S rRNA gene sequence（Genbank accession no. JX437933）, the strain K5 has been identified as Bacillus shackletonii, which has rarely been reported in the literature, and this report is the first time that B. shackletonii has been found to accumulate PHB. The strain K5 was able to utilize glucose as carbon source to synthesize PHB at a broad range of temperatures（from 35 to 50 °C）, and the ideal temperature was 45 °C. The strain K5 could effectively yield PHB of up to 69.9% of its cell dry weight（CDW）（2.28 g/L） in flask experiments employing glucose as carbon source at 45 °C, followed by 56.8% and 52.3% of its CDW when using sodium succinate and glycerol as carbon source, respectively. For batch cultivation, the strain K5 was able to produce PHB of up to 72.6% of its cell dry weight（9.76 g/L） employing glucose as carbon source at 45 °C and pH 7.0.     

自制新型液相色谱柱同时测定土壤中两种农药

用自制的新型N-苄氧羰基-(-)-L-苯甘氨酰-(-)-L-苯甘氨酰基键合硅胶液相色谱固定相(简称BCPGPG色谱固定相)在正相条件下对土壤中氰戊聚酯和氯氰菊酯两种农药进行了分析与测定,建立了可同时测定土壤中的氰戊菊酯和氯氰菊酯含量的正相高效液相色谱方法。样品用流动相(正己烷/二氯甲烷=8/1,V/V)溶解,过滤,然后以BCPGPG固定相柱进行色谱分离,在254nm处进行测定。结果表明,氰戊菊酯和氯氰菊酯的质量浓度为0～2.0mg/L时其峰面积与质量浓度的线形关系良好;批间(n=4)测定的平均相对偏差(RSD)分别为5.70%和5.5%;回收率分别为81.0%～96%和88.0%～96.7%。该方法适合于测定氰戊聚酯和氯氰菊酯两种农药的含量测定,方法准确,操作简便。     

Influence of short-term variations on energy-saving opportunities in a pulp mill

Significant opportunities for energy savings have been identified in the hot and warm water system of a kraft pulp mill. The energy-saving opportunities found at the mill studied, 15.7 MW of steam savings and 24.8 MW of usable excess heat, correspond to 18% of the mill's total steam use. Short-term variations in the process have been studied in order to identify and quantify the influence of these variations on the energy-saving opportunities. Daily and 10-min averages of measured data were used as varying input data in the retrofitted heat exchanger network. When the short-term variations were considered, the total energy-saving opportunities fell by 8% when daily averages are used and by 11% when 10-min averages are used. At least 65% of the influence of short-term variations was detected when seasonal variations are considered.     

Methane emission in a rice field of Thailand

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Minimization of the environmental impact of chrome tanning: a new process reusing the tanning floats

A chrome tanning process which allows the reuse of tanning floats has been developed. The most commonly used chromium salts were replaced by highly masked and basified ones. This substitution eliminates basification operation and prevents pH change and the considerable neutral salts concentration increase in the tanning float. Consequently, tanning float can be reused several times. An optimum chromium salt concentration in the tanning float between 10% and 12.5% has been determined. It has been shown that the number of times the tanning float can be reused depends on the quality of the leather grain to be manufactured. In the best case, a saving of 18 L of water per kilogram of tanned leather is calculated. This means savings of 90% of water normally used.     

Hyperechogenic fetal bowel and Down syndrome. Results of a French collaborative study based on 680 prospective cases

Hyperechogenic fetal bowel is prenatally detected by ultrasound during the second trimester of pregnancy in 0.1% to 1.8% of foetuses. It has been described as a normal variant and has often been associated with severe diseases, notably Down syndrome. The aim of the present study was to determine the risk of trisomy 21 in a prospective study of 680 fetuses with hyperechogenic foetal bowel. Karyotyping was performed on amniotic cells in 632 cases, and outcome was known in 655 cases. A 2.5% risk of Down syndrome and a 1% risk of other severe chromosomal anomalies were observed. Hyperechogenicity was isolated in 11/17 Down syndrome cases, and associated with other ultrasound anomalies in all seven cases of severe chromosomal anomalies. In conclusion, fetal bowel hyperechogenicity indicates a risk of chromosomal anomalies ten-fold higher than that expected on the basis of maternal age, therefore justifying invasive procedures. Copyright © 2002 John Wiley & Sons, Ltd.     

新型高效生活污水净化系统的研制

采用新型填料Ｙａｋｕｌｔ和中心导流式曝气方式，设计制作了一体化设备对生活污水进行处理，试验表明，停留时间３０h左右，ＣＯＤｃｆ去除率〉８５％，ＢＯＤ５去除率〉９ ０％，ＳＳ去除率〉８７％，ＮＨ３－Ｎ去除经〉９２％，出水水质达到国家一级排放标准。     

穿龙薯蓣制备皂素新工艺污染分析

文章简述了传统皂素生产工艺的主要问题,即半纤维素和淀粉水解产生的污染问题.针对此问题提出了穿龙薯蓣提取皂素的新工艺,并研究了新工艺所产生的固体废物污染和水污染.首先,用重量法对三种固体废物分别进行了测定,含量分别为原料重量的35.6%、24.4%、3.4%.固体废物弃置占用大量土地,污染环境,产生严重的环境危害,将固体...     

糖矿浆尿素复合秸杆处理剂的应用研究

用处理造纸废液的资源化产品──精矿浆与尿素混合处理秸杆,可提高秸杆作为家畜饲料的利用率。本实验用绵羊瘤胃内４８ｈ干物质消失率（ＤＭｄｐ）作为对家畜可利用程度的指标。用河北涿州市造纸厂的糖矿浆处理的稻草干物质消失率提高了４０％,中性洗涤纤维含量降低了２２．６％。稻草和玉米杆经糖矿浆尿素混合处理后饲喂绵羊日增重较氨化秸杆分别提高了２２．８％和９．２５％。