医疗废物熔融底渣毒性特性及资源化利用探讨

为探讨热等离子体处理医疗废物后产生的熔融底渣资源化利用可行性,对医疗废物熔融底渣的重金属浸出毒性、重金属总量及长期淋滤环境下的重金属浸出情况进行了分析。结果表明,医疗废物熔融底渣的重金属浸出浓度远低于危险废物鉴别限值,在长期模拟酸雨淋滤的环境下重金属均无浸出,重金属较为稳定,可进行资源化利用。

医疗废物焚烧底渣毒性特性及处置研究

对医疗废物焚烧底渣进行毒性浸出、二恶英含量特性分析。结果表明:医疗废物底渣的毒性浸出浓度远低于危险废物鉴别限值,属于第Ⅱ类一般工业固体废物,应进入一般工业固体废物处置场安全填埋。此外,其毒性浸出浓度和二恶英含量远低于生活垃圾填埋场的入场限值,在不具备一般工业固体废物处置场条件的区域可进入生活垃圾填埋场填埋处置。

危废焚烧灰渣的等离子熔融特性研究

通过直流等离子体电弧熔融技术对危废焚烧灰渣熔融固化的处理效果的实验室研究,着重研究了其添加剂用量和熔融温度对灰渣中重金属固化效果和重金属的毒性浸出特性的影响,并对飞灰、底渣和熔渣的化学组成、物相组成、重金属毒性浸出特性和微观结构等进行了深入分析。结果表明,随着添加剂用量增加,熔渣中重金属固化率提高,重金属浸出质量浓度显著降低。熔融温度从1 250℃升高到1 450℃,重金属Cr、Ni、Cu、Zn的固化率显著提高,Pb、As的固化率逐渐降低。等离子体熔融产出的熔渣重金属浸出质量浓度都远低于毒性标准限值。本试验对于灰渣等离子熔融机理进行了深入研究,试验出最佳运行工况,对灰渣等离子技术装备的工业化开发具有重要意义。

高温反应合成莫来石实现钒渣氯化残渣的无毒高效利用

采用氯化法从钒渣中提取有价元素(Ti、Cr、Fe、Mn和V)后得到的浸出渣主要成分为Al_(2)O_(3)和SiO_(2),还含有少量有害元素Cr和V。为了减少Cr和V对环境的污染,提出一种浸出渣无毒和有效利用的新方法。以浸出渣为原料,加入适量SiO_(2),在1600℃下固相烧结5 h,合成抗压强度为133.345 MPa、密度为3.20 g/cm^(3)的纯莫来石。浸出渣中的微量元素Ti和有害元素V和Cr在高温反应过程中进入莫来石晶格形成固溶体,稳定在莫来石相中。合成的样品采用毒性特性浸出程序(TCLP)和GB5085.3—2007进行检测。结果表明,莫来石符合毒性浸出标准,是一种安全无毒产品。

铅锌尾矿回收制备环保型超高性能混凝土研究

超高性能混凝土(UHPC)是一种具有高强度、高耐久性能的新型复合水泥基材料,但由于其高水泥用量,也面临高能耗的问题。为降低UHPC能耗,使用铅锌尾矿部分取代超高性能混凝土水泥,研究尾矿取代量对UHPC的工作项目,强度,耐久性以及浸出毒性特性的影响,同时利用寿命周期评估技术进行环境评价。结果表明:当用铅锌尾矿取代UHPC中部分水泥后,随着取代率的增加,UHPC的流动性和抗压强度均呈现下降趋势;铅锌尾矿的掺入可大幅度降低UHPC的自收缩,其中掺量为20%时自收缩量达最小值;UHPC对重金属离子具有较强的固结能力,在中性环境下重金属离子平均固结率大于99.9%,在酸性条件下为95.5%;UHPC能耗较高,掺入铅锌尾矿后可降低能耗,减少碳排量,达到了节能减排的效果。

混合氯盐对水泥固化和河道底泥稳定化的影响

以上海市黄浦江流域复兴岛运河段底泥为研究对象,通过添加混合氯盐对河道底泥进行水泥固化稳定化试验,根据固化样品的无侧限抗压强度及重金属浸出毒性试验结果,探究混合氯盐对河道底泥固化稳定化的影响。结果表明,以固化体养护7 d后的抗压强度作为指标,在水泥:干底泥质量比为4:6、含水率为40%的最优条件下,抗压强度可达1.72 MPa;最优配比下,在固化过程中添加2%的混合氯盐(25%氯化钾、30%氯化钠、25%氯化镁和20%氯化钙),底泥固化力学性能可增强52%,其原因可能是水化反应中Cl^-与Ca^(2+)结合生成了氯化钙,再与水泥中的其他物质反应时,可增大固化过程中的固相比例,从而增强力学性能。材料的重金属浸出试验结果表明其重金属稳定效率基本高于90%,说明该方法对重金属污染底泥的稳定化效果良好,但掺杂混合氯盐对金属稳定化的效果影响不大。

铜尾矿提铁尾渣用作矿物掺和料的实验研究

为能高效利用铜尾矿提铁尾渣,将其用作矿物掺合料进行了试验研究,利用XRF、XRD等技术分析了铜尾矿提铁尾渣的微观组成,并借助TG技术、XRD技术及扫描电镜微观观察对矿物掺和料的反应机理进行了分析。结果表明:经球磨后的尾渣具有一定的火山灰活性;当尾渣掺量在25%以内时,掺尾渣砂浆的强度与基准组强度持平甚至更高;掺尾渣砂浆的抗氯离子渗透性能与基准组相比较好;掺尾渣砂浆的重金属离子固结率较好,中性环境下均值99. 8%,酸性环境下均值为97. 1%。

利用热等离子体熔融垃圾焚烧飞灰

为了评价垃圾焚烧飞灰的热等离子体熔融处理效果,研究SiO2和CaO对重金属固化效果和重金属毒性浸出特性的影响.在飞灰中添加一定比例的SiO2和CaO,配置成不同的配灰样品,利用纯氩热等离子体在1 400～1 500℃下,对飞灰及配灰进行熔融玻璃化的实验研究,分别利用X射线能量色散谱仪(EDX)、场发射扫描电子显微镜(FSEM)、X射线衍射仪(XRD)和毒性浸出方法(TCLP)分析飞灰和熔渣的化学组成、微观结构、晶相组成和重金属毒性浸出特性.结果表明,热等离子体熔融所得熔渣为无定形的玻璃体,重金属浸出质量浓度均远低于毒性标准.SiO2和CaO的添加都可以改善重金属固化效果,CaO比SiO2对Cu、Zn、Cd和Pb挥发的抑制效果更好.SiO2的添加可以改善熔渣中重金属的浸出特性,而CaO的作用与之相反.

等离子体熔融危废焚烧灰渣中试试验研究

为等离子技术装备开发提供具有工程应用价值的数据,采用中试规模的直流等离子体炉对危废焚烧灰渣进行高温熔融处理,考察了开弧、埋弧等对熔融特性的影响,研究了熔渣的组成、微观结构、重金属浸出特性及二次飞灰的特性和产生机理,并测算了熔融处理单位质量灰渣的能耗。结果表明,埋弧和开弧操作对熔渣的成分和晶体结构影响不大。但是,与开弧相比,埋弧操作利用了电阻、电弧加热熔渣,提高热效率,熔融单位质量灰渣的能耗为0.709 k W·h/kg。熔渣中的重金属浸出质量浓度远低于国家标准限值;二次飞灰的产率为7.5%,其主要成分为NaCl。

Physicochemical and environmental properties of arsenic sulfide sludge from copper and lead-zinc smelter

Physicochemical properties of arsenic sulfide sludge(ASS) from copper smelter(ASS-I) and lead-zinc smelter(ASS-II) were examined by XRD, Raman spectroscopy, SEM-EDS, TG-DTA, XPS and chemical phase analysis method. The toxicity characteristic leaching procedure(TCLP), Chinese standard leaching tests(CSLT), three-stage sequential extraction procedure(BCR) and batch leaching experiments(BLE) were used to investigate the environmental stability. The ASSs from different smelters had obviously different physicochemical and environmental properties. The phase composition and micrograph analysis indicate that ASS-I mainly consists of super refined flocculent particles including amorphous arsenic sulfide adhered with amorphous sulfur and that ASS-II mainly consists of amorphous arsenic sulfide. The valence state of arsenic in both sludges is trivalent, but the valence composition of sulfur is quite different. The ASSs have thermal instability properties. The results of TCLP and CSLT indicate that the concentrations of As and Pd in the leaching solution exceed the standard limits. More than 5% and 90% of arsenic are in the form of acid soluble and oxidizable fractions, respectively, which explains the high arsenic leaching toxicity and environmental activity of ASS. This research provides comprehensive information for the disposal of ASS from copper and lead-zinc smelter.

Genetic characteristics and pathogenicity of human hepatitis E virus in Nanjing,China

AIM： To investigate the genetic characteristics and pathogenicity of hepatitis E virus （HEV） and assess the potential risk factors for sporadic hepatitis E.

Characterization of Natural Killer Cells in the Liver of Young Mice

OBJECTIVE To determine the quantity and quality of liver NK cells from young and adult mice and compare their characteristics. METHODS C57BL/6 mice were used at 2 weeks （young） and 8 weeks （adult） of age. The percentage and absolute number of NK cells in the liver and spleen were analyzed. The cytotoxicity of NK cells in the liver and spleen against various targets were detected by a 4 h ^51Cr-release method. FACScan was used to analyze the expression of CD69, Mac-l1 Ly49C/I and CD94 on the NK cells. Perforin mRNA levels were analyzed by the reverse transcription polymerase chain reaction （RT-PCR）. RESUTLS The percentages of NK cells in the liver of young and adult mice were similar （11.9%＋1.7% vs. 9.9%＋1.6%, P〉0.05）, but the absolute number per liver weight was higher in the young animals （11.6＋2.5×10^5/g vs. 3.4＋0.8×10^5/g, P〈0.05）. The level of NK cytotoxicity was extremely high in the liver of young compared to adult mice （71.0%＋5.5% vs. 23.8%＋4.4%, P〈0.05）, but this difference was not observed in the spleen. Phenotypes of the liver NK cells from young and adult mice were completely different from each other. The liver NK cells from young mice were CD69^high Mac-1^low Ly49C/ I^low, whereas NK cells from older mice displayed inverse antigen levels （CD- 69^low Mac-1^high Ly49C/I^high）. The expression levels of other NK cell-related markers were similar in both groups.The perforin mRNA level in the liver lymphocytes from young mice was consistently greater compared to adult mice. CONCLUSION From 2 to 8 weeks C57BU6 mice liver NK cells undergo age-associated changes. At 2 weeks of age the liver NK cells showed a high level of NK cytotoxicity and a unique phenotype which was not apparent at 8 weeks of age.

Potential implications of Helicobacter pylori-related neutrophil-activating protein

Helicobacter pylori （H. pylori） virulence factors pro- mote the release of various chemoattractants/inflam- matory mediators, including mainly the neutrophil- attractant chemokine interleukin-8 and neutrophil- activating protein （NAP）, involved in H. pylor/-induced gastric pathologies. Co-administration of Chios mastic gum （CMG）, which inhibits H. pylor/NAP, with an H. pylori eradication regimen might add clinical benefits against H. pylori-related gastric pathologies, but pos- sibly not CMG as main therapy. Although H. pylori NAP and other H. pylori-related cytotoxins [i.e., vaculating cytotoxin （VacA）] appear to play a major role in gener- ating and maintaining the H. pylori-associated gastric inflammatory response and H. pylor/NAP is a promising vaccine candidate against H. pylori infection （H. pylori-1）, concerns regarding its potential drawbacks, particularly neurogenic ones, due to possible cross- mimicry, should be considered. Possible cross-mimicry between H. p, vlor/ NAP and/or bacterial aquaporin （AQP） and neural tissues may be associated with the anti-AQP-4 antibody-related neural damage in multiple sclerosis （MS）/neuromyelitis optica patients. Moreover, the sequence homology found between H. pylori VacA and human Na＋/K＋-ATPase A subunit suggests that antibodies to VacA involve ion channels in abaxonal Schwann cell plasmalemma resulting in demyelination in some patients. A series of factors have been im- plicated in inducing blood-brain barrier （BBB） disrup- tion, including inflammatory mediators （e.g., cytokines and chemokines induced by H. pylor/-I） and oxidative stress. BBB disruption permits access of AQP4-specific antibodies and T lymphocytes to the central nervous system, thereby playing a major role in multiple sclero- sis pathogenesis. Relative studies show a strong asso- ciation between H. pylori-I and MS. H. pylor/-I induces humoral and cellular immune responses that, owing to the sharing of homologous epitopes （molecular mim- icry）, cross-react with components of nerves, thereby contributing and perpetuating neural tissue damage. Finally, H. pylori NAP also plays a possible pathoge- netic role in both gastric and colon oncogenesis.

Expression and Identification of Inclusion Forming-related Domain of NS80 Nonstructural Protein of Grass Carp Reovirus

Grass carp reovirus （GCRV）, a double stranded RNA virus that infects aquatic animals, often with disastrous effects, belongs to the genus Aquareovirus and family Reoviridea. Similar to other reoviruses, genome replication of GCRV in infected cells occurs in cytoplasmic inclusion bodies, also called viral factories. Sequences analysis revealed the nonstmctural protein NS80, encoded by GCRV segment 4, has a high similarity with μNS in MRV（Mammalian orthoreovimses）, which may be associated with viral factory formation. To understand the function of the μNS80 protein in virus replication, the initial expression and identification of the immunogenicity of the GCRV NS80 protein inclusion forming-related region （335-742） was investigated in this study. It is shown that the over-expressed fusion protein was produced by inducing with IPTG at 28℃. In addition, serum specific rabbit antibody was obtained by using super purified recombinant NS80（335-742） protein as antigen. Moreover, the expressed protein was able to bind to anti-his-tag monoclonal antibody （mouse） and NS80〈335.742） specific rabbit antibody. Further western blot analysis indicates that the antiserum could detect NS80 or NS80C protein expression in GCRV infected cells. This data provides a foundation for further investigation of the role of NS80 in viral inclusion formation and virion assembly.

H5N1 influenza viruses： outbreaks and biological properties

All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortality rates. More importantly, influenza A viruses cause respiratory disease in humans with potentially fatal outcome. Local or global outbreaks in humans are typically characterized by excess hospitalizations and deaths. In 1997, highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Hong Kong that transmitted to humans, resulting in the first documented cases of human death by avian influenza virus infection. A new outbreak started in July 2003 in poultry in Vietnam, Indonesia, and Thailand, and highly pathogenic avian H5N1 influenza viruses have since spread throughout Asia and into Europe and Africa. These viruses continue to infect humans with a high mortality rate and cause worldwide concern of a looming pandemic. Moreover, H5N1 virus outbreaks have had devastating effects on the poultry industries throughout Asia. Since H5N1 virus outbreaks appear to originate from Southern China, we here examine H5N1 influenza viruses in China, with an emphasis on their biological properties.

IL-13Ra2-and glioma stem cell-pulsed dendritic cells induce glioma cell death in vitro

Objective Gliomas are the most common malignant tumors in the central nervous system.Despite multiple therapies including surgery,chemotherapy,and radiotherapy,the prognosis of patients remains poor.Immunotherapy is an alternative method of treating glioma,and the use of dendritic cell vaccines is one of the promising treatment options.However,there is no specific tumor cell antigen that can trigger dendritic cells(DCs).IL-13Ra2 is a specific antigen expressed in glioma cells;in the current study,we have attempted to explore whether IL-13Ra2 could be the antigen that triggers DCs and to envisage its application as potential therapy for glioma.Methods The expression of IL-13Ra2 was detected in U251 glioma cell lines and primary glioma tissues using different methods.DCs from human blood were isolated and pulsed with recombinant IL-13Ra2,following which the cytotoxicity of these DCs on glioma cells was detected and analyzed.Results About 55.9% human glioma tissue cells expressed IL-13Ra2,while normal brain tissue cells did not show any expression.DC vaccines loaded with IL-13Ra2,glioma cell antigen,and brain tumor stem cell(BTSC) antigen could significantly stimulate the proliferation of T lymphocytes and induce cell death in the glioma tissue.Compared to other groups,DC vaccines loaded with BTSC antigen showed the strongest ability to activate cytotoxic T lymphocytes(CTLs),while the glioma cell antigen group showed no significant difference.Conclusion IL-13Ra2,which is expressed in gliomas and by glioma stem cells,as well as IL-13Ra2 could prove to be potential antigens for DC vaccine-based immunotherapy.

Structure and Anti-influenza A(H1N1) Virus Activity of Three Polysaccharides from Eucheuma denticulatum

Three polysaccharides （EW, EH and EA） were prepared from a red alga Eucheuma denticulatum by sequential extraction with cold water, hot water and sodium hydroxide water solution. Their monosaccharide compositions, relative molecular mass and structural characterization were determined by gas chromatography, high performance liquid chromatography, fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy methods. EW was hybrid l/k/v-carrageenan （701/17k/13v-car- rabiose）, EH was mainly t-carrageenan, and EA was mainly α-1,4-Glucan （88%） but mixed with small amount of t-carrageenan （12%）. The relative molecular mass ofEW, EH and EA was 480, 580 and 510kDa, respectively. The anti-influenza A （H1N1） virus activity of these three polysaccharides was evaluated using the Madin-Darby canine kidney cells model. EW showed good anti-H1N1 virus activity, its ICso was 276.5 μg mL-1, and the inhibition rate to H1N1 virus was 52% when its concentration was 250 μgmL-1. The ICs0 of t-carrageenan EH was 366.4 μgmL1, whereas EA showed lower anti-H1N1 virus activity （IC50〉430μgmL-1）. Available data obtained give positive evidence that the hybrid carrageenan EW from Eueheuma denticulatum can be used as potential anti-H1N1 virus inhibitor in future.

Leflunomide-induced acute liver failure: a case report

A 27-year-old male patient with rheumatoid arthritis was diagnosed with acute liver failure when he was taking leflunomide, a new immunosuppressant. This case illustrates the risk that leflunomide may lead to severe hepatotoxicity.

Screening of Toxin Mutant of Dickeya zeae and Its Biological Characters

[Objective]This study aimed to screen toxin mutant of Dickeya zeae(Erwinia chrysanthemi pv.zeae)and investigate its biological characters.[Method]We obtained a toxin mutant strain D.zeae Ech7-3-42 by using acridine orange as a mutagenic agent and compared their biological characteristics and virulence between the toxin mutant and wild strain.[Result]There was no significant difference in pectin lyase,protease,cellulase and the production of extracellular polysaccharide and lipopolysaccharide,but significant difference in toxin biological activities and virulence.Ech7-3-42 mutant did not produce toxin,as well as the loss of virulence on rice and HR on tobacco,but did not lose the ability to soft rot on potato.Mutant strain Ech7-3-42 can infect rice root and then enriched in the root neck and stalk,but it could not cause rice foot rot.Dickeya zeae(wild and mutant strain)could be detected by PCR in the root neck and below the 1-2 cm long stem area,but could not be detected in the leaves.[Conclusion]We believed that toxin may be one of the important factors for D.zeae virulence on rice.

铸造废砂的环境毒性研究

采用毒性特性浸出程序、顶空气相色谱技术检测了5种铸造废砂中的重金属与有机污染物,采用发光细菌毒性检测技术和土壤酶活性实验研究了废砂的生物效应.结果表明,由于浇注金属与造型材料的不同,5种铸造废砂中的金属与有机污染物成分和浓度均有较大差异.其中,铸铁与铸钢废砂浸出液中的铁离子,铸铝废砂中的As离子超出了《地表水环境标准》规定的最大允许检出浓度.5种废砂中的有机污染物种类十分复杂,对发光细菌表现出不同程度的抑菌活性,发光强度的抑制率在30%～95%之间.此外,土壤酶活性实验结果表明,废砂中的金属污染物可能会抑制土壤中微生物的活性,而有机物则对土壤微生物的活性有一定的促进作用.因此,铸造废砂的随意排放将会对环境造成较严重的威胁.