废弃鸡毛化学降解工艺研究

研究了酸、碱条件下不同化学药品对鸡毛降解的影响,从而筛选出有效的助剂以提高复合氨基酸的产率;并在水解温度恒定、水解剂硫酸3mol·L-1或氢氧化钾6mol·L-1及常压条件下,采用正交试验研究了固液比、助剂用量、水解时间对水解率的影响。结果表明:酸、碱处理条件下不同处理间差异显著,酸处理条件下以金属盐作用效果最好,增产率18. 0%;碱处理条件下以硫化钠作用效果最好,增产率达39. 8%。在水解温度115~120℃及常压条件下,水解剂为3mol·L-1硫酸处理的最佳水解工艺为固液比1∶3、助剂用量120g·kg-1、水解时间10h; 6mol·L-1氢氧化钾作为水解剂时的最佳水解工艺为固液比1∶3、助剂用量120g·kg-1、水解时间12h。     

甲酰氨基嘧磺隆在模拟环境中的降解特性

甲酰氨基嘧磺隆是一种新型磺酰脲类除草剂,其在环境中的归趋备受关注.采用室内模拟试验方法,研究了甲酰氨基嘧磺隆在不同土壤中的降解性、水解和光解特性.结果表明,甲酰氨基嘧磺隆在光照强度4000 lx,紫外强度25μW·cm~(-2)的人工光源氙灯条件下,甲酰氨基嘧磺隆的光解半衰期为1.72 h,易光解.25℃时,pH4、pH7和pH9条件下水解半衰期分别为4.17、91.2、97.6 d,50℃时的水解半衰期分别为1 d、4.75 d和14.5 d,温度和p H值对水解速率具有较大影响.甲酰氨基嘧磺隆在江西红壤、太湖水稻土和东北黑土中的降解半衰期分别为10.8、16.6、31.5 d,该药在酸性土壤中降解较快,影响其在土壤中降解速率的主要因素为土壤pH值.     

铜镉复合胁迫下温度对小麦幼苗生长及其对铜、镉和矿质营养元素吸收与各元素在亚细胞分布的影响

为了研究重金属复合胁迫下温度变化对陆生植物的毒性效应的影响,实验采用水培的方法,设置对照和Cu-Cd复合胁迫(10 μmol·L1 Cu+10μmol·L-1Cd)2个处理,每个处理分别设置3个不同的培养温度(8/4℃、25/20℃和35/30℃),对小麦进行48 h的暴露实验,测定小麦幼苗的生长及其对重金属和矿质营养...     

柱前衍生化-气相色谱/质谱法测定细胞中的对-正壬基酚

采用柱前衍生化-气相色谱/质谱法测定染毒细胞以及细胞质中对-正壬基酚(4-n-NP)的含量,并初步探讨了4-n-NP在细胞中的分布.在不同介质中加标回收率在76.5%-98.9%之间.利用本方法测定实际样品发现:在浓度为10μmol·1-1和20μmol·1-1的4-n-NP溶液中暴露12h,105个细胞中4-n-NP的含量分别为21.0ng和43.0ng,而相应的细胞质中4-n-NP的含量分别为14.2ng和28.4ng,显示有67.6%和66.0%的4-n-NP分布在细胞质中.     

土壤中植物有效态镉提取方法比较

通过温室盆栽试验研究了滩潮土、青紫泥田和黄泥砂田中添加镉对青菜镉吸收的影响,评价了人工螯合剂、无机盐和硝酸溶液对污染土壤中镉的浸提性及其植物有效性.结果表明,青菜地上部镉与土壤镉含量呈非线性关系.土壤pH值和碳酸钙含量是影响镉植物有效性的主要因素,青菜对镉的吸收与土壤pH呈显著负相关.在土壤镉含量相同条件下,黄泥砂田、青紫泥田、滩潮土3种土壤中青菜地上部镉含量依次降低.青菜地上部镉含量与0.43mol·L-1HNO3、0.05mol·L-1EDTA和0.01mol·L-1CaCl2提取态镉均呈显著相关(r2=0.73～0.96).笔者认为,这3种提取剂提取的土壤镉可视为植物有效态镉.     

贵州丹寨金汞矿区尾渣和水土中汞砷分布特征及潜在风险

贵州丹寨金汞矿在开采期间,将大量的废渣露天堆放在环境中,这些尾渣不仅含有金,还含有有毒有害重金属汞和砷。本文研究丹寨尾渣中汞和砷的淋出特征以及矿区周边土壤、农作物和地表水汞砷分布特征,并通过尾渣中金含量来评估利用植物提取技术来回收金的可能性。研究结果表明,利用0.1mol·L-1Na H2PO4和0.1 mol·L-1Na2HPO4(3:2 V/V)的混合溶液淋洗尾渣,淋滤出的砷含量达到9 929.8μg·L-1;利用0.1 mol·L-1CH3COONH4溶液淋洗尾渣,淋滤液汞含量达到12.12μg·L-1。矿区周边土壤总汞含量和总砷含量分别为11.5~79.7 mg·kg-1和23.7~356.5 mg·kg-1,利用污染程度法和尼梅罗综合污染指数发对其Hg和As污染程度进行了评价,结果显示土壤汞污染严重,污染因子高达10.5~78.7;尼梅罗综合污染指数为62.97;同时该土壤还受到严重的As污染,除了其中一个样点的As污染程度小于0属于未超标,其它样点As污染程度均大于0;尼梅罗综合污染指数为13.41。农作物中总汞含量和总砷含量均超过国家食品卫生限量标准,分别是《食品安全国家标准》(GB2762-2012)中所允许最大总汞和最大总砷的10~1 150倍和1.6~7.4倍。位于尾渣堆放点上游的地表水中总汞和总砷浓度分别为102.4 ng·L-1和2 262.1 ng·L-1,流经尾渣堆后,浓度大幅度增加,分别为160.3 ng·L-1和11 571.8 ng·L-1,说明丹寨尾渣可能是潜在的汞和砷污染源。尾渣中金含量为0.54 g·t-1,可以探索利用植物提取技术来回收尾渣中的金。     

两种生态型东南景天根系分泌物的差异性

东南景天(Sedum alfredii Hance)具有很强的耐高Zn 胁迫、吸收和运输Zn的能力,但其根系如何通过分泌作用实现对Zn胁迫的适应和对土壤难溶性Zn的活化作用,还缺乏机理方面的解释.因此,本研究运用离子色谱、氨基酸自动分析等技术较系统地研究了两种生态型东南景天根系分泌物组成的差异性及其对土壤中不同化合物Zn的活化效应,旨在探明根系分泌物与东南景天超积累Zn的关系.结果表明,两种东南景天的根系分泌物均能够活化土壤中难溶态的ZnO、ZnCO3和Zn3(PO4)2,而对ZnS没有明显地活化作用.通过对根系分泌物组成成分分析,两种生态型东南景天根系分泌物中可溶性糖占绝对优势,有机酸和氨基酸含量很低,且均以非超积累生态型>超积累生态型.超积累生态型东南景天根系分泌物中的可溶性总糖、有机酸(苹果酸除外)、氨基酸等各成分含量均以Zn 1.0 μmol·L-1处理>Zn 500 μmol·L-1处理,非超积累生态型东南景天根系分泌物中糖和有机酸含量也随着Zn浓度的增加而减少,而绝大多数氨基酸含量则随着Zn浓度的增加而增加.这说明本试验条件下测定的根系分泌物组分在东南景天超积累Zn过程中并不起主导作用.     

不同粒径土壤活性有机碳测定方法的探讨

选择不同肥力的沙质栗钙土、潮褐土和草甸栗钙土三种土壤.采用干筛法对其进行处理,获得四种不同粒级的土壤,分别为:<0.15 mm、0.15～0.25 mm、0.25～0.50 mm和0.5～1.0 mm,用目前最常用的两种化学方法分别对不同粒级土壤活性有机碳进行了测定.结果表明:不同粒级土壤活性有机碳含量差异显著(P<0.05),并且土壤活性有机碳含量随粒级增大而降低,其大小顺次为:小于0.15 mm土壤>0.15～o.25mm土壤>0.25～o.5 mm土壤>0.5～1.0mm土壤;与KMnO4氧化法相比,0.2 mol·L-1(1/6K2Cr2O7-1:3H2SO4)氧化,130～140℃油浴煮沸5 min测定土壤活性有机碳的方法结果稳定,重现性好,变异系数小,且时间短,适宜大批土壤样品活性有机碳的测定.     

碱熔-离子色谱法测定土壤中全硫的研究

研究了用碱熔-离子色谱法测定土壤中全硫的方法,样品采用氧化镁—碳酸钠(2:1)混合熔剂,在恒温马弗炉中800℃加热1 h,使土壤中各种形态的硫转化为SO_4~(2-),冷却,用水超声浸提.离子色谱法测定.分析柱AS14A4-mm(4 mm×250mm),淋洗液0.008mol·L~(-1)Na_2CO_3、0.001 mol·L~(-1)INaHCO_3,再生液0.05mol·LH_2SO_4~(-1),流量1.0mL·min~(-1),进样体积20μL,外标峰面积定量.该方法测定土壤中硫检测限为0.8 mg·kg~(-1),在测量浓度范围内具有良好的线性关系.用该方法做精密度,相对标准偏差为3.91%.与不同地区的标准土做对比实验,所测结果跟标准值相比均在标准值范围内.实验证明该方法操作简便、快速.     

酱油曲霉（Aspergillus sojae）利用甘蔗渣产絮凝剂条件筛选及优化

通过Plackett-Burman实验（PB实验）对酱油曲霉（Aspergillus sojae）利用甘蔗渣分泌微生物絮凝剂的8个营养条件和培养条件进行考察,筛选出影响微生物生长、微生物絮凝剂质量和产量的显著性因素,并对显著性因素进行单因子实验,优化酱油曲霉利用甘蔗渣分泌絮凝剂的最佳营养条件和培养条件。实验结果表明：K2HPO4、还原性糖质量浓度、培养时间是影响菌体生长的显著因素,培养基的初始pH是影响絮凝率的显著因素,还原性糖质量浓度、（NH4）2SO4是影响絮凝剂粗产量的显著因素。对显著因素进行单因子实验确定最佳营养条件和培养条件为甘蔗渣的酶解液（还原性糖质量浓度（13.67±0.54）g.L-1）,4 g.L-1的硫酸铵,pH=5,于30℃培养60 h。     

Photosynthetic sulfur bacteria from Zimapan Reservoir (Mexico): Seasonal variations and toxic effects of zinc in a microcosm system

Photosynthetic sulfur bacteria oxidize the sulfide produced by dissimilatory sulfate-reducing bacteria, thus preventing the occurrence of pollution by these compounds in the oxygenic zone of aquatic systems. Zinc is one of the most abundant heavy metals. Its toxic effects have been documented in various organisms that can photosynthesize, but a lack of information prevails in this respect, about photosynthetic sulfur bacteria. The aim of the present study was to evaluate the toxic effects of zinc on green sulfur bacteria (Chlorobiaceae) and purple sulfur bacteria (Chromatiaceae) in a microcosm as well to explore the possible relationships between the bacterial population growths with the physicochemical properties of the metalimnion of Zimapan Reservoir (Mexico) during a 1-year period. Hydrosoluble organic carbon (HOC) and light availability in the metalimnion were the limiting factors for growth in these bacteria. Higher HOC levels occurred in Spring, at the end of the wet season and in Winter. Current zinc levels in the reservoir seem to elicit toxic effects. At lethal zinc concentrations, the best concentration-response relationship was shown. The biomarker for purple sulfur bacteria was the bacteriochlorophyll content, while total reducing sugar was the best biomarker for green sulfur bacteria. At sublethal concentrations, zinc alters adenosine triphosphate levels, total reducing sugar, total protein content, and bacteriochlorophyll content. The observed responses indicate that green sulfur bacteria are more sensitive than purple sulfur bacteria and are suitable target organisms for use in establishing the accepted threshold concentration of zinc (NOEC 0.056–0.097 mg L^?1 of Zn) in anoxic deep water.     

亚热带水库沉积物钻孔中有机质的历史记录及其环境意义

氢指数(HI)是重要的有机质评价参数,能够反映沉积有机质中脂肪大分子物质的相对含量,并用于反演水生生态系统的历史初级生产力,有助于研究藻类生产力对污染物的富集作用。为了探讨氢指数的环境指示作用,选择了亚热带的3座水库作为研究对象,采用Rock-Eval热解与生物标志物-中性糖方法相结合的研究技术,研究了沉积钻孔有机质的来源与特征;并结合210Pb和137Cs定年技术,综合运用氢指数和总糖含量对水库的初级生产力进行了重建。结果表明:中富营养的增塘和联安水库沉积有机质主要来源于浮游藻类,且受降解的程度较小,而贫营养的新丰江水库钻孔下层有机质主要是受降解作用或陆源高等植物等的影响。近年来,3个水库的HI值都有显著性的增加,且与其对应的总糖含量以及近50年来的滑动平均温度都高度的相关,说明这些水库都经历了气候变暖所引起的初级生产力增长。同时,升高的水库生产力扩大了沉积物剖面中重金属和多环芳烃的累积。     

Organic acid profile and phenolic and sugar content in Salix purpurea × viminalis L. cultivated with different spent mushroom substrate and copper additions

The aim of the study was to determine the response of Salix purpurea?×?viminalis L. growing on Pleurotus ostreatus spent mushroom substrate (SMS) with different copper (Cu) addition. The content of Cu in roots, leaves and shoots was reduced by SMS addition. A decrease of biomass was observed with simultaneous Cu concentration increase. SMS induced leaf and root elongation of Cu-treated plants. Variation in the profile of low molecular weight organic acids with the domination of oxalic and acetic acids was observed. The total phenolic content significantly increased for plants cultivated with SMS, while the biosynthesis of salicylic acid was considerably weakened. The content of sugars was generally reduced by SMS. Alteration in the level of the stress-related molecules suggests mitigation of the harmful effect of Cu on Salix hybrid metabolism by SMS addition. This pointed to the possibility of using SMS in contaminated soil to reduce the toxic effect of metals on plants used in phytoextraction.     

Damage-inducibility of primary and secondary metabolites in the wild parsnip (Pastinaca sativa)

Summary. Induction of secondary metabolites to herbivore damage is a widespread phenomenon among plants and serves to enhance resistance by reducing suitability or increasing toxicity of foliage. Post-damage responses of primary metabolites are less well known; reductions in primary metabolites may increase resistance by decreasing palatability or nutritional suitability for herbivores or by potentiating toxicity of secondary metabolites. In this study, we examined response to simulated herbivory in Pastinaca sativa, the wild parsnip, in both primary and secondary metabolites. We found that induction of secondary metabolites in response to damage is largely restricted to a single class of compounds, the furanocoumarins. These prooxidant compounds are known to be toxic to a wide variety of insect herbivores. The only primary metabolite that responded to damage was total soluble protein, which increased significantly 24 h after damage. After 24 h, the correlation between total furanocoumarins and total sugars was significant and negative (r = − 0.697). This correlation likely reflects an independent response of sugar to damage, rather than a diversion of resources into furanocoumarin production, inasmuch as this correlation at 3 h, after furanocoumarin induction had taken place, was not significant. In other secondary metabolite pathways, damage produced a significant decline in farnesene and a C-16 unsaturated fatty acid, 7,10,13-hexadecatrienoic acid, each of which may potentiate the furanocoumarin defense response. Farnesene may enhance photooxidative activation of the furanocoumarins and 7,10,13-hexadecatrienoic acid may serve as a precursor to jasmonic acid, a key hormone in regulating induction responses. With few key exceptions, quantities of both primary and secondary metabolites in wild parsnip foliage are unaffected by damage. Those that are affected may well play a role in resistance of parsnips to herbivores. Received 1 July 1998; accepted 28 September 1998.     

Chemical determinants of resistance in winter-dormant seedlings of European white birch (Betula pendula) to browsing by the mountain hare

Summary A sample of one-year-old seedlings of European white birch (Betula pendula) was analyzed to determine the content of sugars, phenolics and terpenoid compounds. Two vertical segments of each seedling were analyzed separately. The number of resin droplets, which correlates strongly and negatively with feeding by the mountain hare, was also counted on the bark of experimental seedlings. The variation in the palatability of birch seedlings to mountain hare was determined primarily by the most abundant terpenoid, papyriferic acid. On the other hand, the resistance to hare feeding at the seedling bases, which are frequently attacked by voles, appeared to be dependent on other components, apparently phenolic substances. Sugars did not affect the resistance of the tested seedlings. The variation among experimental seedlings was much greater for secondary substances, especially terpenoid compounds, than for sugars. It is suggested that this high variation in protective compounds may be an adaptive trait selected for by the feeding of generalist herbivores.     

幽门螺杆菌研究进展

幽门螺杆菌（Ｈｅｌｉｃｏｂａｃｔｅｒｐｙｌｏｒｉ）是１９８２年Ｗａｒｒｅｎ和Ｍａｒｓｈａｌｌ等人［１］在培养人体胃粘膜活检组织样品时发现的,当时名为幽门弯曲杆菌（Ｃａｍｐｙｌｏｂａｃｔｅｒｐｙｌｏｒｉ）;以后随着各方面研究的深入,Ｇｏｏｄｗｉｎ等［２］１９８９年建立了螺杆菌属（Ｈｅｌｉｃｏｂａｃｔｅｒ）,才将Ｃ．Ｐｙｌｏｒｉ正式命名为Ｈ．ｐｙｌｏｒｉ．Ｈ．ｐｙｌｏｒｉ是人类慢性活动性胃炎（Ｂ型胃炎）及胃,十二指肠溃疡的重要病原菌,并且是肠型胃癌的诱发因素之一．因而,引起世界范围内对Ｈ．ｐｙｌｏｒ…     

基因污染与生态环境安全

论述了基因污染可能对生态环境安全造成的影响。转基因作物有可能污染天然物种的基因库；有可能破坏传统农作物品种的遗传多样性，加速作物种植品种的单一化及基因资源的流失；使抗除草剂作物的基因向野生或半野生植物漂移的可能性加大，有可能创造出“超级杂草”；带有病毒型转基因作物的基因重组，有可能创造出新的植物病毒，导致新的病害；BT转基因抗虫作物分泌的毒素，在食物链中传递，很难加以控制，对非目标生物造成危害，并最终破坏自然生态系统的平衡。文章还从不同角度分析了基因污染的严重性。     

市场经济与土肥科技

土肥的基础地位是不随社会性质或社会经济类型的变化而变化的，它既具重要性，又具长久性．市场经济是仍然需要土肥科技的．土肥科技的教学、科研和推广的力度必须加大，局面必须改观，且宜快不宜迟．土肥科技工作者一定要将培肥地力作为中心工作．根据广东的实际，增施有机肥是培肥地力的主要措施，因而抓秸秆还田和发展冬绿肥是我们工作的重点．     

Indoor and outdoor air pollution and lung cancer in New Hampshire and Vermont

Indoor and outdoor air pollution is known to contribute to increased lung cancer incidence. This study is the first to address the contribution of home heating fuel and geographical course particulate matter (PM₁₀) concentrations to lung cancer rates in New Hampshire, USA. First, Pearson correlation analysis and geographically weighted regression were used to investigate spatial relationships between outdoor PM₁₀ and lung cancer rates. While the aforementioned analyses did not indicate a significant contribution of PM₁₀ to lung cancer in the state, there was a trend towards a significant association in the northern and southwestern regions of the state. Second, case-control data were used to estimate the contributions of indoor pollution and secondhand smoke to the risk of lung cancer with adjustment for confounders. Increased risk was found among those who used wood or coal to heat their homes for more than 10 winters before the age of 18, with a significant increase in risk per winter. Resulting data suggest that further investigation of the relationship between heating-related air pollution levels and lung cancer risk is needed.     

Heavy metals and pesticides in anuran spawn and tadpoles,water, and sediment

High concentrations of metals (cadmium, copper, lead, and zinc) and of lindane were measured in the sediment and in the spawn and tadpoles of Bufo bufo, Rana dalmatina, and Rana ridibunda from two Austrian locations. Residues in spawn suggest maternal transfer. Increase of the metal concentrations from spawn to advanced tadpole stage is explained by the larval microphaguous feeding habits which cause high exposition of the tadpoles to substances concentrating in sediments and suspended particles. Metal and pesticide concentrations in spawn and tadpoles are toxic to various other aquatic organisms and are furthermore considered to be potentially hazardous to the anurans themselves. The results are conform with world‐wide observations of contamination of anuran larvae with heavy metals, and prove the significance of non‐point source chemical exposure due to allochthonous toxicant input by wind load and precipitation.