Subcellular Mn compartation, anatomic and biochemical changes of two grape varieties in response to excess manganese

To explore the underlying mechanism for the high tolerance to excess manganese stress in the grape species (Vitis vinifera Linn), we observed the subcellular compartment of Mn element, anatomic and biochemical responses of two grape cultivars (Combier and Shuijin) under excess Mn stress in semi-controlled environmental condition. Grape species exhibited typical detoxifying or tolerant mechanism as following: first, majority of Mn element accumulated in leaf was excluded into cell wall or comparted into cell vacuole to avoid cellular Mn-toxicity; Mn and other elements were also secreted into leaf surface or deposited in vascular wall; second, only small amount of Mn was located in cellular organ, and excess Mn in chloroplast was detoxified by depositing in starch granule, which serve as a novel detoxifying strategy; additionally, the cellular Mn was further chelated by phytochelatins; third, to quench the toxic oxygen radicals, the total phenolic compounds and polyamine (putrescine and spermidine) were enhanced. Although the obvious symptom of Mn-toxicity was not detected, we observed the dessication symptom under high level of Mn treatment in the two cultivars, such as sunk stomata, thickened palisade tissue, enhanced palisade/spongy tissue ratio and abscisic acid concentration. The growth inhibition and dessication symptom in the two grape cultivars could be largely associated with osmotic stress resulted from high concentration of leaf Mn.     

4种蔬菜对土壤Mn转运累积特征及食用安全性研究

为探究土壤中锰(Mn)污染对蔬菜食用安全性的影响,以上海市常见的4种蔬菜(青椒,CA;黄瓜,CS;豇豆,VU;菠菜,SO)为试验材料,采用温室盆栽土培试验方法研究了不同土壤Mn含量梯度下的蔬菜生物量变化以及各部位Mn转运累积特征,并基于各蔬菜食用安全分析了土壤中Mn的安全阈值。研究结果表明,Mn对4种蔬菜的生长均表现出低含量促进、高含量抑制现象,SO和VU对Mn的耐受度强于CA和CS。Mn主要富集在SO的茎叶,以及CA、CS和VU的茎叶和根部,可食部分中Mn含量大小排序为SO>VU>CS>CA。SO可食部分Mn含量与土壤Mn含量呈显著对数相关(P<0.01),其他3种蔬菜的可食部分Mn含量与土壤Mn含量均呈显著指数相关(P<0.01)。依据新鲜蔬菜中Mn食用安全限量值,推导出各蔬菜对应的土壤Mn安全阈值预测区间为:SO 992.5～1 097.3 mg·kg~(-1),VU 2 607.5～2 910.0 mg·kg~(-1),CS 3 147.5～3 494.6 mg·kg~(-1),CA3 618.0～3 921.5 mg·kg~(-1)。Mn污染土壤的安全利用应优先选择种植CA、CS和VU等低累积品种。     

阿哈水库流域含铁、锰面源废水河流控制系统

饮用水源地阿哈水库流域面积190km2,由于国营煤矿及乡镇个体煤窑的开发,造成含高浓度Fe,Mn酸性面源废水,分散无规律排入河流污染水库。为此,对大面积面源废水采用河流控制系统进行治理研究,并付诸工程实施,经运转表明,该河流控制系统是十分有效的。      

土壤酸化对油松生长的影响

褐色森林土酸化后,pH值下降,同时淋溶出大量Al离子和Mn离子。播种在酸化土壤中的油松种子萌发率稍有提高。生长在酸化土壤的油松苗的叶绿素含量,蒸腾强度,光合速率,相对生长率和干重均下降,原因是Al离子和Mn离子对油松的有毒害作用,并且阻止油松对钙离子和镁离子的吸收。表3参12     

粤东凤凰山茶区土壤锰、锌赋存形态特征及对茶叶的有效性

采用连续化学提取法对粤东凤凰山茶区12个茶园土壤Mn和Zn的5种赋存形态特征及对茶叶的有效性进行了研究。结果发现,茶区土壤Mn平均含量为337 mg.kg-1,Zn平均含量为166.0 mg.kg-1,Mn和Zn的形态分布规律均表现为残渣态>铁锰氧化物结合态>有机束缚态>可交换态>碳酸盐结合态。土壤铁锰氧化物结合态和碳酸盐结合态Mn含量以及碳酸盐结合态、有机束缚态和铁锰氧化物结合态Zn含量分别与土壤pH值呈显著正相关,可交换态Mn含量与土壤pH值呈显著负相关;有机束缚态Mn、Zn含量以及铁锰氧化物结合态Zn含量分别与土壤有机质含量呈显著正相关,而铁锰氧化物结合态Mn含量与土壤有机质含量呈显著负相关。茶区茶叶Mn平均含量为1 046.3 mg.kg-1,Zn平均含量为42.0 mg.kg-1。茶叶Zn含量分别与土壤可交换态、有机束缚态、碳酸盐结合态Zn含量以及有机质含量呈显著正相关;茶叶Mn含量分别与土壤可交换态、碳酸盐结合态、有机束缚态Mn含量呈显著正相关,而与土壤pH值呈显著负相关。土壤pH值和有机质含量对茶区土壤Mn和Zn的化学形态分布及茶叶中Mn和Zn的累积有重要影响。     

Distribution of mercury and methylmercury in river water and sediment of typical manganese mining area

Manganese (Mn) ores contain substantial concentrations of mercury (Hg), and mining and smelting of Mn ores can bring Hg into the surrounding aquatic environment through atmospheric deposition, leaching of electrolytic Mn residue and Mn gangue dump. However, limited is known that how these processes influence the environmental behaviors of Hg in waterbody. Therefore, the seasonal distribution and existing form of Hg in water and sediment in one Mn ore area in Xiushan County, Chongqing were investigated. Our results showed that the mean Hg and methylmercury (MeHg) concentrations in water (n=35) were 5.8 ± 4.6 ng/L and 0.22 ± 0.14 ng/L, respectively. The mean Hg concentrations in retained riverbed and fluvial bank sediment (n=35) were 0.74 ± 0.26 mg/kg and 0.63 ± 0.27 mg/kg, respectively (the mean MeHg concentrations were 0.64 ± 0.40 µg/kg and 0.51 ± 0.30 µg/kg, respectively). It indicated that the mining and smelting of Mn ores were the main sources of anthropogenic Hg, and Mn may inhibit Hg methylation in rivers in Mn ore areas. Mercury in the bound to iron/ Mn (Fe/Mn) oxides of low crystallinity fraction (Hg-OX) accounted for 4.01% and 5.25% of the total Hg concentrations in the retained riverbed and fluvial bank sediment, respectively. The amount of Hg bound to Fe/Mn oxides in sediment increased significantly due to the manganese mining activities in the investigated area. Therefore, it could be hypothesized that high Hg concentrations in river sediment in Mn mining areas are closely related to high Mn concentration in sediment.     

固定化生物活性炭深度处理白龟山水厂出水的净化效能研究

采用人工固定化生物活性炭处理技术对白龟山水厂出水的深度净化效果显著:高锰酸盐指数去除率在40%左右,氨氮的去除率在97%以上,对浊度、细菌总数及大肠杆菌群数也有良好的去除效果。     

不同菌株培养顺序对添加铁铝锰氧化物白浆土腐殖质组成的影响

文章旨在探索巨大芽孢杆菌(Bacillus megaterium)、黑曲霉(Aspergillus niger)和灰色链霉菌(Streptomyces griseus)3种菌株、6种培养顺序在添加铁、铝、锰氧化物情况下对混有木质素白浆土腐殖质组成的差异影响.采用室内培养法,在针铁矿、三羟铝石和δ-MnO_2参与条件下,通过6种菌株培养顺序的设置,探讨其对木质素白浆土混料腐殖质组成的影响.结果表明:基于针铁矿添加条件,在以巨大芽孢杆菌为Ⅰ期培养菌株时更有利于白浆土腐殖化系数(CHA/CFA)的促进.而在针铁矿和δ-MnO_2添加条件下,A.niger→S.griseus→B.megaterium的培养顺序更有利于白浆土胡敏酸(HA)向富里酸(FA)的转化.基于三羟铝石添加条件,灰色链霉菌为Ⅰ期培养菌株时更有利于白浆土CHA/CFA的促进,而以巨大芽孢杆菌为Ⅰ期培养菌株时可使CHA/CFA降低;除S.griseus→A.niger→B.megaterium外的5种菌株培养顺序,δ-MnO_2均能有效促进白浆土HA的降解、使其分子结构更加简单;无论哪一菌株培养顺序,针铁矿均有利于微生物对混料胡敏素(Hu)的矿化,δ-MnO_2可使混料总有机碳(TOC)发生较大程度矿化;与对照相比,δ-MnO_2亦可促进微生物对混料水溶性物质(WSS)的消耗,且对可提取腐殖酸(HE)的形成有促进作用.     

云贵高原湖泊沉积物一水界面铁、锰、硫体系的研究进展

通过对云贵高原湖泊沉积物一水界面铁、锰、硫体系的研究 ,揭示了湖泊铁、锰循环受氧化还原边界层、沉积物一水界面等多重界面的控制 ;湖水中硫酸盐的浓度制约着其扩散的物理过程 ,进而影响着硫酸盐还原作用 ;硫酸盐还原对铁、锰循环产生亚扩散层屏蔽效应 ;铁、锰循环伴随有微量金属元素的沉积后再迁移现象 ;沉积物一水界面为认识湖泊污染问题、有效地解决湖泊铁、锰的季节性污染等提供了科学依据。     

库区高锰酸盐指数变化趋势及控制对策

分析了晋江金鸡闸库区12年来丰、平、枯各期的高锰酸盐指数监测数据，结果显示，枯水期均值上升趋势显著，说明点源污染逐年上升，应引起重视，并提出相应控制措施。