O3对水稻叶片氮代谢、脯氨酸和谷胱甘肽含量的影响

臭氧(O3)被认为是重要的气污染物之一,水稻又是主要的粮食作物,因而准确地评估O3浓度升高对水稻生长发育的影响具有十分重要的意义。采用开顶式气室法模拟研究了O3对水稻叶片可见伤害症状、氮代谢、脯氨酸和谷胱甘肽含量的影响。结果显示,O3污染胁迫会导致水稻叶片产生明显的伤害症状,具体表现为:老叶叶鞘褪绿,有褐斑,直至完全干枯;稻穗小且黄化,籽粒不饱满;水稻成熟期提前等。O3浓度升高对水稻叶片的硝酸还原酶活性有显著影响。当O3浓度为40、80和120nL.L-1时,水稻叶片硝酸还原酶活性与对照组相比均降低,其中,分蘖期分别降低了25.3%、67.4%和86.3%;拔节期分别降低了57.4%、75.7%和97.8%;抽穗期分别降低了91.0%、97.2%和99.3%;乳熟期分别降低了89.5%、89.5%和96.7%。水稻叶片铵态氮和硝态氮含量随着O3浓度的升高而显著地降低,例如当O3浓度为40、80和120nL.L-1时,与对照相比,水稻叶片硝态氮含量分别降低46.3%、52.7%和65.7%,铵态氮含量分别降低6.5%、12.9%和43.4%。O3污染胁迫下水稻叶片脯氨酸含量在不同生长期变化不同,分蘖期、拔节期和抽穗期脯氨酸含量在40nL.L-1浓度O3熏蒸下急剧地提高,但是随着O3浓度的增加,脯氨酸含量又不断地降低。在水稻乳熟期,脯氨酸含量均随着O3浓度的增加而显著地下降。O3污染胁迫导致水稻叶片还原型谷胱甘肽(GSH)含量显著低于对照组,而氧化型谷胱甘肽(GSSG)含量显著高于对照组。当O3浓度为40、80和120nL.L-1时,乳熟期水稻叶片GSH含量分别比对照组降低68.7%、80.2%和78.2%,GSSG含量分别比对照提高494.4%、527.2%和439.8%。研究表明,O3污染胁迫对水稻叶片氮代谢和抗氧化系统产生了极显著的影响。     

Effect of effluent organic matter on ozonation of bezafibrate

The influence of three effluent organic matter (EfOM) model compounds, humic acid (HA), bovine serum albumin (BSA), and sodium alginate (AGS), on the ozonation of bezafibrate (BF), a typical pharmaceutical and personal care product (PPCP), was investigated. The results show that ozonation efficiently removed BF from aqueous solution with removal efficiencies>95% within 8 min for all conditions. The reaction rate of BF decreased with increasing model compounds concentrations and the influence was more pronounced for HA and BSA, while less pronounced for AGS. Although BF concentration was significantly reduced, the degree of mineralization achieved was only approximately 11%. The addition of HA and BSA improved the mineralization of the solution, while the influence of AGS was minor. The acute toxicity of BF solution during ozonation was determined using the Luminescent bacteria test, and the toxicity exhibited an initial increase and a successive reduction. An overall decreased acute toxicity was observed with an increase of HA. The presence of BSA increased the formation rate of toxicity intermediates and resulted in inhibition peak forward.     

钙对甜樱桃贮藏品质、钙形态及细胞超微结构影响

研究了氯化钙（Chlo-Ca）、螯合钙（Che-Ca）和纳米钙（Nano-Ca）对甜樱桃Cerasus pseudocerasus（Lind l.）G.Don贮藏品质及钙形态的影响,并采用焦锑酸钾沉淀-透射电子显微镜观察了不同钙处理樱桃贮藏后果肉细胞的超微结构特点。结果表明,Che-Ca处理提高了果实硬度,且有效的抑制了樱桃贮藏后硬度的降低和VC的消耗,但对果实采摘时维生素C含量影响差异不显著。3种钙处理增加了樱桃可溶性固形物的含量,对可溶性糖、可滴定酸和糖/酸影响较小。喷钙处理樱桃的全钙、水提取钙（H2O-Ca）、乙醇提取钙（ALc-Ca）的含量均有不同程度增加。樱桃果肉中的钙主要以ALc-Ca的形式存在,且Che-Ca处理中的ALc-Ca所占比例要显著高于Chlo-Ca和Nano-Ca处理。贮藏后NaCl溶液提取钙（NaCl-Ca）、H2O-Ca和ALc-Ca含量下降,醋酸提取钙（HAC-Ca）和盐酸溶液提取钙（HCl-Ca）的含量有所上升。贮藏60d后的樱桃细胞超微结构照片显示对照处理的细胞壁有断裂,细胞膜系统部分消失,细胞内较干净,且少部分细胞有收缩现象,3种钙处理,细胞壁结构比较完整,发现较多的黑色物质存在,不均衡的分布于细胞壁、细胞膜、液泡膜和线粒体等系统中。     

Study on the regional atomized dust suppression technological system based on the measured law of dust concentration distribution in longwall fully mechanized mining faces

Environment, Development and Sustainability - In order to reveal the distribution and migration law of downwind and upwind coal cutting, total dust (TD) and respirable dust (RD) concentration...     

A bibliometric analysis of solid waste research during the period 1993–2008

This study is a bibliometric analysis of solid waste research to evaluate the current trends, using the literature in the Science Citation Index (SCI) database from 1993 to 2008. Analyzed aspects included document type, language, and publication output as well as distribution of journals, subject category, countries, institutes, title-words, author keywords, and ‘Keywords Plus’. An evaluating indicator, h-index, was applied to characterize the solid waste publications. The trend of publication outputs during 1993–2008 coincided with a power and an exponential model. Based on the exponential model during 2001–2008, the number of articles on solid waste in 2013 is predicted to be twice that in 2008. The most common subject category is environmental science and the most productive journal is Waste Management. The USA with most publications and China with the highest growth rate were compared. Finally, author keywords, words in title, and ‘Keywords Plus’ were analyzed to provide research emphasis. The results showed that mainstream research was centered on the following methods: recycling, landfilling, composting and waste-to-energy. Heavy metals, fly ash and sewage sludge were considered recent research hotspots.     

Arbuscular mycorrhizae enhance metal lead uptake and growth of host plants under a sand culture experiment

A sand culture experiment was conducted to investigate whether mycorrhizal colonization and mycorrhizal fungal vesicular numbers were influenced by metal lead, and whether mycorrhizae enhance host plants tolerance to metal lead. Metal lead was applied as Pb(NO3)2 in solution at three levels (0, 300 and 600 mg kg(-1) sand). Five mycorrhizal host plant species, Kummerowia striata (Thunb.) Schindl, Ixeris denticulate L., Lolium perenne L., Trifolium repens L. and Echinochloa crusgalli var. mitis were used to examine Pb-mycorrhizal interactions. The arbuscular mycorrhizal inoculum consisted of mixed spores of mycorrhizal fungal species directly isolated from orchard soil. Compared to the untreated control, both Pb concentrations reduced mycorrhizal colonization by 3.8-70.4%. Numbers of AM fungal vesicles increased by 13.2-51.5% in 300 mg Pb kg(-1) sand but decreased by 9.4-50.9% in 600 mg Pb kg(-1) sand. Mycorrhizae significantly enhanced Pb accumulation both in shoot by 10.2-85.5% and in root by 9.3-118.4%. Mycorrhizae also enhanced shoot biomass and shoot P concentration under both Pb concentrations. Root/shoot ratios of Pb concentration were higher in highly mycorrhizal plant species (K.striata, I. denticulate, and E. crusgalli var. mitis) than that in poorly mycorrhizal ones (L. perenne and T. repens,). Mycorrhizal inoculation increased the root/shoot ratio of Pb concentration of highly mycorrhizal plant species by 7.6-57.2% but did not affect the poorly mycorrhizal ones. In the treatments with 300 Pb mg kg(-1) sand, plant species with higher vesicular numbers tended to show higher root/shoot ratios of the Pb concentration. We suggest that under an elevated Pb condition, mycorrhizae could promote plant growth by increasing P uptake and mitigate Pb toxicity by sequestrating more Pb in roots.     

大型水生植物混合腐解对入湖河口水质的影响及适宜生物量研究

为探究水生植物腐解释放的营养盐在泥-水-植物系统中迁移规律以及冬春季衰亡期大型水生植物的最适生物量,在塑料通风大棚内,开展不同梯度生物量下多种水生植物混合腐解试验.选择冬季蠡湖-陆典桥浜河口区的水生植物为研究对象,根据实际收割规律,设定腐解试验的生物量依次为除根部以外总生物量的0%、20%、40%、60%、80%、100%,于2018年12月25日开展试验,共150 d.结果表明:①与恒温室内条件相比,近自然条件下多种混合水生植物腐解的前2个阶段具有长时性和持续性.②水生植物腐解致使含C、N、P元素的指标在0~30 d内快速升高,70 d左右达到峰值,100 d后缓慢降低直至稳定,整个变化过程持续近120 d,但植物茎叶未彻底分解,多数沉积在底泥表面.③泥-水-植物系统中,试验初期底泥以释放营养盐为主,30 d后以吸附为主;相关性分析表明,茎叶生物量与水体和底泥中养分浓度均呈正相关.研究显示,与其他试验组相比,收割后水生植物生物量剩余20%时更有利于入湖河口水质的改善.      

三步沉淀全循环法处理焙烧—氰化工艺中含氰废水的应用

辽宁新都黄金有限责任公司成功应用三步沉淀全循环法处理焙烧一氰化工艺中含氰废水，该处理工艺不但可回收有价金属，有效地利用废水中的氰化物，且能够提高金、银的氰化浸出率，实现了闭路全循环含氰废水零排放的目的，其环境效益经济效益和社会效益非常显著。     

Extracellular polymeric substance induces biogenesis of vivianite under inorganic phosphate-free conditions

Vivianite is often found in reducing environments rich in iron and phosphorus from organic debris degradation or phosphorus mineral dissolution. The formation of vivianite is essential to the geochemical cycling of phosphorus and iron elements in natural environments. In this study, extracellular polymeric substances (EPS) were selected as the source of phosphorus. Microcosm experiments were conducted to test the evolution of mineralogy during the reduction of polyferric sulfate flocs (PFS) by Shewanella oneidensis MR-1 (S. oneidensis MR-1) at EPS concentrations of 0, 0.03, and 0.3 g/L. Vivianite was found to be the secondary mineral in EPS treatment when there was no phosphate in the media. The EPS DNA served as the phosphorus source and DNA-supplied phosphate could induce the formation of vivianite. EPS impedes PFS aggregation, contains redox proteins and stores electron shuttle, and thus greatly promotes the formation of minerals and enhances the reduction of Fe(III). At EPS concentration of 0, 0.03, and 0.3 g/L, the produced HCl-extractable Fe(II) was 107.9, 111.0, and 115.2 mg/L, respectively. However, when the microcosms remained unstirred, vivianite can be formed without the addition of EPS. In unstirred systems, the EPS secreted by S. oneidensis MR-1 could agglomerate at some areas, resulting in the formation of vivianite in the proximity of microbial cells. It was found that vivianite can be generated biogenetically by S. oneidensis MR-1 strain and EPS may play a key role in iron reduction and concentrating phosphorus in the oligotrophic ecosystems where quiescent conditions prevail.     

SBR中生物除磷颗粒污泥的反硝化聚磷研究

反硝化聚磷菌(DNPAOs)可利用厌氧储存的聚.3.羟基丁酸(PHB)以硝酸盐和亚硝酸盐为电子受体进行过量吸磷和反硝化,从而达到在低碳源下脱氮除磷的双重目的.本试验在SBR反应器中,采用厌氧,缺氧/好氧(A/A/O)交替运行的方式.将富集聚磷菌(PAOs)的颗粒污泥成功地诱导为具有反硝化聚磷能力的颗粒污泥.诱导结束后P的去除率在90%以上,NOx-N的去除率在93%以上,厌氧段释磷量在25-33 mg/L,缺氧段每去除lg NOx-N吸收P约1.3 g;典型周期运行结果显示,厌氧段最大比释磷速率(SRPR)为18.39 mg/(g.h),缺氧段最大比吸磷速率(SUPR)为23.72 mg/(g·h),最大比反硝化速率(SDNR)为18.19mg/(g·h),好氧段最大SUPR为17.15 me,/(g·h):颗粒污泥中DNPAOs的数量由诱导前的14.9%增加到80.7%.与除磷颗粒污泥相比.反硝化聚磷颗粒污泥沉速提高0.16-0.7倍,比重提高0.003 1.