Enhanced anaerobic fermentation with azo dye as electron acceptor： Simultaneous acceleration of organics decomposition and azo decolorization

Accumulation of hydrogen during anaerobic processes usually results in low decomposition of volatile organic acids（VFAs）. On the other hand, hydrogen is a good electron donor for dye reduction, which would help the acetogenic conversion in keeping low hydrogen concentration. The main objective of the study was to accelerate VFA composition through using azo dye as electron acceptor. The results indicated that the azo dye serving as an electron acceptor could avoid H2 accumulation and accelerate anaerobic digestion of VFAs. After adding the azo dye, propionate decreased from 2400.0 to 689.5 mg/L and acetate production increased from 180.0 to 519.5 mg/L. It meant that the conversion of propionate into acetate was enhanced. Fluorescence in situ hybridization analysis showed that the abundance of propionate-utilizing acetogens with the presence of azo dye was greater than that in a reference without azo dye. The experiments via using glucose as the substrate further demonstrated that the VFA decomposition and the chemical oxygen demand（COD） removal increased by 319.7 mg/L and 23.3% respectively after adding the azo dye. Therefore, adding moderate azo dye might be a way to recover anaerobic system from deterioration due to the accumulation of H2 or VFAs.     

凤眼莲对铜绿微囊藻生长及藻毒素与营养盐释放的影响

针对目前我国凤眼莲治理富营养化水体技术的规模化应用现状,考虑到大面积控养的凤眼莲与暴发的水华蓝藻(尤其是产毒铜绿微囊藻)会在湖湾区短期内密集共存的情况,开展了凤眼莲对产毒铜绿微囊藻生长、生理特性、藻毒素生产与释放影响的研究,另外,也考察了短期共存下藻类营养盐释放与凤眼莲对藻毒素积累的情况.半连续共培养实验结果表明,凤眼莲能够有效抑制铜绿微囊藻的生长,促进藻细胞的衰亡.虽然凤眼莲未对铜绿微囊藻光合系统Ⅱ的电子传递产生影响,但减少了其光合系统中的藻蓝蛋白(PC)含量和藻蓝蛋白/别藻蓝蛋白(PC/APC)水平,10%和20%水体交换率处理的PC/APC水平第8 d时分别降至相应空白对照的54.93%±7.07%和55.81%±1.97%.凤眼莲对铜绿微囊藻形成了一定的氧化伤害,最终促进其抗氧化系统中超氧化物歧化酶比活显著下降,丙二醛含量显著提高,10%和20%水体交换率处理的丙二醛含量第8d时分别升至相应空白对照的2.95倍±0.074倍和2.22倍±0.086倍.凤眼莲通过促进蓝藻的衰亡和分解,加速了营养盐的释放.12 d内,可溶性总氮浓度回升到初始水平,而水体可溶性总磷的释放速度比氮营养盐更快.另一方面,凤眼莲并没有促进铜绿微囊藻毒素的生产,也没有使水体藻毒素含量显著提高.相反,和自然衰减不同,短期内显著促进了水体藻毒素的降解,第12 d时10%和20%水体交换率处理的水体藻毒素分别下降至12.07μg·L-1±0.63μg·L-1和11.36μg·L-1±0.04μg·L-1.而凤眼莲整株的藻毒素短期积累量(FW)仅为5.95 ng·g-1±0.76 ng·g-1.增加水体交换率能够在一定程度上减缓凤眼莲对铜绿微囊藻的伤害,减缓营养盐的释放速度,但对水体藻毒素消减的影响不显著.     

限量曝气进水时间对硝化颗粒污泥的影响特性研究

缺氧-好氧环境的交替循环对氨氧化细菌和亚硝酸盐氧化细菌具有重要影响.本研究通过逐渐增加限量曝气进水时间(从10 min至120 min)延长缺氧时段,考察柱形SBR中硝化颗粒污泥对不同缺氧-好氧环境交替循环的响应特性.整个研究过程中,硝化颗粒污泥保持着稳定的颗粒特征,粒径大于0.8 mm的颗粒污泥占总污泥量的质量分数始终在95%以上,颗粒平均沉降速率维持在125～130 m·h-1之间.尽管缺氧时段不断延长,但NH+4-N去除率和NO-2-N累积率分别稳定在(60±5)%、(85±5)%;此外,在每个周期的曝气反应时段,NH+4-N的去除速率以及NO-2-N和NO-3-N的累积速率分别保持在90mg·(L·h)-1、70 mg·(L·h)-1和15 mg·(L·h)-1左右.以上结果表明,限量进水时间的延长及其所造成的不同时间跨度的缺氧环境对硝化颗粒污泥没有较为显著的影响.     

灾害信息的采集及其成果积累

首先叙述信息、灾害信息及其相互关系,提出关于灾害信息的个人观点．在此基础上,按照作者长期灾害信息的研究实践,用大量事例阐明灾害信息的采集、及成果积累的有关技术问题,最后归纳出几点认识。     

PESTICIDE ACCUMULATION IN A NEW IMPOUNDMENT IN IOWA1

ABSTRACT: Estimates were made of the amounts of selected pesticides entering and leaving Saylorville Reservoir, a new partly filled impoundment on the Des Moines River. Samples were collected at 1– or 2-week intervals at stations above, in, and below the reservoir. Atrazine, alachlor, and cyanazine were found only in the dissolved state, and dieldrin and p, p′ -DDE in both the, dissolved and suspended state. Heptachlor epoxide, p,p-DDT. p, p′ -DDD, 2,4-D, 2,4,5-TP, endrin, lindane, methoxychlor, propachlor, and toxaphene were not detected or were at very low concentrations. Estimated deposition in the reservoir from September 1977 to October 1978 was 281 kg atrazine, 251 kg alachlor, 26 kg cyanazine, 16 kg dieldrin, and 20 kg p, p′ -DDE.     

USE OF TIME-LAPSE PHOTOGRAPHY TO ASSESS POTENTIAL INTERCEPTION IN ARIZONA PONDEROSA PINE1

ABSTRACT: The behavior of intercepted snow on a stand of uneven-aged ponderosa pine in east-central Arizona was evaluated with the use of a super 8-mm time lapse movie camera to determine the relative significance of snowfall interception in the water yield of this type forest. A snow load index was developed to estimate interception storage for two trees in the field of view for discrete time periods. The snow load index. photographs, and climatic data were combined to describe accumulation and to identify and rank according to relative magnitudes the basic processes of canopy snow removal. The rate of snow accumulation was nonlinear with initial storage being rapid. then slowing with time. Most of the intercepted snow eventually reached the snowpack on the ground by snowslide and wind erosion or by snowmelt and subsequent stemflow and drippmg of meltwater, and was therefore not considered a significant loss to the water budget on site. Some water apparently was disposed of by the evaporation of meltwater and sublimation of canopy snow, but these losses appeared to be comparatively minor.     

GIS在巨灾保险风险管理中的应用研究

近年来 ,巨灾的不断发生 ,使得许多保险和再保险公司遭受巨大赔偿 ,乃至可能造成破产。究其原因 ,除了人们对巨灾自身难以抗拒这一客观原因外 ,保险企业对巨灾保险的风险管理方法、技术和手段的不适也是一个很重要的因素。为此 ,笔者分析了利用GIS辅助巨灾保险风险管理的优越性 ,并就GIS在巨灾保险的信息管理、风险累积预测和风险管理专家系统中所起的作用和发挥的功能分别进行了探讨。利用GIS辅助巨灾保险风险管理 ,不仅可以了解巨灾的发生和变化规律 ,进行危险性区域和费率区域的划分 ,而且可以优化保险和再保险方案 ,并通过专家系统设计出符合实用灾情的风险管理及保险管理的对策 ,对保险公司的巨灾保险风险管理起到了重要的指导作用。     

Ecotoxicological implications of aquatic disposal of coal combustion residues in the United States: a review

We provide an overview of research related to environmental effects of disposal of coal combustion residues (CCR) in sites in the United States. Our focus is on aspects of CCR that have the potential to negatively influence aquatic organisms and thehealth of aquatic ecosystems. We identify major issues of concern, as well as areas in need of further investigation.Intentional or accidental release of CCR into aquatic systemshas generally been associated with deleterious environmental effects. A large number of metals and trace elements are presentin CCR, some of which are rapidly accumulated to high concentrations by aquatic organisms. Moreover, a variety of biological responses have been observed in organisms following exposure to and accumulation of CCR-related contaminants. In some vertebrates and invertebrates, CCR exposure has led to numerous histopathological, behavioral, and physiological (reproductive, energetic, and endocrinological) effects. Fish kills and extirpation of some fish species have been associatedwith CCR release, as have indirect effects on survival and growth of aquatic animals mediated by changes in resource abundance or quality. Recovery of CCR-impacted sites can be extremely slow due to continued cycling of contaminants withinthe system, even in sites that only received CCR effluents forshort periods of time. The literature synthesis reveals important considerations for future investigations of CCR-impacted sites. Many studies have examined biological responses to CCR with respect to Se concentrations and accumulation because of teratogenic andreproductively toxic effects known to be associated with thiselement. However, the complex mixture of metals and traceelements characteristic of CCR suggests that biologicalassessments of many CCR-contaminated habitats should examine avariety of inorganic compounds in sediments, water, and tissuesbefore causation can be linked to individual CCR components. Most evaluations of effects of CCR in aquatic environments havefocused on lentic systems and the populations of animalsoccupying them. Much less is known about CCR effects in loticsystems, in which the contaminants may be transported downstream,diluted or concentrated in downstream areas, and accumulated bymore transient species. Although some research has examinedaccumulation and effects of contaminants on terrestrial and avianspecies that visit CCR-impacted aquatic sites, more extensiveresearch is also needed in this area. Effects in terrestrial orsemiaquatic species range from accumulation and maternal transferof elements to complete recruitment failure, suggesting that CCReffects need to be examined both within and outside of theaquatic habitats into which CCR is released. Requiring specialattention are waterfowl and amphibians that use CCR-contaminatedsites during specific seasons or life stages and are highlydependent on aquatic habitat quality during those periods.Whether accidentally discharged into natural aquatic systems or present in impoundments that attract wildlife, CCR appears topresent significant risks to aquatic and semiaquatic organisms. Effects may be as subtle as changes in physiology or as drasticas extirpation of entire populations. When examined as a whole,research on responses of aquatic organisms to CCR suggests thatreducing the use of disposal methods that include an aquaticslurry phase may alleviate some environmental risks associatedwith the waste products.     

The accumulation and effects of environmental contaminants on snakes: a review

In any ecological risk assessment, afull complement of the relevant members of theecosystems being studied should be considered. Reptiles in general, and snakes in particular, areimportant although often neglected components ofterrestrial and aquatic ecosystems and should beincluded in any study on environmental contamination. By neglecting reptiles, the risks posed by aparticular contaminant cannot be fully assessed. Since all snakes are secondary, tertiary, and toppredators, they are susceptible to the bioaccumulationof environmental contaminants. Their unique lifehistories make their roles in food webs diverse andimportant, and they are crucial to the properfunctioning of many ecological processes. We reviewand summarize organic and inorganic contaminant andradionuclide/radiation residue and lethal andsublethal effects data for snakes to stress theimportance of snakes and encourage their inclusion inecological risk assessments, to demonstrate thepaucity of available contaminant data on snakes andreveal the main information gaps, to encourage furtherecotoxicological studies on snakes, and to facilitatethe use of existing snake contaminant data inecological risk assessments. This review is the mostcomprehensive review currently available on theeffects on and accumulation of environmentalcontaminants in snakes.     

Metal concentrations in deciduous tree leaves from urban areas in Poland

Accumulation of metals in deciduous tree foliage fromurban areas in western-south Poland was monitored duringthe vegetation season of 2000 year. Concentrations of Al,Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr, Ti and Znwere measured in birch, willow, linden and maple leavesusing the ICP-AES method. Seasonal variations of metalconcentrations and their relations with sampling sitewere investigated. The most dynamic accumulation of Al,Cd, Cr, Ni and Pb was observed for examined species. Thehighest differences in element concentrations forinvestigated sites were found for Ba, Cd, Mn and Ni.Interelement correlations were investigated. In allfoliar samples synergistic relationships between Al–Crand Ca-Sr were found. Statistically significant negativecorrelations were observed only for Cd and Ti in birch leaves.