基于GIS的中国近岸海域1950—2020年赤潮时空变异格局

基于1950—2020年的赤潮公报等数据,采用GIS方法分析了中国近岸海域赤潮的时空分布规律与赤潮优势种演变.结果表明,过去70年中国近岸海域赤潮事件共发生1701次,累计赤潮面积超过25万km²,整体呈先增后减的趋势.赤潮高发期主要在4—8月,其中5月赤潮发生次数最多,累计面积最大.赤潮发生月份由南到北呈季节性变化趋势,南部海域赤潮发生月份要早于北方.赤潮事件主要以180 km²以内的小面积赤潮为主,大部分在11 d以内.赤潮高发区集中在河口、海湾、港湾及污染排放量较大的海域.诱发赤潮次数较多的赤潮优势种包括夜光藻、中肋骨条藻、东海原甲藻和米氏凯伦藻等.其中,夜光藻、中肋骨条藻和米氏凯伦藻在中国近岸海域均有分布,而东海原甲藻均发生在东海海域.夜光藻和中肋骨条藻一年四季均具备生长条件,米氏凯伦藻和东海原甲藻则在5—6月最为频繁.海水水质状况分析表明,中国近岸海域赤潮发生次数与海水水质污染程度密切相关;赤潮优势种的发生月份也与温度和盐度相关,赤潮优势种的季节性生长和空间分布可直接影响中国近岸海域的赤潮发生规模.     

象山港海域富营养化与赤潮的关系

根据 2 0 0 0年 5月 2 4日至 6月 7日对象山港口门附近海域由原甲藻和多甲藻引发的赤潮进行跟踪监视监测的资料 ,用相关分析的方法探究了赤潮发生时各水化要素间的关系 ,分析了象山港海域富营养化的程度、范围、形成原因及其与赤潮的关系。结果表明 ,在赤潮发生期间 ,水体中赤潮生物———原甲藻数量与溶解氧呈现明显的正相关 ,多甲藻和裸甲藻数量与无机氮呈现明显的负相关 ,可见此次赤潮是以无机氮为营养盐主要限制因子。象山港海域的有机污染、富营养化现象 ,是赤潮发生的物质基础和必要条件。     

福建省沿岸赤潮生物——东海原甲藻生态探讨

对近年来福建北部海域的东海原甲藻赤潮应急跟踪监测资料及赤潮发生海域的生态浮标连续监测数据进行初步分析,分析结果表明,东海原甲藻赤潮发生的最适水温和盐度范围分别为18.2～25.2℃、29.7～32.2‰;赤潮发生前期大气压均有较大幅度的下降,赤潮持续期间风速较小,偏南风为主;在富营养化和贫营养化的海域都有发生该藻种的赤潮,特别是存在磷限制赤潮海域.赤潮发生发展过程中存在硅藻与甲藻之间的演替,赤潮发生期间时常伴有高密度的有毒甲藻.     

近岸海域赤潮发生机制及其控制途径研究进展

近岸海域赤潮灾害是目前我国海洋环境的主要问题之一。本文总结了国内、国际上对近岸海域赤潮发生机制研究的主要理论与研究方法,探讨了近岸赤潮发生的控制原理与技术手段。同时提出,在加强近岸水体赤潮发生机理研究的基础上,要将流域、河口与近岸海域系统作为一个整体进行研究。并且,考虑近岸海域水环境的复杂性以及生态系统演进的不确定性,不仅要加强近岸海域生态治理修复,还需注意加强近岸水体水质的监控,预防赤潮的暴发。     

2006年夏季浙江海域赤潮生物群落分布

研究了2006年夏季浙江海域(120°～128°E,26°～30°N)91个站位赤潮生物物种组成及群落分布,共检出赤潮生物4门30属69种,其中角毛藻属和原多甲藻属种类数占优势.赤潮生物种类数及数量分布由近岸向外海递减且有随水深增加而减少的趋势,高值区为舟山群岛和南麂列岛海域.舟山群岛海域夏季赤潮生物优势种为旋链角毛藻,是新的引发赤潮的潜在藻种;南麂列岛海域夏季赤潮生物优势种为中肋骨条藻,与往年调查结果相符.舟山群岛和南麂列岛海域仍然是浙江海域赤潮发生敏感区.     

长江口及其邻近海域赤潮时空分布研究

收集了1972～2009年长江口及其邻近海域（29°25＇～32°00＇N、124°00＇E以西）所记载的赤潮事件,基于GIS软件平台,系统分析赤潮的时空分布规律,并绘制长江口及邻近海域赤潮分布图.分析表明：①近40年来,长江口及邻近海域赤潮发生多达174次,暴发面积〉1 000 km2的有25次.赤潮发生核心区集中在...     

申南指数在大连湾海域环境质量评价及赤潮调查中的应用

本文通过三年来对大连湾海域浮游植物监测,按春、夏、秋三季及赤潮时的连续监测,将获得的分类及定量资料应用 Shinnonqueaver指数公式处理后发现,用生物多样性指数值,能客观,综合地反映海域不同水期的环境质量;同时发现,在赤潮发生时,指数值小于1大于零的符合率占82.1%,越趋于零的站住,赤潮程度越严重.未发生赤潮时,多样性指数值大于1的符合率占86.3%,H 值能客观的反映赤潮程度.     

营养物质输入对赤潮发生的影响

以国内外7个典型海湾为例,分析了营养物质输入对赤潮发生的影响。结果表明,陆源污染物排人及海水养殖业自身污染是是近岸海域营养物质输入的主要来源。水体富营养化的不断加剧是赤潮频发的重要原因,而富营养化程度降低的海域发生赤潮的风险也会下降,营养盐比例的改变是浮游植物种类的重要控制因子。     

河北省近岸海域赤潮灾害特征分析

对河北省近岸海域1989~2014年间发生的赤潮灾害进行综合分析,结果表明:全省赤潮灾害发生的频次及累计面积呈现上升趋势;每年的5~10月是赤潮灾害的发生期,其中5~6月是赤潮频发期;秦皇岛市、黄骅市附近海域是河北省赤潮灾害的多发海域,也是深受赤潮灾害危害较为严重的海域;甲藻门引发赤潮灾害的比例较大,尤其夜光藻引发的赤潮灾害的次数最多;有毒赤潮生物种较多,达12种;新的赤潮生物种抑食金球藻引发的赤潮灾害扩散快,影响面积大,持续时间长。建议采取有效措施,严格控制陆源污染物超标排放;加强海水养殖业的科学管理,控制养殖废水的排放;加大对抑食金球藻引发赤潮的机理、快速检测与识别方法的研究,减少或避免赤潮灾害的发生。     

我国东海海域赤潮发生年际变化趋势及其影响因素分析

为了研究我国东海海域近年来赤潮发生年际变化趋势及其影响因素,对渤海、黄海、东海和南海四大海域2000～2006年赤潮年发生次数及年累计发生面积进行分析比较,着重分析了影响东海赤潮发生的主要因素、长江口营养盐含量的变化趋势、长江口营养盐含量与东海赤潮现象的关联.结果表明,东海赤潮发生频率最高,且年累计发生面积位于我国海域之首;指出营养盐含量的年变化量对东海赤潮发生现象具有重要影响.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Removal of cadmium using MnO2 loaded D301 resin

MnO2 loaded weak basic anion exchange resin D301 （Anion exchange resin, macroreticular weak basic styrene） as adsorbent has been prepared and applied to the removal of cadmium. The adsorption characteristics have been investigated with respect to effect of pH, equilibrium isotherms, removal kinetic data, and interference of the coexisting ions. The results indicated that the Cd^2＋ could be efficiently removed using MnO2 loaded D301 resin in the pH range of 3-8 from aqueous solutions with the co-existence of high concentration of alkali and alkaline-earth metals ions. The saturate adsorption capacity of the Cd^2＋ was 77.88 mg/g. The adsorption process followed the pseudo first-order kinetics. The equilibrium data obtained in this study accorded excellently with the Langmuir adsorption isotherm.     

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.     

Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on Al,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.     

Simultaneous removal of ammonium and phosphate by zeolite synthesized from coal fly ash as influenced by acid treatment

Zeolite synthesized from fly ash （ZFA） without modification is not efficient for the purification of NH4＋ and phosphate at low concentrations that occur in real effluents, despite the high potential removal capacity. To develop an effective technique to enhance the removal efficiency of ammonium and phosphate at low concentrations, ZFA was modified with acid treatment and the simultaneous removal of ammonium and phosphate in a wide range of concentration was investigated. It was seen that when compared with untreated ZFA, only the treatment by 0.01 mol/L of H2SO4 significantly improved the removal efficiency of ammonium at low initial concentrations. The behavior was well explained by the pH effect. Treatment by more concentrated H2SO4 led to the deterioration of the ZFA structure and a decrease in the cation exchange capacity. Treatment by 0.01 mol/L H2SO4 improved the removal efficiency of phosphate by ZFA at all initial P concentrations, while the treatment by concentrated H2SO4 （≥0.9 mol/L） resulted in a limited maximum phosphate immobilization capacity （PIC）. It was concluded that through a previous mild acid treatment （e.g. 0.01 mol/L of H2SO4）, ZFA can be used in the simultaneous removal of NH4＋ and P at low concentrations simulating real effluent.