水体污染及其防治

高效广谱灭菌药物。对该药物的杀藻效率进行生物测试的结果表明,它能有效地杀灭引发水华的绿藻、蓝藻和硅藻,弟62.sppm(有效氯含址,下同)曝露%h,4种被试藻类的死亡率可达92%-100%。高浓度(soopPm)条件下,绿藻、蓝藻和硅藻分别在几分钟和1h内全部死亡,‘lppm的浓度对4种被试藻类基本上不造成严重伤害。表4参7X522(X曰刀183颗粒活性炭柱与淹没式中空纤维膜过滤装置联用的试验研究/张捍民…(哈尔滨工业大学二区市政与环境工程学院)//给水排水/中国建筑技术研究院一2(X)1,27(5)一33一37环图TU一2 介绍了颗粒活性炭柱一淹没式中空纤维膜过滤装…     

2008-2010年洱海水质及藻类初步分析

根据2008～2010年洱海水质和藻种监测数据,得出洱海水质现状及藻类的变化状况。监测结果表明:近3年洱海水质总体呈好转趋势,三个监测站点水质好转表现为海东>才村>团山;总藻细胞密度则恰恰相反,其大小为团山>才村>海东。藻类种属方面,洱海共检出8门61属;蓝藻、绿藻门数目占总数的80%以上,其次为硅藻,约10%左右,洱海的藻类植物群落组成主要为蓝藻-绿藻-硅藻类型。此外,2010年以前三个监测点以蓝藻居多,2010年后绿藻及硅藻比重跃增,其他藻种出现频率升高,导致洱海藻类浮游植物群落组成有所变化,洱海藻类丰度提高,其原因可能与2010年云南气候的反常引发环境变化造成。     

石岩水库叶绿素a时空分布及其影响因子分析

2013年4月至2014年6月对典型调水供水型水库石岩水库蓝藻、绿藻和硅藻叶绿素a浓度[ρ(Chla)]及相环境因子进行监测,分析了ρ(Chla)时空分布特征,探讨了藻类与环境因子的相关关系.结果表明石岩水库ρ(TChla)为9.59~123.29μg·L~(-1),平均52.03μg·L~(-1),其中蓝藻ρ(Chla)为4.54~76.30μg·L~(-1),平均为28.39μg·L~(-1);硅藻ρ(Chla)为3.16~46.09μg·L~(-1),平均为15.02μg·L~(-1);绿藻ρ(Chla)为0.77~26.21μg·L~(-1),平均为8.62μg·L~(-1).2013年4~12月上旬以及2014年5~6月优势藻为蓝藻,其他时期硅藻占优势,绿藻全年处于较低水平.石岩水库ρ(Chla)空间异质性低,整体呈现由南向北逐渐降低的空间分布特征,汛期整个库区和高温无雨期南半库区存在蓝藻水华风险.径流污染是石岩水库藻类叶绿素a空间异质性的主要原因.相关分析和CCA分析显示:水温是3种藻类的首要影响因子,汛期径流量与蓝藻相关性极大.氮磷比与3种藻类负相关,磷是石岩水库藻类生长的限制性因子.蓝藻主要相关因子还包括TOC、TN、pH、透明度和硝酸盐氮,硅藻主要相关因子还包括硅酸盐、TOC、硝酸盐氮和COD,绿藻主要相关因子还包括TOC、COD、pH、透明度和硝酸盐氮.     

鄱阳湖悬浮颗粒物絮凝沉降典型藻类的动力学研究

为了探讨鄱阳湖水动力条件改变引起的悬浮颗粒物浓度变化可能导致的鄱阳湖浮游植物群落结构的变化,本文研究了鄱阳湖悬浮颗粒物絮凝沉降3种典型藻类的动力学过程.以铜绿微囊藻(蓝藻)、四尾栅藻(绿藻)和菱形藻(硅藻)为研究对象、鄱阳湖采集沉积物为悬浮颗粒物,使用混凝试验搅拌仪模拟动力学条件,在颗粒物投加量为20 mg·L-1时分别研究了静置沉降时间、扰动强度和扰动时间对颗粒物絮凝沉降藻细胞的影响.结果表明,絮凝沉降效率:蓝藻绿藻硅藻.在扰动强度为20 s-1、扰动时间为30 min时,0.5~4 h静置沉降时间均促进3种藻类的絮凝沉降.绿藻和硅藻的絮凝沉降效率随着静置沉降时间的延长而降低,前0.5 h的絮凝沉降效率最大;而蓝藻的絮凝沉降效率变化无明显规律.扰动时间和静置沉降时间均为30 min时,随着扰动强度在2~40 s-1增加时,3种藻的絮凝沉降效率逐渐增大.扰动强度为20 s-1、静置沉降时间为30 min时,5~60 min扰动时间均促进藻细胞的絮凝沉降,并且随着扰动时间的增加,絮凝沉降效率呈先增大后降低的趋势.30 min为蓝藻絮凝沉降的最佳扰动时间,絮凝沉降效率为12.56%;45 min为绿藻和硅藻絮凝沉降的最佳扰动时间,絮凝沉降效率分别为11.93%和7.54%.因此,水动力条件的改变可以引起悬浮颗粒物与藻类的絮凝沉降效率发生变化,从而对藻类的群落结构以及水华发生规律产生影响.     

湖泊水质模型SALMO在太湖梅梁湾的应用

改进了湖泊水质模型SALMO,针对太湖梅梁湾,利用2005年实测数据进行模型参数率定,并模拟了2006年水质.结果发现,绿藻、蓝藻、硅藻3种藻类的模拟结果与藻类的实测年变化格局一致,反应了3种藻类的季节性演替,其中,硅藻、绿藻在冬末春初占优势,蓝藻在夏秋季占优势;溶解氧模拟结果与实测数据非常一致,年平均相对误差为14.3%;NO-3-N和PO3-4-P的变化趋势与实测结果基本一致.研究结果表明,SALMO能很好地模拟藻类和营养盐的浓度动态,并在一定程度上揭示水华机制.     

应用不同材料过滤去除海河蓝藻水华研究

于2012年7月海河蓝藻爆发期间,对水体藻类群落组成进行了分析,对生活中常见材料过滤除藻能力进行了研究.结果表明海河蓝藻爆发期间共发现藻类5门42种,藻类细胞密度达1.89×108个/L,其中蓝藻门的铜绿微囊藻为本次藻类爆发的优势种类.所选过滤材料处理藻细胞密度和叶绿素a效率超过80％的有3种,分别为:脱脂棉、快速滤纸和腈纶.蓝藻去除效率超过80％的材料有5种,其中脱脂棉的处理效果最佳,处理效率达96.02％,群体和体积较大蓝藻大部分能被过滤去除.过滤材料过滤藻类速率由快至慢依次为:海绵4层＞植物秸秆纤维＞尼龙擦洗布＞纱布16层＞腈纶＞25号浮游生物网＞细铜丝网＞脱脂棉＞无纺布4层＞快速滤纸.     

剑潭水库浮游植物群落特征与水环境因子关系研究

2010年6—12月对剑潭水库浮游植物群落及11项水环境因子进行了采样调查,并对调查区域内的54种浮游植物和11个环境因子进行了典范对应分析(CCA).结果表明,调查期间共检出浮游植物7门78属103种,浮游植物群落组成以绿藻为主,硅藻其次;藻类细胞密度季节差异大,7月最高,为8.04×106cells·L-1,12月最低,为2.23×105cells·L-1,浮游植物群落变化规律为夏季的蓝藻和绿藻向秋季的隐藻、蓝藻、绿藻,以及冬季的绿藻、硅藻转变,剑潭水库富营养化程度较蓄水初期有加剧趋势,且富营养程度夏季比冬季严重.CCA分析结果表明,水温和TP是影响剑潭水库浮游植物群落分布最主要的环境因子.     

草甘膦对沉积物-水界面藻类群落结构影响研究

为了探究环境中残留除草剂草甘膦对沉积物-水界面藻类群落结构演替的影响,分别以九龙江两个断面拱桥溪和石龟头的沉积物-水界面藻类群落结构为研究对象,并添加0.05 mg·L^-1草甘膦作为磷源进行实验模拟.结果表明：拱桥溪沉积物-水界面藻类生物量占比为蓝藻：绿藻∶硅藻∶甲藻=0.3%∶7.8%∶91.5%∶0.3%,蓝藻生物量占比低于1%,以硅藻门直链藻属为优势种属;石龟头沉积物-水界面藻类生物量起点占比为蓝藻∶绿藻∶硅藻∶甲藻=20.8%∶58.5%∶19.5%∶1.2%,蓝藻生物量占比大于20%,绿藻门栅藻属、蓝藻门微囊藻属和硅藻门直链藻属为优势种属.草甘膦调控15 d后,拱桥溪沉积物-水界面蓝藻生物量占比从0.3%增长到22.6%,生物量是无机磷组的7.6倍,但硅藻仍为优势门类,这与蓝藻生物量占比低于1%的拱桥溪表层水体藻类群落演替结果类似;而石龟头沉积物-水界面蓝藻生物量占比从20.8%增长到57.8%,生物量是无机磷组的近5倍,蓝藻演替为优势门类,这与蓝藻生物量占比大于15%的石龟头表层水体藻类群落演替结果相似.调控实验表明,在草甘膦胁迫下蓝藻门的增殖能力均表...     

基于宏条形码技术的白洋淀水华藻类识别及其驱动因子分析

浮游藻类是引起水华暴发的主要原因.为筛选潜在水华藻类,评估白洋淀水华风险区域,于2020年8月对白洋淀373点位展开浮游藻类调查.利用宏条形码技术分析,解析水华藻类群落组成,同时采用显微镜计数法统计藻密度.根据总藻密度对白洋淀不同区域的水华程度进行评估,同时进一步针对水华藻类群落,耦合淀区水质条件,探究白洋淀不同区域水华藻类群落空间差异驱动因子,以甄别影响水华藻类群落结构关键环境因子.结果表明,95%以上采样区域无水华风险(藻类密度<2×10⁶个·L^-1),仅5个样点存在轻微水华风险.但水华藻类群落分析共检测到了90种水华藻类,其中优势水华藻种有20种,隶属于以绿藻门、蓝藻门和裸藻门为主.水华藻类群落结构在不同区域上具有显著空间异质性(P<0.05).关键驱动因子解析结果表明,总磷(TP)、总氮(TN)和氨氮(NH⁺₄-N)是造成水华藻类群落结构差异的关键因子.其中,门水平上,蓝藻门水华藻类与以上关键因子显著正相关;种水平上,硅藻门和绿藻门水华藻类与关键因子响应更显著.因此,水华藻类群落...     

不同形态磷对沉积物-水界面浮游植物增殖及群落结构演替的影响

探讨了不同磷形态对沉积物-水界面浮游植物增殖及群落结构演替的影响,以九龙江北溪西陂水库沉积物-上覆水体(水体藻类丰度为7.2×10~4cells·L~(-1),以硅藻、绿藻、蓝藻为主,分别占藻类丰度的49.16%、32.40%、17.32%)为研究对象,磷源包括:无机磷(NaH_2PO_4·2H_2O)、有机磷(单磷酸腺苷,AMP)、SMT方法提取沉积物总无机磷(SMT-TP)、鲜沉积物(Sediment)和野外原水(OW).结果表明,无机磷和有机磷(N∶P=20∶1)培养组对藻类增殖有明显促进作用.其中,无机磷组中浮游植物群落结构演替为以蓝藻和绿藻为主,分别占藻类丰度的76.67%和23.34%;有机磷组中浮游植物群落则演替为以绿藻为主,占藻类丰度的92.51%.在低磷组(N∶P=25∶1)、野外原水(N∶P=17∶1)、SMT-TP组(N∶P=10∶1)中,浮游植物群落结构从硅藻、绿藻和蓝藻演替为以蓝藻和绿藻为主,与无机磷组结果趋于一致.而鲜沉积物(N∶P=10∶1,含有无机磷和有机磷)组群落结构演变为蓝藻占优势,所占比例为71.80%.该结果表明,磷的形态对浮游植物群落结构具有重要的影响.模拟环境无机磷组、有机磷组和SMT-TP培养组中,浮游植物群落多样性具有降低的趋向,硅藻逐渐消失;而野外原水和鲜沉积物组中浮游植物群落多样性稳定,硅藻仍然存在,表明自然环境中其他元素调控水体中浮游植物群落多样性.鲜沉积物组中浮游植物群落结构逐渐演替为以蓝藻为主,暗示沉积物对蓝藻水华暴发具有重要贡献.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.