武汉东湖湖水的藻类生长潜力(AGP)测试

在东湖湖水样品中添加排入东湖的主要污水或营养物(氮和磷)进行藻类测试,观察它们对斜生橱藻(Scenedesmus obliquus)的生长促进作用.生长反应与添加的污水浓度成正比,其SC_(20)(促进20％增长的浓度)为0.5—4％.单独添加氮或磷,在高浓度情况下也很少促进藻类生长,但共同添加时大多有促进作用.东湖为一严重富营养型湖泊,为了控制其富营养化进程,污水截流应是首先要采取的一项措施.     

珠江广州河段西航道河水藻类测试研究

采集珠江广州河段西航道现场河水,进行河水及添加氮、磷和氮磷比的室内藻类测试研究.研究结果表明:珠江广州河段西航道河水对藻类增长有不同程度的促进作用,氮磷浓度越高促进藻类生长越明显,其中磷尤为显著,是藻类生长的主要限制因素,氮磷浓度的增加成为西航道藻类生长的刺激因子.     

营养盐输入对太湖水体中磷形态转化及藻类生长的影响

外源营养盐输入会对湖泊水体中磷的形态转化及藻类生长产生影响.为研究其影响规律,于春季选取太湖梅梁湾水体为研究对象,以KNO3和K2HPO4添加系列氮磷负荷,在试验过程中对各形态磷的浓度、藻类生物量(Chl-a)和碱性磷酸酶活性(APA)进行同步分析测定.结果表明,春季太湖梅梁湾水体中浮游植物的生长主要受到磷限制,加氮对其生长没有明显的促进作用.加磷至SRP=0.015 mg·L-1的水体中浮游植物生长情况最好,叶绿素a的含量和生长速率(μ)最大.添加硝酸盐能显著促进APA的增长,提高水生生物对磷的吸收利用能力,加快磷循环的速率;磷酸盐对APA则具有活性诱导-抑制机制,当水体中磷酸盐浓度在一定范围内(PO3-4-P≤0.025 mg·L-1)时,酶活性有显著提高.对水体中磷的循环转化过程和碱性磷酸酶的活性诱导-抑制机制的研究结果有助于揭示藻类生长过程中营养盐的补偿途径,为深入揭示藻类暴发机制提供理论基础.     

三峡澎溪河水华期间水体CH4浓度及其通量变化特征初探

三峡库区温室气体的排放近年来备受关注.为了揭示三峡库区澎溪河地区水华过程中不同氮磷浓度下藻类生长死亡过程中CH₄吸收释放的规律,于2016年4月22日至2016年5月9日,通过添加不同氮磷浓度在澎溪河高阳平湖水域展开野外原位实验.结果表明,在开始实验当日CH₄通量从（1.8093±0.0632）μmol·（m²·h）^-1到6 d急剧减少至（0.0776±0.0146）μmol·（m²·h）^-1.6 d后变化相对较小,相比较于其他水样只添加磷的水样明显有所回升.在本次实验中藻类的生长与死亡受到了不同N、P浓度梯度的影响.N对藻类的生长影响不大,各种指标与未加N、P营养盐的原水基本一致;在适宜的P浓度下,促进藻类的生长.当P浓度过多时,藻类的生长受到抑制.水样中的CH₄通量的吸收与释放和添加的硝态氮有关.     

藻类生物膜技术脱氮除磷效果研究

利用藻类生物膜去除水体氮磷为富营养化的防治提供了1种新途径,实验室条件下研究了以巨颤藻（Oscillatoria princeps）占优势的藻类生物膜对人工合成污水、污水处理厂二级污水和富营养化湖水氮（N）、磷（P）的去除效果.结果表明,通过5 d的处理,藻类生物膜对人工合成污水、污水处理厂二级污水和富营养化湖水总氮（TN）去除率分别为57.1%、94.5%和93.8%,对总磷（TP）去除率分别为93%、73%和79%.藻类产量达到3.7～7.2　g·(m²·d)^-1;收获藻体总凯氏氮（TKN）达5.7%～7.2%,TP达0.78%～2.44%,对污水N、P的回收率分别达20%～39%和65%～82%.     

调水型水库藻类对调水氮、磷浓度与水量的响应

以南方某典型的调水型水库为研究对象,采用EFDC模型建立了水库的三维水动力和富营养化模型,并根据长历时的水文和水质数据对模型进行了率定和验证.基于模型计算结果,分析了水库氮、磷浓度对藻类生长的影响,计算了藻类对调水氮、磷浓度及调水量的响应关系.结果表明,水库氮、磷浓度对藻类生长的限制作用很小.在降幅相同的情况下,降低磷浓度比降低氮浓度的藻类浓度降幅更大,削减60%的氮,叶绿素a无明显下降,削减60%的磷,叶绿素a平均下降12.4%,分别削减90%的氮和磷,叶绿素a分别平均下降17.9%和35.1%.当调水量高于现状的20%,藻类浓度随调水量增大而降低,当调水量低于20%,藻类浓度随调水量增大而升高,调水量比现状增大1倍,叶绿素a平均降低25.7%,调水量降至20%,叶绿素a平均升高38.8%.本研究对于支撑水源地的富营养化控制工作具有重要意义.     

水体及沉积物氮磷水平对附植藻类的影响

为了探讨湖泊富营养化过程中沉积物及水体氮、磷浓度对附植藻类的影响,通过室内模拟实验,研究了水体及沉积物氮、磷升高对苦草(Vallisnerianatans(Lour.) Hara)上附植藻类生长、群落组成及其体内氮、磷含量的影响.结果表明,在实验条件下,随着水中氮、磷含量升高,附植藻类生物量及附植藻类氮、磷含量均呈极显著增加(p0.01).随着水体可获得的氮、磷浓度升高,附植藻类的相对丰度有所变化,舟形藻(Navicula)、小球藻(Chlorella)及微囊藻(Microcystis)相对丰度随着氮、磷水平的升高而下降,直链藻(Melosira)则相反,但舟形藻、直链藻、微囊藻、小环藻(Cyclotella)和小球藻均为群落的优势属种.沉积物氮、磷含量升高对附植藻类生物量、优势种丰度及群落氮、磷含量影响较小,均未达到显著水平(p0.05).在实验条件下,沉积物氮、磷含量对附植藻类影响不大,而水体氮、磷浓度升高显著地促进了附植藻类生长.研究结果也为解释富营养化湖泊沉水植物衰退及消亡提供了一定的科学依据.     

氮磷胁迫下藻-菌群落的变化研究

近年来,由于水体富营养化而导致的蓝藻水华在我国太湖与滇池等淡水湖泊频繁爆发,已成为严重的环境问题,而氮、磷则是引起水体富营养化的重要营养因子。文章通过藻细胞计数、细菌群落的DGGE监测,以及典型对应CCA分析,系统研究了不同的氮磷浓度、N/P比对藻-菌群落结构的影响及其相互关系。结果表明,氮磷浓度和N/P比均会影响藻类生长,其中,氮磷浓度较N/P比对藻类生物量的影响更大;N/P=12为藻类生长的最适条件,氮限制(N/P=3)和磷限制(N/P=48)均会抑制藻类生长;添加外源氮磷可促进细菌的生长,提高其多样性,但随着N/P比的提高,其种群多样性呈逐渐下降趋势;细菌群落主要由β-proteobacteria类细菌组成,其次是α-proteobacteria,然后是Bacteroidetes和γ-proteobacteria。与氮、磷营养盐相比,藻类群落对细菌群落的影响更大。     

磷对云龙湖富营养化优势藻及混合藻生长的影响

氮磷等营养盐的增加和藻类的过度增殖是富营养化的主要标志。大多数湖泊水体富营养化受磷元素的制约。研究表明富营养化水体的不同藻类对磷含量的依赖性各不相同。通过研究在相同氮浓度,相同温度条件下,不同磷浓度对纯种小球藻和硅藻以及天然混合藻生长速度的影响,发现在氮浓度充足的情况下,磷含量高促进小球藻生长;对硅藻却没有明显的相关性;天然水体混合藻生长速度与磷浓度呈正相关。     

太湖不同湖区夏季蓝藻生长的营养盐限制研究

采集太湖6个湖区水样,利用营养盐添加,现场培养实验研究了水华蓝藻在不同湖区水体中生长的氮、磷限制情况和蓝藻的生长潜力.结果表明,梅梁湾水体只有氮、磷同时添加才对蓝藻生物量具有显著的促进作用,表明该湖区水华蓝藻的生长不仅存在磷限制,而且存在明显的氮限制.在太湖西部河口区、竺山湾和贡湖湾,蓝藻对单独的氮添加没有反应,而单独磷添加和氮磷同时添加对蓝藻生长具有同样的促进作用,表明磷是这些区域藻类生长的主要限制因子.东太湖水体不论氮磷单独还是同时添加对蓝藻生长均没有促进作用,表明存在氮磷以外的限制因子.氮磷供应充足的情况下,梅梁湾和西部河口区水体培养的蓝藻生长速率最高,表明这两个水域蓝藻的生长潜力最大,氮磷输入极易刺激蓝藻大量增殖,这在一定程度上解释了为什么蓝藻水华在这两个区域更为严重.蓝藻在贡湖湾和胥口湾水体中生长速率较低,在东太湖水体中的生长速率最低,因此这些水域的蓝藻增殖潜力较低.     

Growth characteristics of algae during early stages of phytoplankton bloom in Lake Taihu, China

Three treatments, sediment plus lake water (S+W), sterilized sediment plus lake water (SS+W), and sediment plus filtered lake water (S+FW), were recruited to investigate the growth characteristics of algae during pre-bloom and the importance of algal inocula in the water column and sediment. The results showed that in the water column, biomass of all algae increased in all treatments when recruitment was initiated, whereas this tendency differed among treatments with further increment of temperature. The process of algal growth consisted of two stages: Stage I, the onset of recruitment and Stage II, the subsequent growth of algae. Compared with S+W, in Stage I, SS+W significantly increased the biomass of cyanophytes by 178.70%, and decreased the biomass of non-cyanophytes by 43.40%; In Stage II, SS+W notably stimulated the growth of all algae, thus incurring the occurrence of phytoplankton bloom. Further analyses revealed that both metabolic activity and photochemical activity of algae were enhanced in SS+W, which resulted from the releasing of nutrients from sediment. These results suggest that algal growth in Stage II and algal inocula in the water column can be important factors for the formation of phytoplankton bloom. In addition, possible mechanisms promoting algal recruitment and subsequent growth of algae were explored.     

Phytoplankton community from Lake Taihu, China, has dissimilar responses to inorganic and organic nutrients

To evaluate the response of phytoplankton from Lake Taihu to di erent types of nutrients, the phytoplankton responses were measured after adding inorganic nitrogen (N) and phosphorus (P) or decomposed algal scum (Microcystis spp.) into the lake water. Both types of nutrients promoted an increase in phytoplankton biomass as determined by chlorophyll a and algal wet weight. The addition of decomposed algal scum resulted in a significantly greater phytoplankton response than the addition of inorganic N and P alone. The dissolved inorganic N and P in the inorganic nutrient treatment were found not limit phytoplankton growth. The higher algal biomass obtained in the treatment with decomposed algal scum indicated the importance of other organic nutrients besides N and P such as trace elements, as well as the importance of the form of N since the levels of ammonia nitrogen (NH4 +-N) from the decomposed algal treatment were actually higher than that of the inorganic N and P addition. Microcystis spp. (Cyanobacteria), Scenedesmus spp. (Chlorophyta) and Synechocystis spp. (Cyanobacteria) were the dominant taxa in the control, inorganic N and P treatment, and the decomposed algal scum treatment, respectively. Microcystis never bloomed in response to both types of nutrient additions indicating that the bloom propagation is not solely related to nutrient additions, but may be related to the absence of selective grazing from zooplankton.     

近十年洪泽湖富营养化状态变化趋势及原因分析

通过2011～2020年洪泽湖全湖逐月监测数据的分析,厘清了近十年洪泽湖富营养化状态变化趋势、时空变化特征和驱动要素,为洪泽湖富营养化控制提供针对性建议.作为洪泽湖最主要的入湖河流,淮河近十年来高锰酸盐指数显著上升、 TN显著下降.洪泽湖近十年水体总体透明度、 TP浓度和高锰酸盐指数平均值显著上升,TN和Chl-a浓度的平均值显著下降,富营养化状态指数（TLI）有下降趋势.洪泽湖富营养化状态的变化趋势在空间上存在差异：洪泽湖东区是淮河的过水通道,由于较短的水体停留时间,即使在营养盐浓度较高的情况下,藻类生物量仍显著低于其他区域,同时由于淮河水质的改善,TLI显著下降;北区具有较高的水生植被覆盖度,不仅降低了水体营养盐浓度,并为浮游动物和鱼类提供了栖息地,有效地抑制了藻类的生长,富营养状态要明显低于其余湖区,近十年TLI呈现下降趋势;西区富营养化程度最高,由于内源释放的加剧,藻类生物量最高,富营养化程度并没有得到改善.洪泽湖富营养化状态也存在显著的季节差异,夏季富营养化指数最高,藻类生物量因温度升高而相对较高,同时夏季藻类生物量主要受营养盐浓度影响,其中NO^-     

洱海水华高风险期水体氮磷变化及其指示意义

为揭示水华高风险期水体氮磷变化对洱海的指示意义,结合洱海2009年、2013年和2018年采样检测数据及三维荧光、紫外光谱技术,研究了洱海上覆水氮磷组成和结构变化及影响因素.结果表明:①ρ(TN)和ρ(TP)均先降后升,由2009年氮磷以DON(0.231 mg/L,占36.90%)和DOP(0.016 mg/L,占42.05%)为主,转变为2018年以NH₄+-N(0.197 mg/L,占32.89%)和PP(0.033 mg/L,占70.00%)为主,NH₄+-N和溶解性有机氮磷质量浓度变化是引起氮磷变化的主要因子.各形态氮磷质量浓度空间变化差异较大,北部和中部湖区ρ(TN)、ρ(TP)及其增幅均大于南部湖区;ρ(DON)在北部和南部湖区总体呈下降的趋势,中部湖区ρ(DON)先降后升,增幅为3.32%;ρ(DOP)在北部和中部呈递减,南部湖区则先升后降,总体增加了70.21%;ρ(NH₄+-N)在中部和南部湖区显著增加,北部湖区先降后升.②上覆水氮磷质量浓度及形态时空变化受外源负荷、内源释放和藻类生长共同影响,其中入湖河流是影响氮磷质量浓度变化的主因,且农村生活污染和农田面源污染影响也较大;有机氮磷变化主要受外源输入和湖泊微生物代谢影响,而ρ(NH₄+-N)变化则主要受沉积物释放和藻类生长影响.③洱海水华高风险期上覆水腐殖化程度明显降低,有机氮磷分子量减小,而活性增加,一定程度上可促进藻类生长.研究显示,近10年洱海氮磷质量浓度有增加趋势,有机氮磷质量浓度虽有所下降,但其活性较高,藻类水华风险并未降低,除进一步加强外源负荷控制,关注TN和TP的同时,洱海保护治理还应关注有机氮磷输入以及中部和南部湖区沉积物氮磷释放的水质影响.      

滇池水华特征及成因分析

滇池水华的规模大,持续时间长。水华的主要种类是蓝藻门的微囊藻属,其中以铜绿微囊藻占绝对优势。每年4～11月为水华发生期,常在外草海南部、海埂、灰湾一带形成大面积水华,盛时可遍及全湖,水体表层藻类叶绿素含量高达5 000 mg/m3。滇池水体中高含量的N和P营养物在水华的形成中起着关键作用,适宜的温度及充足的光照为水华的频发提供了有利条件,并且随着滇池富营养化的加剧及水温逐年升高,将促使水华暴发日趋严重。      

藻源性黑水团环境效应:对水-沉积物界面氮磷变化的驱动作用

利用自制的静态模拟实验装置,通过连续抽取间隙水来研究藻细胞沉降在沉积物表面后对水-沉积物界面处的N、P变化的驱动作用及影响效果.结果表明,藻细胞沉降后,在50 min内就完全消耗掉水-沉积物界面处的溶解氧,同时水体出现严重的发黑、发臭现象;形成的厌氧、强还原环境,使得死亡的藻细胞在界面处发生强烈的厌氧矿化作用,界面处的水溶性PO34--P、NH 4+-N在实验的第2 d开始向上覆水中扩散,含量不断增加.至实验结束时(实验第8 d),界面处PO34--P、NH 4+-N的含量分别达到4.00 mg/L、39.45 mg/L,分别为同期对照实验样柱中的10倍和241倍(对照样柱中的PO43--P、NH 4+-N的含量分别为0.42 mg/L、0.16 mg/L).藻细胞的厌氧矿化加剧了氮磷营养盐向上覆水的扩散,在加重水体营养盐含量的同时,也为藻华的再次发生提供了物质基础.     

Long-term joint e ect of nutrients and temperature increase on algal growth in Lake Taihu, China

To study how global warming and eutrophication a ect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature (AT), water temperature (WT), and their average temperature (ST), while substrate variables were calculated using annual mean total nitrogen (TN), total phosphorus (TP), and their weighted aggregate (R), respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0°C. Results also showed that the more eutrophic the lake, the greater the e ect AT had on algal growth. Subsequently, the long-term joint e ect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.     

Long-term joint effect of nutrients and temperature increase on algal growth in Lake Taihu, China

To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature (AT), water temperature (WT), and their average temperature (ST), while substrate variables were calculated using annual mean total nitrogen (TN), total phosphorus (TP), and their weighted aggregate (R), respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0℃. Results also showed that the more eutrophic the lake, the greater the effect AT had on algal growth. Subsequently, the long-term joint effect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.     

绿潮硬毛藻分解对天鹅湖水体氮磷水平的影响

为了解绿潮硬毛藻衰亡分解对上覆水体营养水平的影响,以荣成天鹅湖不同湖区的沉积物和暴发的硬毛藻为试材,通过室内模拟研究了藻类分解过程中水体氮磷水平及理化性质的变化,并评价了不同湖区沉积物中氮磷的释放潜力.结果表明:硬毛藻衰亡分解使上覆水体中ρ(TN)和ρ(NH₄+-N)均明显上升,并且前期(0~16 d)上升较快,ρ(TN)和ρ(NH₄+-N)最高分别可达12.40和7.98 mg/L;水体中ρ(TP)和ρ(SRP)表现为前期变化不大,19 d后大幅增加,含量变幅分别为0.02~1.14和0.01~0.40 mg/L.在试验中后期(约16 d后),不同湖区沉积物处理的水体中ρ(TN)、ρ(NH₄+-N)、ρ(TP)、ρ(SRP)均表现为有沉积物含藻处理>无沉积物含藻处理>有沉积物无藻处理.在藻分解的条件下,不同湖区沉积物的氮磷释放能力存在很大差异,氮释放量的顺序为湖中心>西北部>南部,而磷表现为西北部>湖中心>南部.在硬毛藻绿潮的衰亡阶段,由于初期藻体营养盐的直接释放和后期促进沉积物内源释放的间接影响,水体中ρ(TN)和ρ(TP)均明显增加,进而加重了天鹅湖水体的富营养化水平.