镇江市金山湖沉积物磷元素分布特征研究

以镇江市金山湖为研究区域,于2019年1月（冬季）和2019年7月（夏季）采集了10个点位的表层沉积物样品,参照欧洲标准测试测量组织建立的沉积物磷形态分析方法（SMT）测定沉积物总磷（TP）、无机磷（IP）、有机磷（OP）、铁/铝-磷（Fe/Al-P）和钙-磷（Ca-P）质量分数,研究金山湖表层沉积物磷元素及其赋存形态的季节分布特征。结果表明,金山湖表层沉积物中TP质量分数在冬、夏季分别为727.39~1 073.70 mg/kg和700.90~1 002.17 mg/kg,处于中等污染水平;金山湖表层沉积物磷以IP为主,IP在TP中的占比在冬、夏季分别为68.58%~88.86%,73.09%~87.21%;除了Fe/Al-P以外,OP作为生物有效磷源,其冬、夏季质量分数分别为69.37~190.93 mg/kg和108.45~210.42 mg/kg;其平均值分别为129.01,160.15 mg/kg。金山湖冬、夏季沉积物各形态磷质量分数所占比例均表现为Ca-P>Fe/Al-P>OP,表明该研究区域沉积物以Ca-P占优势。金山湖表层沉积物pH值呈现弱碱性,通过Ca-P直接释放到上覆水中的磷较少,故金山湖沉积物磷元素的潜在风险较小。各形态磷的相关性分析结果发现,冬季沉积物TP与Fe/Al-P、IP呈极显著正相关（P<0.01）。夏季沉积物TP与IP、Fe/Al-P之间呈极显著正相关（P<0.01）,与Ca-P呈显著正相关（P<0.05）。此外,金山湖沉积物OP、Fe/Al-P以及Ca-P的来源不一致。pH值对沉积物IP会产生一定影响,而其余磷形态则受pH值的影响程度较小。     

洪泽湖湖滨带表层沉积物氮、磷、有机质分布及污染评价

洪泽湖作为中国第四大淡水湖泊,是江苏北部地区重要的水源地,同时也是南水北调东线工程的重要调蓄湖泊之一,研究其湖滨带表层沉积物氮、磷、有机质的污染情况对维持洪泽湖水安全和生物多样性具有重要现实意义。基于2020年8月于洪泽湖湖滨带采集的43个表层（0~10 cm）沉积物样品,分析了总氮（TN）、总磷（TP）和有机质（OM）含量的空间分布特征及相关性,并运用综合污染指数法和有机污染指数法评价其污染程度。结果表明,洪泽湖湖滨带表层沉积物TN、TP、OM含量范围分别为232~2 152 ,123~439,0.91~18.65 mg/kg,均值分别为985,276,10.93 mg/kg;空间分布上均表现为东部大堤、成子湖和西部区域的TN、TP、OM含量高于过水通道;Pearson相关性分析显示,表层沉积物中ω(OM)与ω(TN)（r=0.705,P<0.01）、ω(TN)与ω(TP)（r=0.504,P<0.01）呈显著正相关;洪泽湖湖滨带表层沉积物综合污染指数范围为0.45~1.88,平均值为0.93,有机污染指数范围为0.001~0.221,平均值为0.067,2种评价方法均显示洪泽湖湖滨带表层沉积物中TN、TP、OM整体处于清洁—轻度污染状态。     

淀山湖沉积物的污染特征及其风险评价

对上海淀山湖代表性表层沉积物中的重金属、磷、PAHs及OCPs等典型污染物质进行了分析和风险评价。其中总磷含量范围为1 072~1 229 mg/kg,以无机磷为主,生物可利用磷含量较高,对水体富营养化具有潜在的威胁。重金属Cu、Cr、Zn、Pb的平均含量分别为25.5、34.1、244.5、32.2 mg/kg,污染程度大小依次为ZnPbCuCr,潜在生态风险程度依次为PbCuZnCr。∑PAHs、∑OCPs含量范围分别为617.1~843.2 ng/g以及22.03~28.94 ng/g,风险结果表明PAHs和大部分OCPs均未超出ERL值,生态风险水平低。     

玄武湖沉积物中磷的形态分布特征

利用分级提取法分析了玄武湖的沉积磷形态,在玄武湖沉积物中,铝结合态磷的含量较低,平均值为64 mg/kg,其余形态磷中,铁结合态磷为241 mg/kg,有机磷为335 mg/kg,钙结合态磷为394 mg/kg.在环境变化的条件下,铁结合态磷可以释放到间隙水和上层水体中,是湖泊产生富营养化的重要因素;铝结合态磷由于含量少,对湖泊富营养化影响很小;钙结合态磷相对稳定且很难被生物利用,对湖泊富营养化影响不大;有机磷对水体有机负荷影响较大,并影响水体富营养化程度.     

海南八门湾沿岸表层沉积物重金属分布特征及污染评价

通过在海南八门湾内布设15个调查站位,监测分析表层沉积物中重金属分布、污染来源及潜在生态风险。结果表明,研究区表层沉积物中Cu、Pb、Zn、Cr、Cd、Hg和As平均值分别为19.78 mg/kg、5.94 mg/kg、36.27 mg/kg、15.99 mg/kg、0.18 mg/kg、0.04 mg/kg和6.82 mg/kg;Pb、Cr及Zn,Cu与Cd、As可能具有相同或相似污染源;重金属污染程度以轻微生态危害为主,其次为中等生态危害及强生态危害;重金属Cd与Hg为主要潜在生态危害因子,潜在生态风险由高到低依次为CdHgAsCuPbZnCr。     

北方某水库表层沉积物重金属的赋存形态及其环境影响因子分析

为了解北方某水库重金属污染状况,采用BCR连续提取法对该水库表层沉积物中Cu、Pb、Zn、Cd的赋存形态进行了分析,对其含量及空间分布进行了研究,结合重金属总量讨论了各元素的潜在环境风险。结果表明,该水库表层沉积物中Cu、Pb、Zn、Cd的平均质量比分别为65.20 mg/kg、36.69 mg/kg、137.5 mg/kg、2.38 mg/kg,与该地区土壤元素背景值、该地区水系沉积物平均值及全国水系沉积物平均值相比,4种重金属元素均有一定程度的累积,其中Cd累积最为严重。形态分析结果表明,Cd主要以醋酸可提取态及可还原态存在,具有很高的环境风险;Pb主要以极高比例的可还原态存在,潜在风险较高;Zn和Cu存在较大比例的酸可提取态及可还原态,也具有一定程度的潜在风险。各元素生物有效性即可提取态含量排序为:Cd>Cu>Pb>Zn。     

乌鲁木齐表层土壤中氟元素的分布特征

研究了乌鲁木齐市不同功能区表层土壤中水溶性氟（Ws-F）的含量。结果表明：土壤Ws-F平均含量为5.36 mg/kg,变幅为1.55~12.53 mg/kg。其中,工业区（7.13 mg/kg）〉绿化区（5.73 mg/kg）〉商业区（5.71 mg/kg）〉居民区（4.93 mg/kg）〉农业区（3.08 mg/kg）。乌鲁木齐市土壤中Ws-F含量已高于我国地氟病发生区表层土壤Ws-F的平均值（2.50 mg/kg）,应引起有关部门的高度重视。     

洪泽湖沉积物中磷的形态研究

采用改进的七步连续提取法对洪泽湖9个采样点沉积物中的各形态磷进行了分析,结果表明,所测洪泽湖沉积物中总磷(TP)含量范围为580.7～1 447.7 mg/kg,无机磷(IP)是TP的主要部分,占TP含量的64.32％～88.60％;有机磷(0P)占TP的11.40％～35.68％.受河流注入和人为活动的影响,TP、I...     

碱熔浸取-离子选择电极法测定沉积物中总氟

采用氢氧化钠高温熔融浸取沉积物,用离子选择电极法测定浸取液中的总氟,通过试验确定最佳浸取条件,使方法在5.00μg~500μg范围内线性良好。当取样量为0.2 g时,方法检出限为12.4 mg/kg。用该方法测定沉积物有证标准物质,结果均在标准值范围内,测定3个沉积物实际样品,总氟质量比为254 mg/kg~1 389 mg/kg,6次测定结果的RSD为4.1%~4.8%,3个质量比水平加标回收率为99.2%~101%。     

铋磷钼蓝分光光度法测定土壤中磷含量

土壤中磷含量的分析是土壤环境监测的主要项目之一.建立了铋磷钼蓝分光光度法测定土壤中磷含量的新方法,与现有的《土壤全磷测定方法》(GB 9837-88)和土壤总磷快速检测仪方法进行了比较讨论.方法的检出限为5.0 mg/kg,对磷含量为475 mg/kg和292 mg/kg的标准土壤样品进行测定,结果与标准值吻合,其相对...     

Phosphate adsorption characteristics at the sediment–water interface and phosphorus fractions in Nansi Lake, China, and its main inflow rivers

Phosphorus fractions and phosphate adsorption characteristics of 16 sediments from a shallow freshwater lake (Nansi Lake, China) and its inflow estuaries were investigated. In the present study, the sediment phosphorus is fractionated into exchangeable P (exch-P), Al-P, Fe-P, Ca-P, organic P (OP), inorganic P (IP) and total P (TP). The results show that the total phosphorus (TP) content in the sediments ranges from 571.67 to 1,113.55 mg kg(-1), and calcium bound phosphorus (Ca-P) is the main fraction of IP. The biologically available phosphorus (BAP) ranges from 32.02 to 229.67 mg kg(-1) in the Nansi Lake sediments. Phosphate adsorption on the sediments mainly occurs within 10 h and is completed within 48 h. The content of native adsorbed phosphorus (omega(NAP)) varies greatly from 6.05 to 194.37 mg kg(-1), showing a significant correlation with the total maximal amount of phosphorus adsorbed (TQ(max)). Adsorption efficiency (m) ranges from 574.79 to 3,220.68 l kg(-1) and zero equilibrium phosphorus concentration (C(EPC)) ranges from 0.010 to 0.157 mg l(-1). After the South-to-North Water Diversion Project, the inherent phosphorus present in sediments will be a major threat to the diverted water quality and be a predominant factor determining the trophic status of the lake even if the external load is reduced.     

A regional inventory and monitoring setup to evaluate bark peeling damage by red deer (Cervus elaphus) in coniferous plantations in Southern Belgium

Sediment phosphorus (P) fractions and sorption characteristics and P release from intact sediment cores of Baiyangdian Lake in North China in spring 2009 were investigated. Results of chemical fractionation showed that total P (TP) content in sediment ranged from 443 to 611 mg kg(?-1). Of the P fractions including inorganic P (IP) and organic P (OP), IP was a dominant component of TP and present in the form of P bounded to calcium (Ca-P) while the bioavailable P content bounded to Al, Fe, and Mn oxides and hydroxides (Fe/Al-P) varied from 14 to 102 mg kg(?-1). The batch experiments showed that the sediments had appreciable maximum P adsorption capacity from 141.86 to 377.37 mg kg(?-1). However, the zero P equilibrium concentration (C?(eq))in most sampling sites was larger than the P concentration in water column. Accordingly, the sediments from those sampling sites would release P into the overlying water at the positive P flux rates as a P release source. Significant positive correlation between P flux rates and Fe/Al-P revealed that the sediment P release would mainly originate from the bioavailable P fraction. It is evident that the inherent phosphorus present in lake sediments would be a major threat to the water quality and ecosystem reservation in Baiyangdian lake.     

Characterisation of road sediments near Bordeaux with emphasis on phosphorus

Road sediments from the region of Bordeaux (France) were analysed for trace metals, hydrocarbons (including Polycyclic Aromatic Hydrocarbons, PAHs) and phosphorus. The aim of the study was to assess their potential risk for the environment. The sediments were collected by means of a sweeper. The particles are mostly sandy clay loam and silty clay loam with 5.6-8.3% CaO. Heavy metal concentrations are generally below the French and Dutch standards for polluted soils, but a few samples have higher concentrations, e.g., 547 mg kg(-1) for Zn, and 222 mg kg(-1) for Pb. PAH concentrations are above the Dutch target value for polluted soils, and could be a threat to the environment: pyrene (2600 microg kg(-1)) and fluoranthene (1400 microg kg(-1)) have the highest concentrations, whereas chrysene (340 microg kg(-1)) has the lowest. Consequently, these sediments must be considered as waste according to the French circular no 2001-39 from 18 June 2001 and cannot be disposed of anywhere. The Standards Measurements and Testing (SMT) protocol for sequential extraction of phosphorus in sediments was used to determine the forms of phosphorus in the samples. Total phosphorus concentration is 620 mg kg(-1) on average, with a maximum of 933 mg kg(-1); organic phosphorus content is low (36 mg kg(-1) on average). The protocol could be slightly amended, especially with regards to organic phosphorus at low concentrations and could then be used for the determination of phosphorus in other materials such as sludge from detention ponds.     

Impact of urbanization on the concentrations and distribution of organic contaminants in boreal lake sediments

The main goal of this study was to evaluate the impacts of a middle-sized Finnish urban area on the quality of sediments in an adjacent boreal lake. We investigated the sources and distribution of organic pollutants (polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)) in the sediments from urban stormwater traps and from Lake Vesijärvi. Grab surface sediment samples were taken from Lake Vesijärvi at various distances (25–2,000 m) from four major stormwater drainage outlets and at 15 urban stormwater traps in areas with different degrees of urbanization. These samples were analysed for 16 PAHs and 28 PCBs with gas chromatography–mass spectrometry. The concentrations of pollutants in the lake sediments were elevated in the vicinity of the urban shore (∑PAH 3–16, ∑PCB up to 0.02–0.3 mg/kg dw) and decreased as a function of distance (∑PAH 0.1–2.5, ∑PCB 0.01–0.3 mg/kg dw at a distance of more than 500 m from the shore), whereas contamination levels in suburban areas were notably lower (∑PAH 0.1–3, ∑PCB?<?LOQ–0.03 mg/kg dw; did not decline with distance). Possible sources and pathways of contamination were also investigated. The majority of stormwater trap sediments contained predominantly asphalt-derived PAHs due to pulverized pavement. PAHs in lake sediments were of pyrogenic origin, including the combustion of gasoline, diesel and coal. Suggested pathways of lake contamination are urban runoff discharge, boat traffic and atmospheric deposition.     

Near-shore distribution of heavy metals in the Albanian part of Lake Ohrid

The heavy metal contamination in Lake Ohrid, a lake shared between Albania and Macedonia, was studied. Lake Ohrid is believed to be one of the oldest lakes in the world, with a large variety of endemic species. Different anthropogenic pressures, especially heavy metal influxes from mining activities, might have influenced the fragile equilibrium of the lake ecosystem. Heavy metal concentrations in water, sediment, emergent vegetation, and fish were investigated at selected sites of the lake and a study of the heavy metals in five tributaries was conducted. The lake surface water was found to have low levels of heavy metals, but sediments contained very high levels mostly near river mouths and mineral dump areas with concentrations reaching 1,501 mg/kg for Ni, 576 mg/kg for Cr, 116.8 mg/kg for Co and 64.8 g/kg for Fe. Sequential extraction of metals demonstrates that heavy metals in the sediment are mainly present in the residual fraction varying from 75% to 95% in different sites. High heavy metal levels (400 mg/kg Ni, 89 mg/kg Cr, and 39 mg/kg Co) were found in plants (stem of Phragmites australis), but heavy metals could not be detected in fish tissue (gill, muscle, and liver of Salmo letnica and Salmothymus ohridanus).     

沧州地区氟元素在不同介质中的分布

以沧州地区的地下水、土壤和小麦中的氟元素为研究对象,探讨氟元素在地下水、土壤和小麦等不同介质中的含量、空间分布与来源成因。通过绘制各介质中氟元素分布图,获得氟元素在各介质中不同深度的含量及水平空间上的分布特征。结果显示,当地深层地下水氟含量平均为2.25 mg/L,高于浅层地下水的平均值0.80 mg/L;深层和浅层土壤氟含量接近,平均值分别为557.18、569.20 mg/kg;小麦中的氟含量最高值为0.96 mg/kg,当地小麦氟含量均低于国家标准限值(1.0 mg/kg)。根据氟元素的分布特点分析,当地深层地下水与土壤的氟元素来源一致,而不同于浅层地下水中的氟;小麦的氟元素分布受浅层土壤氟影响较大。     

Bacterial community composition of sediments from Artificial Lake Maslak, Istanbul, Turkey

Small artificial lakes are ubiquitous in various natural environments. Small impoundments increase the residence time of water, thereby increasing the potential for retention of nutrients through biological and physical processes. We examined bacterial community structure of Lake Maslak, a small freshwater impoundment located in a densely populated region. The objective of our study was to investigate bacterial communities of the lake sediment which has not been determined and to elucidate the factors controlling bacterial diversity and the biogeochemical processes within the lake. For these purposes, surface water, lake bed sediments, and one core sample were collected. Microbiological characteristic of the lake bed and core sediments was determined by denaturing gradient gel electrophoresis targeting the 16S rRNA gene. Along with the microbiological studies, physicochemical (O(2), pH, temperature) and geochemical properties of the surface (NO (3) (-) , NO (2) (-) , NH (4) (+) ,PO (4) (-) ,SO (4) (2-) , K(+), Mg(2+), Ca(2+)) and pore water (K(+), Mg(2+), Ca(2+)) were determined in addition to heavy metals contents (Co Cu, Fe, Zn, Pb, Cd). Eight lake bed and one core sediments were also collected and analyzed for heavy metals and elemental compositions. Nitrate concentration in the surface water ranges from 0.27-1.8 mg/L, and ammonium (0.0-0.83 mg/L) appears to follow nitrate concentration. Sulfate concentration in the surface water (mean 60 mg/L) is greater than those measured in the pore water (mean, 37.5 mg/L). Fe, Zn, Pb, and Cd were not determined in the surface water, whereas Co was significantly higher both in the surface and pore water. Unlike Co, Pb, Zn, and Cd were not measured in the pore water. Lakebed and core sediments show significant enrichment in Pb, Zn, and Cu, indicating anthropogenic pollution. Consistent with geochemical parameters, microbiological analysis suggests a diverse bacterial community in the lake sediments and influence of anthropogenic pollution (e.g., atmospheric emission) on bacterial community.     

Migration of As, Hg, Pb, and Zn in arroyo sediments from a semiarid coastal system influenced by the abandoned gold mining district at El Triunfo, Baja California Sur, Mexico

Extensive waste deposits (tailings) and ash from the ignition oven of the abandoned gold mine of mining district El Triunfo (MD-ET) in Baja California Sur, Mexico have released trace elements into the sediments of the Hondo-Las Gallinas-El Carrizal arroyo, which connects to the Pacific Ocean through an evaporitic basin. Migration of these elements through the arroyo is mainly caused by winds or tropical hurricanes that occur sporadically during the summer and cause the otherwise dry arroyo to overflow. To evaluate the concentration and distribution of the elements As, Hg, Pb, and Zn along the 48 km arroyo, surface sediments were collected from 26 sites, ranging from close to the MD-ET to the mouth of the arroyo at the Pacific Ocean. Concentrations in tailings and ash were for As 8890 and 505?000 mg kg(-1); for Hg 0.336 and 54.9 mg kg(-1); for Pb 92,700 and 19,300 mg kg(-1); and for Zn 49,600 and 1380 mg kg(-1). The average of the Normalized Enrichment Factor (Av-NEF) in surface sediments, calculated using background levels, indicates that the sediments are severely contaminated with As and Zn (Av-NEF = 22), Pb (Av-NEF = 24) and with a moderate contamination of Hg (Av-NEF = 7.5). The anthropogenic influence of those elements is reflected in the arroyo sediments as far as 18 km away from the MD-ET, whereas the samples closest to the discharge into the Pacific Ocean show a natural to moderate enrichment for As and Zn and low or no enrichment for Hg and Pb. A principal components analysis identified four principal components that explained 90% of the total variance. Factor 1 was characterized by a high positive contribution of the anthropogenic source elements, especially As, Pb, and Zn (37%), whereas Factor 2 was strongly correlated with the oxy-hydroxides of Fe and Mn (27%). Factor 3 was correlated with Li (16%) and Factor 4 with Al (10%), which indicates more than one source of lithogenic composition, though they played a minor role in the distribution of the elements.