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广西沿海地处我国东南沉陷地震带,地震活动比较活跃,热带气旋影响频繁,地质环境和灾害风险性问题日益突出,但缺乏有效的海陆联测手段和长期监测资料。通过综合物探、地质取样、海水取样及海流剖面测量等综合技术手段,首次在北部湾广西近岸进行了5年次的海洋地质环境综合监测,对地形、地层、沉积物、矿物、重金属以及水质要素等进行了分析和评价。结果显示: 广西海岸带环境要素时空变化较大,滩面平衡点摆动,冲淤变化较大; 海水污染物主要是营养盐、石油类和部分重金属; 局部岸段人为改造明显,水质总体趋好与加大环境治理力度有关; 海岸脆弱性较高,灾害的突发性风险增加,需要进一步加强监测工作。 相似文献
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沉积物中的重金属属于持久性污染物,具有富集性、难降解性和毒性,长时间累积会对生态环境和人体健康造成威胁。为研究珍珠湾红树林湿地表层沉积物中的重金属含量分布特征及质量现状,2021年9月在珍珠湾红树林分布区采集13件表层沉积物样品,分析测试重金属含量。结果表明: 与国内其他红树林湿地相比,珍珠湾红树林湿地表层沉积物中的重金属含量处于相对较低水平; 地累积指数法显示大部分表层沉积物样品无重金属污染,仅有2个站位受到Cd和Hg的轻微污染,潜在生态风险指数法表明湾内各站位均为低生态风险; 相关性分析和主成分分析表明,Cd主要受江平江输入和珍珠湾东南部海水养殖的影响,其他元素主要为自然背景的岩石风化沉积,利用主成分-多元线性回归模型对重金属的来源进行解析认为,表明江平江输入的重金属贡献率为57%,海水养殖影响的重金属贡献率为43%。综上所述,珍珠湾红树林湿地整体生态状况良好,但仍需重点关注Cd的输入。 相似文献
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钦州湾是广西最大的海湾,有丰富的港口资源,是广西海洋产业发展主要支柱区域之一.近年来的开发建设活动,加强了人为地质作用,地质环境问题越来越复杂,发展给环境带来了越来越大的压力.2006-2010年,中国地质调查局广州海洋地质调查局在北部湾广西沿海执行"北部湾广西近岸海洋地质环境与地质灾害调查"项目,对研究区进行了地质环境及人类活动影响的调查研究.论文根据海底表层沉积物和柱状样品测试资料,分析了钦州湾海底沉积物中有害元素Hg的平面分布和垂向分布特征,表明Hg污染主要来自于船舶影响.钦州湾口门内的Hg污染小于口门外,向外海则污染逐渐降低;Hg含量愈近海底,其值愈高.通过分析,认为Hg值在海底70 cm以下趋于稳定,确认约700年前开始,钦州湾受人类活动影响增加;约130年前,人类活动影响加剧.总体上,Hg测量值均低于标准值,说明钦州湾环境目前尚好.但环境已受到经济发展的影响.因此,必须加大保护环境的力度,防止污染程度加深. 相似文献
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北京市作为我国的经济和文化中心,高速的城市化进程带来了一系列的环境问题。城市道路尘可以通过不同途径进入人体,对人体健康造成伤害。本研究采集了春、冬两季北京市6类功能区中道路尘样品46件,研究了其中Cr、Pb、Cd、As和Hg元素的含量和空间分布特征,并采用单因子指数法和内梅罗污染指数法,评价了道路尘中重金属污染程度。结果表明:除冬季As元素外,其余元素平均含量均高于北京市土壤背景值; 5种重金属元素平均含量一般为市区最高,郊区最低。单因子污染评价表明,冬、春两季各个功能区道路尘中除As元素无污染外,其余元素均具有一定程度的污染,其中Cd元素污染程度最高;冬季各功能区道路尘中重金属元素综合污染指数评价均为轻度污染;春季郊区为尚清洁,工厂区、居民区和商业区为轻度污染,休闲区和教育区为中度污染。 相似文献
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山东半岛典型海岸带多环芳烃分布特征、来源解析及风险评价 总被引：1，自引：0，他引：1
山东半岛海岸带面临着各类复杂的环境问题,尤其是受到了多环芳烃(PAHs)等持久性有机物的污染,本文研究了整个山东半岛典型海岸带62个站点表层沉积物中PAHs的含量及其分布特征,并对其来源和潜在风险进行解析与评价。研究表明,该地区表层沉积物中16种PAHs总含量为0.06~3191.40 ng/g(平均值262.08 ng/g),与国内外海岸带相比,山东半岛海岸带表层沉积物中PAHs整体污染状况处于较低水平,但个别站点的PAHs含量偏高。运用特征比值法、相关性分析及主成分分析法解析研究区PAHs主要来源为木柴、煤炭、油类的燃烧以及油类泄露的联合作用。采用效应区间低值法(ERL)和中值法(ERM)对PAHs进行生态风险评价,结果表明莱州湾周边所有站点及威海、青岛周边个别站点苊、芴浓度位于ERL值与ERM值之间,但多数站点对生态环境潜在负面效应很小。山东半岛典型海岸带中PAHs对生物的毒副作用尚在安全可控范围内,极少对生态环境产生负面效应。 相似文献
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秦皇岛近岸海域沉积物重金属含量及污染评价 总被引：2，自引：1，他引：1
重金属是近岸海域的主要污染物之一,了解其在沉积物中的含量和污染程度对海洋环境保护研究具有重要意义。文章分析了秦皇岛近岸海域沉积物重金属含量分布特征,并采用修正综合指数法对其污染状况进行分析评价。结果表明:重金属平均含量由高至低的顺序是CuPbAsCdHg,超出环境背景值较高的是Hg和Cu;沉积物重金属污染程度总体处于很低-低等级,石河口、人造河口等近岸海域污染程度略高于其他临近海域。 相似文献
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黄河内蒙古段上覆水、悬浮物和底泥重金属特征及生态风险研究 总被引：24，自引：12，他引：12
系统地采集黄河内蒙古段上覆水、悬浮物和底泥样品,分析其中重金属元素的含量。采用地质累积指数法和潜在生态危害系数法,研究了黄河干流内蒙古段的上覆水、悬浮物和底泥的重金属沿程分布特征、污染程度和生态风险。分析结果显示:除了As元素,悬浮物中重金属元素含量总体上高于底泥中的含量。地质累积指数法评价结果表明:悬浮物和底泥属于无污染—中度污染,悬浮物总体上比底泥污染严重;潜在生态危害系数法评价结果表明:底泥和悬浮物中重金属的生态危害总体上属轻微状态;因此,生态风险指数法和地质累积指数评价结果基本一致。 相似文献
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通过对渤海湾西部永定新河河口潮间带区海水及沉积物中重金属含量及污染状况的研究,认为海水中重金属含量平均值的大小顺序为Zn＞Cu＞Pb＞Hg＞Cd;因海水中重金属输入径的不同,不同潮期海水中重金属含量存在差异:大潮期海水中重金属Cu,Pb和Hg的含量大于小潮期海水中的含量,而重金属Zn和Cd的含量则小于小潮期海水中的含量;因受海水中悬浮物含量、种类及河口区成淡水混合发生絮凝作用等的影响,海水中重金属含量在垂向上也存在差异.无论是大潮期还是小潮期,海水中重金属舍量总是表层略大于底层;按一类水质标准对海水中重金属污染状况的分析,认为研究区海水已局部受到重金属污染,污染最严重的是重金属Zn,其次为重金属Pb,Hg和Cu,不存在重金属Cd污染;沉积物中重金属舍量平均值的大小顺序与海水中的相同,说明海水与沉积物中重金属循环处于相对平衡状态.沉积物中重金属含量平均值均在渤海湾环境背景值范围内,且是渤海海域含量最低的区域.经过对沉积物重金属污染状况的分析,研究区沉积物重金属污染轻微. 相似文献
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Tillamook Bay, Oregon, is a drowned river estuary that receives freshwater input from 5 rivers and exchanges ocean water through
a single channel. Similar to other western United States estuaries, the bay exhibits a strong seasonal change in river discharge
in which there is a pronounced winter maximum and summer minimum in precipitation and runoff. The behavior of major inorganic
nutrients (phosphorus, nitrogen, and silica) within the watershed is examined over seasonal cycles and under a range of river
discharge conditions for October 1997–December 1999. Monthly and seasonal sampling stations include transects extending from
the mouth of each river to the mouth of the estuary as well as 6–10 sites upstream along each of the 5 major rivers. Few studies
have examined nutrient cycling in Pacific Northwest estuaries. This study evaluates the distributions of inorganic nutrients
to understand the net processes occurring within this estuary. Based upon this approach, we hypothesize that nutrient behavior
in the Tillamook Bay estuary can be explained by two dominant factors: freshwater flushing time and biological uptake and
regeneration. Superimposed on these two processes is seasonal variability in nutrient concentrations of coastal waters via
upwelling. Freshwater flushing time determines the amount of time for the uptake of nutrients by phytoplankton, for exchange
with suspended particles, and for interaction with the sediments. Seasonal coastal upwelling controls the timing and extent
of oceanic delivery of nutrients to the estuary. We suggest that benthic regeneration of nutrients is also an important process
within the estuary occurring seasonally according to the flushing characteristics of the estuary. Silicic acid, nitrate, and
NH4
+ supply to the bay appears to be dominated by riverine input. PO4
−3 supply is dominated by river input during periods of high river flow (winter months) with oceanic input via upwelling and
tidal exchange important during other times (spring, summer, and fall months). Departures from conservative mixing indicate
that internal estuarine sources of dissolved inorganic phosphorus and nitrogen are also significant over an annual cycle. 相似文献
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The degree and the contribution of each point source to the pollution were determined in the Izmit Bay during the period 1999–2000.
During 8 campaigns, samples from 11 points in the channels and water samples from 5 points in the coastal sea were collected
for chemical analysis. The important pollutant parameters taken into account are inflow of total organic carbon (TOC), total
suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), nitrate, ortho-phosphate, ammonia and total polycyclic aromatic hydrocarbons (t-PAHs) in the discharge channels, and TOC, TSS, nitrate,
ortho-phosphate, chlorophyll-a, temperature, dissolved oxygen (DO), and salinity in the coastal stations of the Bay. It should
be pointed out that the industrial wastewaters entering the bay are partially treated but domestic wastes are discharged directly
into the surface waters without any treatment. Of the pollution parameters measured in the channels, the highest concentrations,
except TP, were observed in the Dil River and in the Eastern Channel. Concentrations of TOC, TSS, TN, TP, ammonia, nitrate
and o-phosphate were found at concentrations of 231, 290, 152, 3.8, 16, 79, and 3.07 mg/L, respectively. Annual inflows of TOC
were 21,301, 580, and 775 t/year and for TSS were 26,742, 585, and 1505 t/year in the western, central and eastern parts,
respectively. The results show that the water quality of the bay has been deteriorated and 80% of the pollution was caused
by Dil River for all parameters measured. 相似文献
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碳酸盐型尾矿在缓冲期/中性矿山废水(NMD)释放期的重金属污染问题易被忽视。本文以广西大厂锡石-硫化物尾矿作为研究对象,采用柱淋滤实验方法,探讨碳酸盐型尾矿在缓冲期重金属的释放机制,为此类型尾矿重金属污染的防治提供依据。实验结果表明,大厂尾矿在缓冲期(约7年,pH值为6. 6～8. 0)存在Sb、Zn、Cd、As(Pb)释放污染问题。在尾矿堆放初期(0. 5年,pH值由7. 6降至7. 2),Zn、Sb、Cd快速、大量释出;中期(0. 5～2. 5年,pH值由7. 2波动升高至8. 0),Sb较平稳释出;后期(2. 5～7年,pH值变化范围为8. 0～6. 6,呈降低趋势),受气温及pH值影响,As、Sb(Pb)呈波动或间歇振荡释出,即在夏季高温、pH值较高时,释出元素浓度较高,反之,在冬季低温、pH值较低时,释出元素浓度较低。重金属的释放与尾矿中硫化物的氧化程度高低及氧化先后顺序有关。这些矿物的氧化顺序大致为:闪锌矿(Zn、Cd)、辉锑锡铅矿(Sb)→脆硫锑铅矿(Sb)→毒砂(As)、方铅矿(Pb)。因此,对于(广西大厂)碳酸盐型尾矿在缓冲期的重金属污染应分阶段、季节(夏季),采取有针对性的防治措施;在缓冲期(7年)后应注意尾矿酸性矿山废水(AMD)+重金属(如As、Sb)复合污染的防治。 相似文献
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Delivery of Trace Metals (Al,Fe, Mn,V, Co,Ni, Cu,Cd, Ag,Pb) from the Trinity River Watershed Towards the Ocean 总被引：2，自引：0，他引：2
The Trinity River (Texas, USA) contains in its watershed 23 different reservoir lakes, the largest one being Lake Livingston
situated in the lower Trinity River watershed and two potentially polluting metroplexes, Dallas and Houston. In order to determine
fluxes of nutrients and trace metals to Galveston Bay, a survey that included 24 discreet samples collected over a year and
at various stages of discharge was carried out during 2000–2001. Geochemical (i.e., sorption by Fe oxyhydroxides), biological
(i.e., seasonal uptake by sinking algae in Lake Livingston), and hydrological (i.e., dilution effects by increasing flow rates)
controls were found to be mainly responsible for variations in dissolved trace metal concentrations rather than pollution
sources. The Trinity River loads of suspended sediments and pollutant trace metals entering Galveston Bay at Anahuac were
<20% of those reaching Lake Livingston, and only a few percent of the total upstream trace metal load is entering the Gulf
of Mexico. Thus, during the transit through the 23 man-made lakes and an estuary, >96% of the pollutant trace metal load is
lost to sediments. 相似文献
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Countermeasures of heavy metal pollution 总被引：2，自引：0，他引：2
This article gives a review on heavy metal pollution prevention and control,and it also discusses heavy metal pollutant discharge,prediction and evaluation of environmental impact,and pollution prevention and monitoring. 相似文献
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根据2010-2012年西宁市基本探空气象站逐日07：00时和19：00时两个时次的逆温资料,及西宁市环境监测站监测的大气污染物（SO2、NO2、PM10）日均值数据,分析了西宁市逆温基本特征及其与空气污染物浓度之间的相关关系. 结果表明：西宁市2010-2012年07：00时逆温出现频率为69%,19：00时逆温出现频率为41%;近地逆温层厚度冬季最厚,夏季最薄. 07：00时和19：00时月平均逆温厚度变化趋势基本一致;西宁市逆温发生频率冬半年明显高于夏半年;秋、冬季产生的逆温强度明显比春、夏季强. 3 a来西宁市空气污染共出现148 d,逆温频率和空气污染物月平均浓度有较好的正相关性. 08：00时西宁市逐日空气污染物浓度与逆温厚度呈正相关,与逆温强度呈负相关关系. 冬、春季平均空气污染物浓度值与逆温厚度、强度均呈正相关关系. 相似文献
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Intensive research in Chesapeake Bay has indicated that reductions in nitrogen inputs to the bay will be necessary to restore water quality to levels needed for resurgence of bay living resources. Fall-line water quality monitoring efferts have characterized diffuse-source nitrogen inputs from a large percentage of the bay drainage basin, but relatively little information exists regarding rates of nitrogen delivery to tidal waters from coastal plain regions. Extensive nitrate contamination of shallow groundwater due to agricultural activities, coupled with the dominant role of subsurface flow in discharge from Coastal Plain regions of the drainage basin, creates the potential for high rates of nitrogen delivery to tidal waters via groundwater seepage. This study utilized intensive hydrologic and water chemistry monitoring from April 1992 through September 1994 to determine the spatial characteristics of the groundwater-estuarine interface, as well as the rates of subsurface nitrogen transport from an agricultural field into nearshore waters of the Wye River, a subestuary of Chesapeake Bay. The hydrogeologic characteristics of the study site resulted in groundwater discharge to the Wye River occurring almost exclusively within 15 m of the shoreline. Calculated groundwater discharge rates were found to vary widely in the short term due to tidal fluctuations but in the long term were driven by seasonal changes in groundwater recharge rates. The zone of groundwater discharge contracted shoreward during summer months of low discharge, and expanded to a maximum width of approximately 15 m during high discharge periods in late winter. Average discharge rates were more than five times higher in winter versus summer months. Groundwater nitrate concentrations entering the discharge zone were relatively stable throughout the study period, with little evidence of denitrification or nitrate uptake by riparian vegetation. Consequently, nitrogen discharge patterns reflected the strong seasonality in groundwater discharge. Annual nitrate-N discharge was approximately 1.2 kg m?1 of shoreline, indicating drainage basin rates of nitrogen delivery to tidal waters of approximately 60 kg ha?1. 相似文献
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鉴于海域覆盖面积大而污水排放形成混合区相对集中的特点,基于四叉树网格布设的思想,分层次对不同研究区域按不同尺度网格对近海水域进行嵌套网格联合布置,重点模拟污水排放形成的混合区范围,在此基础上建立了Godunov型通量差分裂(FDS)格式有限体积法计算模式,实现了在不同尺寸的网格联立求解,提高了数值计算效率,又保证了计算精度.以海州湾近海水域为例,对海州湾近海水域流场及污染物混合区的范围进行了模拟计算,由此建立了排污量与混合区面积之间的响应关系,为环境管理部门对入海排污量的总量控制提供了依据. 相似文献