光催化处理海洋重金属污染的分析及应用

人为生活生产向近岸海域排放的污染物威胁生态环境和人类健康,重金属污染的治理是环境问题的重点和难点。传统工艺存在效率低、成本高和副产品多等局限性。光催化以光为能源,是一种新兴的催化氧化和高效的清洁技术,广泛应用于水中多种污染物的处理。由于光催化在环境修复中具有优异的适应性,可用于重金属的去除。综述海洋等水体各重金属污染现状和对人类健康的影响;相对于其他处理技术,分析探究光催化技术处理海水重金属污染物的反应原理及优势;总结不同催化剂去除水体中各种重金属污染的最新进展及去除效果,并针对光催化重金属现存问题提出相应建议;以期为光催化处理海洋重金属污染的检测及风险防控提供科学指导及理论依据。

海洋重金属污染及其对海藻的毒害作用

藻类通过主支和被动吸叫在体内累积海洋中的重金属离子，其微量元素对藻类无害，甚至是藻类生长发育的必需条件。当重金属离子在藻体内达到一定浓度时产生毒害作用。本文叙述了藻类对重金属污染的耐受程度、机理，以及重金属污染对藻类的生长、光合作用、蛋白质合成和酶活性的影响。

2021—2022年涠洲岛近岸海域表层海水重金属分布特征及质量分析

海洋重金属污染是海洋生态环境修复重点关注的问题,也是众多学者重点研究的对象。北海涠洲岛是广西著名的海岛风景区,随着涠洲岛旅游产业的快速发展,客流量和常驻商户与日俱增,人类活动日益频繁,涠洲岛近岸海域表层海水重金属污染状况也备受关注。研究小组根据《广西海岸带沉积动力监测与研究项目》(原《广西海洋重大工程建设和重点旅游区海岸带地质环境监测项目》)的调查资料,对2021―2022年涠洲岛近岸海域表层海水重金属分布特征及质量进行分析,以期为涠洲岛海洋生态资源保护与开发提供参考。

底栖有孔虫对海洋重金属污染响应研究进展

海洋与人类生存息息相关并受人类活动影响巨大,有孔虫作为一种高敏感、低成本的指示生物,在开展海洋环境污染指示工作中起着重要的作用。本文综述了国内外海洋重金属污染环境中有孔虫的生态指示应用及响应机理研究。已有研究表明,在人类活动影响为主导的重金属污染海域有孔虫个体和种群均出现显著响应,分别表现为个体形态畸形,种群分异度降低、耐受种比例增加等特征,微体生物实验与超微结构研究也提供了相应佐证。但在自然环境压力较大(如高盐、强水文动力环境)的海域,上述响应特征需谨慎应用,可通过历史时期的溯源研究区分自然与人类活动的影响。

陆海统筹背景下海洋环境污染生态修复治理研究

海洋生态环境治理易受气候、水质质量、微生物种群等问题的影响,且海洋污染物种类较多,导致海洋生态修复难度较大。为此,提出陆海统筹背景下新的海洋环境污染生态修复治理方法。根据上海市海洋污染现状,采用微生物修复方法、水生动物修复方法以及水生植物修复方法,实现海洋污染修复。确定实验材料和实验仪器,通过计算修复后的海洋水质因子,得知海洋水质得到明显改善,海洋污染程度为清洁,浮游植物丰度与生物量、最终生态修复效果评分较高,验证了陆海统筹背景下海洋环境污染生态修复治理研究的有效性。

浅谈双壳软体动物作为水域重金属富集指示生物的应用

在繁多的海洋底栖生物中,以蛤蜊、牡蛎、贻贝等双壳软体动物(Bivalve mollu-scs)对重金属污染物的富集能力最强。上述动物在海洋中分布广泛,活动性小,生活海域相对固定,能较好的反映环境质量状况。海洋双壳软体动物普遍具有可食性,与人体健康的关系密切。通过监测该种动物对重金属污染物富集程度,不仅可了解海洋重金属污染情况,而且可掌握海洋污染对沿海居民健康潜在的危害。因而,双壳软体动物被国内外环境科学工作者试为较理想的海样重金属富集指示生物。国内,将贻贝作为海洋污染鉴测使用的“标准物质”,已于1989年通过了部级鉴定。

海滨城市婴儿铅来源的抽样分析

用电感耦合等离子体质谱（inductively coupled plasma mass spectrometry,ICP-MS）测量某海滨城市50例胎儿脐血中铅（Pb）质量浓度,发现Pb超标（＆gt;100μg/L）为8%.根据婴儿母体是否常食用海产品,将50例样品分为常食用海产品（A组）、偶尔食用海产品（B组）和极少食用海产品（C组）,用X射线荧光光谱分析（X-ray fluorescence,XRF）测量这3组婴儿毛发中的Pb质量分数,发现婴儿毛发中Pb质量分数具有显著性差异,由高至低依次为A组＆gt;B组＆gt;C组,其相应的脐血Pb质量分数也具有相同特征.同时对婴儿中的溴（Br）质量分数也进行了测量,发现Pb质量分数高的婴儿,其Br质量分数也显著偏高,由于海产品中Br质量分数远高于淡水产品,从另一方面说明,常食用海产品组的婴儿Pb质量分数偏高与母亲食用海产品有关.此外,对同一海滨城市393例儿童（2～11岁）血液中Pb质量分数进行统计学分析,得出Pb超标（〉100μg/L）为8.9%,说明海滨城市Pb污染仍对儿童具有一定的威胁.最后,通过对环境中常见的铅源（PM2.5、大气、油漆和海产品等）及人体摄入状况进行分析比较,认为食用铅污染的海产品是造成海滨城市胎儿铅超标的主要原因之一.

Distribution and ecological evaluation of heavy metals in multi-medium of the Dongzhai Harbor

The distribution characteristics of heavy metals such as Cu, Zn, Pb, Cd, Hg. As in seawater, superficail sediments and several marine organisms of Dongzhai Harbor in Hainan were analyzed. Index methods of the single factor and geo-accumulation were used to assess the pollution degree of heavy metals. The results showed that the heavy metal levels in the seawater of Dongzhai Harbor accorded with the first category of the seawater except Pb, and were much lower than the fishery water quality standard; the concentration of the heavy metal in surface sediments did not exceed the national benchmark of the first-class of marine sediment quality basically, and the superficial sediments were essentially uncontaminated; the heavy metal content in wetland sediments was slightly higher than those in other typical mangrove wetland island of Hainan and marine sediments in Dongzhai Haibor, which indicated this area might has been affected by land-based pollution influence, and this should cause the attention of related departments; the heavy metal concentrations in marine organisms were up to the first category. All were not beyond the standard of non-environmental pollution aquatic products.

Comparative Studies on Uptake Pathway of Cadmium by Perna viridis

Experiments were designed to expose the filter-feeding bivalve Perna viridis to different Cd-contaminated water environments in order to compare the different pathways through which Cd is accumulated. Results show that mussels can accumulate Cd through seawater, food, sediment and suspended particle pathways in a short period of time. Mussels＇ uptake of Cd through the seawater pathway reaches the highest concentration approximately 3 and 9 times larger than through the algae and sediment pathways respectively after 7 d. This indicates that the Cd-accumulation through seawater is most efficient. Results also indicate that the uptake directly through contaminated algae, particles or sediments ingested by mussels is less important when compared with the uptake of Cd by mussels through the seawater pathway. Metal uptake pathways and mechanisms of bioaccumulation by marine bivalve are also discussed in this paper.

Heavy metal research in lacustrine sediment:a review

Heavy metals are released into environment from a wide range of natural and anthropogenic sources. Aquatic ecosystems are normally at the receiving end and in many cases, with lakes as intermediaries. Lacustrine sediments are important sinks for heavy metals and play a significant role in enrichment and remobilization of heavy metals in aquatic systems. Therefore, characteristics of heavy metal in lacustrine sediments become one of the important issues in environmental sciences. Progress in heavy metal research of lake sediments since late 1980s is reviewed comprehensively in this paper from over 100. The Highlights are placed on the establishment of aquatic sediment quality guidelines, references chemical speciation of heavy metals, heavy metal transport mechanisms in lakes, and high-resolution study of lake borehole cores. Meanwhile, suggestions for heavy metal research in lacustrine sediment in the future are proposed, including such issues as using integrated approaches to assess aquatic ecosystem, modem lake dynamic process, high-resolution evolutionary sequence and spatial differentiation of environments and international lake database, which should be referential to the promotion of research on heavy metal in aquatic system.

Distribution of heavy metals and nutrients in rainwater in coastal regions between the southern Yellow Sea and East China Sea

Rainwater samples were collected in series in Qianliyan Island (southern Yellow Sea) and Shengsi Archipelago (East China Sea) between May 2000 and May 2002, chemical analysis for pH values, concentrations of heavy metals (Cu, Pb, Zn and Cd) and nutrients (NH4+, NO3-, PO43-, SiO32-) were performed. Results indicate that concentrations of most of the heavy metals and nutrients in rainwater show clear seasonal variation, i.e. high level in winter and low level in summer. Regionally, concentrations are higher in the southern Yellow Sea than in the East China Sea, but the annual input of heavy metals into oceans by wet deposition is similar in both stations. However, the input of nutrients by wet deposition in the East China Sea is 2–3 times higher than that in the southern Yellow Sea. In individual, Pb and PO43- are input to the sea mainly by dry deposition; whereas Cu, Zn, Cd and N compounds are input dominantly by wet deposition, the N/P ratios in the rainwater from two stations are much higher than those in seawater, showing a significant impact of atmospheric wet deposition on marine production and biogeochemical circulation of nutrients in these sea regions.

Heavy Metal Bioaccumulation and Toxicity with Special Reference to Microalgae

The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key compo- nent of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Pro- duction of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmen- talization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mecha- nisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.

Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea around Xiaoheishan Island in China

Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea area around Xiaoheishan Island are investigated in the present study. Xiaoheishan Island is located at 37°58′14″N and 120°38′46″E in Shandong Province, China. A total of 65 species of phytoplankton belonging to three phyla and 27 genera were identified, with Bacillariophyta having the largest number of species. The annual average chlorophyll a concentration for this area was 3.11 μg/L, and there occurs a Skeletonema costatum bloom in winter. The Shannon-Weaver indexes(log_2) of the phytoplankton from all stations were higher than 1, and the Pielou indexes were all higher than 0.3. The results of the canonical correspondence analysis(CCA) indicated that water temperature, PO_4^(3ˉ) and Cu were the environmental factors that had the greatest influence on the distribution of the phytoplankton community throughout the entire year. Although the concentration of heavy metal is well up to the state standards of the first grade of China(GB 3097-1997), these metals still have an impact on the phytoplankton community from this area.

Concentration and Biomagnification of Heavy Metals in Biota of the Coastal Marine Areas of Tanzania

The concentrations of heavy metals （As, Hg, Cr, Pb and Zn） were measured in the macroalgae, macrobenthos and fish from the Tanzanian coastal marine environment in order to ascertain the biomagnification using stable isotopes of C and N. Macroalgae samples from the central marine areas of the Tanzanian coast had higher mean concentrations of Hg （0.17 ± 0.01 μg/g） and Cr （23.7 ± 4.15 μg/g） compared to other locations. Higher concentration of Hg （0.06 ±0.02 μg/g） was detected in the Ulva fasciata close to the Msimbazi Creek in Dares Salaam, whereas the highest concentration of Cr （45.5 ± 6.83 μg/g） was found in Ulva petrusa near Dares Salaam port. The crab Portunus pelagicus collected from Pangani river estuary contained 411.5 ± 13.04 μg/g of Zn. The other metals were uniformly distributed in macrobenthos from the entire coast. Mercury and lead in the biota were found to biomagnify along the Arius dussumieri and Lethrinus lentjan food chains as suggested by the significant positive relationships between log-pollutant concentrations in fish muscle tissues vs. 615N signatures. Zinc in muscle tissues was found to be transferred along the food webs although no biomagnification was observed. Arsenic and chromium were found to decrease with the rise of the trophic position. Metal concentrations in macroalgae, macrobenthos and fish were compared with quality guidelines values by FAO （Food and Agricultural Organization） in 1983 and they all were below permissible limits for human consumption.δ

Heavy metal content in coral reef sediments from Red Sea of Yemen and its significance on marine environment

In order to determine and assess the concentrations of trace elements in coral reefs sediments from Red Sea of Yemen, sediment samples were collected, treated and analyzed for cadmium, chromium, cobalt, copper, manganese, nickel, lead, iron, zinc and vanadium by the atomic absorption spectrometric analysis. The result is that cadmium, cobalt and lead concentrations were high and other elements are low or the same as natural background. It is concluded that the high cadmium, cobalt and lead levels in coral reefs sediments will have negative effects on marine life of the sites, so further researches are needed to characterize the sources fate, biogeochemical processes and impacts of these trace elements on coral reefs and marine of the region.

Potential Impacts of Discharges from Seawater Reverse Osmosis on Algeria Marine Environment

Desalination processes have environmental impacts. The brine water discharge has an impact on marine ecosystem. This is mostly due to the highly saline brine that is discharged into the sea, which may be increased by temperature, contain residual chemicals from the pretreatment process, heavy metals from corrosion or intermittently used cleaning agents. The effluent from desalination plants is a multi-component waste, with multiple effects on water, sediment and marine organisms. Therefore, it affects the quality of the resource which it depends on. In this study, selected water quality parameters in the seawater and the presence of heavy metals of concern in the sediments and algae were monitored to investigate the impacts of the discharges by seawater desalination plants using reverse osmosis on the receiving marine environment. In light of the results obtained, the analyzed water has a physicochemical quality more or less adequate, moreover, chemical analyzes in seaweed and sediments show relatively low levels of heavy metals.