Trace metals as tracers of dredging activity in Cleveland Bay — field and laboratory studies

This study has investigated in detail trace metal concentrations in Cleveland Bay in the central Great Barrier Reef and assessed the significant carrier phases of several metals during a simulated disturbance of sediments designed to investigate the effects of dredging. Organic, iron oxide and carbonate phases were shown to be important carrier phases for several trace metals. The application of an acid-leach technique to monitor labile or pollutant concentrations of copper, zinc, lead and nickel in sediments collected from coral reefs sampled before and after two dredging events in 1991 yielded useful information on the fate of dredged sediment. Trace metal contamination close inshore was attributed to port activities, sewage discharge and urbanization.

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Analysis of Trace Metal Contamination in Pahang River and Kelantan River, Malaysia

MATEC Web of Conferences ◽

10.1051/matecconf/201926604003 ◽

2019 ◽

Vol 266 ◽

pp. 04003 ◽

Cited By ~ 1

Author(s):

Norpadzlihatun Manap ◽

Kavitha Sandirasegaran ◽

Noor Shahifah Syahrom ◽

Amnorzahira Amir

Keyword(s):

Trace Metals ◽

Trace Metal ◽

Metal Contamination ◽

Sediment Quality ◽

Primary Objective ◽

Trace Metal Concentration ◽

Trace Metal Contamination ◽

Quality Guidelines ◽

Fish Samples ◽

Negative Impacts

The primary objective of this study is to determine trace metal contamination in environmental samples obtained from Pahang River and Kelantan River, Malaysia which may help to identify the risk of sustainable dredging in these areas. This research also proceeds to compare the trace metal concentration with the National Water Quality Standards of Malaysia, Interim Canadian Sediment Quality Guidelines and Malaysian Food Act 1983 to determine its limits and risks. Samples of water, sediment, snails and fishes were collected and analyzed for As, Cu, Cd, Cr, Fe, Pb, Ni, Mn, and Hg by using atomic absorption spectrophotometer. It was found that the concentration of trace metals namely As, Cu, Cd, Cr, Pb, Ni, and Hg in river water, sediment, snail and fish samples in Pahang River were lower than the maximum allowable limits, except for Fe and Mn. In Kelantan River, the concentration of trace metals indicating that it is contaminated with Fe, Mn, Pb, Cr, Cu, Hg, and As as all trace metals exceeded the maximum allowable limits. Negative impacts may arise, and the river may contaminate more in future if there is no proper management to tackle this issue during execution of dredging activities.

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A suitable model for the biomonitoring of trace metal bioavailabilities in estuarine sediments: the annelid polychaete Nereis diversicolor

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315406012872 ◽

2006 ◽

Vol 86 (1) ◽

pp. 71-82 ◽

Cited By ~ 44

Author(s):

Laurence Poirier ◽

Brigitte Berthet ◽

Jean-Claude Amiard ◽

Anne-Yvonne Jeantet ◽

Claude Amiard-Triquet

Keyword(s):

Trace Metals ◽

Trace Metal ◽

Metal Contamination ◽

Estuarine Sediments ◽

Suitable Model ◽

English Channel ◽

Metal Concentrations ◽

Trace Metal Contamination ◽

Nereis Diversicolor ◽

Total Sediment

The need to use biomonitors representative of the sedimentary compartment has been recognized, particularly in estuaries. Thus, trace metal contamination has been monitored in an infaunal polychaete worm Nereis diversicolor and sediments in the Seine estuary and comparatively in the relatively clean Authie estuary (French coast of the English Channel) over two years taking samples every three months at both sites. No correlations were shown between total metal (Ag, Cd, Cu, Pb, Zn) concentrations in raw sediments and ragworms. Because these worms are known to be good biomonitors of the bioavailabilities of sedimentary trace metals, it follows that total sediment metal concentrations have a poor predictive ecotoxicological value. Using a correction factor to minimize the influence of weight, it is possible to make a good estimation of the average metal concentrations in a population of worms at a given site, sampling only a limited number of specimens. Metallothioneins are often considered to be good biomarkers of the presence of significant availabilities of trace metals. Metallothionein-like proteins (MTLPs) are present in N. diversicolor, but there is no significant relationship between MTLPs and metal concentrations. This situation might result from the importance of metal-containing granules, both extra- and intracellular, in ragworms.

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Farmland Trace Metal Contamination and Management Model—Model Development and a Case Study in Central Taiwan

Sustainability ◽

10.3390/su122310066 ◽

2020 ◽

Vol 12 (23) ◽

pp. 10066

Author(s):

Hsin-Yi Yang ◽

Sheng-Kung Chen ◽

Jiun-Shiuan Wang ◽

Chih-Jen Lu ◽

Hung-Yu Lai

Keyword(s):

Water Quality ◽

Trace Metals ◽

Trace Metal ◽

Paddy Soil ◽

Irrigation Water ◽

Metal Contamination ◽

Metal Species ◽

Management Model ◽

Trace Metal Contamination ◽

Central Taiwan

In this study, the water quality of the irrigation system and concentration of trace metals in the sediments were combined to establish a farmland trace metal contamination and management model (FTM_CMM). The purpose of this model was to clarify the main sources of the trace metals that have caused the contamination of paddy soil in central Taiwan. The results of the model simulation showed that the trace metals in the paddy soil mainly came from the irrigation water and especially from the sediments in the irrigation channels. The contribution of the sediments in the irrigation channel to the individual trace metals in the paddy soil ranged from 56% to 72% as the contributions for Cr, Cu, Ni, and Zn were 72%, 68%, 56%, and 62%, respectively. The trace metal species according to their concentration in the contaminated soil ranked in the order of Zn > Cr ≈ Cu > Ni, which is about the same as in the channel sediment. During the simulation process, Cr, Cu, Ni, and Zn exceeded the control standards for farmlands in the 18th, 12th, 13th, and 17th years, respectively. This highlights that, in addition to the management of irrigation water quality, the management of trace metal contaminated sediment in adjacent canal irrigation systems is also an important part of the prevention of trace metal contamination in farmland.

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Silicon Cleaning Methods Compared at Metal Concentrations Below 1E10 atoms/cm2

MRS Proceedings ◽

10.1557/proc-606-245 ◽

1999 ◽

Vol 606 ◽

Author(s):

Joseph Ilardi ◽

Rajananda Saraswati ◽

George Schwartzkopf

Keyword(s):

Hydrogen Peroxide ◽

Trace Metals ◽

Trace Metal ◽

Silicon Wafer ◽

Metal Contamination ◽

Single Step ◽

Wafer Surface ◽

Trace Metal Contamination ◽

Wide Range ◽

Contamination Levels

AbstractAn alkaline aqueous silicon wafer cleaner has been developed which reduces trace metal contamination levels on “p-type” unpatterned silicon wafers to below 1E10 atoms/cm2 without acidic cleaning. This patented technology uses a specially formulated buffering system consisting of an oxidation resistant chelating agent and salt of a weak acid. The aqueous cleaner maintains a stable pH of about 9.5 over a wide range of dilutions, temperatures, hydrogen peroxide concentrations and bath aging times. A single-step bath, megasonic bath or spray clean with this formulation leaves the chemical oxide on the silicon wafer surface free of particles, atomically smooth, free of organics and lower in trace metal contamination levels than similar surfaces cleaned with conventional formulations.An analytical method was developed which allows the reliable detection of trace metals on silicon wafer surfaces down to 1E8 atoms/cm2 for aluminum, calcium, copper, iron, nickel, sodium and zinc. The procedure uses an ICP-MS with a concentric nebulizer and a desolvator. The acids used were ultrapure to keep the blanks to a very minimum and analyses were run in a class 10 clean room. The trace metals on the wafer were extracted using known amounts of ultrapure acids and were directly aspirated using a special arrangement with the concentric nebulizer. The J.T. Baker cleaner was compared to and outperformed the conventional RCA-1&2 clean and dilute RCA-1&2 chemistries using ultrapure ammonium hydroxide, hydrochloric acid and hydrogen peroxide.

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Method of Detecting Trace Metal Contamination in Thick-Film SOI Device

ISTFA 2005: Conference Proceedings from the 31st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2005p0220 ◽

2005 ◽

Author(s):

Yasunori Goto ◽

Hiroomi Eguchi ◽

Masaru Iida

Keyword(s):

Trace Metal ◽

Thick Film ◽

Metal Contamination ◽

Semiconductor Device ◽

Trace Element Analysis ◽

Silicon On Insulator ◽

Element Analysis ◽

Trace Metal Contamination ◽

Trace Metal Elements ◽

Output Characteristics

Abstract In the automotive IC using thick-film silicon on insulator (SOI) semiconductor device, if the gettering capability of a SOI wafer is inadequate, electrical characteristics degradation by metal contamination arises and the yield falls. At this time, an automotive IC was made experimentally for evaluation of the gettering capability as one of the purposes. In this IC, one of the output characteristics varied from the standard, therefore failure analysis was performed, which found trace metal elements as one of the causes. By making full use of 3D perspective, it is possible to fabricate a site-specific sample into 0.1 micrometre in thickness without missing a failure point that has very minute quantities of contaminant in a semiconductor device. Using energy dispersive X-ray, it is possible to detect trace metal contamination at levels 1E12 atoms per sq cm. that are conventionally detected only by trace element analysis.

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