Detection Of Heavy Metals In Water Research Articles

A Review of Microfluidic Detection Strategies for Heavy Metals in Water

Heavy metal pollution of water has become a global issue and is especially problematic in some developing countries. Heavy metals are toxic to living organisms, even at very low concentrations. Therefore, effective and reliable heavy metal detection in environmental water is very important. Current laboratory-based methods used for analysis of heavy metals in water require sophisticated instrumentation and highly trained technicians, making them unsuitable for routine heavy metal monitoring in the environment. Consequently, there is a growing demand for autonomous detection systems that could perform in situ or point-of-use measurements. Microfluidic detection systems, which are defined by their small size, have many characteristics that make them suitable for environmental analysis. Some of these advantages include portability, high sample throughput, reduced reagent consumption and waste generation, and reduced production cost. This review focusses on developments in the application of microfluidic detection systems to heavy metal detection in water. Microfluidic detection strategies based on optical techniques, electrochemical techniques, and quartz crystal microbalance are discussed.

Magneto-Optical Measurements of Magnetic Nanoparticles Using Laser for Environmental Applications

The project presents the use of laser and magnetic nanoparticles like iron oxide (Fe3O4) in heavy metal detection in water. In this method, metal Nanomagnets particles result in a magnetic reagent for the rapid removal of heavy metals from solutions or water of magnitude to concentration 0.25wt%. This can be done by measuring the magneto-optical parameters (as a hysteric loop) of the solution as an indication of the change in concentrations of the detected heavy metal. The samples used in this work using the Tigris River water that supported from al-Wathba lab. water projects of the Baghdad water directorate at Baghdad-Iraq. Putting here a study of the effect of graphene and metal oxide such as cobalt and nickel which doped the ferrofluid (iron oxide) /polymer/water (Tigris river water) composite on the magneto-optical properties. The graphene adding had the best result in low threshold magnetic field which was 67mGauss, give the motive to use it in fast sensing and detecting of heavy metal in Tigris river water.

Detection of Lead in River Water Samples Applying Cantilever Nanobiosensor

Contamination of water sources with lead has been a problem because it is a toxic heavy metal. Detection and monitoring are important for both the environment and human health. In this paper, we present an application of cantilever nanobiosensors that can detect contamination traces of lead (Pb) in real river water samples. The urease and alkaline phosphatase enzymes are used in the device as a biological element with high sensitivity in Pb detection. By change in deflection of the cantilever nanobiosensor in contact with the liquid solution (water), the response was the detection of trace amounts of Pb in water. When using ultrapure water (white), the nanobiosensors did not demonstrate voltage response. The detection limit was in femtograms per milliliter (parts per trillion) for phosphatase alkaline and urease nanobiosensors with good recovery results. The matrix effect was minimized with the dilution of river water in the ratio 1:1 with the working solution. The nanobiosensors demonstrated are efficient in the detection of the presence of Pb in real samples. Thus, the developed cantilever nanobiosensors showed suitability for heavy metal detection in water and could be a promising tool in the environmental area.

OMONITERING OF HEAVY METAL POLLUTION BY BIOLUMINESCENT BACTERIAL BIOSENSORS

Objectives: The current study focuses on the isolation of bioluminescent bacteria from the gut of Sea urchin and using its luminescence property as a potential biosensor for detecting chromium toxicity in water. Methodology: Bioluminescent bacteria, JAAKP J2 was isolated from the gut of Pseudoboletia indiana species of Sea urchin collected from Pondicherry university beach. The morphological, biochemical, enzyme profiling and molecular characterization through 16S sequencing were performed to identify the strain. Growth kinetic assays and spectrophotometric analysis under chromium stress condition were performed on bioluminescent strains for luminescence inhibition studies. The bioluminescent bacteria was then immobilized in nutrient agar cubesand used as a biosensor for the detection of hexavalent chromium concentration in water samples. Findings: The morphological, biochemical and molecular characterization revealed that the isolate JAAKP J2 was closely related to Vibrio campbellii. Industrially important enzymes like Protease, Lipase, Agarase, Cellulase, Xylanase and Gelatinase were also screened in this study. The developed biosensor using bioluminescence property of the isolate was able to detect the level of chromium toxicity in water samplesat concentration not more than 9 mg L-1 . Further we have elucidated a possible hypothetical pathway for reduction in luminescence property due to ROS (Reactive oxygen species) caused by hexavalent chromium toxicity in bacteria. Novelty: The study is first of its kind in isolation of bioluminescent strain from sea urchin and using it as a biosensor for heavy metal detection in water. Our study also throws lights on futuristic approach of detecting other heavy metals like lead, zinc, cadmium, mercury in water samples by bacterial luminescence. Keywords: Bioluminescent Bacteria, Biosensor, Chromium Toxicity, Enzyme Profiling, Sea Urchin

On-line/on-site analysis of heavy metals in water and soils by laser induced breakdown spectroscopy

The enrichment method of heavy metal in water with graphite and aluminum electrode was studied, and combined with plasma restraint device for improving the sensitivity of detection and reducing the limit of detection (LOD) of elements. For aluminum electrode enrichment, the LODs of Cd, Pb and Ni can be as low as several ppb. For graphite enrichment, the measurement time can be less than 3min. The results showed that the graphite enrichment and aluminum electrode enrichment method can effectively improve the LIBS detection ability. The graphite enrichment method combined with plasma spatial confinement is more suitable for on-line monitoring of industrial waste water, the aluminum electrode enrichment method can be used for trace heavy metal detection in water. A LIBS method and device for soil heavy metals analysis was also developed, and a mobile LIBS system was tested in outfield. The measurement results deduced from LIBS and ICP-MS had a good consistency. The results provided an important application support for rapid and on-site monitoring of heavy metals in soil.

Comparative analysis of quantitative method on heavy metal detection in water with laser-induced breakdown spectroscopy

The quantitative analysis models of multiple linear regression, neural network regression and support vector machine regression with laser-induced breakdown spectroscopy are established in this paper. Heavy metal Ni in water selected as research object is tested and comparativly analyzed. The average relative standard deviations of multiple linear regression, neural network regression and support vector machine regression are 7.60%, 4.86% and 2.35%, and the maximum standard deviations are 23.35%, 15.20% and 8.29% respectively, the average relative errors are 25.98%, 10.58% and 2.72%, and the maximum relative errors are 116.47%, 47.38% and 9.89% respectively. Methods and reference data are provided for the further study of fast measurement of tracing heavy metals in water by laser induced breakdown spectroscopy technique.