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Fulltext Zinc removal and recovery from industrial wastewater with a microbial fuel cell: Experimental investigation and theoretical prediction

Lim SS, Fontmorin JM, Pham HT, Milner E, Abdul PM, Scott K, et al.

Sci Total Environ, 2021 Jul 01;776:145934.
PMID: 33647656 DOI: 10.1016/j.scitotenv.2021.145934

Microbial fuel cells (MFCs) that simultaneously remove organic contaminants and recovering metals provide a potential route for industry to adopt clean technologies. In this work, two goals were set: to study the feasibility of zinc removal from industrial effluents using MFCs and to understand the removal process by using reaction rate models. The removal of Zn2+ in MFC was over 96% for synthetic and industrial samples with initial Zn2+ concentrations less than 2.0 mM after 22 h of operation. However, only 83 and 42% of the zinc recovered from synthetic and industrial samples, respectively, was attached on the cathode surface of the MFCs. The results marked the domination of electroprecipitation rather than the electrodeposition process in the industrial samples. Energy dispersive X-ray (EDX) analysis showed that the recovered compound contained not only Zn but also O, evidence that Zn(OH)2 could be formed. The removal of Zn2+ in the MFC followed a mechanism where oxygen was reduced to hydroxide before reacting with Zn2+. Nernst equations and rate law expressions were derived to understand the mechanism and used to estimate the Zn2+ concentration and removal efficiency. The zero-, first- and second-order rate equations successfully fitted the data, predicted the final Zn2+ removal efficiency, and suggested that possible mechanistic reactions occurred in the electrolysis cell (direct reduction), MFC (O2 reduction), and control (chemisorption) modes. The half-life, t1/2, of the Zn2+ removal reaction using synthetic and industrial samples was estimated to be 7.0 and 2.7 h, respectively. The t1/2 values of the controls (without the power input from the MFC bioanode) were much slower and were recorded as 21.5 and 7.3 h for synthetic and industrial samples, respectively. The study suggests that MFCs can act as a sustainable and environmentally friendly technology for heavy metal removal without electrical energy input or the addition of chemicals.

Matched MeSH terms: Metals, Heavy*
Effects of land use configuration, seasonality and point source on water quality in a tropical watershed: A case study of the Johor River Basin

Pak HY, Chuah CJ, Yong EL, Snyder SA

Sci Total Environ, 2021 Aug 01;780:146661.
PMID: 34030308 DOI: 10.1016/j.scitotenv.2021.146661

Land use plays a significant role in determining the spatial patterns of water quality in the Johor River Basin (JRB), Malaysia. In the recent years, there have been several occurrences of pollution in these rivers, which has generated concerns over the long-term sustainability of the water resources in the JRB. Specifically, this water resource is a shared commodity between two states, namely, Johor state of Malaysia and Singapore, a neighbouring country adjacent to Malaysia. Prior to this study, few research on the influence of land use configuration on water quality have been conducted in Johor. In addition, it is also unclear how water quality varies under different seasonality in the presence of point sources. In this study, we investigated the influence of land use and point sources from wastewater treatment plants (WWTPs) on the water quality in the JRB. Two statistical techniques - Multivariate Linear Regression (MLR) and Redundancy Analysis (RA) were undertaken to analyse the relationships between river water quality and land use configuration, as well as point sources from WWTPs under different seasonality. Water samples were collected from 49 sites within the JRB from March to December in 2019. Results showed that influence from WWTPs on water quality was greater during the dry season and less significant during the wet season. In particular, point source was highly positively correlated with ammoniacal‑nitrogen (NH3-N). On the other hand, land use influence was greater than point source influence during the wet season. Residential and urban land use were important predictors for nutrients and organic matter (chemical oxygen demand); and forest land use were important sinks for heavy metals but a significant source of manganese.

Matched MeSH terms: Metals, Heavy
Characteristics and health effect of heavy metals on non-exhaust road dusts in Kuala Lumpur

Wahab MIA, Razak WMAA, Sahani M, Khan MF

Sci Total Environ, 2020 Feb 10;703:135535.
PMID: 31767333 DOI: 10.1016/j.scitotenv.2019.135535

This study aimed to assess the concentrations and health effect of trace metals [cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn)] on the road dust of selected locations in the city of Kuala Lumpur. Sampling was conducted thrice at four locations, namely, Tun Razak Road, Raja Abdullah Road, Tunku Abdul Rahman (TAR) Road, and Ayer Molek Road. The concentrations of trace metals in road dust were analyzed by inductively coupled plasma mass spectrometry. TAR Road presented the highest Cd, Cu, Ni, and Pb contents compared with the other roads. The pollution level of trace metals in road dust was assessed by pollution index and pollution load index (PLI), showing that all studied locations were highly contaminated except Ayer Molek Road. Based on the PLI value, the sequence of pollution in descending order is as follows: TAR Road > Raja Abdullah Road > Tun Razak Road > Ayer Molek Road. Health risk assessment was performed to assess the health effects of carcinogenic and noncarcinogenic pollutants caused by the exposure to trace metals in road dust on adults and children. Based on the integrated hazard index values for children at all locations, >1 indicates a possible noncarcinogenic effect. All incremental lifetime cancer risk values for adult and children at all locations are within acceptable limits and are considered safe.

Matched MeSH terms: Metals, Heavy/analysis*
Fulltext Passive in situ remediation using permeable reactive barrier for groundwater treatment

Zafira Madzin, Faradiella Mohd Kusin, Mohd Shakirin Md Zahar, Siti Nurjaliah Muhammad

The Pertanika Journal of Scholarly Research Reviews, 2016;2(2):1-11.
MyJurnal

The contamination of water bodies from heavy metals, either from natural sources or
anthropogenic sources, has become a major concern to the public. Industrial activities with improper
water treatment, and then leach into the water body, have become contaminated and harmful to
consume. Passive remediation is one of the treatments introduced to counter this problem as it is a low
cost but effective technique. After being widely acknowledged and through research conducted, the
most suitable remediation technique found is the permeable reactive barriers (PRBs). PRB is defined
as an in situ permeable treatment zone filled with reactive materials, designed to intercept and
remediate a contaminant plume under natural hydraulic gradients. There have been many findings
made from PRB which can be used to remove contaminants such as heavy metal, chlorinated solvents,
carbonates and aromatic hydrocarbons. The most crucial criteria in making a successful PRB is the
reactive media used to remove contaminants. The current paper presents an overview of the PRB
selective medias that have been used and also the unresolved issue on the long term performance of
PRB. The overall methodology for the application of PRB at a given site is also discussed in this
paper. This inexpensive but effective technique is crucial as a sustainable technology in order to treat
the drainage before it enters water tables to prevent water pollution and can be used as an alternative
raw water source.

Matched MeSH terms: Metals, Heavy
Fulltext Sediment quality index in mangrove forest

Ahmad Mustapha, Gandaseca, Seca, Ahmad Hanafi, Siti Nurhidayu, Mohammad Roslan, Khan, Waseem, et al.

The Pertanika Journal of Scholarly Research Reviews, 2017;3(3):41-50.
MyJurnal

The objectives of this review are to determine the types of indices to use, to assess the current sediment quality index (SQI) of a mangrove forest and to select the appropriate index to describe the mangrove sediment quality index. Amongst the many indices considered in this review are the enrichment factors (EFs), the geo-accumulation index (Igeo), the pollution load index (PLI), the marine sediment pollution index (MSPI) and sediment quality index (SQI). The different indices give diverse perspectives of the status of mangrove sediment quality. This review also highlights the appropriate parameters that need to be used in assessing sediment quality, such as the physical, chemical and biological properties. As the comparison review, the sediment quality can be utilized for Mangrove quality index (MQI) development like to assess the heavy metal, complete laboratory parameters and a classification following the Interim Sediment Quality Guidelines ISQG, PCA and HACA. For the heavy metal content of sediment, the suggested parameters are Pb, Zn, Cu, Co and Mn. Lastly, for the indices, the enrichment factor (EFs), geo-accumulation index (Igeo), pollution load index (PLI) and marine sediment pollution index (MPSI) are used in develop SQI on mangrove forest.

Matched MeSH terms: Metals, Heavy
Fulltext CsoR metalloregulatory protein: function, mechanism and relevance

Mangavelu, Ashwaani, Yahaya M. Normi, Leow, Adam Thean Chor, Mohd Shukuri Mohammad Ali, Raja Noor Zaliha Raja Abd. Rahman

The Pertanika Journal of Scholarly Research Reviews, 2017;3(1):24-31.
MyJurnal

Transition metals are required constituent in bacterial metabolism to assist in some enzymatic reactions. However, intracellular accumulations of these metal ions are harmful to the bacteria as it can trigger unnecessary redox reactions. To overcome this condition, metalloregulatory proteins assist organisms to adapt to sudden elevated and deprived metal ion concentration in the environment via metal homeostasis. CsoR protein is a copper(I) [Cu(I)] sensing operon repressor that is found to be present in all major classes of eubacteria. This metalloregulatory protein binds to the operator region in its apo state under Cu(I) limiting condition and detaches off from the regulatory region when it binds to the excess cytosolic Cu(I) ion, thus derepressing the expression of genes involved in Cu(I) homeostasis. CsoR proteins exist in dimeric and tetrameric states and form certain coordination geometries upon attachment with Cu(I). Certain CsoR proteins have also been found to possess the ability to bind to other types of metals with various binding affinities in some Gram positive bacteria. The role of this metalloregulatory protein in host pathogen interaction and its relation to bacterial virulence are also discussed.

Matched MeSH terms: Metals
Fulltext Metal oxide based optical fiber for methane gas detection

Nor Akmar Mohd Yahya, Siti Azlida Ibrahim, Norizah Abdul Rahman, Mohd Adzir Mahdi, Mohd Hanif Yaacob

The Pertanika Journal of Scholarly Research Reviews, 2017;3(2):97-101.
MyJurnal

Semiconductor metal oxide (SMO) as a sensing layer for gas detection has been widely used. Many researches have been performed to enhance the sensing performance including its sensitivity, reliability and selectivity. Electrical sensors that use resistivity as an indicator of its sensing are popular and well established. However, the optical based sensor is still much to explore in detecting gas. By integrating it with SMO, the sensor offers good alternative to overcome some drawbacks from electrical sensors.

Matched MeSH terms: Metals
Fulltext The use of dental drill in removing entrapped finger by metal ring in emergency department

Shamsuddin SR, Hashim AA, Nazer B, Hashairi F, Shaik Farid AW, Abu Yazid MN

Med J Malaysia, 2012 Jun;67(3):349-50.
PMID: 23082436 MyJurnal

Ring removal is indicated in a number of clinical circumstances to manage or prevent tourniquet effect of the digit. A ring made from hardened metal may defy commonly known methods of removal. We reported a case of unusual difficulty in removing a ring of hardened metal composition using a dental drill. We believed the unusual circumstances of this case is likely to be repeated in some other clinical practice and this instrument is an appropriate option to consider in such cases.

Matched MeSH terms: Metals
Optimization of process conditions for removal of cadmium using bioactive constituents of Moringa oleifera seeds

Jamal P, Muyibi SA, Syarif WM

Med J Malaysia, 2008 Jul;63 Suppl A:105-6.
PMID: 19025007

Pollutants, especially heavy metals like cadmium, Chromium, lead and mercury, play a significant role in causing various water-borne diseases to humans. This study evaluates the sorption properties of bioactive constituents of Moringa oleifera seeds for decontamination of cadmium at laboratory scale. The performance of the bioactive constituent extracted by salt extraction method was enhanced by process optimization with various concentration of bioactive dosages, agitation speed, contact time, pH and heavy metal concentrations. Statistical optimization was carried out for evaluating the polynomial regression model through effect of linear, quadratic and interaction of the factors. The maximum removal of cadmium was 72% by using 0.2 g/l of bioactive dosage.

Matched MeSH terms: Metals, Heavy
Plasma-sprayed coating of hydroxyapatite on metal implants--a review

Talib RJ, Toff MR

Med J Malaysia, 2004 May;59 Suppl B:153-4.
PMID: 15468864

Metal implants such as titanium, stainless steel and Co-Cr-Mo are used for load bearing purposes such as hip joint prostheses, fixing plates and dental root implants. For practical application, plasma-sprayed coatings of hydroxyapatite (HA) on metal implants are applied to promote early formation of strong bonds between metal implant and living bone. Plasma spray coating involves heating of HA material to a semi-molten or molten state and then propels its to a metal substrate. The plasma flame temperature is in the range of 6,000 degrees C to 16,000 degrees C but the surface temperature of the substrate rarely exceeds 150 degrees C. The HA materials are feed into the spray gun in the form of powders. Furthermore, this paper will discuss the processes of plasma-sprayed coating of HA on various types of metal implants.

Matched MeSH terms: Metals*
Fulltext Early results of metal on metal articulation total hip arthroplasty in young patients

Mohamad JA, Kwan MK, Merican AM, Abbas AA, Kamari ZH, Hisa MK, et al.

Med J Malaysia, 2004 Dec;59 Suppl F:3-7.
PMID: 15941153

We report our early experience of 20 cases of metal on metal articulation total hip arthroplasty in 19 young patients. Avascular necrosis of the femoral head (63%) was the commonest diagnosis for patients undergoing this procedure, followed by osteoarthritis (21%). In general, most of the patients were young and physically active with an average age of 43.1 years (range, 25 to 58 years). The average follow-up period was 18 months (range, 7 to 46 months). The mean total Harris Hip Score preoperatively and at final follow-up was 31 points and 89 points respectively. The mean total Pain Score improved from an average of 11.5 to 41.1 points at final follow-up. Sixteen (84%) of the patients had a good to excellent hip score. There was one dislocation, which stabilized after reduction and conservative management. One case of early infection underwent a two-staged revision.

Matched MeSH terms: Metals
Fulltext New hips for old! Lessons from the Arabian Nights

Harwant S

Med J Malaysia, 2004 Dec;59 Suppl F:2.
PMID: 15941152
Matched MeSH terms: Metals
An investigation into health conditions in a tin smelter with special reference to stannosis

DICKEN DY, SCOTT MJ

Med J Malaya, 1961 Sep;16:1-13.
PMID: 13886183
Matched MeSH terms: Metals, Heavy*
Occlusal re-establishment and clinical complications of resin-bonded fixed partial dental prostheses cemented at an increased occlusal vertical dimension: A retrospective study

Lim TW, Ab Ghani SM, Mahmud M

J Prosthet Dent, 2020 Dec 02.
PMID: 33279159 DOI: 10.1016/j.prosdent.2020.06.034

STATEMENT OF PROBLEM: Resin-bonded fixed partial dental prostheses (RBFPDPs) cemented at an increased occlusal vertical dimension (OVD) (the Dahl concept) to create space for a metal retainer remain controversial because of the lack of reported clinical studies. This study evaluated RBFPDPs by applying the Dahl concept.
PURPOSE: The purpose of this retrospective study was to investigate the clinical factors affecting the occlusal re-establishment and short-term complications of RBFPDPs cemented at an increased OVD.
MATERIAL AND METHODS: Occlusal re-establishment and clinical complications were reviewed in 109 participants (155 RBFPDPs) treated at the Faculty of Dentistry, Universiti Teknologi MARA from January 2013 to May 2018. Types of complications and risk factors were assessed from clinical data. Demographic factors, clinical factors, and prosthesis factors were distinguished and their association with occlusal re-establishment analyzed by using multiple regression analysis.
RESULTS: A total of 155 RBFPDPs (42 anterior, 113 posterior) were placed in 109 participants. All achieved occlusal re-establishment, 89.9% complete occlusal re-establishment and 10.1% partial occlusal re-establishment, a minimum of 4 months after the RBFPDPs had been placed at an increased OVD. The design of the metal retainer coverage was found to be a significant factor affecting occlusal re-establishment and decementation (P

Matched MeSH terms: Metals
The use of intraoral scanning and 3D printed casts to facilitate the fabrication and retrofitting of a new metal-ceramic crown supporting an existing removable partial denture

Patil PG, Lim HF

J Prosthet Dent, 2023 Jul;130(1):14-18.
PMID: 34774303 DOI: 10.1016/j.prosdent.2021.08.005

Fabricating a new crown to retrofit with an existing removable partial denture (RPD) is a complex procedure for both clinician and dental laboratory technician. The presented technique facilitates the fabrication and retrofitting of a metal-ceramic crown onto the principal abutment of the existing RPD by using 2-step intraoral scanning (with and without the RPD in place) and 2 different 3-dimensionally printed casts. The technique enables the dental laboratory technician to precisely reproduce the retentive areas, guiding planes, and rest seats on the retrofitted crown.

Matched MeSH terms: Metals
Preliminary investigations of the bonding strength between irreversible alginate impression material & brass surfaces

Lam KS

Dent J Malaysia Singapore, 1968 Feb;8(1):19-23.
PMID: 4882516
Matched MeSH terms: Metals
Selective magnetic mercury(ii) ion capturing ligand-doped silica gel for water analysis

Khor SW, Lee YK, Tay KS

Analyst, 2019 Mar 21;144(6):1968-1974.
PMID: 30694266 DOI: 10.1039/c8an02362j

Preparation of selective magnetic adsorbents for dispersive micro-solid phase extraction often involves multi-step reactions which are time consuming. This study demonstrates a simplified method for the synthesis of a magnetic adsorbent, which is selective towards the adsorption of mercury(ii) ions (Hg2+). In this method, the incorporation of a metal capturing ligand (3-oxo-1,3-diphenylpropyl-2-(naphthalen-2-ylamino) ethylcarbamodithioate) and the coating of magnetic particles with silica gel was performed in a single step. This adsorbent was then used in solid-phase microextraction for the preconcentration of Hg2+ in water. In this study, a mercury analyzer was used to quantify the Hg2+. Under optimized conditions, the developed analytical method achieved a low detection limit (4.0 ng L-1), satisfactory enrichment factor (96.4) and wide linearity range (50.0-5000 ng L-1) with a good coefficient of determination (0.9985) and good repeatability (<7%). The preconcentration factor of this method was 100. This proposed method was also successfully utilized for the determination of Hg2+ in drinking water, tap water and surface water with good recovery (>91%) and high intra-day and inter-day precision.

Matched MeSH terms: Metals
Paper-based capacitive sensors for identification and quantification of chemicals at the point of care

Hu J, Yew CT, Chen X, Feng S, Yang Q, Wang S, et al.

Talanta, 2017 Apr 01;165:419-428.
PMID: 28153277 DOI: 10.1016/j.talanta.2016.12.086

The identification and quantification of chemicals play a vital role in evaluation and surveillance of environmental health and safety. However, current techniques usually depend on costly equipment, professional staff, and/or essential infrastructure, limiting their accessibility. In this work, we develop paper-based capacitive sensors (PCSs) that allow simple, rapid identification and quantification of various chemicals from microliter size samples with the aid of a handheld multimeter. PCSs are low-cost parallel-plate capacitors (~$0.01 per sensor) assembled from layers of aluminum foil and filter paper via double-sided tape. The developed PCSs can identify different kinds of fluids (e.g., organic chemicals) and quantify diverse concentrations of substances (e.g., heavy metal ions) based on differences in dielectric properties, including capacitance, frequency spectrum, and dielectric loss tangent. The PCS-based method enables chemical identification and quantification to take place much cheaply, simply, and quickly at the point-of-care (POC), holding great promise for environmental monitoring in resource-limited settings.

Matched MeSH terms: Metals, Heavy
Development of surface plasmon resonance sensor for determining zinc ion using novel active nanolayers as probe

Fen YW, Yunus WM, Talib ZA, Yusof NA

Spectrochim Acta A Mol Biomol Spectrosc, 2015 Jan 5;134:48-52.
PMID: 25004894 DOI: 10.1016/j.saa.2014.06.081

In this study, novel active nanolayers in combination with surface plasmon resonance (SPR) system for zinc ion (Zn(2+)) detection has been developed. The gold surface used for the SPR system was modified with the novel developed active nanolayers, i.e. chitosan and chitosan-tetrabutyl thiuram disulfide (chitosan-TBTDS). Both chitosan and chitosan-TBTDS active layers were fabricated on the gold surface by spin coating technique. The system was used to monitor SPR signal for Zn(2+) in aqueous media with and without sensitivity enhancement by TBTDS. For both active nanolayers, the shift of resonance angle is directly proportional to the concentration of Zn(2+) in aqueous media. The higher shift of resonance angle was obtained for chitosan-TBTDS active nanolayer due to a specific binding of TBTDS with Zn(2+). The chitosan-TBTDS active nanolayer enhanced the sensitivity of detection down to 0.1 mg/l and also induced a selective detection towards Zn(2+).

Matched MeSH terms: Metals/analysis; Metals/metabolism
Label-free optical spectroscopy for characterizing binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite towards nickel ion

Daniyal WMEMM, Fen YW, Abdullah J, Sadrolhosseini AR, Saleviter S, Omar NAS

Spectrochim Acta A Mol Biomol Spectrosc, 2019 Apr 05;212:25-31.
PMID: 30594850 DOI: 10.1016/j.saa.2018.12.031

Surface plasmon resonance (SPR) is a label-free optical spectroscopy that is widely used for biomolecular interaction analysis. In this work, SPR was used to characterize the binding properties of highly sensitive nanocrystalline cellulose-graphene oxide based nanocomposite (CTA-NCC/GO) towards nickel ion. The formation of CTA-NCC/GO nanocomposite has been confirmed by FT-IR. The SPR analysis result shows that the CTA-NCC/GO has high binding affinity towards Ni2+ from 0.01 until 0.1 ppm with binding affinity constant of 1.620 × 103 M-1. The sensitivity for the CTA-NCC/GO calculated was 1.509° ppm-1. The full width at half maximum (FWHM), data accuracy (DA), and signal-to-noise ratio (SNR) have also been determined using the obtained SPR curve. For the FWHM, the value was 2.25° at 0.01 until 0.08 ppm and decreases to 2.12° at 0.1 until 10 ppm. The DA for the SPR curves is the highest at 0.01 until 0.08 ppm and lowest at 0.1 until 10 ppm. The SNR curves mirrors the curves of SPR angle shift where the SNR increases with the Ni2+ concentrations. For the selectivity test, the CTA-NCC/GO has the abilities to differentiate Ni2+ in the mixture of metal ions.

Matched MeSH terms: Metals

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