Displaying publications 321 - 340 of 1020 in total

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  1. Le DQ, Satyanarayana B, Fui SY, Shirai K
    Biol Trace Elem Res, 2018 Dec;186(2):538-545.
    PMID: 29577182 DOI: 10.1007/s12011-018-1313-2
    The present study, aimed at observing the total concentration of mercury (Hg) in edible finfish species with an implication to human health risk, was carried out from the Setiu mangrove wetlands on the east coast of Peninsular Malaysia. Out of 20 species observed, the highest Hg concentrations were found among carnivores-fish/invertebrate-feeders, followed by omnivores and carnivores-invertebrate-feeders, while the lowest concentrations in herbivores. The Hg concentrations varied widely with fish species and body size, from 0.12 to 2.10 mg/kg dry weight. A positive relationship between body weight and Hg concentration was observed in particular for Toxotes jaculatrix and Tetraodon nigroviridis. Besides the permissible range of Hg concentration up to 0.3 mg/kg (cf. United States Environmental Protection Agency (USEPA)) in majority of species, the carnivore feeders such as Acanthopagrus pacificus, Gerres filamentosus, and Caranx ignobilis have shown excess amounts (> 0.40 mg/kg flesh weight) that raising concerns over the consumption by local people. However, the weekly intake of mercury-estimated through the fish consumption in all three trophic levels-suggests that the present Hg concentrations are still within the range of Provisional Tolerable Weekly Intake (PTWI) reported by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Perhaps, a multi-species design for Hg monitoring at Setiu wetlands would be able to provide further insights into the level of toxicity transfer among other aquatic organisms and thereby a strong health risk assessment for the local communities.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/metabolism
  2. Ranjbar Jafarabadi A, Riyahi Bakhtiari A, Aliabadian M, Laetitia H, Shadmehri Toosi A, Yap CK
    Sci Total Environ, 2018 Jun 15;627:141-157.
    PMID: 29426136 DOI: 10.1016/j.scitotenv.2018.01.185
    The coral reefs of the Persian Gulf are the most diverse systems of life in the marine environment of the Middle East. Unfortunately, they are highly threatened by local and global stressors, particularly oil pollutants. This is the first quantitative and qualitative study aimed at assessing the concentration and sources of n-alkanes and POPs (PAHs, PCBs and PCNs) in coral tissues, symbiotic algae (zooxanthellae), reef sediments and seawaters in coral reefs of Lark and Kharg in the Persian Gulf, Iran. This work was conducted on eight species of six genera and three families of hard corals and one family of soft coral. A significant variation in the concentration of ∑30n-alkanes and POPs (∑40PAHs, ∑22PCBs and 20PCNs) was found in the decreasing order: zooxanthellae > coral tissue > skeleton > reef sediment > seawater. The bioaccumulation of these compounds was 2-times higher in ahermatypic than in hermatypic corals, among which significant variations were observed in both sites. In Kharg, Porites lutea had the highest mean concentration of ∑30n-alkanes and ∑40PAHs in soft tissue, whereas the lowest values were in Platygyra daedalea. A contrasting trend was documented for ∑22PCBs and 20PCNs, with the highest level reported in soft tissue of P. daedalea and the lowest in P. lutea at Kharg. Compositional pattern of AHs and PAHs demonstrated the predominance of LMW-PAHs and n-alkanes. In skeleton and reef sediments, tetra, penta and tri-CBs were the most abundant PCBs congeners followed by di-CB > hexa-CB > hepta-CB > octa-CB,whiletri-CB > di-CB > tetra-CB > penta-CB > hexa-CB > hepta-CB > octa-CB was observed for soft tissue, zooxanthellae and seawater. The results of RAD test indicated significantly negative correlation between total concentration of these compounds with zooxanthellae density, the chlorophyll-a and C2 in corals at both reefs. This is the first report on levels, health assessment and source apportionments of POPs in zooxanthellae and a first step in the implementation of specific coral reef management measures.
    Matched MeSH terms: Water Pollutants, Chemical/metabolism*; Water Pollutants, Chemical/toxicity*
  3. Moradihamedani P, Abdullah AH
    Water Sci Technol, 2018 Jan;77(1-2):346-354.
    PMID: 29377819 DOI: 10.2166/wst.2017.545
    Removal of low-concentration ammonia (1-10 ppm) from aquaculture wastewater was investigated via polysulfone (PSf)/zeolite mixed matrix membrane. PSf/zeolite mixed matrix membranes with different weight ratios (90/10, 80/20, 70/30 and 60/40 wt.%) were prepared and characterized. Results indicate that PSf/zeolite (80/20) was the most efficient membrane for removal of low-concentration ammonia. The ammonia elimination by PSf/zeolite (80/20) from aqueous solution for 10, 7, 5, 3 and 1 ppm of ammonia was 100%, 99%, 98.8%, 96% and 95% respectively. The recorded results revealed that pure water flux declined in higher loading of zeolite in the membrane matrix due to surface pore blockage caused by zeolite particles. On the other hand, ammonia elimination from water was decreased in higher contents of zeolite because of formation of cavities and macrovoids in the membrane substructure.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/chemistry
  4. Khalik WMAWM, Ibrahim YS, Tuan Anuar S, Govindasamy S, Baharuddin NF
    Mar Pollut Bull, 2018 Oct;135:451-457.
    PMID: 30301058 DOI: 10.1016/j.marpolbul.2018.07.052
    The first report on the emergence of microplastic in Malaysian marine waters was documented in this study. Water samples were collected from two regions, namely Kuala Nerus and Kuantan port, as the representatives of different anthropogenic activities. Identification of microplastic was performed based on physical characteristics (colour, shape, density) and chemical characterisation (ATR-FTIR analysis) for a functional group of polymers. Fragment type, black or grey colour and high density (>1.02 g cm-3) of microplastic were the most prevalent characteristics found in both areas. Two principal components (density and colour) rendered explained about 95.3% (Kuantan) and 95.6% (Kuala Nerus) of the total variance. Six possible polymer materials were identified, namely polyester, polystyrene, polyamide, polyvinyl chloride, polypropylene, and polyethylene. The findings of the study provided good baseline information on marine debris issue in Malaysia.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/chemistry
  5. Yanyan L, Kurniawan TA, Zhu M, Ouyang T, Avtar R, Dzarfan Othman MH, et al.
    J Environ Manage, 2018 Nov 15;226:365-376.
    PMID: 30138836 DOI: 10.1016/j.jenvman.2018.08.032
    Acetaminophen (Ace) is a trace pollutant widely found in sewage treatment plant (STP) wastewater. We test the feasibility of coconut shell waste, a low cost adsorbent from coconut industry, for removing Ace from synthetic solution in a fixed-bed column adsorption. To enhance its performance, the surface of granular activated carbon (GAC) was pre-treated with NaOH, HNO3, ozone, and/or chitosan respectively. The results show that the chemical modification of the GAC's surface with various chemicals has enhanced its Ace removal during the column operations. Among the modified adsorbents, the ozone-treated GAC stands out for the highest Ace adsorption capacity (38.2 mg/g) under the following conditions: 40 mg/L of Ace concentration, 2 mL/min of flow rate, 45 cm of bed depth. Both the Thomas and the Yoon-Nelson models are applicable to simulate the experimental results of the column operations with their adsorption capacities: ozone-treated GAC (20.88 mg/g) > chitosan-coated GAC (16.67 mg/g) > HNO3-treated GAC (11.09 mg/g) > NaOH-treated GAC (7.57 mg/g) > as-received GAC (2.84 mg/g). This suggests that the ozone-treated GAC is promising and suitable for Ace removal in a fixed-bed reactor.
    Matched MeSH terms: Water Pollutants, Chemical/isolation & purification*; Water Pollutants, Chemical/chemistry
  6. Ranjbar Jafarabadi A, Riyahi Bakhtiari A, Yaghoobi Z, Kong Yap C, Maisano M, Cappello T
    Chemosphere, 2019 Jan;215:835-845.
    PMID: 30359953 DOI: 10.1016/j.chemosphere.2018.10.092
    This is the first report on bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) and their derivatives (oxygen, nitrogen, sulfur, hydroxyl, carbonyl and methyl-containing PAHs) in three edible marine fishes, namely Lutjanus argentimaculatus, Lethrinus microdon and Scomberomorus guttatus, from Kharg Island, Persian Gulf, Iran. The concentrations (ng g-1dw) of Σ39PAHs resulted significantly higher in fish liver than muscle, with the PAH composition pattern dominated by low molecular weight compounds (naphthalene, alkyl-naphthalenes and phenanthrene). The highest mean concentrations of ∑9 oxygenated and ∑15 hydroxylated PAHs (ng g-1dw) were found ound in L. microdon and L. argentimaculatus, respectively, while the lowest values in S. guttatus. Additionally, the highest mean concentrations of Σ5 carbonylic PAHs (ng g-1dw) were found in L. argentimaculatus, followed by L. microdon. The PAHs levels and distribution in fish liver and muscle were dependent on both the Kow of PAHs congeners and fish lipid contents. Overall, the present findings provide important baseline data for further research on the ecotoxicity of PAHs in aquatic organisms, and consequent implications for human health.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/metabolism
  7. Affandi FA, Ishak MY
    Environ Sci Pollut Res Int, 2019 Jun;26(17):16939-16951.
    PMID: 31028621 DOI: 10.1007/s11356-019-05137-7
    Mining activities are responsible for the elevated input levels of suspended sediment and hazardous metals into the riverine ecosystem. These have been shown to threaten the riverine fish populations and can even lead to localized population extinction. To date, research on the effects of mining activities on fish has been focused within metal contamination and bioaccumulation and its threat to human consumption, neglecting the effects of suspended sediment. This paper reviews the effects of suspended sediment and metal pollution on riverine ecosystem and fish population by examining the possibilities of genetic changes and population extinction. In addition, possible assessments and studies of the riverine fish population are discussed to cope with the risks from mining activities and fish population declines.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/toxicity*
  8. Sutirman ZA, Sanagi MM, Abd Karim KJ, Abu Naim A, Wan Ibrahim WA
    Int J Biol Macromol, 2019 Jul 15;133:1260-1267.
    PMID: 31047925 DOI: 10.1016/j.ijbiomac.2019.04.188
    Grafting of crosslinked chitosan with monomer, N-vinyl-2-pyrrolidone, has been carried out to investigate its adsorption capacity toward Orange G (OG) from aqueous solutions. The adsorption performance of modified chitosan (cts(x)-g-PNVP) was examined and compared with that of the unmodified chitosan. The effects of initial pH, contact time and initial dye concentration were investigated in a batch system. The experimental data were correlated with the Langmuir and Freundlich isotherm models. The maximum adsorption capacity of cts(x)-g-PNVP (63.7mgg-1) based on Langmuir equation was relatively higher than that of the unmodified chitosan (1.7mgg-1). The kinetic studies showed that the adsorption process was consistent with the pseudo-second order kinetic model. Interaction mechanisms between OG and cts(x)-g-PNVP were also proposed. The overall results suggested that the prepared cts(x)-g-PNVP stands a good candidate as adsorbent for removal of anionic dye from aqueous solutions.
    Matched MeSH terms: Water Pollutants, Chemical/isolation & purification; Water Pollutants, Chemical/chemistry
  9. Jawad AH, Norrahma SSA, Hameed BH, Ismail K
    Int J Biol Macromol, 2019 Aug 15;135:569-581.
    PMID: 31150675 DOI: 10.1016/j.ijbiomac.2019.05.127
    In this work, chitosan (Chi) was cross-linked with glyoxal (Gly) and deposited onto glass plate to be a superior adsorbent film for two structurally different reactive orange 16 (RO-16) and methyl orange (MO) dyes by using non-conventional adsorption system without filtration process. The characterizations indicate that the cross-linked chitosan-glyoxal (Chi-Gly) film has a low swelling index, high adherence strength on glass plate, amine group (NH2) content was 32.52%, and pHpzc of ∼6.0 indicating a negative surface charge occurs above pHpzc. The adsorption isotherm data of RO-16 and MO by Chi-Gly film were in agreement with Langmuir isotherm, with maximum adsorption capacities of 1554.3 mg/g and 1451.9 mg/g, respectively. The pseudo-first-order kinetic model best described the kinetic data. The adsorption process was spontaneous and exothermic in nature at Chi-Gly film thickness of 8.55 μm, and pH ~3. The mechanism of adsorption included mainly electrostatic attractions, dipole-dipole hydrogen bonding interactions, n-π stacking attractions, and Yoshida H-bonding. This study reveals that immobilized Chi-Gly film as a good candidate for adsorption of reactive and acid dyes as it does not require any filtration process and adsorbent recovery during and post-adsorption process.
    Matched MeSH terms: Water Pollutants, Chemical/isolation & purification; Water Pollutants, Chemical/chemistry*
  10. Altowayti WAH, Allozy HGA, Shahir S, Goh PS, Yunus MAM
    Environ Sci Pollut Res Int, 2019 Oct;26(28):28737-28748.
    PMID: 31376124 DOI: 10.1007/s11356-019-06059-0
    Several parts of the world have been facing the problem of nitrite and nitrate contamination in ground and surface water. The acute toxicity of nitrite has been shown to be 10-fold higher than that of nitrate. In the present study, aminated silica carbon nanotube (ASCNT) was synthesised and tested for nitrite removal. The synergistic effects rendered by both amine and silica in ASCNT have significantly improved the nitrite removal efficiency. The IEP increased from 2.91 for pristine carbon nanotube (CNT) to 8.15 for ASCNT, and the surface area also increased from 178.86 to 548.21 m2 g-1. These properties have promoted ASCNT a novel adsorbent to remove nitrite. At optimum conditions of 700 ppm of nitrite concentration at pH 7 and 5 h of contact with 15 mg of adsorbent, the ASCNT achieved the maximal loading capacity of 396 mg/g (85% nitrite removal). The removal data of nitrite onto ASCNT fitted the Langmuir isotherm model better than the Freundlich isotherm model with the highest regression value of 0.98415, and also, the nonlinear analysis of kinetics data showed that the removal of nitrite followed pseudo-second-order kinetic. The positive values of both ΔS° and ΔH° suggested an endothermic reaction and an increase in randomness at the solid-liquid interface. The negative ΔG° values indicated a spontaneous adsorption process. The ASCNT was characterised using FESEM-EDX and FTIR, and the results obtained confirmed the removal of nitrite. Based on the findings, ASCNT can be considered as a novel and promising candidate for the removal of nitrite ions from wastewater.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/chemistry*
  11. Kusrini E, Usman A, Sani FA, Wilson LD, Abdullah MAA
    Environ Monit Assess, 2019 Jul 10;191(8):488.
    PMID: 31292792 DOI: 10.1007/s10661-019-7634-6
    This paper presents the adsorption capacity of a biosorbent derived from the inner part of durian (Durio zibethinus) rinds, which are a low-cost and abundant agro-waste material. The durian rind sorbent has been successfully utilized to remove lanthanum (La) and yttrium (Y) ions from their binary aqueous solution. The effects of several adsorption parameters including contact time, pH, concentrations of La and Y, and temperature on the removal of La and Y ions were investigated. The adsorption isotherm and kinetics of the metal ions were also evaluated in detail. Both La and Y ions were efficiently adsorbed by the biosorbent with optimum adsorption capacity as high as 71 mg La and 35 mg Y per gram biosorbent, respectively. The simultaneous adsorption of La and Y ions follows Langmuir isotherm model, due to the favorable chelation and strong chemical interactions between the functional groups on the surface of the biosorbent and the metal ions. The addition of oxygen content after adsorption offers an interpretation that the rare-earth metal ions are chelated and incorporated most probably in the form of metal oxides. With such high adsorption capacity of La and Y ions, the durian rind sorbent could potentially be used to treat contaminated wastewater containing La and Y metal ions, as well as for separating and extracting rare-earth metal ions from crude minerals.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/chemistry*
  12. Karbalaei S, Golieskardi A, Hamzah HB, Abdulwahid S, Hanachi P, Walker TR, et al.
    Mar Pollut Bull, 2019 Nov;148:5-15.
    PMID: 31422303 DOI: 10.1016/j.marpolbul.2019.07.072
    Plastic debris is widespread and ubiquitous in the marine environment and ingestion of plastic debris by marine organisms is well-documented. Viscera and gills of 110 individual marine fish from 11 commercial fish species collected from the marine fish market were examined for presence of plastic debris. Isolated particles were characterized by Raman spectroscopy, and elemental analysis was assessed using energy-dispersive X-ray spectroscopy (EDX). Nine (of 11) species contained plastic debris. Out of 56 isolated particles, 76.8% were plastic polymers, 5.4% were pigments, and 17.8% were unidentified. Extracted plastic particle sizes ranged from 200 to 34,900 μm (mean = 2600 μm ±7.0 SD). Hazardous material was undetected using inorganic elemental analysis of extracted plastic debris and pigment particles. The highest number of ingested microplastics was measured in Eleutheronema tridactylum and Clarias gariepinus, suggesting their potential as indicator species to monitor and study trends of ingested marine litter.
    Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/chemistry
  13. Alomari AH, Saleh MA, Hashim S, Alsayaheen A, Abdeldin I, Bani Khalaf R
    J Water Health, 2019 Dec;17(6):957-970.
    PMID: 31850902 DOI: 10.2166/wh.2019.158
    The current study was conducted to measure the activity concentration of the gross alpha and beta in 87 groundwater samples collected from the productive aquifers that constitute a major source of groundwater to evaluate the annual effective dose and the corresponding health impact on the population and to investigate the quality of groundwater in Jordan. The mean activity concentration of gross alpha and beta in groundwater ranges from 0.26 ± 0.03 to 3.58 ± 0.55 Bq L-1 and from 0.51 ± 0.07 to 3.43 ± 0.46 Bq L-1, respectively. A very strong relationship was found between gross alpha and beta activity concentrations. The annual effective dose for alpha and beta was found in the range of 0.32-2.40 mSv with a mean value of 0.89 mSv, which is nine times higher than the World Health Organization (WHO) recommended limit and one and half times higher than the national regulation limit. The mean lifetime risk was found to be 45.47 × 10-4 higher than the Jordanian estimated upper-bound lifetime risk of 25 × 10-4. The data obtained in the study would be the baseline for further epidemiological studies on health effects related to the exposure to natural radioactivity in Jordan.
    Matched MeSH terms: Water Pollutants, Radioactive/analysis*; Water Pollutants, Radioactive/standards
  14. Ooi L, Okazaki K, Arias-Barreiro CR, Heng LY, Mori IC
    Chemosphere, 2020 May;247:125933.
    PMID: 32079055 DOI: 10.1016/j.chemosphere.2020.125933
    Toxicity Identification Evaluation (TIE) is a useful method for the classification and identification of toxicants in a composite environment water sample. However, its extension to a larger sample size has been restrained owing to the limited throughput of toxicity bioassays. Here we reported the development of a high-throughput method of TIE Phase I. This newly developed method was assisted by the fluorescence-based cellular oxidation (CO) biosensor fabricated with roGFP2-expressing bacterial cells in 96-well microplate format. The assessment of four river water samples from Langat river basin by this new method demonstrated that the contaminant composition of the four samples can be classified into two distinct groups. The entire toxicity assay consisted of 2338 tests was completed within 12 h with a fluorescence microplate reader. Concurrently, the sample volume for each assay was reduced to 50 μL, which is 600 to 4700 times lesser to compare with conventional bioassays. These imply that the throughput of the CO biosensor-assisted TIE Phase I is now feasible for constructing a large-scale toxicity monitoring system, which would cover a whole watershed scale.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/toxicity*
  15. Usman S, Abdull Razis AF, Shaari K, Amal MNA, Saad MZ, Mat Isa N, et al.
    Int J Environ Res Public Health, 2020 Dec 21;17(24).
    PMID: 33371479 DOI: 10.3390/ijerph17249591
    Technological advances, coupled with increasing demands by consumers, have led to a drastic increase in plastic production. After serving their purposes, these plastics reach our water bodies as their destination and become ingested by aquatic organisms. This ubiquitous phenomenon has exposed humans to microplastics mostly through the consumption of sea food. This has led the World Health Organization (WHO) to make an urgent call for the assessment of environmental pollution due to microplastics and its effect on human health. This review summarizes studies between 1999 and 2020 in relation to microplastics in aquatic ecosystems and human food products, their potential toxic effects as elicited in animal studies, and policies on their use and disposal. There is a paucity of information on the toxicity mechanisms of microplastics in animal studies, and despite their documented presence in food products, no policy has been in place so far, to monitor and regulates microplastics in commercial foods meant for human consumption. Although there are policies and regulations with respect to plastics, these are only in a few countries and in most instances are not fully implemented due to socioeconomic reasons, so they do not address the problem across the entire life cycle of plastics from production to disposal. More animal research to elucidate pathways and early biomarkers of microplastic toxicity that can easily be detected in humans is needed. This is to create awareness and influence policies that will address this neglected threat to food safety and security.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/toxicity
  16. Razak MR, Aris AZ, Zakaria NAC, Wee SY, Ismail NAH
    Ecotoxicol Environ Saf, 2021 Mar 15;211:111905.
    PMID: 33453636 DOI: 10.1016/j.ecoenv.2021.111905
    The constant increase of heavy metals into the aqueous environment has become a contemporary global issue of concern to government authorities and the public. The study assesses the concentration, distribution, and risk assessment of heavy metals in freshwater from the Linggi River, Negeri Sembilan, Malaysia. Species sensitivity distribution (SSD) was utilised to calculate the cumulative probability distribution of toxicity from heavy metals. The aquatic organism's toxicity data obtained from the ECOTOXicology knowledgebase (ECOTOX) was used to estimate the predictive non-effects concentration (PNEC). The decreasing sequence of hazardous concentration (HC5) was manganese > aluminium > copper > lead > arsenic > cadmium > nickel > zinc > selenium, respectively. The highest heavy metal concentration was iron with a mean value of 45.77 μg L-1, followed by manganese (14.41 μg L-1) and aluminium (11.72 μg L-1). The mean heavy metal pollution index (HPI) value in this study is 11.52, implying low-level heavy metal pollutions in Linggi River. The risk quotient (RQ) approaches were applied to assess the potential risk of heavy metals. The RQ shows a medium risk of aluminium (RQm = 0.1125) and zinc (RQm = 0.1262); a low risk of arsenic (RQm = 0.0122) and manganese (RQm = 0.0687); and a negligible risk of cadmium (RQm = 0.0085), copper (RQm = 0.0054), nickel (RQm = 0.0054), lead (RQm = 0.0016) and selenium (RQm = 0.0012). The output of this study produces comprehensive pollution risk, thus provides insights for the legislators regarding exposure management and mitigation.
    Matched MeSH terms: Water Pollutants, Chemical/analysis; Water Pollutants, Chemical/toxicity*
  17. Abdul-Rahman R, Tsuno H, Zainol N
    Water Sci Technol, 2002;45(12):197-204.
    PMID: 12201103
    Elevated levels of nutrients in agroindustry wastewaters, and higher reliance on chlorination pose health threats due to formation of chlorinated organics as well as increased chlorination costs. Removals of ammonium and nitrate compounds were studied using activated carbon from palm shells, as adsorbent and support media. Experiments were carried out at several loadings, F:M from 0.31 to 0.58, and hydraulic residence times (HRT) of 24 h, 12 h and 8 h. Results show that the wastewater treatment process achieved removals of over 90% for COD and 62% for Total-N. Studies on removals from river water were carried out in sequencing batch reactor (SBR) and activated carbon biofilm (ACB) reactor. Removals achieved by the SBR adsorption-biodegradation combination were 67.0% for COD, 58.8% for NH3-N and 25.5% for NO3-N while for adsorption alone the removals were only 37.0% for COD, 35.2% for NH3-N and 13.8% for NO3-N. In the ACB reactor, at HRT of 1.5 to 6 h, removals ranged from 12.5 to 100% for COD, 16.7 to 100% for NO3-N and 13.5 to 100% for NH3-N. Significant decrease in removals was shown at lower HRT. The studies have shown that substantial removals of COD, NO3-N and NH3-N from both wastewater and river water may be achieved via adsorption-biodegradation by biofilm on activated carbon processes.
    Matched MeSH terms: Water Pollutants/analysis*; Water Pollutants/metabolism
  18. Yap CK, Ismail A, Omar H, Tan SG
    Environ Int, 2004 Feb;29(8):1097-104.
    PMID: 14680893
    Studies on toxicities and tolerances of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in the brown alga Isochrysis galbana and in the green-lipped mussel Perna viridis were conducted by short-term bioassays using endpoints growth production and mortality, respectively. The 5-day EC(50) and 24-h LC(50) of these heavy metals were determined in the brown alga and mussel, respectively. The EC(50) values calculated for the alga were 0.74 mg/l for Cd, 0.91 mg/l for Cu, 1.40 mg/l for Pb and 0.60 mg/l for Zn. The LC(50) values for the mussels were 1.53 mg/l for Cd, 0.25 mg/l for Cu, 4.12 mg/l for Pb and 3.20 mg/l for Zn. These LC(50) values were within the concentration ranges as reported by other authors who used P. viridis as the test organism. Based on these EC(50) and LC(50) values, the alga was most sensitive to Zn, followed by Cd, Cu and Pb while the mussel was most sensitive to Cu, followed by Cd, Zn and Pb. Differences in the trophic levels, metal handling strategies, biology and ecology of the primary producer (brown alga) and the primary consumer (mussel) are believed to be the plausible causes for the different toxicities and tolerances of the metals studied.
    Matched MeSH terms: Water Pollutants/pharmacology*; Water Pollutants/toxicity*
  19. Sutirman ZA, Sanagi MM, Abd Karim KJ, Wan Ibrahim WA
    Carbohydr Polym, 2016 Oct 20;151:1091-1099.
    PMID: 27474659 DOI: 10.1016/j.carbpol.2016.06.076
    A new poly(methacrylamide) grafted crosslinked chitosan was prepared for removal of lead, Pb(II) ion from aqueous solution. Crosslinked chitosan, in beads form, was grafted with methacrylamide (MAm) using ammonium persulfate (APS) as free radical initiator. Evidence of grafting was determined by comparing FTIR, TGA, SEM and (13)C NMR analyses of chitosan and graft copolymer. The optimal conditions for grafting reaction were as follow: crosslinked chitosan beads (1g), MAm (17.62×10(-1)M), APS (2.63×10(-1)M), reaction time (3h) and temperature (60°C). The modified chitosan bead was then used in laboratory batch experiments to evaluate the removal of Pb(II) ion from water samples. The Langmuir and Freundlich adsorption models were also applied to describe the equilibrium isotherms. The results revealed that the adsorption of Pb(II) ions onto the beads fitted very well with the Langmuir model with the maximum capacity (qmax) of 250mgg(-1).
    Matched MeSH terms: Water Pollutants, Chemical/isolation & purification*; Water Pollutants, Chemical/chemistry*
  20. Auta HS, Emenike CU, Fauziah SH
    Environ Int, 2017 May;102:165-176.
    PMID: 28284818 DOI: 10.1016/j.envint.2017.02.013
    The presence of microplastics in the marine environment poses a great threat to the entire ecosystem and has received much attention lately as the presence has greatly impacted oceans, lakes, seas, rivers, coastal areas and even the Polar Regions. Microplastics are found in most commonly utilized products (primary microplastics), or may originate from the fragmentation of larger plastic debris (secondary microplastics). The material enters the marine environment through terrestrial and land-based activities, especially via runoffs and is known to have great impact on marine organisms as studies have shown that large numbers of marine organisms have been affected by microplastics. Microplastic particles have been found distributed in large numbers in Africa, Asia, Southeast Asia, India, South Africa, North America, and in Europe. This review describes the sources and global distribution of microplastics in the environment, the fate and impact on marine biota, especially the food chain. Furthermore, the control measures discussed are those mapped out by both national and international environmental organizations for combating the impact from microplastics. Identifying the main sources of microplastic pollution in the environment and creating awareness through education at the public, private, and government sectors will go a long way in reducing the entry of microplastics into the environment. Also, knowing the associated behavioral mechanisms will enable better understanding of the impacts for the marine environment. However, a more promising and environmentally safe approach could be provided by exploiting the potentials of microorganisms, especially those of marine origin that can degrade microplastics.

    CAPSULE: The concentration, distribution sources and fate of microplastics in the global marine environment were discussed, so also was the impact of microplastics on a wide range of marine biota.

    Matched MeSH terms: Water Pollutants, Chemical/adverse effects; Water Pollutants, Chemical/analysis*
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