Magnetic hybrid TiO2/Alg/FeNPs triads for the efficient removal of methylene blue from water

A new adsorbent material with combined adsorption, photocatalytic, and magnetic properties has been successfully synthesized and tested for the efficient dye removal from methylene blue (MB) contaminated water. A facile non-thermal method was applied to synthesize a hybrid nanocomposite consisting of TiO₂/calcium alginate (TiO/Alg) and magnetite (Fe₃O₄) nanoparticles (FeNPs). The potential of the adsorbent Alg as a barrier to prevent direct contact between the magnetic core and TiO₂ was experimented by varying the synthesis conditions. The performance of four differently synthesized TiO₂/Alg/FeNPs samples (TiO₂/Alg/FeNPs-1, TiO₂/Alg/FeNPs-2, TiO₂/Alg/FeNPs-3, and TiO₂/Alg/FeNPs-4) was found to be fairly comparable and stable based on their efficiency in removing MB from aqueous solution due to the physico-chemical characterization (surface morphology, functional groups and elemental analysis) which supports the performance of TiO₂/Alg/FeNPs. For the optimization study using the response surface methodology (RSM) with three factorial Box-Behnken experimental designs, TiO₂/Alg/FeNPs-2 was selected as it exhibited the highest MB removal of 97.6% after 120 min under ultra violet irradiation (254 nm wavelength). Among the three independent variables studied (i.e., pH, contact time and initial MB concentration), the initial concentration of MB had significant effect towards the MB removal performance. A recycling study was performed, thus confirming the stability of TiO₂/Alg/FeNPs-2 up to three cycles, with only a slight drop in the removal efficiency from 93.1% to 88.5%. The fabricated TiO₂/Alg/FeNPs nanocomposites could be a potential functional material for treating artificial dye laden wastewater such as in textile, cosmetic, and paper industries.     

Pod razor (Ensis siliqua) shell powder as cost-effective biomineral for removal of nickel(II), copper(II) and zinc(II) from artificially contaminated industrial wastewater

The removal of Ni(II), Cu(II) and Zn(II) from aqueous model solutions and real wastewater samples by using pod razor (Ensis siliqua) shell powder has been investigated under several conditions such as heavy metal concentrations, pH, contact time, powder dosage. It was found that the removal of heavy metals was dependent on the dose of the biomineral and contact time. The results showed that this low-cost material can be fruitfully used for the removal of heavy metal ions such as Ni(II), Cu(II) and Zn(II) below concentration of 200 mg/L applying a shell powder dose of 1.2–4 g/L. The minimal dose for removal of Cu(II) and Zn(II) from industrial wastewater was found to be 1.2 g/L, while for Ni this value amounted to 1.6 g/L. The contact time necessary for quantitative removal was found to be 30–60 min and the optimum initial pH range was between 4 and 5.     

Characterization of bacterial communities exposed to Cr(III) and Pb(II) in submerged fixed-bed biofilms for groundwater treatment

Two pilot-scale submerged-bed microbial biofilms were set up for the removal of Cr(III) and Pb(II) from groundwater, and the biological activities and structure of the bacterial communities developed in the presence of the heavy metals were analyzed. Artesian groundwater was polluted with Cr(III) or Pb(II) (15 mg/l) and amended with sucrose (250 mg/l) as carbon source. While Pb(II) was over 99% removed from groundwater during long-term operation (130 days), the efficiency of the removal of Cr(III) significantly decreased in time (95–73% after 60 days). Cr(III)-amended biofilms displayed significant lower sucrose consumption, ATP cell contents and alkaline phosphatase activity, compared to biofilms formed in the presence of Pb(II), while analysis of exopolymers demonstrated significant differences in their composition (content of carbohydrates and acetyl groups) in response to each heavy metal. According to transmission electron microscopy (TEM) and electron-dispersive X-ray analysis (EDX), Cr(III) bioaccumulated in the exopolymeric matrix without entering bacterial cells, while Pb(II) was detected both extra and intracellularly, associated to P and Si. Temperature-gradient gel electrophoresis (TGGE) profiling based on partial amplification of 16S rRNA genes was used to analyze the differences in the structure of the biofilm bacterial communities developed under exposure to each heavy metal. Prevalent populations in the biofilms were further identified by reamplification and sequencing of isolated TGGE bands. 75% of the sequences in the Pb(II) biofilter were evolutively close to the Rhodobacterales, while in the Cr(III) biofilter 43% of the sequences were found affiliated to the Rhizobiales and Sphingomonadales, and 57% to Betaproteobacteria.     

Column solid phase extraction of iron(III), copper(II), manganese(II) and lead(II) ions food and water samples on multi-walled carbon nanotubes

A column solid phase extraction method for preconcentration of Fe(III), Cu(II), Mn(II) and Pb(II) on multi-walled carbon nanotubes (MWNTs) has been established. The adsorption was achieved quantitatively on carbon nanotube at pH 9.0, then the retained analyte contents on the column were quantitatively eluted with 1 M HNO₃ in acetone. The effects of analytical parameters including pH of the solution, eluent type, sample volume, flow rates of eluent, matrix ions, etc. were investigated for optimization of the presented procedure. The preconcentration factor was calculated as 20. The detection limits for the understudy analyte ions were found in the range of 3.5 μg/L (Mn)–8.0 μg/L (Pb). The validation of the presented procedure was checked by the analysis of TMDA 54.4 fortified lake water and HR-1 River Sediment certified reference materials. The method was applied to the determination of analyte ions in environmental samples.     

Distribution characteristics and ecological risk assessment of toxic heavy metals and metalloid in surface water of lakes in Daqing Heilongjiang Province,China

It is necessary to estimate heavy metal concentrations and risk in surface water for understanding the heavy metal contaminations and for sustainable protection of ecosystems and human health. To investigate the anthropogenic contribution of heavy metal accumulation surrounding an industrial city in China, the concentrations of six heavy metals, including mercury (Hg), arsenic (As), chromium (Cr), lead (Pb), copper (Cu), and cadmium (Cd) were examined; from four different regions of Daqing in autumn 2011 and winter 2012. The results showed heavy metals distributed in the industrial area at concentrations relatively higher than those in other three areas, while concentrations in the farming area and the protected area were lower. The heavy metal concentrations of water bodies in all areas, except those for Hg and As, Cu, Pb and Cr were lower than the cutoff values for the Class I water quality that was set as the highest standard to protect the national nature reserves. While Hg and As of lakes in industry region had a higher level than those in the agriculture and landscape water, the lowest allowed. The concentrations of all the heavy metals in winter were higher than in the autumn. Cu had a higher ecological risks level to freshwater organisms. The discharge of urban sewage and industrial wastewater might be a major pollutant source, thus these sources should identified before remediation efforts. Efforts are needed to protect the lakes from pollution and also to reduce environmental health risks. This study and the valuable data will pave the way for future research on these Lakes in Daqing.     

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman,Turkey

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (< 0.05 and 0.1 microg/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as microg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulation's residue limits, the cadmium level determined in fish tissues was high (0.1 microg/g) and the lead level, especially in liver tissue, was high in August (1 microg/g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.     

Combined toxicity of heavy metal mixtures in liver cells

With rapid industrialization, China is now facing great challenges in heavy metal contamination in the environment. Human exposure to heavy metals through air, water and food commonly involves a mixture consisting of multiple heavy metals. In this study, eight common heavy metals (Pb, Cd, Hg, Cu, Zn, Mn, Cr, Ni) that cause environmental contamination were selected to investigate the combined toxicity of different heavy metal mixtures in HL7702 cells. Toxicity (24 h LC₅₀) of each individual metal on the cells ranked Hg > Cr = Cd > Cu > Zn > Ni > Mn > Pb; toxicity of the different mixtures ranked: M5 > M3PbHgCd > M5+Mn > M5+Cu > M2CdNi > M4A > M8‐Mn > M8 > M5+Zn > M4B > M8‐Cr > M8‐Zn > M8‐Cu > M8‐Pb > M8‐Cd > M8‐Hg > M8‐Ni > M3PbHgNi > M3CuZnMn. The cytotoxicity data of individual metals were successfully used to build the additive models of two‐ to eight‐component metal mixtures. The comparison between additive model and combination model or partly additive model was useful to evaluate the combined effects in mixture. Synergistic, antagonistic or additive effects of the toxicity were observed in different mixtures. These results suggest that the combined effects should be considered in the risk assessment of heavy metal co‐exposure, and more comprehensive investigations on the combined effects of different heavy metal mixtures are needed in the future. Copyright © 2016 John Wiley & Sons, Ltd.     

The design of SnO2-crosslinked-chitosan nanocomposite for microwave-assisted adsorption of aqueous cadmium and mercury ions

Modern day worldwide industrial activities have negatively affected the environment due to daily pollutant accumulation. Evidence of this is seen in the heavy metal deposits found in water resources from mining, well drilling, electroplating, and heavy metals production. Mercury and cadmium ions are among the most hazardous heavy metals of significant concern. The removal of these two toxic metals from wastewater requires effective, low-cost techniques, and, therefore, this current study looks at the design and fabrication of SnO₂-formaldehyde-chitosan to facilitate the rapid microwave-assisted elimination of Hg(II) and Cd(II) ions. This paper explores the microwave-assisted removal of Hg(II) and Cd(II) ions, a highly efficient process which establishes 1050 μmol g^?1 and 600 μmol g^?1 capacity values at pH 6, at 10 s and 15 s, respectively. The application of SnO₂-formaldehyde-chitosan for the microwave-assisted elimination of Hg(II) and Cd(II) ions from natural water and wastewater is also explored. In this respect, the microwave-assisted removal values of Cd(II) achieved were 95.6%, and 99.2% from tap water and wastewater, respectively. In addition, Hg(II) removal percentages were found to be 94.2% and 98.4% from the same two water samples.     

Heavy metals levels in fish from aquaculture farms and risk assessment in Lhasa,Tibetan Autonomous Region of China

Fish is consumed as a common food by humans due to its nutritional and therapeutic benefits. However, they can accumulate toxic chemicals (such as heavy metals, persistent organic pollutants) from water and food chain. Very few studies have been investigated on heavy metal contents in fish from Tibetan Autonomous Region of China. In order to study heavy metals levels in fish from aquaculture farms and evaluate the risk that human consume fish in this area, we collected four types of aquaculture fish species (6 big-head carps, 5 grass carps, 5 carps and 5 tilapias) from fisheries around Lhasa city in this study. 9 heavy metals (Cr, As, Cd, Pb, Cu, Ba, Co, Mn and V) in different tissues of fish were determined by an inductively coupled plasma mass spectrometer. Cr, Ba, Co, Mn and V could easily accumulate in the gill, and Cu was detected in the hearts of all the fishes. Toxic metal (As, Cd and Pb) contents were higher in the liver than those in other tissues, heavy metal levels were the lowest in the muscle among all tissues. Most of heavy metal concentrations in the tilapia tissues were higher than those in other fish tissues, especially arsenic. Arsenic content in the tilapia samples was ~2–4 times higher than the maximum levels (MLs) of contaminants in the national standard, and other metals were all lower than the MLs. Compared the estimated daily intake of heavy metals through fish consumption with tolerable daily intakes recommended by FAO, the metals daily intake of As, Cd and Pb from fish consumption might not pose serious health risk to the local inhabitants. It is therefore necessary to determine the dose level for human, which is considered to be taken daily over a lifetime without adverse effects.     

壳聚糖对重金属离子Cu和Pb的吸附研究

目的处理实验室废水中的重金属离子。方法本文对壳聚糖对模拟废水中的微量重金属离子Cu和Pb的吸附进行了研究,确定了最佳吸附条件。结果在实验室条件下,Cu2＋的最佳pH=9,Pb2＋的最佳pH=6,壳聚糖最佳用量均为10g/L,最佳吸附时间均为20min,温度均为常温,壳聚糖脱乙酰度均为85%。结论壳聚糖对水中微量重金属离子有较好的吸附效果,可作为重金属离子的吸附剂用于实验室重金属离子废水的处理。     

Development of a free beta-galactosidase in vitro test for the assessment of heavy metal toxicity

The effect of heavy metals and organic compounds on the activity of the enzyme beta-galactosidase in a standardized bioassay has been evaluated, considering future applications in environmental monitoring. The tests were done using a commercial extract of a hydrolase from the eukaryote yeast Kluyveromyces lactis and o-nitrophenyl-beta-D-galactopyranoside (ONPG) as substrate. The enzyme was exposed to Cr(VI), Cd(II), Cu(II), Ni(II), Pb(II), Hg(II), phenol, sodium dodecyl sulfate, methanol and pentachlorophenol for 5, 15, 30, and 60 min. According to the results, a 15 min exposure time was considered optimum for the performance of the assay. Results of tests with metals showed IC50 values ranging between 9.25mg/L for Cd(II) and 0.015mg/L for Hg(II), with an order of sensitivity of: Cd(II) < Ni(II) < Cr(VI) = Pb(II) < Cu(II) < Hg(II). Sensitivity to organic compounds ranged from 200 to 4,000 mg/L, showing a higher specificity to heavy metals. The present in vitro free enzyme test showed a similar behavior to other tests based on beta-galactosidase such as the MetPlate. Furthermore, when compared to data from the literature on acute toxicity assays currently used in environmental assessment, test results show good agreement regarding the sensitivity to metals. After standardization, the proposed test could be used as a rapid and low-cost assay when evaluating biological effects of heavy metals in monitoring programs.     

Utilization of membrane filtration for preconcentration and determination of Cu(II) and Pb(II) in food,water and geological samples by atomic absorption spectrometry

A method for separation–preconcentration of Cu(II) and Pb(III) ions by membrane filtration has been presented. The analyte ions were collected on acetate membrane filter as their 1-2-pyridylazo 2-naphthol (PAN) complexes. The analytes were determined by flame atomic absorption spectrometry. The analytical parameters including pH, eluent type, sample volume, amount of PAN, etc. were examined in order to gain quantitative recoveries of analyte ions. The effects of foreign ions on the recoveries of analyte ions were also investigated. The detection limits by three sigma were found to be 1.2 and 3.5 μg L⁻¹ for Cu(II) and Pb(II), respectively. The preconcentration factor was 60 for Cu(II) and 20 for Pb(II). The validation of the presented procedure was checked by the analysis of certified reference materials. The optimized method was successfully applied to food, water and geological samples with good results.     

市售灵芝孢子粉7种重金属元素含量测定及膳食暴露风险评估

目的 测定市售灵芝孢子粉中铅、镉、砷、汞、铜、铬、镍7种重金属元素的残留量并评估其膳食暴露的健康风险。方法 收集市售灵芝孢子粉(包含中药饮片、保健食品、食品和农产品等不同产品类型)40批次，对7种重金属元素进行检测，采用点评估方法对灵芝孢子粉中7种重金属元素的膳食暴露量进行评估。结果 40批灵芝孢子粉中7种重金属元素检出率均为100%，有8批样品重金属元素超出拟定的限度。重金属元素膳食暴露评估显示消费者食用灵芝孢子粉摄入铬的量存在一定的膳食暴露健康风险。结论 灵芝孢子粉中铅、镉、砷、汞、铜、镍6种重金属元素膳食暴露低于暂定可耐受摄入量，对人体健康产生危害的风险可接受；铬元素膳食暴露的最大值和第95百分位数(P₉₅)值超过暂定可耐受摄入量，存在一定的健康风险。     

Spectroscopic,antiproliferative and antiradical properties of Cu(II), Ni(II), and Zn(II) complexes with amino acid based Schiff bases

Novel six Cu(II), Ni(II), and Zn(II) complexes with Schiff bases derived from 4-aminobenzoic acid with terephtaldehyde and amino acids (glycine, β-alanine). Structures have been proposed from elemental analysis, UV–Vis, IR, NMR, TGA, DTA, and magnetic measurements. Spectroscopic studies suggest that coordination occurs through azomethine nitrogen, hydroxyl group, and carbonyl oxygen of the ligands to the metal ions. The elemental analyses of the complexes where L is Schiff base ligands, are confined to the stoichiometry of the type M₂L₂(CH₃COO)₂ [M = Cu(II)]; and M₂L(CH₃COO)₂ [M = Ni(II) and Zn(II)]. The cytotoxicity activities of the compounds against human breast carcinoma MCF-7 cell line have been studied. Ligands and their Zn(II) compounds inhibited cell proliferation of MCF-7 cancer cell lines in a dose- and time-dependent manner. The free radical scavenging activity was measured by 1,1-diphenyl-2-picryl-hydrazil. Our results show that the synthesized compounds induced oxidative damage by increasing the lipid peroxidation in yeast since MDA formation was increased, and it could be concluded that the synthesized compounds caused oxidative stress. In addition, the antioxidant activities of the synthesized compounds were very much lower than those of standard antioxidants.     

Heavy metals (Ni, Cr, Cu) in the Karoon waterway river, Iran

Environmental pollution is a world-wide problem, heavy metals belonging to the most important pollutants. The progress of industries has led to increased emission of pollutants into ecosystems. Karoon is the biggest and only navigable river in the South of Iran. Along the Karoon industrial units such as piping, steel, paint making, agriculture, paper mill, fish cultivation, abbottiors, electroplating industries drain their wastewater into the river. In this study, the concentrations of heavy metals (Ni, Cr, Cu) in the Karoon river have been determined. Samples were collected from 16 stations along the river, in winter and spring 1996. Heavy metal concentrations were measured by graphite furnace atomic absorption spectrometry. The minimal and maximal concentrations of these metals in winter were 69.3-110.7, 1.7-118.3, and 5.5-70.3 microg/l, for Ni, Cr, and Cu, respectively. The minimal and maximal concentrations of these metals in spring were 41.0-60.7, 0.7-19.8, and 0.5-28.7 microg/l, for Ni, Cr, and Cu, respectively. The results show that the pollution has increased along the river, down to the estuary at the Persian Gulf.     

Effects of Ni(II), other divalent metal ions, and glucagon upon plasma glucose concentrations in normal, adrenalectomized and hypyphysectomized rats.

The effects of Ni(II), administered ip as NiCl₂ or NiSO₄, upon plasma glucose and serum insulin concentrations have been investigated in Fischer rats. In fasting rats, hyperglycemia occurred at 0.5 hr after injection of Ni(II) in dosages from 12 to 85 μmol/kg. At dosages ≥34 μmol/kg, hyperglycemia persisted for 4 hr after injection of Ni(II). In approximate order of decreasing magnitude and duration, the hyperglycemic responses to equimolar ip injections of divalent ions of selected first transition metals were: Ni ≥ Co ≥ Cu ≥ Zn > Cr > Fe > Mn. Concurrent administration of insulin antagonized the hyperglycemic response to Ni(II). Concentrations of endogenous immunoreactive insulin in serum were increased from 0.5 to 3 hr after injection of Ni(II) in dosage of 68 μmol/kg. Adrenergic blockade with phentolamine and propranolol did not affect the hyperglycemic response to Ni(II). The hyperglycemic responses to Ni(II), Co(II), and glucagon were greatly suppressed but were not completely prevented by adrenalectomy or by hypophysectomy. These findings are attributed to interruption of the permissive actions of glucocorticoids upon hepatic gluconeogenesis and glycogenolysis.     

Surface response model for prediction of the acute toxicity of Cu(II) and Cr(VI) towardDaphnia magna

A central composite design (CCD) was employed to evaluate the combined effects of pH, hardness and dissolved organic carbon (DOC) on the toxicity of Cu (II) and Cr(VI) towardDaphnia magna. Surface response design (SRD) analysis showed that pH and DOC were found to be most significant for the Cu(II) toxicity (p<0.05), while pH and hardness for the Cr(VI) toxicity. According to the results of chemical speciation using the Visual MINTEQ program, increases in pH and DOC concentration led to decreased toxicity of Cu(II) by reducing the concentration of toxic Cu²⁺ species. For the Cr(VI) toxicity, increases in pH and hardness led to decreased toxicity towardD. magna by reducing the concentrations of toxic HCrO₄ ^? and CrO₄ ^2? species. Based on the SRD analysis, surface response models were developed for prediction of the 24-h and 48-h mortalities ofD. magna in the presence of Cu(II) and Cr(VI) under different pH, hardness and DOC conditions.     

Distribution and ecological assessment of heavy metals in surface sediments of the East Lake, China

Concentrations and risk assessment of chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), cadmium (Cd) and mercury (Hg) were investigated in 106 samples of surface sediments from the East Lake, China in this study. The mean concentration of Zn was highest among the eight heavy metals (225 mg kg^?1), followed by As (191 mg kg^?1), Cr (145 mg kg^?1), Cu (55 mg kg^?1), Ni (27.1 mg kg^?1), Pb (7.93 mg kg^?1), Cd (0.94 mg kg^?1) and Hg (0.21 mg kg^?1). Niuchao Hu was less polluted by heavy metals compare to the other four lakelets of the East Lake. The correlations among these heavy metals and the results of principal component analysis indicated that the distribution of Cd, Pb and Hg was related to anthropogenic activities, whereas Cu, As and Cr were affected by the parent rocks. Zinc and Ni were influenced both by anthropogenic activities and parent rocks. Based on the Sediment Quality Guidelines, the results of toxicity assessment indicated that adverse effects caused by Cr and As would be expected frequently. Nickel, Zn, Cd and Hg may cause adverse effects occasionally and Cu and Pb may cause toxicity infrequently. Arsenic was found to have the highest acute toxicity by toxic units (TUs), followed by Cr, Ni, Zn, Hg, Cu, Cd and Pb. The potential ecological risk index analysis indicated that As, Cd and Hg had considerable or high ecological risk, whereas Cr, Ni, Cu, Zn and Pb had low ecological risk. The potential ecological risk index (RI) of the heavy metals in the surface sediments of East Lake was 483, indicating considerable ecological risk. Close attention should be paid to pollution of the heavy metals in East Lake, China.     

Nickel adsorption from aqueous solution using lemon peel biomass chemically modified with TiO2 nanoparticles

Adsorption technique has attracted considerable attention as a promising alternative for reducing heavy metal ions in water sources. This work is focused on the adsorption of nickel ions using lemon peel biomass chemically modified with titanium dioxide (TiO₂) nanoparticles through siloxane bonds. The biomass was characterized by FT-IR and compositional analyses to identify functional groups and elemental composition. From these measurements, it was observed peaks at 1741, 1328, and 1229 cm^?1, characteristics of CO, C–O, and C–H stretching bands, respectively. These organic bonds can be related to the existence of cellulose, lignin, and pectin biopolymers, which are present in the lemon peel biomass, as observed from the compositional analyses. After grafting TiO₂ nanoparticles onto lemon peel biomass surface, it was observed from FTIR the presence of vibrational bands at 1524, 1054, and 943 cm^?1, characteristics of –Ti-O-C, –Si-O-Si, and –Ti-O-Si functional groups. Additionally, the morphology and elemental composition of the lemon peel biomass modified with the titanium dioxide (TiO₂) nanoparticles were determined by SEM microscope, observing the presence of C, O, Ti, and Si atoms from the EDS mapping. Batch adsorption experiments were carried out to determine the effect of pH and biomass particle size on adsorption of Ni (II) ions from aqueous solution. From these experiments, maximum adsorption of Ni (II) ions of 78 ± 0.2% was obtained at pH 6.0, while no significant effects were observed for biomass particle size. Furthermore, the modification of biomass with TiO₂ nanoparticles increased up to 90 ± 0.1% the Ni (II) ions adsorption, suggesting the potential of the biomass modified with metal oxide nanoparticles for removal of heavy metal ions.     

DNA cleavage and antimicrobial investigation of Co(II), Ni(II), and Cu(II) complexes with triazole Schiff bases: synthesis and spectral characterization

The Co(II), Ni(II), and Cu(II) complexes with Schiff bases derived from 3-substituted-4-amino-5-mercapto-1,2,4-triazole and fluvastatin have been synthesized. Schiff bases exhibited thiol–thione tautomerism and coordinated to metal ion through azomethine nitrogen and thiolate sulphur atoms. Square planar geometry for all the metal complexes of the type ML₂ has been proposed in the light of analytical, spectral (IR, UV–Vis., ESR, and FAB-mass), magnetic, and thermal studies. The antimicrobial studies of Schiff bases and their metal complexes against various antibacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis) and antifungal (Aspergillus niger, and Pencillium Chrysogenum) species by Minimum Inhibitory Concentration method revealed that, the metal complexes possess more healing antibacterial activity than the Schiff bases. Co(II), Ni(II), and Cu(II) complexes cleave the DNA isolated from A. niger.