Narrow Results

The samples of common salts available in Japan and Mongolia were analyzed for the presence of heavy elements by PIXE spectrometry using 2.5 MeV proton beam at the Tokyo Institute of Technology Van de Graaff Laboratory. The samples were dissolved in water and insoluble and soluble fractions were determined separately. The soluble constituents were treated with pre-concentration method by using DBDTC to form the complexes appropriate to percolation through a Nuclepore Track - etch Membrane. Insoluble particles were precipitated on the filter surface for subsequent direct irradiation. Combined As and Pb concentrations in insoluble portion of salts were found in the range of 7.2 – 102 ppm based on mass analysis of insoluble materials collected on Nuclepore Track - etch Membrane of the pore diameter 0.4μm. This level of toxic heavy metals makes a caution from the view-point of their safe intake.

Particle-induced X-ray emission (PIXE) was applied for the determination of heavy metals accumulated in natural phytoplankton. We selected four Japanese marine sites to collect phytoplankton: Toni Bay and Kamaishi Bay (Kamaishi, Iwate) as non-polluted areas; and Shimotsu port (Shimotsu, Wakayama) and Toyama new port (Shinminato, Toyama) as polluted areas. After removing the zooplankton and visible dust by passing the seawater through an NXX13 plankton net (95-μm mesh aperture), the phytoplankton were collected on a polycarbonate filter (25 mm diameter, 1.0 μm pore size) by suction filtration. The filter was dried and subjected to scanning electron microscopy (SEM) and a PIXE analysis. The phytoplankton consisted of diatoms, dinoflagellates and coccolithophores were observed by SEM analysis on the filter prepared from 100 ml of Toni Bay seawater. Heavy metals (Pb, Ni, Cu, Cr, Zn, Mn, Hg and As) could be detected by the PIXE analysis in almost all the cases tested, in which 50-200 ml each of respective seawater sample was filtered. There was a linear relationship between the amount of heavy metals on the polycarbonate filter (ng cm^-2) and the volume of seawater (25-200 ml) filtered (i.e. the amount of phytoplankton collected on the filter). Likewise, the PIXE analysis revealed that significant differences in heavy metal contamination between the polluted and non-polluted areas, and also among sampling sites in a polluted area depending on the location and seawater movement. These results indicate that a multi-element analysis of marine phytoplankton by PIXE would be a promising technique for biologically assessing and monitoring heavy metal pollution in the first link of the aquatic food chain.

The contamination of heavy metals in food becomes a serious problem. We analyzed oolong tea from different production areas by PIXE using very simple sample preparation and examined trace elements contained in these samples. From the results of this experiment, we could know oolong tea which analyzed in this experiment contains various minerals such as K, Ca, P, S, Cl, Fe, Mn, Cu and Cr but not toxic element of As which detection limit of PIXE was lower than the standard values given by the food hygiene law in Japan.

Intake of heavy metals from contaminated agricultural products represents a significant pathway for human exposure. Banglish village in the Comilla district is one of the most devastated arsenic (As) contaminated areas in Bangladesh. This study focus whether As is solely responsible for causing arsenicosis or whether some other heavy metals have a synergistic effect on the toxicity of As. The study sampled various leafy and non-leafy vegetables and groundwaters were analyzed by using the Proton Induced X-ray Emission (PIXE) method. The results revealed that both the vegetables and the groundwater were highly contaminated with As and lead (Pb), although the contents in the vegetables and the groundwater varied depending on species and tube wells. As and Pb concentrations in the edible part of all tested vegetables and in groundwater exceeded the permissible intake levels of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). The findings inferred that the inhabitants of the study area are experiencing health risks resulting from the intake of As and Pb, and that Pb might have a synergistic role with As by aggravating the arsenicosis. The potential health risks due to Pb is being reported for the first time in Bangladesh.

An improvement has been made on a liquid target preparation for an external proton beam PIXE which is regarded as an excellent technique for multi-elemental analysis of a liquid specimen. A 2.5 MeV proton beam taken out to the atmosphere through an exit Kapton foil bombards an acidic solution target. Such bombardment enables the comparison of X-ray yields of a liquid sample with those of standard solutions so that one can determine the elemental concentration in a liquid sample more precisely and easily. The dose limit of a 7.5 µm Kapton foil was found to be 0.8~1.0 mC for a 2 MeV proton beam of 10 ~ 20 nA in intensity. An example is given for the analysis of heavy metals in stream water.

Chemical composition of the fluids in the fluid inclusions of quartz from the pegmatite veins of the Yamaguchi W-Cu skarn deposit was measured by a combination of the crush-leach method in deionized water and chemical analysis using PIXE. Chemical composition of the fluids is characterized by a low molar ratio of Na/K and a high Cu concentration. The molar ratio of Cu/(Cu+Fe+Zn) of the fluid inclusions is higher than that of massive sulfide deposits on the seafloor. The molar ratio of Cu/(Cu+Fe+Zn) of the fluid inclusions is similar to the ratios of the vapor-rich fluid inclusions from the quartz-cassiterite veins hosted within the Mole Granite in New South Wales, Australia. The high Cu concentration in fluid inclusions of quartz associated with the pegmatite veins from the Yamaguchi deposit suggests that the fluid emanating from the Miyako granitic melt at the later stage of crystallization had a high Cu content.

The effectiveness of stannum (Sn²⁺) removal from aqueous solution by using magnetic biochar and functionalized multiwalled carbon nanotube (FMWCNT) was investigated. The effect of various factors, namely pH, adsorbent dosage, agitation speed and contact time was statistically studied through analysis of variance (ANOVA). Statistical analysis revealed that the optimum conditions for the highest removal of Sn²⁺ are at pH 5, dosage 0.1 g with agitation speed and time of 100 rpm and 90 min, respectively. At the initial concentration of 0.1 mg/L, the removal efficiency of Sn²⁺ using FMWCNTs was 93% and 85% with magnetic biochar. The Langmuir and Freundlich constant for both FMWCNTs and magnetic biochar were 13.397 L/mg, 18.634 L/mg and 17.719 L/mg, 25.204 L/mg, respectively. Hence, results prove that FMWCNTs are a better adsorbent with a higher adsorption capacity compared to magnetic biochar. Adsorption kinetic obeyed pseudo-second-order.

Chitosan nanofiber membranes by electrospinning technique were used to remove Cu(II) from aqueous solution. The adsorption kinetics, equilibrium isotherms, and pH effect were investigated in batch experiments. The Langmuir isotherm and pseudo second-order kinetic models agree well with the experimental data. The chitosan nanofiber membranes are effective for Cu(II) adsorption at pH6. Results showed that the maximum adsorption capacity of the chitosan nanofiber membranes with Cu(II) is 118.62 mg g^-1. The chitosan nanofiber membranes can be used as an effective adsorbent for the removal of Cu(II) in aqueous solution due to high adsorption capacity.

The design of novel substituted phthalocyanines closely follows the requirement of their planned applications. In this study, synthesize of novel pyridone derivatives metal-free and symmetrical cobalt(II) phthalocyanines was carried out to improve brightness. For this purpose; starting with 4-nitrophthalonitrile and 4-hydroxy-6-methyl-3-nitro-2-pyridone, 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile was prepared. Then 2(3),9(10),16(17),23(24)-tetrakis[6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy] metal-free phthalocyaninato and 2(3),9(10), 16(17),23(24)-tetrakis[6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy] phthalocyaninato Co(II) were synthesized by using 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile, lithium metal and cobalt(II) acetate tetrahydrate in amyl alcohol, respectively. The sensing behavior of the film of derivatives metal-free and symmetrical cobalt(II) phthalocyanines for the online detection of heavy metal ions in water samples was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the analytes on the coating surface cause a reversible negative frequency shift of the resonator. Quartz crystal microbalance (QCM) functionalized with phthalocyanine, derivatives metal-free and symmetrical cobalt(II) phthalocyanines, are demonstrated to be sensors for the detection of heavy metal ions like Cd${}^{2+}$, Zn${}^{2+}$, Cu${}^{2+}$, Cr${}^{2+}$ and Co${}^{2+}$. Thus, QCM based sensor arrays are considered a promising platform for the direct analysis of aqueous samples.

The Chinese mitten crab (Eriocheir sinensis) is one of the most aggressive invasive species globally, and it has spread widely in Asia and Europe. Its unique morphological and physiological characteristics enable it to survive in high-temperature and hypersaline environments. The invasion of the Chinese mitten crab can damage the local aquatic ecology, including flora and fauna, necessitating the implementation of monitoring and control measures. Consuming the invasive crab is a potential strategy to prevent its further spread worldwide. This chapter documents the success of transforming this invasive species into a valuable food source in China. Notably, there is a significant demand for Chinese mitten crabs in China, with potential markets in several other Asian countries. However, natural Chinese mitten crabs often grow in polluted water, accumulating undesirable substances (e.g., pathogens and heavy metals). These substances could pose significant health hazards when consumed by humans. Therefore, adhering to proper cultivation techniques is essential to ensuring the safety of the crabs for human consumption.

The chapter deals with some important aspects of the relationship of lithium and nickel with the ecosystem, which consists mainly of soil, water, plants and air. Some aspects of lithium and nickel use in the energy industry are also mentioned. We begin by considering the fact that the metallic elements lithium and nickel, either alone or in the form of their chemical compounds, are currently considered potential energy materials whose applicability is increasing with the transition to the mass use of electricity and batteries for powering motor vehicles. Both lithium and nickel are commonly found in nature. Even in relatively low concentrations, their presence is very dangerous or even toxic to some animals and biological organisms. On the other hand, certain plants and animals are a natural part of ecosystems and are unable to survive with-out their presence because they are vital to them. This contradiction and its implications form the main content of this chapter. The most significant effects of lithium and nickel in the environment, particularly in soil, water and plant systems, are presented. The interconnectedness between soil, water and plants is shown in relation to each other. Some of the analytical methods used for the detection of lithium and nickel are also given. In addition, some specific results are presented, which are not intended to specify particular locations in the field, but rather to highlight the ability of researchers to monitor the presence of lithium and nickel in the environment and to create conditions for their removal and possible reuse.

Human-induced environmental pollution, which has emerged with the increasing population in recent years, has become a global threat. One of the consequences of its rapid and destructive effects is that heavy metals, such as lithium (Li) and nickel (Ni), threaten soil and plant health, and their presence in soil and water poses a risk to both human health and environmental well-being. The purpose of this chapter is to explore the importance of bioremediation in removing Li and Ni from soil and water by investigating various research studies and approaches. Bioremediation is a solution that utilises microorganisms to remove heavy metals by converting them into less toxic forms. Therefore, it is important to carefully select the appropriate microorganisms and optimise the bioremediation conditions to achieve the best results. Moreover, the effectiveness of these techniques depends on various factors, such as the concentration of Li or Ni in the soil, the duration of the remediation process and the environmental conditions.

The ⁶⁰Co-γ irradiation combined with chestnut shell to absorb the Pb²⁺ and Cd²⁺ ions in stimulated water and real waste water was studied. Compared to the Heating absorption, Irradiation absorption has the same removal rate of Pb²⁺ in simulated waste water, and has the low removal rate of Cd²⁺ in simulated waste water. After Irradiation absorption, addition heating reduced both removal rate of Pb²⁺ and Cd²⁺ ions. In most of the real waste water, the Irradiation absorption has higher removal rate than the Heating absorption. Hence, the ⁶⁰Co-γ irradiation combined can replace the heating as energy source to combine with chestnut shell to absorb the Pb²⁺ and Cd²⁺ ions from the real waste water.

Biochar (BC) has been widely studied for its ability to remove heavy metals from aqueous solutions. In this study, biochars derived from corn straw were prepared by pyrolysis at 300, 400, 500 and 700 °C. The biochar prepared at a higher pyrolytic temperature, particularly those at 700 °C, had a higher aqeuous Cu²⁺ and Cd²⁺ adsorption capacity (BC700, 117.63 mg/g for Cu²⁺ and 110.76 mg/g for Cd²⁺). Langmuir isotherm and both pseudo-first-order and pseudo-second-order kinetic models fit well with Cu²⁺ adsorption on biochars. Freundlich model and pseudo-second-order kinetic model are a better fit for the Cd²⁺ adsorption.

This paper aims to carry out an exhaustive review of the literature on adsorption of poly-γ-glutamic acid for heavy metals. poly-γ-glutamic acid (simply as γ-PGA) shows a notable affinity for various kinds of heavy metals including Cr3+, Cu2+, Pb2+, Hg2+, Ni2+, Cd2+ and Zn2+. Adsorptive selectivity of γ-PGA on common heavy metals was summarized. The influencing factors (pH, temperature, adsorption time and initial concentration) of the adsorption process were discussed. Several effective modification methods of γ-PGA are also reviewed.

Heavy metal stabilization experiment was carried out by adding homemade stabilizer JC1 into high concentration of configuration solution. The results demonstrated, after adding the homemade stabilizer JC1, precipitation rates of heavy metal Pb, Zn, Cd in the solution were all above 90%. Electron microscope scanning presented medicament reactions happened and generated new crystal materials. Further analysis by means of X-ray Diffraction (XRD), new crystal materials were revealed to chemical compounds of homemade reagent and can be used in the stabilization of heavy metals Pb, Zn, Cd repair engineering, but note the change of pH value when reused.

The sorption behavior of nitrification inhibitor 3,4-Dimethylpyrazole Phosphate (DMPP) on four different types of soil (phaeozem, burozem, red soil and organic matter-removed soil) was researched with a batch-equilibration procedure and the influence of pH, Cu(II) and Cd(II) was meanwhile researched. The sorption amount (C^s) of DMPP on 4 soils exhibited phaeozem > burozem > red soil > organic matter-removed soil, indicating that the sorption of DMPP on soil was mainly controlled by soil organic matter content and CEC. With the increase of pH, the C^s of DMPP decreased when the system pH ranged from 2 to 4.5 or 9 to 12, while unaffected when the pH ranged from 4.5 to 9. The addition of heavy metal cation (Cu²⁺ or Cd²⁺) depressed the sorption of DMPP on soils due to the competitive effect.

Based on the data of heavy metals (including total Hg, Cd, Pb, Zn, Cu, Cr and As) in 17 samples in the sediment of Lai Zhou Bay in the year of 2014, the distribution of heavy metals in the sea area and degree of sediment pollution were researched. With Hakanson’s method, potential ecological risk of heavy metals in the sediment of Lai Zhou Bay was primarily assessed. The results demonstrated that the horizontal distribution of total Hg, As, Cd, Pb decreasing from center of Lai Zhou Bay to its west and south and the Yellow River Estuary. The horizontal distribution of Zn increased from northwest to southeast, Cu decreased from offshore to inshore, Cr decreased from inshore to the center of Lai Zhou Bay. Parameter of pollution metals on sediment was lower than 1, the value of RI was among 233.3˜35.1, indicating that the degree of pollution of heavy metals on the sediment and its ecological risk were low. The pollutants in the order of impacting the extent of ecological risk were Cd >Hg >As> Cu> Pb>Cr >Zn.

Coal gangue is a commercially worthless material that closely attaches to or surrounds coal in coalfield. However, it must be reused from an environmental point of view. It can be used for building material as treatment and utilization of coal gangue. The properties of coal gangue from Wulanmulun coalfield located at Inner Mongolia Province in northern China have been studied in this paper. The results show that the coal gangue belong to clay shale gangue. Heavy metal content measured shows that it is safe to produce building material with the coal gangue. Because of the color of the burned coal gangue, it is unsuited to be used for coating or rubber industry. The X-ray diffraction data indicates that mineral components of the coal gangue are quartz (33%), siderite (11%), calcite (13%), plagioclase (17%), feldspar (6%), chlorite (15%), mica (5%). The SEM images show that there exist some mineral crystals. The coal gangue is eminently suitable for making fired brick. It also can be used to product light-weight aggregate, but not good for cement admixture and aerated concrete.

In order to understand potential ecological risk by application of biochar to soil, sewage sludge, cow manure, corn cob were selected as raw materials to prepare biochar under different conditions, and the content of heavy metals of As, Cd, Cr, Pb in biochar were analyzed. The results show that 4 heavy metals exist in all biochars with different concentration, which depend upon feedstocks and temperature obviously. Compared with the 2nd standard of environmental quality standards for soils of China, accumulated amount of heavy metals in soil by application of biochars is limited regardless of low or high application rate in field. The compositive index (RI) of potential ecological risk of 4 heavy metals indicates low risk by applying different biochar to soil. However, the potential ecological risk of Cd in soil through application of biochar from sewage sludge is at level of considerable risk.