Nine trace metals (Zn, Fe, Al, Pb, Mn, Cu, Ni, Cr, and Cd) and Se concentrations were determined in organs and tissues(muscle, bone, kidney, liver and skin) of the striped field mice, Apodemus agrarius collected at Daejeo-dong, Pusan city and the Sorak Mt., Kangwon Province. All the trace elements were detected from all the mice examined. As for the metal concentrations in the mice from Daejeo-dong, Zn, Fe, Al, Mn, Ni and Cr were significantly higher than those in Sorak Mt.(p<0.05), suggesting that pesticides including Zn and factory wastes containing several metals might contaminated the environment of Daejeo-dong.
As regards the element concentrations in each organ and tissue, Fe, Al, Pb, Mn, Cu, Cr and Cd concentrations were high in liver or kidney; Zn in skin and bone; Ni in bone, skin and kidney; and Se in muscle, liver and skin in all the mice examined.
There were significant differences(p<0.05) between juveniles and adults in average concentration of metals(Zn, Fe, Pb, Mn, Ni, and Cd) in every organs and tissues of mice collected at Daejeo-dong. Much higher average levels of metals in juveniles indicate that considerable burdens of metals might be transferred through the placenta. However, there were no significant differences between males and females, and between young and old adults in average metal concentrations, which suggests that the mice might accumulate the metals during their life time, although they might excrete the metals not only through reproductive activities, such as parturition, lactation and ejaculation of semen, but also through molting, judging from higher accumulating ratios of most metals in skin of adults than of juveniles.
Removal of Cu(Ⅱ), Cr(Ⅱ) and Pb(Ⅲ) ions from aqueous solutions using the adsorption process on the loesses has been investigated. Variations of contact time, pH, adsorption isotherms and selectivity of coexisting ions were experimental parameters. pH of KJ and YIK samples diluted to 1% solution, was rearly the same with each value of pH 5.58 and 5.49, and both samples showed weak acidic properties. From chemical analysis, both samples contain remarkably different amounts of SiO2, Al2O3 and Fe2O3. From XRD measurement, quartz was mainly observed in both samples. Kaolinite was also observed, also in both samples, but Feldspar was only observed in KJ sample. Adsorption of metal ions on the loesses were reached at equilibrium by shaking for about 30min. The adsorption of Cr(Ⅲ) ion was higher than that of Cu(Ⅱ) and Pb(Ⅱ) ions. The order of amount adsorbed among the investigated ions was Cr(Ⅲ)>Pb(Ⅱ)>Cu(Ⅱ). In acidic solution, the adsorptivity of loesses was increased as pH increased. The adsorption of Cr(Ⅲ) ion on the loesses were fitted to the Freundlich isotherms. Freundlich constants(l/n) of KJ and YIK loesses were 0.54 and 0.55, respectively.
The interfacial chemical behavior, lattice exchange and dissolution, of FeS(s) as one of the important sulfide minerals was studied. Emphases were made on the surface characterization of hydrous FeS(s), the lattice exchange of Cu(Ⅱ) and FeS(s), and its effect on the dissolution of FeS(s), and also affect some organic ligands on that of both Cu(Ⅱ) and FeS(s), Cu(Ⅱ) which has lower sulfide solubility in water than FeS(s) undergoes the lattice exchange reaction when Cu(Ⅱ) ion contacts FeS(s) in the aqueous phase. For heavy metals which have higher sulfide solubilities in water than FeS(s), these metal ions were adsorbed on the surface of FeS(s) Such a reaction was interpreted by the solid solution formation theory.
Phthalic acid(a weak chelate agent) and EDTA(a strong chelate agent) were used to demonstrate the effect of organic ligands on the lattice exchange reaction between Cu(Ⅱ) and FeS(s). The pHzpc of FeS(s) is 7 and the effect of ionic strength is not showed. It can be expected that phthalic acid has little effect on the lattice exchange reaction between Cu(Ⅱ) and FeS(s), whereas EDTA has very decreased the removal of Cu(Ⅱ) and FeS(s).
This study shows that stability of sulfide sediments was predicted by its solubility. The pH control of the alkaline-neutralization process to treat heavy metal in wastewater treatment process did not needed. Thereby, it was regarded as an optimal process which could apply to examine a long term stability of marshland closely in the treatment of heavy metal in wastewater released from a disused mine.
The three domestic natural zeolites(Yong dong-ri (Y), Daesin-ri (D), Seogdong-ri (S)) harvested in Kyeongju-shi and Pohang-shi, Kyungsangbug-Do, were pretreated with each of the NaOH, Ca(OH)2, and NaOH following HCl solutions, and the removal performances of divalent heavy metals(Cu, Mn, Pb, and Sr) for natural and pretreated zeolites were investigated and compared in the single and mixed solutions. The natural zeolite-heavy metal system attained the final equilibrium plateau within 20 min, irrespective of initial heavy metal concentration. The heavy metal uptakes increased with increasing initial heavy metal concentration and pH. The heavy metal uptakes for natural zeolites decreased in the following sequences : D>Y>S among the natural zeolites; Pb>Cu>Sr>Mn among the heavy metals. The pretreated zeolites showed higher heavy metal removal performances than natural zeolites and decreased in the order of NaOH, NaOH following HCl, Ca(OH)2 treatment among the pretreatment methods. The heavy metal ion exchange capacity by natural and pretreated zeolites was described either by Freundlich equation or Langmuir equation, but it followed the former better than the latter. The heavy metal uptakes for natural zeolites decreased in the mixed solution, in comparing with those in the single solution and especially, the manganese uptake decreased greatly in the mixed solution. The pretreated zeolites showed the improved removal performances of heavy metals in the mixed solution than in the single solution and the heavy metal uptakes by those in the mixed solution showed the same trends in the single solution among the chemical treatment methods and heavy metals.
Among various reactions which metal sulfides can undergo in the reducing environment, the lattice exchange reaction was examined in a attempt to selectively remove heavy metal ions contained in the Fe-Coagulants acid solution.
We have examined Zeta potential along with pHs to investigate surface characteristics of FeS(s). As a result of this experiment, zero point charge(ZPC) of FeS is pH 7 and zeta potential which resulted from solid solution reaction between Pb(Ⅱ) and FeS(s) is similar to that of PbS(s). Solubility characteristics of FeS(s) is appeared to that dissolved Fe(Ⅱ) concentration increased in less than pH 4, and also increased with increasing heavy metal concentration. Various heavy metal ions(Pb(Ⅱ), Cu(Ⅱ), Zn(Ⅱ)) contained in Fe-coagulants acid solution were removed selectively more than ninety-five percent in the rang of pH 2.5∼10 by FeS(s). From the above experiments, therefore, We could know that the products of reaction between heavy metal ions and FeS(s) are mental sulfide such as PbS(s), CuS(s) and ZnS(s).
The effects of benzamidoxime concentration, solvents and temperature on the degree of metal extraction were investigated to apply benzamidoxime to heavy metal extraction as chelating agent.
Benzamidoxime was synthesized from benzonitrile with hydroxylamine. The chemical structure of benzamidoxime was identified. The degree of heavy metal extraction was increased with increasing the concentration of benzamidoxime and decreasing the extraction temperature. Benzamidoxime was found to be an effective extractant for Cu-extraction by benzene or chloroform. The relationship between the thermodynamic overall equilibrium constant and absolute temperature was expressed as log K = -5.56 + 855T-1. Heat of extraction, △H˚ were calculated from overall equilibrium constants at various temperature and the extraction reaction by benzamidoxime was found to be exthothermic.
Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values.
In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(Ⅱ) and Cd(Ⅱ).
Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.
The extent of heavy metal pollution in agricultural soils near the abandoned mine land site was investigated using their concentrations from the 47 sampling sites in B mine. Samples were prepared using 0.1N HCl -Korean Standard Methods- and then analysed for Cd, Cu, Pb, As and Cr by Inductively Coupled Plasma Spectrometer. In addition, soil and mine tailing samples were sequentially extracted to investigate the chemical speciation of heavy metals in them. The soils in the vicinity of mining area are highly contaminated by heavy metals ranging up to 5.96㎎ Cd/㎏, 253.3㎎ Cu/㎏, 76.7㎎ Pb/㎏, and 15.45㎎ As/㎏, according to the analysis of Korean Standard Methods. The heavy metal levels by the sequential extraction are much higher than its level by Korean Standard Methods, and little correlated with each other. Based on the results, it is suggested that the As pollution in agricultural soils near the AMLS should be dealt as of prior significance in establishing reclamation strategies for the area.
Chemical composition of atmospheric aerosols was measured at 4 sites in Pusan. All the samples were collected with a high volume air sampler from January to October 1996, to analyze major ions and heavy metals. Dominant ions of aerosols were SO42- in anion and Na+ in cation. Sulfate, nitrate and ammonium ions in aerosols showed high enrichmentfactor to soil and seawater composition. The concentrations of heavy metals in aerosols was lowest at the site P1 near the coast. The lowest concentrations of major ions and heavy metals mainly appeared in August, probably due to scavenging by frequent rains. Especially, the concentrations of total suspended particulate matter(TSP) and heavy metals in aerosols showed good correlations in Pusan. Based on crustal Al, enrichment factors for some metals(Zn, Cu, Pb, Cd) in aerosols were significantly greater than unity, and the order was Cd > Pb > Zn > Cu. This evidence suggests that Cd and Pb are derived predominantly from non-crustal sources.
The concentrations and wet deposition flux into the sea of heavy metals of precipitation in Pusan area were measured and estimated. The samples were collected by polyethylene bottle(30ℓ) from January to November in 1996, and heavy metals were analyzed by atomic absorption spectrometer.
The concentration order of heavy metals was Al >Fe >Zn >Pb >Mn >Cu >Ni >Cd >Co, and they were high at inland sites and low at coastal sites. The enrichment factors for some metals(Zn, Cu, Pb, Cd), based on crustal Al, were significantly greater than unity, and the order was Cd > Pb > Zn > Cu. This evidence suggests Cd and Pb are derived predominantly from non-crustal sources. Al, Fe and Mn contents showed good correlation with each other. Therefore this enrichment factor indicates similar geochemical behavior of these elements. The annual wet depositional flux(㎎/㎡/yr) from P1 site was as follows: Al (121.1), Fe,(177.2), Zn(12.9), Mn(6.19), Pb(14.4), Cu(0.64), Ni(1.03), Cd(1.02) and Co(1.01).
Pyrite contained in wasted ore dumps induces a strong acid environment when it contacts oxygenated rainfall. Present research was designed to evaluate the pollution of an area that is supposedly contaminated by pyrite of ore wasted dumps form in Chonju Il Mine. Measured are the pH and selected heavy metal elements in the supposedly polluted hydrologic system. The samples include three types those collected from the stream waters; those from the stream sediments; and those from the rice field soil scattered over the area. The dispersion path of the pollution source was also traced.
The pH of the hydrologic system ranged from 3.44 to 5.46, which clearly indicates that the area is on the acid environment. The pH tends to rise as the distance from the minehead increases. The content of heavy metal elements dissolved in the stream water varies as follows; Mn=69.73∼1.99ppm, Cd=0.02∼0.03ppm, Zn=0.77∼1.18ppm, Cu=0.04∼0.13ppm, Pb=0.22∼0.32ppm. The stream water in this state may induce serious heavy metal pollution to the agricultural land and the water for human life especially in the villages down the stream. The content of heavy metal elements dissolved in the stream sediment varies as follows; Mn=245.0∼4685.0ppm, Cd=10.0∼15.0ppm, Zn=105.0∼210.0ppm, Cu=65.0∼155.0ppm, Pb=90.0∼150.0ppm. The content of heavy metal elements dissolved in the rice field soil varies as follows; Mn=185.0∼260.0ppm, Cd=10.0∼15.0ppm, Zn=135.0∼180.0ppm, Cu=65.0∼90.0ppm, Pb=100.0∼130.0ppm. The pollution index in the stream sediment and the rice field soil is 1.36∼2.03, which shows that pollution had already begun all over the area where the samples were collected.
Thirty-eight sediment samples collected from the Youngsan River channel were analysed for Fe, Mn, Co, Cr, Cu, Ni, Zn and Pb to recognize the extent of contamination. Results showed that a wide range of contents was apparent for every metal over the study area. These differences have been mainly related to the textural variability of sediments. Exceptions to this were found in the contents of Cu, Zn, Pb and possibly Mn. The contents of Cu, Zn, Pb and Mn were particularly higher in the sediments from the confluence of tributaries. Downstream profile of metal/Al ratios indicates that pollutant inputs from the Kwangju tributary are mainly responsible for enrichment of these metals in bed sediments of the Youngsan River.
Adsorption of metal elements onto illite and halloysite was investigated at 25℃ using pollutant water collected from the gold-bearing metal mine. Incipient solution of pH 3.19 was reacted with clay minerals as a function of time: 10 minute, 30 minute, 1 hour, 12 hour, 24 hour, 1 day, 2 day, 1 week, and 2 week. Twenty-seven cations and six anions from solutions were analyzed by AAs (atomic absorption spectrometer), ICP(induced-coupled plasma), and IC (ion chromatography). Speciation and saturation index of solutions were calculated by WATEQ4F and MINTEQA2 codes, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and relative abundances between initial solution and reacted solutions. The adsorption results showed that the adsorption extent of elements varies depending on mineral types and reaction time. As for illite, adsorption after 1 hour-reaction occurs in the order of As〉Pb〉Ge〉Li〉Co, Pb, Cr, Ba〉Cs for trace elements and Fe〉K〉Na〉Mn〉Al〉Ca〉Si for major elements, respectively. As for halloysite, adsorption after 1 hour-reaction occurs in the order of Cu〉Pb〉Li〉Ge〉Cr〉Zn〉As〉Ba〉Ti〉Cd〉Co for trace elements and Fe〉K〉Mn〉Ca〉Al〉Na〉Si for major elements, respectively. After 2 week-reaction, the adsorption occurs in the order of Cu〉As〉Zn〉Li〉Ge〉Co〉Ti〉Ba〉Ni〉Pb〉Cr〉Cd〉Se for trace elements and Fe〉K〉Mn〉Al, Mg〉Ca〉Na, Si for major elements, respectively. No significant adsorption as well as selectivity was found for anions. Although halloysite has a 1:1 layer structure, its capacity of adsorption is greater than that of illite with 2:1 structure, probably due to its peculiar mineralogical characteristics. According to FTIR (Fourier transform infrared spectroscopy) results, there was no shift in the OH-stretching bond for illite, but the ν1 bond at 3695 cm-1 for halloysite was found to be stronger. In the viewpoint of adsorption, illite is characterized by an inner-sphere complex, whereas halloysite by an outer-sphere complex, respectively. Initial ion activity and dissociation constant of metal elements are regarded as the main factors that control the adsorption behaviors in a natural system containing multicomponents at the acidic condition.