This study was conducted to determine the contents of heavy metals in leaves of roadside trees according to different growth stages in Daegu city. The orders of heavy metal contents in leaves of roadside tree and soil were Fe＞Mn＞Zn＞Pb＞Cu＞Cr＞Cd and Fe＞Mn＞Zn＞Cu＞Pb＞Cr＞Cd, respectively. The contents of heavy metals in leaves of roadside trees and soil showed an increasing tendency as the levels of traffic volume increased. The contents of heavy metals in leaves on October were higher than those on May. Zelkova serrata and Ginkgo biloba showed high contents of Cr, Cd and Pb.

This experiment was carried out to investigate the effects of heavy metals (copper, cadmium, lead and chrome) on the growth of plant and seed germination of Arabidopsis thaliana treated with various concentrations of heavy metals. Cadmium and chrome among the 4 heavy metals had no effect on the growth of stem even in the concentration fifty times higher than the official standard concentration of pollutant exhaust notified by the Ministry of Environment. The official standard concentration of cadmium, however, stimulated the growth of stem in general, increasing leaf size and surface area, although it had no effect on the length of stem. But the growth of stem was decreased about 18% in the official standard concentration of pollutant exhaust of lead and copper. There was no growth of root in the concentration of lead and copper ten times higher than the official standard concentration. Cadmium and chrome had no effect on the seed germination, but lead and copper decreased the rate of seed germination. Seeds were not germinated in the concentration of copper ten times higher than the official standard concentration and in the concentration of lead fifty times higher than the official standard concentration. From this research three peculiar results were obtained. Chrome in the soil did not have much effect on the plant growth and seed germination of Arabidopsis thaliana. Cadmium stimulated the stem growth in an optimum concentration. But lead and copper reduced the plant growth and seed germination even in a small concentration, especially copper had the worse effect.

The toxicity values of various heavy metals were evaluated by acute immobilization and chronic reproduction impairment tests, using Daphnia magna. Acute tests were evaluated by the inhibition of their mobilization after 24hrs without food addition. The tests of reproductive impairment were investigated for 21 days by food addition and exchange of water. The effect of each concentration was assessed by Probit analysis and t-test. The results obtained from this study were as follows : 1) The change of pH and DO was not significant in the acute tests, while, in the reproductive tests, pH was increased by 0.3∼1.4 and DO also increased. 2) The EiG50 values of immobilization to Daphnia magna in artificial fresh water were 0.030㎎/ℓ(Cu), 0.054㎎/ℓ(Cd), 0.12㎎/ℓ(Cr), 0.74㎎/ℓ(Pb), 3.4㎎/ℓ(As) and the NOEiC values were 0.010㎎/ℓ(Cu), 0.018㎎/ℓ(Cd), 0.010㎎/ℓ(Cr), 0.10㎎/ℓ(Pb), and 1.8㎎/ℓ(As). 3) The EiC50 values of reproductive impairment to Daphnia magna were 13.8㎍/ℓ(Cu), 2.9㎍/ℓ(Cd), 15.5㎍/ℓ(Cr), 61.7㎍/ℓ(Pb), 759㎍/ℓ(As), and NOErC values were 0.95㎍/ℓ(Cu), 0.54㎍/ℓ(Cd), 1.2㎍/ℓ(Cd), 7.4㎍/ℓ(Pb), 110㎍/ℓ(As). The results of tests using OECD artificial culture water were more sensitive than natural water for culturing. The presented data show that an artificial culture water is suitable in the experiment of bioassay for assessing the toxicity of materials.

In order to examine the availability and effectiveness of crab shell for the removal of heavy metals in aqueous solution, the crab shell was compared with cation exchange resin (CER), zeolite, granular activated carbon (GAC) and powdered activated carbon (PAC) on aspects of heavy metal removal capacity, rate and efficiency. In the removal of Pb, Cd and Cr, the heavy metal removal capacity of crab shell was higher than those of any other sorbents (CER, zeolite, GAC, PAC), and the order of heavy metal removal capacity was crab shell > CER > zeolite > PAC =～GAC. However, in the removal of Cu, the result of crab shell was slightly lower than that of CER. The initial heavy metal removal rate was affected by the sorts of sorbents and metals. In all heavy metals, the heavy metal removal rate of crab shell was higher than those of any other sorbents. Under the heavy metal concentration of 1.0 mmole/ℓ, the heavy metal removal efficiency of crab shell was maintained as 93∼100 %, which was much higher than those of any other sorbents.

The hydroxyapatite (HAp) for the present study was prepared by precipitation method in semiconductor fabrication and the crystallized at ambient to950℃ for 30min in electric furnace. The ion-exchange characteristics of HAp for various heavy metal ions such as Cd2+, Cu2+, Mn2+, Zn2+, Fe3+, Pb2+, Al3+, and Cr6+ in aqueous solution has been investigated. The removal ratio of various metal ions for HAp were investigated with regard to reaction time, concentration of standard solution, amount of HAp and pH of solution. The order of the ions exchanged amount was as follows: Pb2+, Fe3+>Cu2+>Zn2+>Al3+>Cd2+>Mn2+>Cr6+. The Pb2+ ion was readily removed by the HAp, even in the strongly acidic region. The maximum amount of the ion-exchange equilibrium for Pb2+ ion was about 45 ㎎/gram of HAp. The HAp would seem to be possible agent for the removal of heavy metal ions in waste water by recycling of waste sludge in semiconductor fabrication.

In order to determine the changes of sediment facies and metal levels in surface sediments after the construction of Shiwha Lake, surface sediments were sampled at 8 sites located on the main channel monthly from June, 1995 to August, 1996 and analysed for 12 metals (Al, Fe, Mn, V, Cr, Co, Ni, Cu, Zn, Cd, As and Pb) by ICP/AES and ICP/MS. Two groups of sampling sites (the inner lake with 3 sites and the outer lake with 5 sites) are subdivided by the surface morphology; the inner lake is a shallow channel area with a gentle slope, while the outer lake is relatively deep and wide channel with a steep slope which has many small distributaries. After the construction of dam, fine terrestrial materials were deposited near the outer lake, which resulted in the change of major sediment facies from sandy silt to mud. With the deposition of fine sediments in the outer lake, anoxic water column induced the formation of sulfide compounds with Cu, Cd, Zn and part of Pb. Metal (Cr, Ni, Cu, Zn and Cd) contents in sediments increased up to twice within 2 years after the construction of dam. This is due to the direct input of industrial and municipal wastes into the lake and the accumulation of metals within the lake. In addition, frequent resuspension of contaminated sediments in a shallow part of the lake may make metal-enriched materials transport near the outer lake with fine terrestrial materials. As the enrichment of Cu, Zn, Cd and part of Pb in the Shiwha Lake may be related to the formation of unstable sulfide compounds by sulfate reduction in anoxic water or sediment column, the effect of mixing with open coastal seawater is discussed.

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).

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.

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).

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.

Laboratory experiments for the removal efficiency of heavy metals in land application of sludge, the accumulation and translocation of heavy metals in x plants after transplanting, and the responses of Minari growth with different ratio of land application of sludge were conducted to determine the potential ability of bioremediation with Minari plants. The removal rate and translocation of copper. zinc. lead. and cadmium in soil and plants were compared after transplanting the Minari plants to soil treated with different ratio of sludge. The removal efficiency of heavy metals in soil incorporated with sludge was different with application ratio, but increased with growing periods of Minari plants. The removal efficiency of Cu, Zn, Pb, and Cd ranged from 67 to 74% from 51% to 63%, from 37% to 71%. and from 15% to 25% after 45 days of transplanting. respectively. The amount removed the copper value. 65.9 mg/kg, observed to be highest in soil incorporated 3% sludge after 45 days. The translocation of Cu. Zn. Pb. and Cd from shoots to roots ranged from 18 to 53%, from 17 to 32%, from 14 to 49%, and from 23 to 38% over growing periods. respectively. In plant responses it appeared to be inhibited the plant growth in the treatment compared with the control at early stage of growth. However, the fresh weights of Minari plant increased from 12.5 to 62.5% in the sludge application after 45 days relative to the control. Therefore the Minari might play a useful role in bioremediation of Cu, Zn, Pb, and Cd in the land application of sludge.

This study was performed to investigate the utilization of waste concretes for neutralization and removal of heavy metals in plating wastewater, because waste concretes have been known to be very porous, to have high specific surface area and to have alkaline minerals such as calcium. The results obtained from this research showed that waste concretes had a buffer capacity to neutralize an acidic alkali system in plating wastewater. Generally, neutralization and removal rate of heavy metals were excellent in the increase of waste concrete amounts and a small size. Because a coefficient of correlation was high, it seemed that removal of heavy metals could be explained by Freundlich and Langmuir isotherms. If we reflected the adsorption capacity(k) and adsorption intensity(l/n) of Freundlich isotherm, we couldn`t consider waste concretes as a good adsorbent, But, we could know that waste concretes were capable of removing a part of heavy metals. In point of building waste debris, if waste concretes substituted for a valuable adsorbent such as actviated carbon, they could look forward to an expected economical effect.

We investigated concentrations of heavy metals(Cr, Cd, Zn, Fe, Pb, Cu, and Mn) and correlations between concentrations of heavy metals in the sediment, soil, weeds, and vegetables on the lower Nakdong river. Concentrations of heavy metals on the lower Milyang river was generally lower than those of other sampling area. In the soil, concentration of Pb is generally larger than that of other heavy metals. Generally, concentrations of heavy metals in the sediment show decreasing tendency as the sampling area moves toward downstream of the river, but those of in the soil and weeds show increasing tendency. There is no significant correlation between concentration of heavy metals in the soil-sediment, soil-vegetables, sediment-weeds, or vegetables-weeds. Only concentrations of Pb in the vegetables and those of in the weeds show very high correlation.

The incineration tests of mixed industrial wastes using the stoker type incinerator are carried out to investigate the partitioning characteristics of heavy metals during incineration. The results obtained from this study are as follow. The partitioning characteristics of heavy metals throughout this incinerator are found that, at given condition of 700℃, the elements with the relatively high boiling point such as Cr, Cu and Pb are partitioned into a bottom ash, a fly ash captured by cyclone, and a flue gas stream, 67∼88%, 2∼19% and 6∼16% of initial amount entering the incinerator, respectively, but the Cd and Hg of 75∼81% is vaporized into the flue gas. It appears that the partitioning characteristics according to the particle size of ash is different between the bottom ash and the fly ash. For bottom ash, the fraction of partitioning into 75㎛ oversized particles is relatively high. For fly ash, the characteristics of distributions with the particle size can not be clearly shown.