Washing is a promising method for separating contaminants bound to the particles of soil ex-situ by chemical mobilization. Laboratory batch washing experi- ments were conducted using deionized water and varying concen...Washing is a promising method for separating contaminants bound to the particles of soil ex-situ by chemical mobilization. Laboratory batch washing experi- ments were conducted using deionized water and varying concentrations of oxalic acid, citric acid, tartaric acid, acetic acid, hydrochloric acid and ethylenediaminetetra acetic acid （EDTA） to assess the efficiency of using these chemicals as washing agents and to clean up heavy metals from two heavily polluted soils from an iron and streel smelting site. The toxicity reduction index and remediation costs were analyzed, and the results showed that the soils were polluted with Cd, Pb and Zn. Hydrochloric acid and EDTA were more efficient than the other washing agents in the remediation of the test soils. The maximum total toxicity reduction index showed that 0.5 mol·L^-1 hydro- chloric acid could achieve the remediation with the lowest costs.展开更多
Archaeological research at the Sungai Batu Archaeological Complex(SBAC),which has been carried out until 2023,aims to complete the chronological data and urbanization process of the ancient Kedah.This study will espec...Archaeological research at the Sungai Batu Archaeological Complex(SBAC),which has been carried out until 2023,aims to complete the chronological data and urbanization process of the ancient Kedah.This study will especially prove that the ongoing urbanization process is aimed at developing the iron smelting industry and trade in ancient Kedah,especially in SBAC.This is because archaeological research at SBAC has proven that with the existence of the ancient Kedah iron smelting workshop at SBAC,river jetties,port management,rituals,and Buddhist monuments began to be erected,all of which can be determined by chronometric dating.The results of the chronometric dating have proven that the ancient Kedah Kingdom existed since the 6th century BC and was oriented towards the trade of iron resources,which allowed the use of the area to grow rapidly.The process of urbanization and land use clearly conforms to Lynch’s principle,which emphasizes the principles of 1)paths,2)edges,3)districts,4)nodes,and 5)landmarks in the development process of land use and urbanization in the complex.展开更多
文摘Washing is a promising method for separating contaminants bound to the particles of soil ex-situ by chemical mobilization. Laboratory batch washing experi- ments were conducted using deionized water and varying concentrations of oxalic acid, citric acid, tartaric acid, acetic acid, hydrochloric acid and ethylenediaminetetra acetic acid （EDTA） to assess the efficiency of using these chemicals as washing agents and to clean up heavy metals from two heavily polluted soils from an iron and streel smelting site. The toxicity reduction index and remediation costs were analyzed, and the results showed that the soils were polluted with Cd, Pb and Zn. Hydrochloric acid and EDTA were more efficient than the other washing agents in the remediation of the test soils. The maximum total toxicity reduction index showed that 0.5 mol·L^-1 hydro- chloric acid could achieve the remediation with the lowest costs.
基金This study was conducted under the grant of Malaysian(1001/PARKE0/870015)Global Archaeological Research(304/PARKE0/650953/L127).Authors are thankful to Center for Global Archaeological Research(CGAR),University Sains Malaysia,Pulau Pinang,Malaysia,for providing all necessary facilities to successfully conducting this research.
文摘Archaeological research at the Sungai Batu Archaeological Complex(SBAC),which has been carried out until 2023,aims to complete the chronological data and urbanization process of the ancient Kedah.This study will especially prove that the ongoing urbanization process is aimed at developing the iron smelting industry and trade in ancient Kedah,especially in SBAC.This is because archaeological research at SBAC has proven that with the existence of the ancient Kedah iron smelting workshop at SBAC,river jetties,port management,rituals,and Buddhist monuments began to be erected,all of which can be determined by chronometric dating.The results of the chronometric dating have proven that the ancient Kedah Kingdom existed since the 6th century BC and was oriented towards the trade of iron resources,which allowed the use of the area to grow rapidly.The process of urbanization and land use clearly conforms to Lynch’s principle,which emphasizes the principles of 1)paths,2)edges,3)districts,4)nodes,and 5)landmarks in the development process of land use and urbanization in the complex.
