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CONTENTS
Volume 5, Number 2, June 2016
 

Abstract
In order to evaluate the contamination and health risk, levels of six hazardous elements i.e., Cr, Ni, Cu, As, Cd and Pb in soils of 12 different land-uses were measured. The average concentration of Cu, Cr, Ni, Pb, As and Cd in soils were 267, 239, 206, 195, 58 and 16 mg/kg, respectively. Levels of each metal exceeded the environmental action level for soils, which could pose significant risk to human. The metal concentrations were subsequently used to establish hazard indices (for adults and children) where the 5th and 95th percentile values were used to derive the hazard index through different exposure pathways (ingestion, dermal contact and inhalation). Considering the total exposure through each of the three pathways, the hazard index elucidates that there was a potency of non-cancer risk at most of the sites for both the adults and children. The findings of this study suggested that different land-use soils were severely contaminated with hazardous elements and attention is needed on the potential health risks to the exposed inhabitants.

Key Words
hazardous elements; land use; exposure pathways; health risk; Bangladesh

Address
Md. S. Islam: Department of Soil Science, Patuakhali Science and Technology University, Dumki,Patuakhali, 8602, Bangladesh

Md. S. Islam, Md. H. Al-Mamun: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai,Hodogaya-ku, Yokohama, Japan

Md. K. Ahmed: Department of Oceanography, University of Dhaka, Dhaka-1000, Bangladesh

Md. H. Al-Mamun: Department of Fisheries, University of Dhaka, Dhaka-1000, Bangladesh

Abstract
Urban geology is the study of urban geologic environments to provide a scientific basis for rational land use planning and urban development and provides information on geologic environments as a basis for city planners. Based on AEG recommendations, urban geological studies covered the urbanism and historical backgrounds, geological setting, engineering geological constraints and environmental assessments of understudied cities. The aim of this study is to provide a good view of urban geology of Tabriz city the capital of East Azerbaijan province in Iran. The topics of discussions about Tabriz city urban geology are included geologic (geomorphology, geology, climatology and hydrogeology), engineering geological (earthquake, landslide and geotechnical hazards investigations) and environmental characteristics (air, soil and water hazards assessment).The results of the urban geologic studies indicated that Tabriz city in terms of engineering geological and environmental constraints is at high risk potential and in terms of seismic activity and landslide instability is highly potential. In terms of air, soil and water pollution there are many important environmental concern in this city.

Key Words
Tabriz; Azerbaijan; geology; engineering geology; civilization

Address
Mohammad Azarafza and Akbar Ghazi: Department of Geology, University of Isfahan, Isfahan, Iran

Abstract
The Dhaka city, the capital of Bangladesh is one of the most densely populated cities in the world. Tongi canal is situated on the north of the city, which connected the Turag river to the west and the Balu river to the east. A total of 26 water samples were collected from the canal to measure irrigation water quality on the basis of their trace metal and major ionic constituents. Trace metals concentrations in water samples were determined using an Atomic Absorption Spectrophotometer. The amount of Fe, Mn, Zn and Pb in water samples ranged from 0.01-0.80, trace-1.02, trace-0.054 and 0.43-0.64

Key Words
urbanization and industrialization; metals; irrigation water quality; Tongi canal; Bangladesh

Address
H. M. Zakir, Md. Mahidul Islam and Md. Sohrab Hossain: Department of Agricultural Chemistry, Faculty of Agriculture, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh

Abstract
The paper is focused on the economic analysis of two hydrometallurgical processes for recovery of yttrium and other rare earth elements (REEs) from fluorescent phosphors of spent lamps. The first process includes leaching with sulphuric acid and precipitation of a mixture of oxalates by oxalic acid, the second one includes leaching with sulphuric acid, solvent extraction with D2EHPA, stripping by acid and recovery of yttrium and traces of other rare earths (REs) by precipitation with oxalic acid. In both cases the REEs were recovered as oxides by calcination of the oxalate salts. The economic analysis was estimated considering the real capacity of the HydroWEEE mobile´s plant (420 kg batch-1). For the first flow-sheet the cost of recycling comes to 4.0 € kg-1, while the revenue from the end-product is around 5.40 € kg-1. The second process is not profitable, as well as the first one, taking into account the composition of the final oxides: the cost of recycling comes to 5.2 € kg-1, while the revenue from the end-product is around 3.56 €kg-1. The process becomes profitable if the final RE oxide mixture is sold for nearly 50 € kg-1, a value rather far from the current market prices but not so unlikely since could be achieved in the incoming years, considering the significant fluctuations of the Res´ market.

Key Words
yttrium; fluorescent; rare earths; hydrometallurgy; lamps

Address
Valentina Innocenzi, Ida De Michelis, Francesco Ferella and Francesco Veglio: Department of Industrial Engineering, Information and Economy, University of L

Abstract
Large amounts of aluminum hydroxide (Al(OH)3) exist in water purification sludge (WPS) because of the added aluminum coagulant in water treatment process. Notably, Al(OH)3 is an amphoteric compound, can be dissolved in its basic condition using sodium hydroxide to form aluminate ions (Al(OH)4-). However, in a process in which pH is increasing, the humid acid can be dissolved easily from WPS and will inhibit the recovery and reuse of the dissolved aluminate ions. This study attempts to fix this problem by a novel approach to separate Al(OH)4 - ions using nanofiltration (NF) technology. Sludge impurity in a alkaline solution is retained by the NF membrane, such that the process recovers Al(OH)4 - ions, and significantly decreases the organic matter or heavy metal impurities in the permeate solution. The Al(OH)4- ion is an alkaline substance. Experimental results confirm that a recovered coagulant of Al(OH)4- ion can effectively remove kaolin particles from slightly acidic synthetic raw water.

Key Words
aluminate; nanofiltration membrane; recovery; coagulant

Address
Wen Po Cheng, Ruey Fang Yu and Dun Ren Tian: Department of Safety, Health and Environmental Engineering, National United University, No.1, Lienda, Miaoli 360, Taiwan, R.O.C

Fung Hwa Chi: Department of Environmental Engineering Kun Shan University, No.195, Kunda Rd., Yongkang Dist., Tainan City 710, Taiwan, R.O.C.


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