Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
Vùng đất than bùn Minerotrophic bồn tự nhiên đối với asen (As) trong groundwaters: chúng loại bỏ Kể từ vùng nước đầu vào như họ tích lũy Như trong than bùn. Trong Gola di Lago (GdL), Canton Ticino, Thụy Sĩ, nồng độ trong than bùn rất cao (khoảng 150x) so với giá trị "nền". Nước suối vào đất than bùn này chứa lên đến 400 g / L Như, nhưng vùng biển rời khỏi đất than bùn chứa ít hơn 2 g / L | Natural Arsenic in Groundwater Occurrence Remediation and Management -Bundschuh Bhattacharya and Chandrasekharam eds 2005 Taylor Francis Group London ISBN 04 1536 700 X Natural enrichment of arsenic in a minerotrophic peatland Gola di Lago Canton Ticino Switzerland and implications for the treatment of contaminated waters Z.I. González-A. M. Krachler A.K. Cheburkin W. Shotyk Institute of Environmental Geochemistry Heidelberg University Heidelberg Germany ABSTRACT Minerotrophic peatlands are natural sinks for arsenic As in groundwaters they remove As from input waters as they accumulate As in peat. In Gola di Lago GdL Canton Ticino Switzerland As concentrations in peat are highly elevated ca. 150x compared to background values. Stream waters entering this peatland contain up to 400 g L As but the waters leaving the peatland contain less than 2 g L. The rates and mechanisms of this process have not yet been studied but offer great promise for the low-cost treatment and remediation of As-bearing waters by natural wetlands. The main goal is to understand how As is removed from the incoming fluid by the peat. We present here a panorama of our research methodology previous results and future work. 1 INTRODUCTION Elevated concentrations of arsenic As in groundwaters represent a potential health hazard in many countries including Argentina Bangladesh China Ghana Hungary India Laos Mexico Mongolia Myanmar Nepal Pakistan Sumatra Taiwan and Vietnam Bhattacharya et al. 2002 Berg 2003 . Arsenic is a metalloid widely distributed in the earth s crust with a typical abundance on the order of 2 mg kg. It occurs in trace quantities in all rocks soils waters and air. Arsenic can exist in four valences states 3 0 3 and 5. Under reducing conditions arsenite As III is the dominant form arsenate As V is generally the stable form in oxygenated environments. Elemental arsenic is not soluble in water. Arsenic salts exhibit a wide range of solubilities depending on pH and the ionic strength
