Effect of straw amendment and plant growth on selenium transfer in a laboratory soil-plant system

Abstract

Camps Arbestain, M. 1998. Effect of straw amendment and plant growth on selenium transfer in a laboratory soil-plant system. Can. J. Soil Sci. 78: [187][188][189][190][191][192][193][194][195]. Knowledge of the transfers of selenium (Se) in the soil-plant-atmosphere environmental compartments is fundamental in assessing Se cycling through the environment. The purpose of this study was to determine the effects of straw amendments and barley (Hordeum vulgare L.) on Se cycling in soils from Kesterson Reservoir, Merced County, CA (0.68 mg soluble Se kg -1 , 6.15 mg total Se kg -1 ), and to evaluate the feasibility of these agricultural practices as bioremediation strategies. Four treatments were evaluated: soil only, soil + straw, soil + plant, and soil + straw + plant. Straw amendments greatly reduced Se from soil solution (92-97% of initial soluble Se). Selenate [Se(VI)] was the predominant species in soil solution. Phosphate-extractable Se did not account for the decline in soluble Se. Selenium volatilized by microbes represented only 4-5% of the soluble Se removed. Highest Se removal from soil solution and highest Se volatilization rates occurred when both microbial activity and growth were maximal. Selenate microbial reduction to more insoluble Se forms is indicated as being responsible for this removal. Plants did not account for as much Se removal from soil solution as did straw amendments. Total shoot Se corresponded to 1-9% of soluble Se removal. At the end of the experiment, Se in plants represented 0.1-0.7% of total Se in the system, and the Se volatilized accounted for 0.2 to 0.5% of total Se inventory. The results obtained in this study suggest the use of straw amendments as a remediation technique for managing Se contamination at Kesterson Reservoir. ce qui s'expliquait en partie par la réduction microbienne des sélénates en formes de Se plus insolubles. La mise en culture n'avait pas un rôle aussi important que l'incorporation de paille dans le sol pour la réduction des concentrations de Se dans la solution du sol. Le Se total contenu dans les parties aériennes de la culture équivalait à 1-9 % du retrait total de Se soluble. Au terme de l'expérience, le Se contenu dans la culture ne formait que 0,1 à 0,7 % du sélénium total présent dans le système sol-plante et le Se volatilisé 0,2 à 0,5 %. Il ressort de ces observations que l'incorporation de paille au sol s'annonce comme une technique efficace de maîtrise biologique des niveaux de Se dans le Kesterson Reservoir.

Development of a Constructed Wetland Water Treatment System for Selenium Removal: Use of Mesocosms to Evaluate Design Parameters

“…; 32 they also increase Se removal through Se volatilization. 20,33 Soluble organic carbon sources (acetate, lactate, glucose, whey, trypticase soy agar, casein, methionine, and molasses) have been applied to enhance microbial reduction of Se 6+ and Se 4+ to Se 0 in contaminated water and soil 34−41 and to decrease potential competitive electron acceptors such as nitrate.…”

“…The anaerobic reduction of Se oxyanions to insoluble Se forms is the major pathway for Se removal in wetlands. , The addition of organic amendments to sediments and soils provide energy for the reduction and removal of SeO 4 2– and SeO 3 2– ; they also increase Se removal through Se volatilization. , Soluble organic carbon sources (acetate, lactate, glucose, whey, trypticase soy agar, casein, methionine, and molasses) have been applied to enhance microbial reduction of Se 6+ and Se 4+ to Se 0 in contaminated water and soil − and to decrease potential competitive electron acceptors such as nitrate …”

SELENIUM PRESENCE AND BEHAVIOUR IN SOIL AND PLANT: 1- Se IN GIZA GOVERNORATE, EGYPT.

“…While the values of threshold concern the above three equations around zero, show the absorption of Se by these plants porportionaly increases with increasing soil Se. Arbestain (1998) reported that total shoot Se corresponded to 1-9% of soluble Se removal.…”

Removal of Selenate in Simulated Agricultural Drainage Water by a Rice Straw Bioreactor Channel System

“…Organic amendments to Se‐contaminated soil and sediment have enhanced the immobilization of Se. For example, Camps Arbestain (1998) used straw as an organic source to increase immobilization of soluble Se in a soil–plant system and Tokunaga et al (1996) added cuttings of soft chess ( Bromus hordeaceus L.) leaves and stem into sediment to enhance the reduction of soluble Se(VI) to Se(0). In bioremediation of Se‐contaminated agricultural drainage water, Bledsoe et al (1999) used whey, a food‐industry waste product, to produce acetate, an essential electron donor for the bacterium Thauera selenatis to efficiently reduce Se(VI) to Se(0).…”