Effects of treated wastewater irrigation on the establishment of young grapevines

Irrigation with treated wastewater could produce excessive accumulations within the plant and soil, negatively affecting the yield and production quality. In addition, the presence of biological and chemical contaminants could harm the agricultural environment, as well as the health of farmers and consumers. During this work, the suitability of secondary and tertiary treated wastewater for use in young grapevines was evaluated by studying the effect of the wastewater irrigation on the soil-plant system, crop yield, fruit quality and the presence of inorganic chemical contamination (salts, elements and heavy metals), organic chemical contamination (polycyclic aromatic hydrocarbons) and microbial contamination (E. coli, total coliforms). The results show that tertiary treated wastewater had positive impact on plant growth and yield while secondary treated wastewater had negative impact on fruit safety in comparison with tap water. Sodium levels in soils irrigated with treated wastewater increased at the end of the irrigation period while decreased during the wet season. The total polycyclic aromatic hydrocarbon concentrations in the soils ranged from 363 μg/kg to 374 μg/kg at the end of the experiment for all irrigation treatments applied. The use of tertiary treated wastewater was recommended for the irrigation of young grapevines as an alternative water source secured protection of environment, plant health and fruit quality

Novel multi-stage aluminium production: part 1 � thermodynamic assessment of carbosulphidation of Al<inf>2</inf>O<inf>3</inf>/bauxite using H<inf>2</inf>S and sodiothermic reduction of Al<inf>2</inf>S<inf>3</inf>

© 2017 Institute of Materials, Minerals and Mining and The AusIMM Published by Taylor & Francis on behalf of the Institute and The AusIMMA novel multi-stage Al production through a carbosulphidation of Al2O3, followed by a sodiothermic reduction of Al2S3, was proposed. In Stage-1, alumina (or bauxite) is reduced to Al2S3 in the presence of carbon and H2S. In Stage-2, Al2S3 is reduced to Al through reactions with Na or NaH. The thermodynamic analysis predicted Al2S3 to be the main intermediate Al-compound when H2S is reacted with Al2S3 and C at 1000-2000°C at 1 atm. Al2S3 formation was predicted to be low at 1100-1300°C at 1 atm (0.1 moles/mole Al2O3) but increased with increasing temperature (0.96 moles/mole Al2O3 at 1800°C). The thermodynamic analysis of sodiothermic reduction predicted that Al metal can be extracted from Al2S3 below 800°C at 1 atm. The Na2S produced can be hydrolysed to form H2S and NaOH. H2S can be re-used and the Na can be reproduced from NaOH and put back into the process