Water environment

About: Water environment is a research topic. Over the lifetime, 13384 publications have been published within this topic receiving 125138 citations.

Eco-environmental degradation in the source region of the Yellow River, Northeast Qinghai-Xizang Plateau.

Abstract: The Yellow River is the second longest river in China and the cradle of the Chinese civilization. The source region of the Yellow River is the most important water holding area for the Yellow River, about 49.2% of the whole runoff comes from this region. However, for the special location, it is a region with most fragile eco-environment in China as well. Eco-environmental degradation in the source region of the Yellow River has been a very serious ecological and socially economic problem. According to census data, historical documents and climatic information, during the last half century, especially the last 30 years, great changes have taken place in the eco-environment of this region. Such changes are mainly manifested in the temporal-spatial changes of water environment, deglaciation, permafrost reduction, vegetation degeneracy and desertification extent, which led to land capacity decreasing and river disconnecting. At present, desertification of the region is showing an accelerating tendency. This paper analyzes the present status of eco-environment degradation in this region supported by GIS and RS, as well as field investigation and indoor analysis, based on knowledge, multi-source data is gathered and the classification is worked out, deals with their natural and anthropogenic causes, and points out that in the last half century the desertification and environmental degradation of this region are mainly attributed to human activities under the background of regional climate changes. To halt further degradation of the environment of this region, great efforts should be made to use land resources rationally, develop advantages animal agriculture and protect the natural grassland.

Molecular Approaches and Breeding Strategies for Drought Tolerance in Barley

Abstract: Barley genotypes, in particular landraces and wild species, represent an important source of variation for adaptive traits that may contribute to increase yield and yield stability under drought conditions, and that could be introgressed into improved varieties. Traits that have been investigated include physiological/biochemical and developmental/ morphological traits. Yield performance under drought is particularly a complex phenomenon, and plants exhibit a diverse range of genetically complex mechanisms for drought resistance. Quantitative trait loci (QTL) studies with and without H. spontaneum have shown that developmental genes, notably those involved in flowering time and plant stature show pleiotropic effects on abiotic stress tolerance and ultimately determine yield. Problems associated with the hybridization of H. spontaneum such as alleles with deleterious effects on field performance could be best addressed in the advanced backcross (AB-) QTL analysis. It was interesting to see that in AB-QTL populations like in balanced populations major QTL overshadowed minor QTL-alleles. Nevertheless, crosses with H. spontaneum, AB-QTL populations and association studies with H. spontaneum have also identified new alleles and genes that are related to abiotic stress tolerance. In order to identify genes that are related to drought tolerance microarrays analysis to monitor gene expression profiles for plants exposed to limited water environment is performed. Several studies with rapid dehydration treatment have shown that osmotic-stress-inducible genes could explain the response to drought stress in plants. Another development is the identification and use of nucleotide polymorphisms (SNP) in genes related to abiotic stress tolerance. An understanding of the combined function and expression of genes involved in various abiotic stresses, could help identify candidate genes underlying QTL of interest.

Amidoxime-functionalized metal-organic frameworks UiO-66 for U(VI) adsorption from aqueous solution

Abstract: In order to improve the U(VI) adsorption capacity of the metal-organic frameworks UiO-66 in the acidic water environment, UiO-66-AO nanocrystals were synthesized on the basis of literature for the first time Scanning electron microscopy and Fourier transform infrared spectra revealed that the successful synthesis of UiO-66-AO nanoparticles The UiO-66-AO nanocomposites were used to remove U(VI) from aqueous solution UiO-66-AO showed the effective adsorption of U(VI) compared to UiO-66 in the acidic environment and Fe3O4@SiO2-AO in the neutral or alkaline environment, respectively The adsorption isotherms of the nanocomposites could be described very well by the Freundlich equation with ultra-high maximum adsorption capacity of 2278 mg/g The synergistic effect of the amidoxime group and the metal-organic frameworks UiO-66 has great significance for the extraction of U(VI) from seawater and industrial wastewater

Gravity Sanitary Sewer Design and Construction

Abstract: Prepared by a Joint Task Force of the Environment and Water Resources Institute and the Committee on Pipeline Planning of the Pipeline Division of ASCE and the Collection Systems Subcommittee of the Technical Practice Committee of the Water Environment Federation (WEF) Gravity Sanitary Sewer Design and Construction provides theoretical and practical guidelines for the design and construction of gravity sanitary sewers. This new edition covers the administrative and organizational phases of sanitary sewer projects, as well as the parameters necessary to establish the design criteria, complete the design, and award a construction contract. The manual offers an in-depth discussion of commonly used trenchless and conventional methods of sanitary sewer construction. With its liberal use of charts, illustrations, and case studies, this practical manual is an indispensable resource for engineers in the field of sanitary sewer structural and hydraulic design.