Removal of phosphate from water by a highly selective La(III)-chelex resin

A new polymer ligand exchanger (PLE) has been developed for the removal of phosphate in wastewater. This PLE, consisting of lanthanum(III) bound to chelex-100 resin, was prepared by passing LaCl3 solution through a column of chelex-100. Uptake of phosphate from water by this La-chelex resin was investigated in the column mode. The La-chelex resin was able to remove phosphate efficiently from water, and the uptake of phosphate was not affected by the presence of large amounts of anions (0.1M) such as chloride and sulfate. The La-chelex resin was also able to efficiently remove phosphate from seawater to <0.1mg-Pl(-1), and regenerated for reuse by removing the sorbed phosphate by eluting with 6M HCl.     

The Sensitivity of California Water Resources to Climate Change Scenarios1

Abstract: Using the latest available General Circulation Model (GCM) results we present an assessment of climate change impacts on California hydrology and water resources. The approach considers the output of two GCMs, the PCM and the HadCM3, run under two different greenhouse gas (GHG) emission scenarios: the high emission A1fi and the low emission B1. The GCM output was statistically downscaled and used in the Variable Infiltration Capacity (VIC) macroscale distributed hydrologic model to derive inflows to major reservoirs in the California Central Valley. Historical inflows used as inputs to the water resources model CalSim II were modified to represent the climate change perturbed conditions for water supply deliveries, reliability, reservoir storage and changes to variables of environmental concern. Our results show greater negative impacts to California hydrology and water resources than previous assessments of climate change impacts in the region. These impacts, which translate into smaller streamflows, lower reservoir storage and decreased water supply deliveries and reliability, will be especially pronounced later in the 21st Century and south of the San Francisco bay Delta. The importance of considering how climate change impacts vary for different temporal, spatial, and institutional conditions in addition to the average impacts is also demonstrated.     

Occurrence and risk assessment of organophosphate esters in urban rivers from Piracicaba watershed (Brazil)

Environmental Science and Pollution Research - Organophosphate esters (OPEs) are substances globally used as flame retardants and plasticizers that have been detected in all environmental...     

Applicability of Montreal Process Criterion 5 — maintenance of rangeland contribution to global carbon cycles

SUMMARY

Within the Montreal Process, Criterion 5 — Maintenance of Forest Contribution to the Global Carbon Cycle — encompasses: Indicator 26, biomass and carbon pools; Indicator 27, carbon fluxes from these pools; and Indicator 28, contribution of forest products. I have reviewed the applicability of each indicator to rangelands, the potential limitations of these indicators for rangelands ecosystems, the data available to quantify these indicators and have identified research needs. Indicator 26, and 27 are applicable to rangeland ecosystems. Estimation of the total ecosystem biomass and carbon pools from rangelands is currently feasible, albeit precision is limited by data availability. Simulation models quantify fluxes from rangeland ecosystems, however, belowground dynamics, particularly under changing management, are not well known. For Indicator 28, rangeland products do not constitute a large potential for carbon sequestration.     

Varying responses of northeastern North American amphibians to the chytrid pathogen Batrachochytrium dendrobatidis

Chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is widespread among amphibians in northeastern North America. It is unknown, however, whether Bd has the potential to cause extensive amphibian mortalities in northeastern North America as have occurred elsewhere. In the laboratory, we exposed seven common northeastern North American amphibian species to Bd to assess the likelihood of population-level effects from the disease. We exposed larval wood frogs (Lithobates sylvaticus) and postmetamorphic frogs of six other species to two different strains of Bd, a northeastern strain (JEL404) and a strain that caused die-offs of amphibians in Panama (JEL423), under ideal in vitro growth conditions for Bd. Exposed American toads (Anaxyrus americanus) all died; thus, this species may be the most likely to die from Bd-caused disease in the wild. Both Bd strains were associated with mortalities of wood frogs, although half the metamorphs survived. The Bd strain from Panama killed metamorphic green frogs (L. clamitans), whereas the northeastern strain did not, which means novel strains of Bd may lead to death even when local strains may not. No mortality was observed in four species (bullfrogs [L. catesbeianus], northern leopard frogs [L. pipiens], spring peepers [Pseudacris crucifer], and blue-spotted salamanders [Ambystoma laterale]) and in some individuals of green frogs and wood frogs that we exposed. This finding suggests these six species may be Bd vectors. Our results show that systematic exposures of amphibian species to Bd in the laboratory may be a good first step in the identification of species susceptible to Bd-caused declines and in directing regional conservation efforts aimed at susceptible species.     

Safety climate dimensions,leader–member exchange,and organizational support as predictors of upward safety communication in a sample of rail industry workers

The freedom employees feel to communicate safety concerns with their supervisors, termed upward safety communication, has been shown to be related to adverse safety events (Hofmann and Morgeson, 1999). Research to date has demonstrated that good supervisor–employee relationships (leader–member exchange), a sense that the organization values an employee (perceived organizational support) and safety climate (including perceived management attitudes toward safety, job demands interfering with safety, and pressure from coworkers to behave safely) all contribute to employees’ comfort in bringing up safety issues with their supervisors. However, little is known about which specific dimensions of safety climate are most predictive of upward safety communication. Using a sample of 548 railway workers, we found that when all factors were considered simultaneously using dominance analysis, the dominant factor predicting upward safety communication was perceived management attitudes toward safety, followed by job demands interfering with safety and then leader–member exchange. Implications for research and practice are discussed.     

Cloud Albedo,Greenhouse Effects,Atmospheric Chemistry,and Climate Change

Changes in global atmospheric chemistry and climate are taking place as a result of observed trends in long-lived species such as CO₂, CH₄, N₂O, and the CFCs. The continuation of these trends is expected to eventually lead to a major atmospheric warming that might profoundly affect the society we live in. Trends in short-lived species such as NOx and SOx are also suspected. These trends are not as well established, because the shorter-lived species vary spatially and temporally. Trends in NOx would be expected to lead to increases in tropospheric ozone that would add to the warming created by the other greenhouse gases. Trends in NOx could also alter tropospheric OH concentrations that could lead to changes in CH₄ and some of the CFCs. On the other hand, increases in sulfur emissions may alter cloud optical properties. The changes in cloud optical properties could possibly offset the warming expected from increases in greenhouse gases, depending on the role of natural oceanic sulfur emissions. This paper summarizes recent research in these areas and the interactions of climate and atmospheric chemistry.     

运用卫星数据和来自国家森林清查的野外数据进行全国森林变量估计

瑞典约有55%的土地面积被森林所覆盖.目前,瑞典的森林覆盖没有统一的和地理学上明晰的描述.现存的独立性数据源是Landsat TM和SPOT HRV卫星数据、地图蒙片(map mask)和森林清查样地.它们在一起,使森林变量(如材枳和林分年龄)的计算机估计成为可能.这些估计的精确度在像素水平上是低的,但在林分水平上较高.在规划木材资源应如何加以利用或出于监测目的时,这类基于栅格的森林数据对政府来说是有帮助的.本文描述了以有效成本建立森林变量估计全国数据库的生成流程.我们在林分水平上评价了瑞典西南部某地森林变量估计的精确度.结果表明,总材积估计的整体均方根误差为33%,年龄估计的整体均方根误差为23%.