Occurrence,fate, and transport of potentially toxic metals (PTMs) in an alkaline rhizosphere soil-plant (Maize,Zea mays L.) system: the role of Bacillus subtilis

Environmental Science and Pollution Research - Utilization of microbes is one of the most promising methods to remediate potentially toxic metals (PTMs) from soil. In this study, a systematic...     

Ten years later: The progress and future of integrating sustainable principles,practices, and metrics into remediation projects

In 2009, the Sustainable Remediation Forum released a white paper entitled “Integrating sustainable principles, practices, and metrics into remediation projects” (Ellis & Hadley, 2009, Remediation, 19, pp. 5–114). Sustainable remediation was a relatively new concept, and the white paper explored a range of approaches on how sustainability could be integrated into traditional remediation projects. This paper revisits the 2009 white paper, providing an overview of the early days of the evolving sustainable remediation practice and an assessment of the progress of sustainable remediation over the last 10 years with a primary focus on the United States. The current state of the sustainable remediation practice includes published literature, current practices and resources, applications, room for improvement, international progress, the virtuous cycle that applying sustainable remediation creates, and the status of the objectives cited in the 2009 white paper. Over the last decade, several sustainable remediation frontiers have emerged that will likely be a focus in advancing the practice. These frontiers include climate change and resiliency, weighting and valuation to help better consolidate different sustainable remediation metrics, programmatic implementation, and better integration of the societal impacts of sustainable remediation. Finally, as was the case for the 2009 white paper, this paper explores how sustainable remediation may evolve over the next 10 years and focuses on the events and drivers that can be significant in the pace of further development of the practice. The events and drivers include transformation impacts, societal influences, and the continued development of new technologies, approaches, and tools by remediation practitioners. The remediation industry has made significant progress in developing the practice of sustainable remediation and has implemented it successfully into hundreds of projects. While progress has been significant, an opportunity exists to implement the tenets of sustainable remediation on many more projects and explore new frontiers to help improve the communication, integration, and derived benefits from implementing sustainable remediation into future remediation projects.     

River use profile of the Central Niger Delta based on traditional eco-livelihood knowledge (TELK)

The Central Niger Delta is made up of a network of rivers and creeks that constitute the inland surface waters. These surface waters have historically influenced settlement patterns and are of diverse use to residents of the Central Niger Delta. Surface water like many ecological system are complex, whose complexity has been associated with seasonal variability. Traditional knowledge (TK), traditional ecological knowledge (TEK) and the traditional eco-livelihood knowledge (TELK) of residents of four rural communities in the Central Niger Delta have been explored in developing a river use profile of rural communities of the Central Niger Delta. A questionnaire survey has been carried out in four communities, two each from the Otuoke and Kolo Creeks. The result shows that river use varies across seasons and affected by: physico-chemical water quality and characteristics of surface water; the hydrological characteristics; the biological/ecological characteristics; cultural use and demand; need for development projects; and access to this vital resource. Fishing constitute one of the major livelihood source in the Central Niger Delta and the TELK of fishers in the sample communities have specifically been explored to understanding fishing patterns across seasons. The five seasons identified from this study are: flood season; flood recession season; dry season; early rainy season; and rainy season. Therefore, the thesis of this paper is that there is the need to balance the current usage of surface water in the developing world such as the Central Niger Delta with the demand for development as well as future use if development is to meet the criteria for equitable development. The river use profile could be a promising tool in planning for equitable development.

Comparison of biosorbents with inorganic sorbents for removing copper(II) from aqueous solutions

In comparison with several other reported inorganic sorbents, Camellia tree leaf and primary sludge obtained from a settling tank as a pretreatment to the activated sludge system in a Hong Kong sewage treatment plant were evaluated for removing Cu(II) from aqueous solutions. Experimental data were modeled by the Langmuir isotherm equation to estimate the maximum sorption capacity (q_max). Results show that, at pH 5.6, biosorbents, Camellia tree leaf and primary sludge in particular, exert higher sorption capacities (q_max > 40 mg g⁻¹) than inorganic sorbents, Na-montmorillonite (q_max = 33.3 mg g⁻¹), fly ash (q_max = 18.8 mg g⁻¹), and goethite powder (10.3 mg g⁻¹). Furthermore, a pseudo second-order kinetic model was found to properly describe the experimental data for both bio- and inorganic sorbents. Sorption of Cu(II) on the Camellia tree leaf and primary sludge were much faster than that on the inorganic sorbents. In addition, desorption tests revealed that the desorption capacities of the two biomaterials are higher than the other selected materials; and much more Cu(II) can be retrieved from the Cu(II)-loaded biosorbents. Finally, increasing solution pH was found to greatly increase q_max and accelerate sorption processes.     

High biomass removal limits carbon sequestration potential of mature temperate pastures

Decades of plowing have depleted organic C stocks in many agricultural soils. Conversion of plowed fields to pasture has the potential to reverse this process, recapturing organic matter that was lost under more intensive cropping systems. Temperate pastures in the northeast USA are highly productive and could act as significant C sinks. However, such pastures have relatively high biomass removal as hay or through consumption by grazing animals. In addition, the ability to sequester C decreases over time as previously depleted stocks are replenished and the soil returns to equilibrium conditions. The objective of this research was to use eddy covariance systems to quantify CO(2) fluxes over two fields in central Pennsylvania that had been managed as pastures for at least 35 yr. Net ecosystem exchange measurements averaged over 8 site-years suggested that the pastures were acting as small net C sinks of 19 g C m(-2) yr(-1) (positive values indicate uptake). However, when biomass removal and manure deposition were included to calculate net biome productivity, the pastures were a net source of -81 g C m(-2) yr(-1) (negative values indicate loss to the atmosphere). Manure generated from the hay that was consumed off site averaged 18 g C m(-2) yr(-1). Returning that manure to the pastures would have only partially replenished the lost C, and the pastures would have remained net C sources. Heavy use of the biomass produced on these mature pastures prevented them from acting as C sinks.     

Maternal age in the epidemiology of common autosomal trisomies

The birth prevalence rate of each common autosomal trisomy generally increases with advancing maternal age and there is a substantial fetal loss rate between late first trimester and term. The literature is reviewed in order to provide the best estimates of these rates, taking account where possible of biases due to prenatal diagnosis and selective termination of pregnancy. There is an almost exponential increase in Down syndrome birth prevalence between ages 15 and 45 but at older ages the curve flattens. There is no evidence of the claimed relatively high birth prevalence at extremely low ages. Gestation-specific intra-uterine fetal loss rates are estimated by follow-up of women declining termination of pregnancy after prenatal diagnosis, comparison of observed rates with those expected from birth prevalence and comparison of age-specific curves developed for prenatal diagnosis and birth. Down syndrome fetal loss rates reduce with gestation and increase with maternal age. Edwards and Patau syndrome birth prevalence is approximately 1/8 and 1/13 that of Down syndrome overall, although the ratio differs according to maternal age, particularly for Patau syndrome where it reduces steadily from 1/9 to 1/19. Fetal loss rates are higher for Edwards and Patau syndromes than for Down syndrome.