Assessment of metal enrichments in tsunamigenic sediments of Pichavaram mangroves, southeast coast of India

The 26 December 2004-Tsunami has deposited sediments in the Pichavaram mangrove ecosystem, east coast of India. Ten surface and three core sediment samples were collected within thirty days of the event. High concentrations of Cd, Cu, Cr, Pb, and Ni were observed in the tsunamigenic sediments. With respect to Fe, Zn, and Mn, there was little variation as compared to pre-tsunami values. The geo-accumulation index was calculated in order to assess the contamination of heavy metals in the sediments. The sediments were extremely contaminated with respect to Cd and they showed moderate to strong contamination with respect to Cr, Pb and Ni. The study highlighted the future risk of enhanced metal pollution in near future in this mangrove ecosystem.     

Forest biomonitoring of the largest Slovene thermal power plant with respect to reduction of air pollution

The condition of the forest ecosystem in the vicinity of the largest Slovene power plant [the ?o?tanj Thermal Power Plant (?TPP)] was monitored during the period 1991–2008 by determining the total concentration of sulphur, ascorbic acid and chlorophyll in Norway spruce needles. After 1995, the introduction of cleaning devices at the ?TPP dramatically reduced the former extremely high SO₂ and dust emissions. The most significant findings of this comprehensive, long-duration survey are as follows: (1) the chosen parameters are suitable bioindicators of stress caused by air pollution in Norway spruce needles; they reflect both spatial and temporal variations in air pollution as well as the degree of efficiency of the cleaning devices; (2) observations show that the physiological condition of Norway spruce in northern Slovenia has significantly improved since 1995, when the first desulphurization device at ?TPP was built, together with a reduction in the area influenced by pollution from ?TPP; (3) metabolic processes in spruce needles react to air pollution according to the severity of the pollution and the length of exposure; exposure to high SO₂ ambient levels and/or spread over a long duration can damage the antioxidant defence mechanisms of spruce trees as well as diminishing the concentration of ascorbic acid; (4) a reduction in the exposure to air pollution improves the vitality of the trees (e.g. higher concentrations of total (a?+?b) chlorophyll), as well as restoring their defence capabilities as shown by higher concentrations of ascorbic acid; and (5) forest monitoring should be continued and focused on integrating the effects of multiple stressors, which can additionally affect a forest ecosystem.     

Speciation of Cr and its leachability in coal by-products from spanish coal combustion plants

This study evaluates the behaviour of total Cr and Cr (VI) during coal combustion in two Spanish power stations. The content and distribution of Cr in the feed coal and combustion wastes was determined and the Cr contents were normalized using enrichment factor indexes. The speciation of Cr in the fly ash fractions from the different hoppers of the electrostatic precipitators was established and the possibility that the Cr (VI) might lixiviate when ashes are disposed of at landfill sites was assessed. Differences in the distribution and behavior of Cr in the two power stations were observed. According to European directive 1999/31/CEE, soluble Cr(VI) in the fly ashes studied would be unlikely to pose an environmental or health risk when the ash is disposed of.     

Origination and assessment of metal pollution in Qarechay River bed sediments

In the present investigation, bulk and chemical partitioning of elements (Cu, Mn, Ni, Zn, Fe, Ca) together with organic matter as a loss in ignition in the Qarechay River bed sediments have been studied. The concentration of metals in Qarechay River bed sediments is governed by the geological units of the study area. The study of anthropogenic portion shows that a small proportion of elemental concentration belongs to this phase. However, Mn has a large portion of anthropogenic sources (43 %). Also, Mn has a share of 13.6 % in sulfide fractions. This result indicates that Mn is a highly mobile element and can easily enter the water column. The presence of Mn in sulfide fraction might be indicative of initial stages of conversion of oxidation state into reduction in Qarechay River. Share of metals in anthropogenic portion is in the following order: Mn (43 %)?>?Cu (19 %)?>?Zn (10 %)?>?Ni (3 %)?>?Fe (0 %). Organic metallic bonds are not significantly present in the study area. Geochemical index (I _geo), pollution index (I _poll), enrichment factor (EF), and pollution load index (PLI) values are indicative of a clean environment throughout the river course. These values are in well agreement with results of chemical partitioning data. Eventually, based on the results of chemical partitioning, regional standard of elements for Qarechay River bed sediments has been established.     

Biodegradation of chlorpyrifos by either single or combined cultures of some soilborne plant pathogenic fungi

Abstract

Biodegradation of chlorpyrifos was studied in liquid culture media amended with either single or combined eight different plant pathogenic fungi isolated from the continuous cropping wheat fields. The average recovery of chlorpyrifos from the liquid media was found to be 86.1%. The detection limit of chlorpyrifos by the analytical method used was 19 ppb. Data showed that the growth of mixed fungi at concentrations up to 200 ppm of chlorpyrifos was higher than in the control treatment. Chlorpyrifos concentrations declined in the medium of combined fungi more than it did in the medium of any single fungus with increase in the incubation period. The amount of chlorpyrifos recovered was 79.8 ppm (39.9%) in the combined fungal cultures after 21 days. However, those recovered from the media of Fusarium graminearum, F. oxysporum, Rhizoctonia solani, Cladosporhim cladosporiodes, Cephalosporium sp., Trichoderma viridi, Alternaria alternata, and Cladorrhinum brunnescens, ranged from 48.0 to 74.8%. The half‐life value (T_1/2) for chlorpynfos was 15.8 day in the medium amended with mixed fungi. However, for the single cultures it ranged from 19.3 to 33.0 day.     

Production of magnesium from desalination brines

Recovery of minerals from desalination brines is considered to be a very attractive source of minerals. It is usually recommended for reducing fresh-water production cost and minimizing waste disposal. This paper discusses the production of magnesium from a Saudi desalination brine with reference to the Arabian Gulf conditions.     

A geomorphic framework for developing a sustainable greenery programme in arid environments

Summary This paper attempts to demonstrate that the study of geomorphology can provide a useful framework for understanding the natural processes and factors that are critical for the development of ecologically sustainable and economically viable greenery projects in the desert and arid environments.The surface of Kuwait was subdivided into 15 geomorphic zones and each zone was assessed in terms of its potentiality for establishing greenery activities. The assessment considered the implications of relief, soil type and fertility, aeolian processes, sand encroachment and presence or absence of indurated bedrocks and pavements for the greenery plan of Kuwait. Accordingly, areas with the most favourable conditions for revegetation were identified and strategies for enhancing the conservation value and sustainability of the greenery programme were outlined.The study pointed out that while the adopted approach provided useful environmental guidelines at the planning level, further investigations would be required, at the project level, if the principles of ecologically sustainable development were to be fully incorporated within such a large scale greenery undertaking.Dr Dhia Al Bakri is a Lecturer in Environmental Management at the Orange Agricultural College, University of Sydney, Australia. He worked as a Research Scientist for the Kuwait Institute for Scientific Research from 1980 to 1990. During that time Dr Al Bakri undertook a wide range of studies and research projects within the context of Environmental and Earth Sciences.     

Reengineering the environmental function: Making tough decisions

The process outlined in this article includes tools that can be used to achieve the efficiencies necessary for effective reengineering. This process can help ensure that management will not just cut out resources and expect the same services performed the same way. Environmental professionals will be able to show in black and white what their objectives are and what will and will not be done as a result of reengineering.     

AN ECONOMIC ASSESSMENT OF GROUND WATER RECHARGE IN THE TUCSON BASIN1

ABSTRACT: Bringing water from Colorado River via the Central Arizona Project was perceived as the sole solution for Tucson Basin's water problem. Soon after Central Arizona Project's water arrived in Tucson in 1992, its quality provoked a quarrel over its use for potable purposes. A significant outcome of that quarrel was the enactment of the 1995 Proposition 200. The Proposition 200 precludes the use of Central Arizona Project's water for potable purposes, unless it is treated. Yet, it encourages using it for non‐potable purposes and for replenishing the Tucson aquifer through recharge. This paper examines the economic issues involved in utilizing Central Arizona Project's water for recharge. Four planning scenarios were designed to measure and compare the costs and benefits with and without Central Arizona Project's water recharge. Cost‐benefit analysis was utilized to measure recharge costs and benefits and to derive a rough estimate of cost savings from preventing land subsidence. The results indicate that the institutional requirements can be met with Central Arizona Project's water recharge. The economic benefits from reducing pumping cost and saving groundwater are not economically significant. Yet, when combining the use of Central Arizona Project's water for recharge and non‐potable purposes, it demonstrates positive net economic benefits.