Coastal Flood Risk Analysis Using Landsat-7 ETM+ Imagery and SRTM DEM: A Case Study of Izmir, Turkey

The Intergovernmental Panel on Climate Change (IPCC) reports an acceleration of the global mean sea-level rise (MSLR) in the twentieth century in response to global climate change. If this acceleration remains constant, then some coastal areas are most likely to be inundated by the year 2100. The ability to identify the differential vulnerability of coastlines to future inundation hazards as result of global climate change is necessary for timely actions to be taken. Yildiz et al. (Journal of Mapping, 17, 1-75, 2003) reported that the local MSLR in the city of Izmir rose at a rate of 6.8 +/- 0.9 mm year(-1) between 1984 and 2002. In this study, the spatial distribution of the coastal inundation hazards of Izmir region was determined using not only land-use and land-cover (LULC) types derived from the maximum likelihood classification of Landsat-7 Enhanced Thematic Mapper Plus (ETM+) multi-spectral image set but also the classification of the digital elevation model (DEM) acquired by the shuttle radar topography mission (SRTM). Coastal areas with elevations of 2 and 5 m above mean sea-level vulnerable to inundation were found to cover 2.1 and 3.7% of the study region (6,107 km(2)), respectively. Our findings revealed that Menemen plain along Gediz river, and the settlements of Karsiyaka, Alacati, Aliaga, Candarli and Selcuk are at high risk in order of decreasing vulnerability to permanent and episodic inundation by 2100 under the high MSLR scenarios of 20 to 50 mm year(-1).     

Groundwater Pollution Around an Industrial Area in the Coastal Stretch of Maharashtra State, India

The main objective of this paper is to examine pollution threat, especially to the groundwater resources, around Tarapur industrial area (also called the Tarapur MIDC area) located on the Arabian Sea Coast in Thane District of Maharashtra State, India and suggest remedial measures that may also be relevant to other industrial areas on the Indian Sea Coast. One hundred and thirty one samples were collected from various sources, such as dugwells, borewells, dug-cum-borewells, effluent sumps, drainage channels (effluent channels), creeks and ocean, for chemical analyses. These analyses show that the area in general is characterized by hard water and high salinity hazard, possibly due to its proximity and hydraulic connection with the sea. Although the potability of groundwater is questionable in certain pockets, it is good enough for irrigation purposes at present. Low pH value and high heavy metal contents in the adjoining Muramba creek water is a matter of great concern and may be attributed to the indiscriminate disposal of industrial effluents to the drainage channels connecting the creek. Muramba Creek is well connected with the Arabian Sea, and there are evidences of seawater intrusion around this creek. Because of the fact that Muramba Creek is highly polluted, and is hydraulically connected with the dugwells and borewells surrounding the creek, it cannot be ruled out that the groundwater around this creek is susceptible to contamination. Unless measures are not taken immediately to stop the indiscriminate disposal of the solid wastes and liquid effluents in open ground and drainage channels, and measures are not taken to maintain the appropriate pH values at the effluent treatment facilities before their disposal, the problem would indeed be formidable one day, and it will be too late then for the authorities to take care of the resulting maladies. Few suggestions have been given for controlling and managing the industrial pollution around the Tarapur MIDC area. These suggestions are relevant to other industrial areas situated on the 7,000 km long Indian Sea Coast.     

Comparative evaluation of a bioluminescent bacterial assay in terrestrial ecotoxicity testing

Despite the widespread and successful use of luminescence-based bioassays in water testing, their applications to soils and sediments is less proven. In part this is because such bioassays have mainly been carried out in an aqueous-based medium and, as such, favour contaminants that are readily water-soluble. In this study, aqueous solutions and soils contaminated with heavy metals (HM), polar organic contaminants and hydrophobic organic contaminants (HOCs) were tested using a range of luminescence-based bioassays (Vibrio fischeri, Escherichia coli HB101 pUCD607 and Pseudomonas fluorescens 10586r pUCD607). For the first two chemical groups, the assays were highly reproducible when optimised extraction procedures were employed but for HOCs the bioassay response was poor. Quantitative structure-activity relationships (QSARs) obtained from aqueous solutions had a linear response although correlation for the chemicals tested using bacterial bioassays was significantly less sensitive than that of sublethal tests for Tetrahymena pyriformis. Bacterial and Dendrobaena veneta bioassay responses to extracts from HM amended soils showed that a clear relationship between trophic levels could be obtained. There is no doubt that the wide range of bioluminescent-based bioassays offers complementary applications to traditional testing techniques but there is a significant need to justify and optimise the extraction protocol prior to application.     

Combining passive sampling and toxicity testing for evaluation of mixtures of polar organic chemicals in sewage treatment plant effluent

Effluent from sewage treatment plants has been associated with a range of pollutant effects. Depending on the influent composition and treatment processes the effluent may contain a myriad of different chemicals which makes monitoring very complex. In this study we aimed to monitor relatively polar organic pollutant mixtures using a combination of passive sampling techniques and a set of biochemistry based assays covering acute bacterial toxicity (Microtox), phytotoxicity (Max-I-PAM assay) and genotoxicity (umuC assay). The study showed that all of the assays were able to detect effects in the samples and allowed a comparison of the two plants as well as a comparison between the two sampling periods. Distinct improvements in water quality were observed in one of the plants as result of an upgrade to a UV disinfection system, which improved from 24x sample enrichment required to induce a 50% response in the Microtox assay to 84x, from 30x sample enrichment to induce a 50% reduction in photosynthetic yield to 125x, and the genotoxicity observed in the first sampling period was eliminated. Thus we propose that biochemical assay techniques in combination with time integrated passive sampling can substantially contribute to the monitoring of polar organic toxicants in STP effluents.     

A novel way to upgrade the coarse part of a high calcium fly ash for reuse into cement systems

Reject fly ash (rFA) represents a significant portion of the fly ashes produced from coal-fired power plants. Due to the high carbon content and large particle mean diameter, rFA is not utilized in the construction sector (for example, as supplementary cementing material) and is currently dumped into landfills, thus representing an additional environmental burden. Recently, the feasibility of using rFA in a relatively small number of applications, like solidification/stabilization of other wastes, has been investigated by different researchers. However, as the overall amount of fly ash utilized in such applications is still limited, there is a need to investigate other possibilities for rFA utilization starting from a deeper understanding of its properties. In the work presented herein, mechanical and hydration properties of cementitious materials prepared by blending the coarse fraction of a lignite high-calcium fly ash with ordinary cement were monitored and compared with the respective ones of a good quality fly ash-cement mixture. The results of this work reveal that a relatively cheap, bilateral classification-grinding method is able to promote the pozzolanic behavior of the rFAs, so that the overall performances of rFA containing cements are drastically improved. The evaluation of these results supports the belief that appropriate utilization of non-standardized materials may lead to new environmental-friendly products of superior quality.     

Performance results from the Tucumán solid waste bioreactor

Performance results obtained from a 6200 ton demonstration-scale anaerobic bioreactor, constructed on the Pacara Pintada Landfill in Tucumán, Argentina, are described. The operational aspects over a 30-month period for the Tucumán bioreactor demonstrate the ability to maintain the bioreactor in the mesophilic range, with the result that the generation and collection of the biogas has been maintained at accelerated rates with a rate constant of approximately 0.5 year(-1). Field measurements of metal concentrations in leachate indicated significant attenuation over time. Refuse subsidence, measured over a 28-month period, ranged from 4% to 19%, with an average of 11% subsidence across the Tucumán cell.     

Management of MSW in Spain and recovery of packaging steel scrap

Packaging steel is more advantageously recovered and recycled than other packaging material due to its magnetic properties. The steel used for packaging is of high quality, and post-consumer waste therefore produces high-grade ferrous scrap. Recycling is thus an important issue for reducing raw material consumption, including iron ore, coal and energy. Household refuse management consists of collection/disposal, transport, and processing and treatment - incineration and composting being the most widely used methods in Spain. Total Spanish MSW production exceeds 21 million tons per year, of which 28.1% and 6.2% are treated in compost and incineration plants, respectively. This paper presents a comprehensive study of incineration and compost plants in Spain, including a review of the different processes and technologies employed and the characteristics and quality of the recovered ferrous scrap. Of the total amount of packaging steel scrap recovered from MSW, 38% comes from compost plants and 14% from incineration plants. Ferrous scrap from incineration plants presents a high degree of chemical alteration as a consequence of the thermal process to which the MSW is subjected, particularly the conditions in which the slag is cooled, and accordingly its quality diminishes. Fragmentation and magnetic separation processes produce an enhancement of the scrap quality. Ferrous scrap from compost plants has a high tin content, which negatively affects its recycling. Cleaning and detinning processes are required prior to recycling.     

Use of inert C&D materials for seawall foundation: quality control measures

The technical viability of using inert construction and demolition (C&D) materials for the construction of seawall and breakwater foundations has been established by laboratory testing of the materials, numerical analysis of foundation stability, and a pilot field-scale engineering performance evaluation. However, quality control measures are still required so that only suitable materials are used for seawall and breakwater foundation construction. The development of different quality control measures for different site conditions is presented in this paper. The rationale, practicality, and implementation of these quality control measures are also discussed.     

Modified Fenton reaction for trichlorophenol dechlorination by enzymatically generated H2O2 and gluconic acid chelate

Glucose oxidase is a well-known enzyme that catalyzes the oxidation of β-d-glucose to produce gluconic acid and hydrogen peroxide. Fenton reaction is a powerful oxidation technology used for the oxidation of groundwater pollutants. For the application of Fenton reaction in groundwater remediation, successful operation of Fenton reaction near neutral pH, and on-site generation of both H₂O₂ and chelate will be beneficial. The focus of this experimental study was to couple the glucose oxidation reaction with chelate-based Fenton reaction. The idea was to use the hydrogen peroxide and chelate gluconic acid generated during glucose oxidation for the dechlorination of 2,4,6-trichlorophenol (TCP) by Fenton reaction. The oxidation of glucose was achieved using the enzyme in free and immobilized forms. The rate of production of hydrogen peroxide was determined for each system, and was used to estimate the time required for complete consumption of glucose during the process, thus avoiding any traces of glucose in the Fenton reaction. In the case of free enzyme reaction, separation of the enzyme was achieved using an ultrafiltration membrane before initiating the Fenton reaction. The oxidation of TCP by Fenton reaction was performed at varying ratios of gluconic acid/Fe, and its effect on the decomposition of TCP and H₂O₂ was studied. TCP degradation was studied both in terms of parent compound degradation and free chloride generation.