Volume 17 [2015]

Phthalic acid esters, commonly called as phthalates, are of a common use in the industrial activities and are known with their hazardous impact on the environment and on humans such as endocrine disrupting agents, carcinogenic and toxic effects. These adverse effects have led to increasing interest and research on the treatment and control of phthalates. Over the past two decades, there has been growing interest in the use of electrochemical techniques such as electrocoagulation (EC) for the treatment of organic pollutants particularly toxic organics. During the course of EC, where iron or stainless steel electrodes are used as electrodes, different mechanisms are operative for the elimination of organic matter, namely (a) adsorption (b) direct anodic oxidation, and (c) indirect oxidation of pollutants in the bulk solution. A statistical-based technique named as response surface methodology (RSM) is a powerful tool for modeling the complex systems (such as EC), evaluating the simultaneous effects of several factors (independent variables), and thus searching optimum conditions for desirable responses (dependent variables). Until now, RSM has not been used as a modeling and optimization tool for the EC treatment of phthalates. In this study, EC treatment, using stainless steel anode, of dimethyl phthalate (DMP), was investigated and optimized via RSM, central composite design (CCD). Initial DMP concentration (DMP_o; 20-100 mg L^-1), current density (J_c; 4.5-22.5 mA cm^-2), electrolyte concentration (NaCl, 750-1750 mg L^-1), treatment time (t_r; 60-180 min) were selected as critical process parameters while DMP, total organic carbon (TOC) removals and electrical energy consumption (EEC, in kWh m^-3) values were selected as the responses. The EC process was optimized to improve the abatements of DMP and TOC and to reduce the EEC values. Separate validation experiments were conducted for each initial DMP concentrations at optimum EC conditions established by the software module to check the goodness of fit and quality of the regression models. According to the established second-order polynomial regression models, DMP, TOC removal efficiencies and EEC values were affected by the process variables in the following decreasing order; J_c>t_r>DMP_o>NaCl (negative impact), t_r>DMP_o (negative impact)>J_c>NaCl (negative impact) and t_r>J_c>NaCl (negative impact)>DMP_o (negative impact), respectively. Analysis of variance indicated that the experimental design models obtained for the EC treatment of aqueous DMP solutions in terms of the model pollutant and mineralization were statistically significant. The response surfaces of DMP established between initial DMP concentration and current density showed that DMP removal efficiencies can be enhanced by increasing the current density to a certain value indicating that an optimum value of current density exists for maximum DMP removal.

The natural environment endures natural and human-induced changes. Remote sensing has been providing monitoring oriented solutions by a series of methodologies which contribute to prudent environmental management. Analysis of multi-temporal satellite images for the observation of the land changes often includes error prone classification and change-detection techniques. The present study takes advantage of the temporal continuity of multi-temporal classified images, in order to model change trends and reduce classification uncertainty, based on reasoning rules. By revealing misclassification prone areas, training site selection is targeted. Moreover, computational tools are developed in order to disclose the alterations in land use dynamics and offer spatial reference to the pressures that land use classes impose. The proposed procedures are tested upon Landsat time series imagery, depicting the National Park of Ainos in Kefallinia, Greece.

The utilization of three novel and distinct agricultural waste materials, namely casuarina fruit powder (CFP), sorghum stem powder (SSP) and banana stem powder (BSP) as low cost adsorbents for reducing chemical oxygen demand (COD) levels of coffee industry wastewater has been examined. Prepared adsorbents were characterized by scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopic (EDAX) and Fourier Transform Infrared Spectroscopy. The effects of parameters like adsorbent dose, pH, temperature, agitation rate and time of adsorption on the reduction of COD levels were analyzed for each adsorbent individually and the efficiency order is CFP>SSP>BSP. Based on the extent of compatibility to Freundlich/Langmuir adsorption isotherm and different models (pseudo-first order and second order, Boyd, Weber’s and Elovich), simultaneous occurrence of chemisorption and physisorption was proposed. Based on the observations, it is proposed that three kinetic stages involve in adsorption process viz., diffusion of sorbate to sorbent, intra particle diffusion and then establishment of equilibrium. As these three adsorbents exhibit adsorption capacity more than 80%, the adsorbents prepared from agricultural wastes have promising role towards reduction of COD from industrial wastewater to contribute environmental protection.  

Proper Hospital healthcare Waste Management (HCWM) is imperative for ensuring public health and environmental protection. In this context, three Prefectural hospitals of Mytilene, Agrinio, and Messolonghi, were studied with respect to planning and management of infectious wastes, cost, training of the white Staff involved, security measures to be taken, and also knowledge related to the implementation of the existing National and European Community, legislation. It was found that the existing legislative procedures were broadly applied. However deviations were reported and it was recognized that serious difficulties in the implementation of the legislation throughout the process i.e. from the phase of separation throughout the processing phase did exist. These deviations frequently originated from conflicts in the directions given by the legislation Joint [Governmental Gazette B1537/8-5-2012]. In order to achieve better implementation of HCWM, recommendations are proposed here.