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New challenges for industrial microbiology and biotechnology of algae are to increase the efficiency of microalgae growth rates and decrease the cultivation costs. Algae could be cultivated in fresh water as well as in salty sea water or wastewater. Microalgae biomass can be used as a sorbent to remove microcontaminants (e.g. heavy metals, biogens) from wastewater. The obtained results showed that there is a possibility of application of a cheap and universal growing medium (Bf) despite common fertilizers: Bristol or BG-11 to cultivate Chlorella vulgaris and Scenedesmus armatus. The mixotrophic condition can be useful for cultivation of Chlorella vulgaris and Scenedesmus armatus. The highest concentrations of algal biomass for both species were determined after the application of the Bf medium, lower after the BG-11 medium and the lowest after the Br medium in autotrophic as well as mixotrophic conditions. The number of C. vulgaris cells in mixotrophic conditions was higher than S. armatus. The utilization of cheap growing media will lowering the production costs of algal biomass on a large scale.

Soil contamination due to industrial activities is very common and discharging of partially treated or untreated textile wastewater into nearby environment in developing countries contaminated soils. The remediation of textile wastewater contaminated soils containing residual organic dyes and inorganic salts is risky. It is required to identify an economic and eco-friendly in-situ remediation technique for the textile wastewater contaminated soil. This paper investigates the effective removal of residual textile dyes and inorganic salts from the soil using electrokinetic remediation. Laboratory scale acrylic reactors were utilized and the soil was collected from the contaminated agricultural site. The experiment was optimized for different electrode combination (Iron-iron, Iron-stainless steel, Iron-aluminium, Iron-graphite), electrode distance (3 cm, 5.5 cm, and 10.5 cm) and electrical potential gradient (3V/cm, 4V/cm, and 5V/cm). Tap water was used as electrolytes in order to prevent further contamination during remediation process. An electroosmotic flow of 256 mL was observed at cathode reservoir for Iron-graphite electrodes and these electrodes removed 93% electrical conductivity and 82% of total organic carbon from soil. It is found that electroosmosis is the dominant mechanism by which residual textile dyes were removed. The proposed remediation technique is found efficient, economic and eco-friendly compared to the existing technologies.

Spatio-temporal methods have been developed for the estimation of concentrations of pollutants such as particulate matter and nitrogen dioxide for application in epidemiological studies. A limited number of city-specific spatio-temporal ozone (O3) models have been proposed until today. Our aim was to develop a spatio-temporal land use regression (LUR) model that estimates daily concentrations of O3, for the whole year, as well as the warm (April-September) and cold season (October-March), within the greater Athens area. We developed models using a semiparametric approach including linear and smooth functions of spatial and temporal covariates and a bivariate smooth thin plate function. The final set of explanatory variables was selected based on the adjusted-R2. We tested the final model in temporal and spatial terms following a leave-one out monitor approach. The adjusted-R2 in the leave-one-out cross validation was 0.73 for the annual model (warm: 0.65 and cold: 0.70). The spatial terms in our annual model explained 32.9% and the temporal 63.2% of the variability in O3. The developed models showed good validity when comparing predicted and observed measurements for the 2015 data. Spatio-temporal LUR modeling provides a useful tool for estimating O3 spatio-temporal variability with adequate accuracy for subsequent use in epidemiological studies.

Excessive use of fossil fuels results in the rapid depletion of non-renewable fossil energy resources, a rise in fuel cost, and an uncontrolled emission of greenhouse gases which causes a severe threat to the environment. Bio-fuels are being scrutinized as substitutes for current high-pollutant fuels obtained from conventional sources. To meet the global demands, it becomes necessary to find an alternate source of fuel which is bioethanol. In this work, a strategy to promote ethanol production from Leftover Cooked Rice (LCR) by comparing the different types of hydrolysis was proposed. Process integration comprised of mechanical pretreatment of the leftover cooked rice followed by hydrolysis which was then followed by fermentation. The food wastes of weight 50g taken in each of the 3 fermenters were subjected to acid hydrolysis, enzyme hydrolysis, and combined hydrolysis respectively. Commercially available Baker’s yeast (Saccharomyces cerevisiae) was used for the fermentation process. The fermented samples were subjected to distillation to separate the bioethanol from them. The amount of bioethanol obtained from combined hydrolysis, acid hydrolysis, and enzyme hydrolysis was 400ml, 150ml, and 350ml respectively. Qualitative analysis of ethanol was done by using the Jones reagent. Hence, bioethanol can be produced from leftover cooked rice using the yeast Saccharomyces cerevisiae.