Volume 19 [2017]

The aim of this study is to achieve a greater insight regarding quiet areas in agglomerations and contribute to their identification. The small urban setting of Mytilene located in the island of Lesvos (North Aegean, Greece), was the case study of this research. Based on citizen contribution, a number of “places” derived that are perceived as “quieter” than others, by the permanent residents of Mytilene. The “places” mentioned from this procedure were checked by means of acoustic measurements, concerning the noise levels that occurred within the 24h period. A novel method regarding the duration, repetition, check spot and the positioning of measurement was used, in order to calculate the day, evening and night period’s noise levels (Lden). A performance matrix was then created in order to compare the results, in relation to acoustical, functional and visual criteria. Furthermore, by incorporating perceptual criteria we assisted the quiet area selection procedure. The provision of quietness, as a direct ecosystem service, is a major indicator of environmental quality. Nevertheless, the way that city inhabitants perceive their acoustic surroundings could determine the character of the landscape along with the quality of the soundscape and define the meaning of quietness that still remains vague.

Aerobic granules were cultivated using pure oxygen aeration (POAG) in SBR for wastewater treatment under high organic loading condition (HOLC) to reveal its performance and potential causes. Compared to conventional granules and activated sludge, mature POAG with more compact and dense structure were formed in a shorter term using pure-oxygen aeration in SBR. The system shows high and stable COD and NH4+-N removal efficiencies with an average value of 91% and 84%, respectively, under HOLC. Adequate dissolved oxygen (DO) supplied by pure-oxygen aeration is the prerequisite explaining the elevated performance. POAG have more stable compact granular structure and elevated biomass than that of conventional biogranules and bioflocs under HOLC. High EPS content facilitate the formation of POAG and maintain its integrity and stability of spatial structure, which is in favor of biomass growth. Abundant catalase synthesized by its biomass ensure the ability to hydrolyze and mineralize organic substance under HOLC. A great deal of dehydrogenase secreted by POAG play a critical role in maintaining its metabolism under HOLC, which in turn enhance multiplication capacity of living organism in POAG and elevate removal performance of organic pollutants from wastewater.

With increased contribution of household and kitchen wastes in overall MSW and its preferred conversion by biomethanation there is a need to study decomposition rates and kinetics, ‘leachate potential’ and related issues– especially to promote decentralized treatment. Anaerobic digestion characteristics of ten predominant types of the fermentable components (fruits, vegetables and their mixture) commonly found in urban solid waste in Bangalore were examined under lab conditions by monitoring biogas production in micro-digesters at room temperatures (25±3°C). The rate of decomposition, the pattern of fit and extent and rate of biogas production from these potential feedstocks are analyzed to understand the degradation kinetics. All feedstocks showed a two stage linear fit for gas production comprising of a rapid initial phase lasting 10-20days accounting for >70% gas production followed by a slower second phase. Degradation could be predicted using a two stage linear fit transiting from initial to a second stage at an appropriate unique transition point, yet similar amongst fruits or vegetables. The need for large aceticlastic capability (rapid initial degradation) thus becomes a criteria for biomethanation process of such feedstocks.

There is increasing concern about indoor air pollution worldwide due to its adverse health effects. One of the predominant indoor air pollutant groups is assumed to be volatile organic compounds (VOCs), including a variety of hydrocarbons with different functional groups. Among VOCs, some species have carcinogenic effects, and some are widely used in many consumer products. CO2 is assumed to be an indicator of ventilation adequacy. Thus, elevated indoor CO2 levels are linked with the discomfort level of occupants. Residential exposure to VOCs and CO2 in 6 different homes located in 3 different towns in Canakkale, Turkey were assessed for about a year. Also, a home inventory was used to identify the potential sources of VOCs and CO2 as well as environmental concerns of the occupants. The highest levels of indoor CO2, total volatile organic compounds (TVOC), benzene, toluene, and xylenes were found at industrial sampling sites. A connection between aspects of the outdoor environment (i.e. availability of potential sources) and residential exposure to air pollutants was found. Also, some activities (e.g. heating fuel type, house cleaning frequency, etc.) and factors (e.g. characteristics of the outdoor environment) influenced residential exposure to VOCs and CO2.