Christina Chroni

Microbial characterization during composting of biowaste

Windrow composting of source-separated biowaste was studied in a pilot plant in Crete, with regard to abiotic factors, gas concentration in the pile and succession of functional microbial groups. The pH, C/N ratio and VS content, as well as the O(2) and CO(2) concentration, correlated well with composting time, indicating typical composting behaviour. Most of the microbial groups examined exhibited their highest counts towards the end of the thermophilic phase, with declining trends thereafter. The population of total mesophilic and thermophilic bacteria increased during the mild thermophilic phase and followed the temperature decline thereafter. Results on these microbial groups and fungi indicate that the timing of the thermophilic stage in the composting process, in addition to the peak temperature and duration of the stage, affects the microbial succession. Escherichia coli were detected for over 2 months of processing, in spite of the high temperatures achieved; only after about 3 months of composting did its population decline below the detection limit.

Investigation of the microbial community structure and activity as indicators of compost stability and composting process evolution.

In a bid to identify suitable microbial indicators of compost stability, the process evolution during windrow composting of poultry manure (PM), green waste (GW) and biowaste was studied. Treatments were monitored with regard to abiotic factors, respiration activity (determined using the SOUR test) and functional microflora. The composting process went through typical changes in temperature, moisture content and microbial properties, despite the inherent feedstock differences. Nitrobacter and pathogen indicators varied as a monotonous function of processing time. Some microbial groups have shown a potential to serve as fingerprints of the different process stages, but still they should be examined in context with respirometric tests and abiotic parameters. Respiration activity reflected well the process stage, verifying the value of respirometric tests to access compost stability. SOUR values below 1 mg O(2)/g VS/h were achieved for the PM and the GW compost.

Attitudes and behaviour of Greek households regarding food waste prevention.

Food waste is a waste stream with serious economic, environmental and social implications. The emphasis of the reported research is on the food waste generated by households in Greece. A structured questionnaire was utilised in order to identify the attitudes of the respondents and investigate the prevalence of certain behavioural good practices that can prevent the generation of food waste. The research, to our knowledge the first of its kind in Greece, took place in February and March 2012. Face-to-face interviews were employed, resulting to a total of 231 consumers fully completing the questionnaire. Results indicate that, based on self-reported behaviour, people in Greece have positive attitudes towards food waste prevention and that their habits are close to the good practices suggested in the literature for reducing food waste. For instance, most respondents do plan their food shopping in a multitude of ways and are very careful in their purchases of fresh food supplies. However, about 40% misunderstand the meaning of food date labels. The positive findings are strongly influenced by the severe recession experienced in the country, which makes consumers more conscious of their spending. Results may serve as a yardstick to further promote and establish food waste prevention behaviour at the household level on an environmental and social awareness basis that may outlast the economic crisis.

Household waste compositional analysis variation from insular communities in the framework of waste prevention strategy plans.

Waste management planning requires reliable data regarding waste generation, affecting factors on waste generation and forecasts of waste quantities based on facts. In order to decrease the environmental impacts of waste management the choice of prevention plan as well as the treatment method must be based on the features of the waste that are produced in a specific area. Factors such as culture, economic development, climate, and energy sources have an impact on waste composition; composition influences the need of collecting waste more or less frequently of waste collection and disposition. The research question was to discover the main barriers concerning the compositional analysis in Insular Communities under warm climate conditions and the findings from this study enabled the main contents of a waste management plan to be established. These included advice to residents on waste minimisation, liaison with stakeholders and the expansion of kerbside recycling schemes.

Food waste prevention in Athens, Greece: The effect of family characteristics

Food waste is a stream that becomes increasingly important in terms of its prevention potential. There is a large number of behaviours that can be associated with food waste generation and the efforts towards food waste prevention. A questionnaire study was carried in order to study consumer behaviour related to food provision and wastage in Greece. Proper practices of the respondents that can prevent the generation of food waste were investigated using nine behavioural scales, which were defined on the basis of similar studies in other countries. A structured questionnaire was utilised in order to test those behaviours against the socio-demographic characteristics of respondents. The results of the study indicate that in terms of inferential statistical analysis, among the numerous variables examined, those that enhance food waste prevention are the involvement of the respondent in cooking, the annoyance towards food waste generation and the education level.

Promoting Sustainable Waste Prevention Strategy Activities and Planning in Relation to the Waste Framework Directive in Insular Communities

Citizen’s daily activities produce huge quantities of waste affecting the quality of life. On the other hand, citizens are attacked from the media regarding the new products entering the market. Moreover, waste management plans, are sometimes too complex as facilities, like separation and collection, become routine. The production of waste on daily basis is continually increasing; however, the main solution for treatment in insular communities is to send their waste to landfill. According to the Waste Framework Directive (2008/98/EC), prevention is in the top in waste hierarchy. In order to build up our strategy we must first find out what our waste consists of and then develop our waste prevention campaign and strategic plan.

Life cycle assessment of food waste home composting in Greece

Home composting is a waste prevention measure related to the management of the households food waste, garden trimmings, and other smaller organic household waste streams. Thus, home composting is an alternative way of exploitation of the “biomass” generated from the households. It is an alternative to centralized composting. Biomass utilization is explicitly stated as a principle of green chemistry. The aim of this paper is presentation of the results of a case study dealing with the life cycle environmental assessment of home composting of food waste in households in Greece. The results of the study indicate that home composting is environmentally preferable over the current organic waste management situation in Greece.