Development and trial of a methodology for the quantification and evaluation of home composting in Palmerston North, New Zealand : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Environmental Management (without major) at Massey University, Palmerston North, New Zealand

Home composting and commercial composting can be regarded as part of the Municipal Solid Waste Management system. Currently, in Palmerston North and more broadly in New Zealand, home composting plays an important, but an unquantified role in waste diversion. In Palmerston North, the quantity of organic waste diverted from landfill via home composting is not captured in the City’s official ‘waste assessment’ or recorded in the ‘waste management and minimisation plan’. Additionally, there appears to be little local social and technical data on why, who, when, what and how well home composting is practised. The aim of this study was to develop and implement a methodology for a mixed-method quantitative-qualitative study for the quantification and evaluation of home composting practices in Palmerston North. The development process for the research methodology drew upon an international literature review of scientific research, a range of municipal best practice guidelines for home composting and referenced elements of the New Zealand composting standard. The data collection for this study involved a combined telephone and door-to-door survey of 300 households (that is, approximately 1% of occupied dwellings, randomly selected from across all 15 suburbs in the City). To support the physical data collection, a novel home composting evaluation tool was also developed and trialled for empirical and quality assurance evaluation. The overall participation rate recorded in the present study (64%) was high and both data collection methods proved to be viable, yielding positive results. 36% of the households who participated in the present study were home composters which could mean that about 10,761 households in the occupied dwellings of the City practise home composting. At the time of the survey, it appears that nearly 4005 tonnes of organic waste was being treated via home composting processes. The results also indicated positive quality assurance of the home composting process and the resulting compost in the City. Whilst most of the study participants have a positive experience towards home composting, nuisance insects, rodents and odour problems were reported as issues. In terms of motivation around current and future home composting practices, a range of support options appears to be available for Councils to encourage and enhance this positive environmental practice

Enhancing sustainable biowaste management in the UK: the role of the commercial and community composting sectors

This paper considers the different roles of the commercial and community composting sectors in contributing to sustainable biowaste management in the UK. Legislation and policy have driven the rapid development of a diverse composting sector. The next section sets out this policy context. This is followed with an analysis of the growth in, and characteristics of, the commercial composting sector and then the community composting sector. It is contended that both sectors have different strengths in contributing to sustainable biowaste management. For commercial composting this is based around large-scale composting and quality products, for the community sector this is based around services in difficult collection environments, local sustainability, promoting social cohesion and building stronger communities. The extent to which the benefits from the commercial and composting sectors will be realised in the future will depend on whether the sectors can develop synergistically and the extent to which this is encouraged by national and local policies

Composting case study

This report was presented at the UK Organic Research 2002 Conference. Garden waste delivered by the public to a recycling centre is stockpiled, shredded and delivered to the on-farm composting site. The material is forced, together with aeration pipes into 60 metre long EcoPods using specialist machinery. The temperatures achieved during the composting process are fully monitored and controlled using a forced aeration system. The composting site operates under a waste management licence exemption and has temporary planning approval. Concerns raised about the site include increased heavy traffic, leachate, noise nuisance, birds and vermin, odours, dust and bio-aerosols harmful to health. Local residents remain intolerant of the composting system. The planning authority acknowledge that current legislation can be a barrier to the development of large scale composting operations

Study of a composting process in the green waste processing plant

Composting of sewage sludge together with green waste such as grass, leaves, branches, etc. is carried out in Poland in a number of facilities. A common problem of all compost plant operators is the selection of the type of composting technology and its modification to the conditions prevailing in a particular region. This is because the waste, the facilities are exposed to, differs and the technology must be adapted to the conditions prevailing in the given facility. In the field of technological research of the composting process, the research aims to characterize the conditions for composting organic waste in relation to the efficiency achieved, indication of the optimal technological parameters and assistance in the selection of the target composting technology. Waste composting technology is based on the appropriate selection of the composition of prisms and the periodic transfer of the prisms by means of a special turning machine. For the purpose of this research, hypotheses were formulated on the intensity of the composting process depending on the technological parameters of the prism (the size of the prism. the types of waste), the properties of the waste, and the intensity of aeration by turning. The results may be useful for compost plant operators and waste processing companies

Reduced GHG emissions due to compost production and compost use in Egypt

Composting has been acknowledged as an emission reduction methodology by the UNFCCC. The emission reduction reached by a composting project is determined by comparing the composting scenario with the applicable baseline scenario. The objective of this study was on the one hand to clarify the emission reduction methodology of a composting facility in Egypt and on the other hand to extend this methodology with an example to illustrate the effect of compost use on greenhouse gas emissions. In this study, the emissions in a scenario where compost originating from a compost facility near Alexandria is used on a citrus farm in Egypt, were compared with a hypothetical baseline scenario where organic waste is not recycled and chemical fertilizer is used on the farm. The results show that the composting scenario causes significant lower emissions than the baseline scenario. This is mainly due to the avoidance of methane emissions from organic waste dumping, but also emissions due to chemical fertilizer production are avoided. The third reason for lower emission in the composting scenario is soil carbon sequestration. The composting scenario on the other hand also causes extra emissions due the transportation of biomass and fuel use for windrow turning. Although not showed in this study, it must be mentioned that compost has other beneficial effects, like improving soil fertility, improving the buffering capacity and reducing the risk for pathogens

Managing biowaste and promoting sustainability - profiling community composting

The voluntary and community waste sector makes an important contribution to waste objectives (Williams et al, 2006). The community composting sector would appear to be leading the development of innovative biowaste collection and processing systems in areas unsuitable for traditional kerbside. Such schemes can contribute to developing local areas by improving local soils and green spaces as well as diverting waste from landfill. However, this is often only part of the story. Well managed community activity has huge potential for providing work and volunteering opportunities, as well as bringing people together and improving skills, knowledge and self-confidence. Considered collectively these factors may contribute to local sustainability more effectively than reliance on meeting particular targets. Although there is some anecdotal and financial evidence for the growth in, and diversity of, community composting, there is very little comprehensive data that draws together the activity of the sector as a whole. The paper addresses this gap by presenting findings from a national survey profiling community based composting. Results show that a range of activities fall under the umbrella of community composting and these include: collecting / receiving and processing material, running education campaigns, promoting home composting and facilitating others to develop / promote community composting. The survey recorded over 100 groups actively engaged in at least one of these activities with many involved in more than one. Overall 80% of groups are involved in collecting and composting material and 20% are involved in composting related activity other than collecting and composting, such as educational and promotional activities. The sector has a large potential for providing work and volunteering opportunities and results indicate over 1,300 volunteers, trainees and staff involved in community composting. In addition, most groups (68%) carry out composting alongside other waste and recycling activities or, more commonly, alongside non-waste activities such as community gardens, city farms, local food production, day and residential services and work integration schemes. These activities may bring about positive environmental impacts and social benefits over and above quantities of material diverted from landfill, and these benefits often cut across different policy agendas. Knowing and understanding these impacts and benefits is important in understanding the role of the community composting sector. In addition to results from profiling the sector, this paper will also present findings from participatory research with groups to develop ways to better understand and demonstrate the impacts of their work

Implementation of food waste composting in Malaysia

As urbanisation continues to occurring, waste management is becoming one of the major environmental problems around the world, including Malaysia. The generation of Municipal Solid Waste (MSW) in Malaysia has increased more than 91% over the past decades. Based on waste composition, food waste was indicated as the main waste component. Thus, recycling of food waste through composting had emerged as a potentially viable means that local governments can reduce the waste volume that is entering the landfills. Furthermore, MSW management in Malaysia can be considered as relatively poor and disorganized. The most preferred of MSW disposal method is through landfill due to various factors. This article elaborates on composting that gives benefits to Malaysian. This paper also exposes strategy to implement the composting in Malaysia by focusing on Food Waste Management Development Plan for the Industry, Commercial and Institution Sector. The current methods of food waste composting that are applied in Malaysia are also discussed in this paper. Finally, this paper reveals the challenges towards food waste composting in Malaysia

EVALUATION OF DIFFERENT BIOLOGICAL WASTE TREATMENT STRATEGIES

Biological treatment of organic waste by aerobic composting and anaerobic digestion (biogas production) was compared with respect to a number of environmental effects and sustainability criterias including energy balance, nutrient recycling, global warming mitigation potential, emission of xenobiotic compounds and economy. The parameters were assessed based on case studies in the literature as well as our own research. Assessment of energy balance, nutrient recycling and global warming came out in favour of biogas production, but especially the results regarding estimation of global warming mitigation differ according to the assumptions made. Our calculations showed that a fugitive loss of approx. 14% of the biogas produced by anaerobic digestion will turn the scale in favour of composting regarding global warming mitigation. In Europe actual biogas losses from 3.5 to 8.4% are reported but this may be exceeded in developing countries. Regarding emission of xenobiotic compounds composting is much in favour, as recent experiments show that a number of organic micro-pollutants are rapidly degraded during composting as opposed to anaerobic treatment. In most cases, composting is more cost-effective compared to biogas production but estimations of actual costs differ considerably. Published results of Life Cycle Assessment of organic waste management using the ORWARE model generally showed biogas production to have less environmental impact than composting, but it was demonstrated that changes in, e.g. system boundaries or functional units can result in substantial differences on the conclusions as well. In conclusion, the optimum waste planning strategy may be the implementation of an integrated waste treatment system operating with different scales of composting and anaerobic treatment, depending on local conditions

Factors influencing the nematode community during composting and nematode-based criteria for compost maturity

Pilot studies indicate that shifts in the nematode species composition, life strategies and feeding behavior during composting appear to be fairly consistent and, therefore, promising as a potential tool to assess compost maturity. However, this has been only based on a limited number of, mainly, non-replicated observations. In this study, we tested whether the nematode community succession patterns are recurrent for parallel processes and assessed the relationship between the changes in the nematode community and potential important variables (i.e., temperature, duration of composting and the microbial community). The nematode and microbial community of three simultaneously running Controlled Farm Composting and a reference Green Waste composting process were analyzed through time. Bacterial-feeding enrichment opportunists were most numerous during and directly after the heat peaks. Subsequently, the bacterial-feeding/predator community dominated and the fungal-feeding nematodes became more dominant during maturation, confirming general community patterns from previous experiments. Nematode abundances significantly fluctuated with temperature and the relative abundance of fungal-feeding nematodes increased as the duration of the curing process increased. The amount of fungal-feeding nematodes was associated significantly with both duration of composting and temperature, and the F/(F + B) ratio was only significantly associated with duration of composting. Based on these results, and additional data from an industrial reference compost process and on available literature, a Nematode-based Index of Compost Maturity (NICM) is proposed, combining four nematode-based criteria (i.e., nematode abundance, F/(F + B) ratio, the presence of more than one fungal-feeding taxon and the presence of diplogasterids). Nevertheless, the NICM should be considered as work in progress which should be tested for a wider range of composts from diverse feedstock mixtures, locations (sites) and composting techniques, to validate the use of the index and allow more reliable interpretation of particular values of this index

Critical parameters in the life cycle inventory of palm oil mill residues composting

Palm oil mill's co-products (empty fruit bunch – EFB and palm oil mill effluent – POME) management is a matter of concern in Indonesia. Co-composting is a promising waste management practice that would allow a reduction of environmental impact and a restitution of organic matter to the soil. This study is a part of a Life Cycle Assessment (LCA) project and aims to pinpoint the most environmentally impacting compartments of the palm oil production chain. It deals more specifically with the Life Cycle Inventory of data on the composting process based on site specific data. Data on the recycled biomass, energy demand and yielded compost properties were recorded in an industrial palm oil mill over one year. Due to the local conditions, high nutrient leaching from the compost were recorded and the compost remained very wet and hot (thermophilic phase). The composting process only led to 40% of methane avoidance compared to anaerobic digestion of POME, and the global nutrient recovery efficiency was below 50%. We identified the following critical parameters to increase environmental benefits from composting: i) the POME/FFB ratio from the mill ii) the roofing of the composting platform, iii) the POME/EFB ratio, iv) the turning frequency, v) the recycling of leachates and vi) the process duration and drying period. The nutrient recovery and the doses of compost applied in the field depend on all of those inter-connected parameters. The data presented will be used within LCA models to assess net environmental benefits from various POME and EFB co-composting systems