From life cycle talking to taking action

Introduction - The biannual Life Cycle Management conference series aims to create a platform for users and developers of Life Cycle Assessment (LCA) and related tools to share their experiences. A key concern of the LCM community has been to move beyond the production of LCA reports toward using the developed knowledge. This paper reports and evaluates some of the main outcomes of the 4th International Life Cycle Management Conference (LCM 2009). Results - Conference focus: While the focus of the conference was LCM, LCA remains a main analytical tool for supporting LCM. This is clearly shown by the overall program in which roughly half of the contributions focused on or used LCA. Some products and resources and environmental themes were markedly represented in the presentation subjects. Conference participation: The 180 delegates included 40 South Africans, 20 from other African countries, and 140 from as far afield as Brazil, Sweden, Japan, and Australia. The surveyable number of delegates and conference rooms, in combination with the well-balanced scientific and social program, facilitated optimal professional exchange and discussion. Conference structure: LCM 2009 featured some 140 contributions from 47 leading environmental practitioners, consultants, and academic researchers. The interactive conference format included three plenary sessions and training workshops. Conclusions - LCM 2009 successfully engaged with the critical questions of what it means to manage (not merely shift) the environmental and social impacts of global economic activity, what this entails for industry and public services in emerging economies, and how supply chains, networks, and partnerships can be stimulated and managed to deliver truly sustainable practic

A comparative life cycle assessment of process water treatment technologies at the Secunda industrial complex, South Africa

The increasingly poor quality of South Africafs natural water sources requires industries and power stations to treat raw water extensively prior to industrial use in, for example, boilers. Two different raw water desalination technologies, an existing ion exchange plant and a proposed reverse osmosis intervention, are compared by life cycle assessment for the production of 1 M. of boiler feed water, in the context of the Secunda industrial complex situated in Mpumalanga, South Africa. The proposed reverse osmosis option would perform 22% worse for global warming potential, which relates to the use of coal-derived electricity, but would reduce burdens of the ion exchange option on human toxicity and freshwater aquatic ecotoxicity due to the use of an aluminium sulphate coagulant. Significantly, the assessment predicts the reverse osmosis option to effect a 78% overall reduction in storage of problematic salts, from 599 kg/M. to 133 kg/M.. Notwithstanding the fact that the power generated within the complex and used by the RO process is associated with a high salts burden (mine water is desalinated at the power station), it was found that the reverse osmosis intervention would incur a lower salts footprint than the IX/S technology and would not shift salts burdens

A comparison of air emissions of thermal power plants in South Africa and 15 European countries

Data recorded in the recently established European Pollutant Emission Register (EPER) is potentially useful for benchmarking of the environmental performance of industrial activity against European practice. Entries in the category of large power plants in the reporting year 2001 for 15 European Union (EU) countries were evaluated to estimate total and fuel specific emissions of NOx, SO2, particulate matter, and CO2. Since the EPER data quality is unknown and since it records only absolute values for emissions and thus does not allow for an eco-efficiency analysis, environmental or sustainability reports made available online by a subset of the operators were sourced to compile a set of specific emissions (per kWh of electricity generated) for the major fossil fuel types, viz. natural gas, fuel oil, coal and lignite. With a few exceptions, notably for PM10 for eight countries and NOx in one case, the large power plant data reported to the EPER is shown to be sufficiently representative of fossil-fuel based generation of electricity and is trustworthy. The fuel mix differs considerably, and together with the varying standard of pollution control technologies, this results in a wide variation in the combustion-related environmental burdens of the generated electricity. Emissions data for South African thermal electricity generation was sourced from Eskom’s 2000 environmental report; in absolute terms they are the highest in this comparison, and in specific terms amongst the three highest per unit of electricity generated from coal

Life-cycle assessments in the South African water sector: A review and future challenges

This paper reviews South African water sector life-cycle assessments (LCAs) and develops a position on how this tool could be strategically employed in the future. It summarises the studies undertaken, highlighting the significant findings and the lessons learnt. In addition, international trends and their implications for the local LCA community and the water sector are presented and strategic recommendations for the future are included. The various LCA studies undertaken in the local water industry have shown that the abstraction of water from the environment (in a country where it is a limited resource) and the use of energy for treating and pumping water and wastewater have the highest environmental burdens. These studies have also demonstrated the versatility of LCA as a decision-making tool in the water industry by comparing technologies and scenarios, identifying improvement opportunities and prioritising interventions and their consequences in complex water systems. Recent international work has confirmed the usefulness of a life-cycle approach also for water footprinting. Therefore, in South Africa it is important to promote the use of LCAs for the water sector in order to improve efficiency of processes and systems, but also to promote life-cycle based water footprinting and to include differentiated water consumption data into life-cycle inventories to make more efficient use of water as a resource.Keywords: life cycle assessments, water footprinting, urban water system

Estimation of incidence and social cost of colon cancer due to nitrate in drinking water in the EU: a tentative cost-benefit assessment

<p>Abstract</p> <p>Background</p> <p>Presently, health costs associated with nitrate in drinking water are uncertain and not quantified. This limits proper evaluation of current policies and measures for solving or preventing nitrate pollution of drinking water resources. The cost for society associated with nitrate is also relevant for integrated assessment of EU nitrogen policies taking a perspective of welfare optimization. The overarching question is at which nitrogen mitigation level the social cost of measures, including their consequence for availability of food and energy, matches the social benefit of these measures for human health and biodiversity.</p> <p>Methods</p> <p>Epidemiological studies suggest colon cancer to be possibly associated with nitrate in drinking water. In this study risk increase for colon cancer is based on a case-control study for Iowa, which is extrapolated to assess the social cost for 11 EU member states by using data on cancer incidence, nitrogen leaching and drinking water supply in the EU. Health costs are provisionally compared with nitrate mitigation costs and social benefits of fertilizer use.</p> <p>Results</p> <p>For above median meat consumption the risk of colon cancer doubles when exposed to drinking water exceeding 25 mg/L of nitrate (NO₃) for more than ten years. We estimate the associated increase of incidence of colon cancer from nitrate contamination of groundwater based drinking water in EU11 at 3%. This corresponds to a population-averaged health loss of 2.9 euro per capita or 0.7 euro per kg of nitrate-N leaching from fertilizer.</p> <p>Conclusions</p> <p>Our cost estimates indicate that current measures to prevent exceedance of 50 mg/L NO₃are probably beneficial for society and that a stricter nitrate limit and additional measures may be justified. The present assessment of social cost is uncertain because it considers only one type of cancer, it is based on one epidemiological study in Iowa, and involves various assumptions regarding exposure. Our results highlight the need for improved epidemiological studies.</p

N2O Release from agro-biofuel production negates global warming reduction by replacing fossil fuels

The relationship, on a global basis, between the amount of N fixed by chemical, biological or atmospheric processes entering the terrestrial biosphere, and the total emission of nitrous oxide (N2O), has been re-examined, using known global atmospheric removal rates and concentration growth of N2O as a proxy for overall emissions. For both the pre-industrial period and in recent times, after taking into account the large-scale changes in synthetic N fertiliser production, we find an overall conversion factor of 3–5 % from newly fixed N to N2O–N. We assume the same factor to be valid for biofuel production systems. It is covered only in part by the default conversion factor for ‘direct’ emissions from agricultural crop lands (1 %) estimated by IPCC (2006), and the default factors for the ‘indirect’ emissions (following volalilization/deposition and leaching/runoff of N: 0.35–0.45 %) cited therein. However, as we show in the paper, when additional emissions included in the IPCC methodology, e.g. those from livestock production, are included, the total may not be inconsistent with that given by our “top-down” method. When the extra N2O emission from biofuel production is calculated in “CO2-equivalent” global warming terms, and compared with the quasi-cooling effect of ‘saving’ emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), depending on N fertilizer uptake efficiency by the plants, can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings. Crops with less N demand, such as grasses and woody coppice species, have more favourable climate impacts. This analysis only considers the conversion of biomass to biofuel. It does not take into account the use of fossil fuel on the farms and for fertilizer and pesticide production, but it also neglects the production of useful co-products. Both factors partially compensate each other. This needs to be analyzed in a full life cycle assessment

A cleaner production assessment of the ultra-fine coal waste generated in South Africa

The South African coal mining industry is currently disposing of about 10 million tons of ultra-fine coal (<150 µm) per year. Once discarded, these sulphur-containing ultra-fines contribute to several environmental problems. As part of a project initiated by the Water Research Commission to investigate the use of Cleaner Production (CP) in the mining industry, a study was carried out to determine whether a CP approach could be used to identify opportunities to reduce this coal waste, and to determine which of these opportunities would be most feasible. In order to do this, a CP assessment was conducted at three case study collieries in the South African Witbank coalfield. Mass-balancing and sampling, followed by laboratory characterisation tests and site surveys, were used to determine the quantity, quality and sources of the ultra-fine coal at the three collieries. Literature reviews, brainstorming sessions and interviews then followed to generate the CP options. An environmental, economic and technical feasibility assessment was then prepared for each option, to determine the most viable interventions for implementation. A number of opportunities were identified through the assessment. By preventing coarser coal from being discarded with the ultra-fine coal, the quantity of coal disposed of could be decreased at all three collieries, and by up to 24% in one case. Increasing the crusher top size would reduce the amount of coal that is milled to less than 150 µm, so that less is wasted. The ultra-fines that have already been disposed of on slurry dams can be completely reclaimed and converted into a valuable product, which can be sold as power station feedstock. The newly processed ultra-fines could be beneficiated using flotation and exported together with the coarser coal. The results of the assessments thus suggested that workable CP opportunities to reduce ultra-fine coal wastage exist at the sites investigated, and that their feasibility is colliery-specific. The associated financial benefits of the proposed options suggested that CP is a realistic approach to addressing environmental problems