Water supply and sustainability: life cycle assessment of water collection, treatment and distribution service

Purpose

The aim of the present paper is to describe the development of a life cycle assessment study of the service of potable water supply in Sicily, Italy. The analysis considers the stages of collection, treatment and distribution of potable water through the regional network, whilst the use stage of water is not included.

Methods

The selection of a methodological pattern coherently with the requirements of an environmental label, such as the EPDs, aims at allowing comparability among different studies.

Results and discussion

The analysis shows the shares of impacts along the life cycle chain, i.e. outputs by well fields and spring groups, purification and desalination plants, water losses in the waterworks, electrical consumption of waterworks systems and impacts of network maintenance. With regard to global warming potential (GWP), the impact of purification plants represents a 6–7 % share of the total, whilst desalination is at 74 %. Water losses in the waterworks show an impact of 15–17 %; the contribution owing to electrical consumption of waterworks systems and network maintenance results to be 3 %. Desalination plants represent the major contribution to all impact categories considered.

Conclusions

In respect to management issues, the most relevant impact categories resulted to be GWP, non-renewable energy resources and water consumption. Since the results for non-renewable energy resources are strictly connected to GWP emissions, carbon footprint and water footprint can be profitably used as single-issue indicators without the risk of burden shifting in studies aiming to evaluate the impact of potable water distribution.     

Effects of irrigation on the soil CO2 efflux from different poplar clone plantations in arid northwest China

Aims

Soil respiration in forest plantations can be greatly affected by management practices such as irrigation. In northwest China, soil water is usually a limiting factor for the development of forest plantations. This study aims to examine the effects of irrigation intensity on soil respiration from three poplar clone plantations in this arid area.

Methods

The experiment included three poplar clones subjected to three irrigation intensities (without, low and high). Soil respiration was measured using a Li-6400-09 chamber during the growing season in 2007.

Results

Mean soil respiration rates were 2.92, 4.74 and 3.49 μmol m^?2 s^?1 for control, low and high irrigation treatments, respectively. Soil respiration decreased once soil water content was below a lower (14.8 %) or above an upper (26.2 %) threshold. When soil water content ranged from 14.8 % to 26.2 %, soil respiration increased and correlated with soil temperature. Fine root also played a role in the significant differences in soil CO₂ efflux among the three treatments. Furthermore, the three poplar hybrid clones responded differently to irrigation regarding fine root production and soil CO₂ efflux.

Conclusions

Irrigation intensity had a strong impact on soil respiration of the three poplar clone plantations, which was mainly because fine root biomass and microbial activities were greatly influenced by soil water conditions. Our results suggest that irrigation management is a main factor controlling soil carbon dynamics in forest plantation in arid regions.     

Assessing environmental impacts associated with freshwater consumption along the life cycle of animal products: the case of Dutch milk production in Noord-Brabant

Purpose

The assessment of water footprints of a wide range of products has increased awareness on preserving freshwater as a resource. The water footprint of a product was originally defined by Hoekstra and Hung (2002) as the sum of the volumetric water use in terms of green, blue and grey water along the entire life cycle of a product and, as such, does not determine the environmental impact associated with freshwater use. Recently, several papers were published that describe building blocks that enable assessment of the site-specific environmental impact associated with freshwater use along the life cycle of a global food chain, such as the impact on human health (HH), ecosystem quality (EQ) or resource depletion (RD). We integrated this knowledge to enable an assessment of the environmental impact associated with freshwater use along the life cycle of milk production, as a case for a global food chain.

Material and methods

Our approach innovatively combined knowledge about the main impact pathways of freshwater use in life cycle assessment (LCA), knowledge about site-specific freshwater impacts and knowledge about modelling of irrigation requirements of global feed crops to assess freshwater impacts along the life cycle of milk production. We evaluated a Dutch model farm situated on loamy sand in the province of Noord-Brabant, where grass and maize land is commonly irrigated.

Results and discussion

Production of 1 kg of fat-and-protein corrected milk (FPCM) on the model farm in Noord-Brabant required 66 L of consumptive water. About 76 % of this water was used for irrigation during roughage cultivation, 15 % for production of concentrates and 8 % for drinking and cleaning services. Consumptive water use related to production of purchased diesel, gas, electricity and fertiliser was negligible (i.e. total 1 %). Production of 1 kg of FPCM resulted in an impact on HH of 0.8?×?10^?9 disability adjusted life years, on EQ of 12.9?×?10^?3 m²?×?year and on RD of 6.7 kJ. The impact of producing this kilogram of FPCM on RD, for example, was caused mainly by cultivation of concentrate ingredients, and appeared lower than the average impact on RD of production of 1 kg of broccoli in Spain.

Conclusions

Integration of existing knowledge from diverse science fields enabled an assessment of freshwater impacts along the life cycle of a global food chain, such as Dutch milk production, and appeared useful to determine its environmental hotspots. Results from this case study support earlier findings that LCA needs to go beyond simple water volume accounting when the focus is on freshwater scarcity. The approach used, however, required high-resolution inventory global data (i.e. especially regarding crop yield, soil type and root depth), and demonstrated a trade-off between scientific quality of results and applicability of the assessment method.     

A regulated deficit irrigation strategy for hedgerow olive orchards with high plant density

Background & Aims

There is not a consensus on the best irrigation approach for super-high density (SHD) olive orchards. Our aim was to design and test a regulated deficit irrigation (RDI) strategy for a sustainable balance between water saving, tree vigour and oil production.

Methods

We tested our RDI strategy for 3 years in an ‘Arbequina’ orchard with 1,667 trees ha^?1. Two levels of irrigation reduction were applied, 60RDI and 30RDI, scaled to replacing 60 % and 30 %, respectively, of the of irrigation needs (IN). We also had a full irrigation (FI) treatment as control, with IN totalling 4,701 m³ ha^?1

Results

The 30RDI treatment showed the best balance between water saving, tree vigour and oil production. With a yearly irrigation amount (IA) of 1,366 m³ ha^?1, which meant 72 % water saving as compared to FI, the reduction in oil yield was 26 % only.

Conclusions

Our results, together with recent knowledge on the effect of water stress on fruit development, allowed us to suggest a potentially improved RDI strategy for which a total IA of ca. 2,100 m³ ha^?1 was calculated. Both some management details and the benefits of this suggested RDI strategy are still to be tested.     

Reducing the impact of irrigated crops on freshwater availability: the case of Brazilian yellow melons

Purpose

This study quantifies freshwater consumption throughout the life cycle of Brazilian exported yellow melons and assesses the resulting impact on freshwater availability. Results are used to identify improvement options. Moreover, the study explores the further impact of variations in irrigation volume, yield, and production location.

Methods

The product system boundary encompasses production of seeds, seedlings, and melon plants; melon packing; disposal of solid farm waste; and farm input and melon transportation to European ports. The primary data in the study were collected from farmers in order to quantify freshwater consumption related to packing and to production of seeds, seedlings, and melons. Open-field melon irrigation was also estimated, considering the region's climate and soil characteristics. Estimated and current water consumptions were compared in order to identify impact reduction opportunities. Sensitivity analysis was used to evaluate variations in the impact because of changes in melon field irrigation, yield, and farm location.

Results and discussion

This study shows that the average impact on freshwater availability of 1 kg of exported Brazilian yellow melons is 135 l H₂O-e, with a range from 17 to 224 l H₂O-e depending on the growing season's production period. Irrigation during plant production accounts for 98 % of this impact. Current melon field water consumption in the Low Jaguaribe and Açu region is at least 39 % higher than necessary, which affects the quality of fruits and yield. The impact of melon production in other world regions on freshwater availability may range from 0.3 l H₂O-e/kg in Costa Rica to 466 l H₂O-e/kg in the USA.

Conclusions

The impact of temporary crops, such as melons, on water availability should be presented in ranges, instead of as an average, since regional consumptive water and water stress variations occur in different growing season periods. Current and estimated water consumption for irrigation may also be compared in order to identify opportunities to achieve optimization and reduce water availability impact.     

Effects of drip irrigation on deep root distribution, rooting depth, and soil water profile of jujube in a semiarid region

Aims

Aimed to understand how soil water was depleted by deep roots, the effects of drip irrigation and stand age on the deep root distribution, rooting depth, and soil water profile dynamics were investigated in a jujube (Ziziphus jujube Mill. CV. Lizao) plantation.

Methods

A soil coring method with a LuoYang shovel was used for sampling until no more roots were found.

Results

It showed that the maximum fine rooting depth (<2 mm in diameter) increased with stand age and it extended deep into the soil rapidly during the first 4 years, but more slowly in the subsequent 4 years. The maximum rooting depth reached 5 m in a 9-year-old jujube plantation, but it stabilized and did not increase thereafter. However, it was 10 m in a 12-year-old jujube plantation that lacked irrigation.

Conclusions

We found that the application of 33.3 mm of irrigation water (equivalent to 7 % of the local annual precipitation) could halve the maximum rooting depth, thereby reducing deep soil water depletion. Our results showed that a low-volume water supply reduced the maximum rooting depth in jujube and prevented the depletion of the deep soil water. Appropriate drip irrigation is an effective water management strategy for sustainable artificial forest development in semiarid regions.     

Freshwater use analysis of cassava for food feed fuel in the Mun River basin,Thailand

Purpose

This research aims to assess the current freshwater use in the cassava supply chain for food, feed fuel in the Mun basin, and the water scarcity impact and possible options to increase cassava production to meet the future demand following the Renewable and Alternative Energy Development Plan (AEDP) target.

Methods

This research analyzes freshwater use based on ISO 14046 water footprint assessment. The analysis was implemented based on a life cycle perspective that determines the impact on freshwater use from cassava products along their supply chain. Both direct water use and indirect water use that associated are analyzed. Midpoint impact of water use was assessed using water stress index (WSI) to calculate water scarcity footprint.

Results and discussion

The results show that in the current situation, total freshwater use of all cassava-related product in Mun basin in the base case is 1140 million m³/year. When WSI was applied, water scarcity footprint of all cassava-related products in the Mun basin in the base case was only 147 million m³/year. In the scenario 1, increasing irrigation to increase yield in the existing cassava cultivation area in the Mun basin has the largest water use compare to other scenarios. Scenarios 2 and 3, expanding cassava cultivation area in Mun basin and in other regions, have lower water and water scarcity impact than scenario 1. The benefit from transforming paddy rice (in unsuitable areas) to cassava cultivation was also good. However, more resources are required including land, energy, or fertilizer, and other environmental impacts such as greenhouse gas emission or eutrophication could be increased from the increasing resource use. Therefore, the decision-making process needs to consider the trade-off between those factors, and a more complete life cycle assessment (LCA) on the envisioned alternatives should be applied for further analysis.

Conclusions

The increasing demand of biofuels derived from cassava can increase stress on water in the Mun River basin. Increasing irrigation water use in the area as per requirement could possibly increase yield to meet the future feedstock demand but has large water scarcity impact. However, this could be alleviated by using groundwater from additional wells in the farm. Expanding cassava cultivation area could be another option having low water scarcity impact, but it requires more resources and could increase other environmental impacts that need to be further analyzed by a complete LCA.

     

Life cycle consumptive water use for oil shale development and implications for water supply in the Colorado River Basin

Purpose

Oil shale is an unconventional petroleum source that can be produced domestically in the USA. Oil shale resources are primarily located in Utah, Wyoming, and Colorado, within the Colorado River Basin. In this paper, we analyze the life cycle consumptive water use for oil shale production and its impacts on water resources of the Colorado River Basin.

Methods

The study is focused on life cycle consumptive water use for oil shale development. Consumptive water use is defined as “water that is evaporated, transpired, incorporated into products, or otherwise removed from the immediate water environment.” The analysis includes direct consumptive water requirements to extract, process, and refine shale oil, as well as indirect consumptive water use for generating the electricity associated with the extraction and processing. From the results, strategies for water supply certainty are discussed, and strategies for implementation are suggested. In addition, refining the shale oil outside of the oil shale region (removing the need for local water), using dry cooling systems for electricity generation, and building desalination plants in California (to replace water) are evaluated.

Results and discussion

Life cycle consumptive water use for oil shale is significant and could impact water availability for consumers in the lower Colorado River Basin. At a level of oil production of 2 million barrels per day, the life cycle consumptive water use would be significant: between 140 and 305 billion gallons (0.4 and 0.9 million acre-ft.) of water per year if surface mining and retorting is done, or between 150 and 340 billion gallons (0.5 and 1 million acre-ft.) of water per year if the Shell in situ process is used. Strategies could be implemented to provide water supply certainty including refining the shale oil outside of the region (removing some need for local water), using dry cooling systems for electricity generation, and building desalination plants in California (to replace water).

Conclusions

Water supply in the Colorado River Basin could be a primary constraint to the development of oil shale. At a level of oil production of 2 million barrels per day, the life cycle consumptive water use would be significant. Energy companies or governments may want to invest in water management and supply strategies that would eliminate the uncertainty associated with the water availability in the Colorado River Basin for oil shale development.     

Life cycle assessment of sugarcane ethanol production in India in comparison to Brazil

Purpose

India’s biofuel programme relies on ethanol production from sugarcane molasses. However, there is limited insight on environmental impacts across the Indian ethanol production chain. This study closes this gap by assessing the environmental impacts of ethanol production from sugarcane molasses in Uttar Pradesh, India. A comparative analysis with south-central Brazilian sugarcane ethanol is also presented to compare the performance of sugarcane molasses-based ethanol with sugarcane juice-based ethanol.

Methods

The production process is assessed by a cradle-to-gate life cycle assessment. The multifunctionality problem is solved by applying two variants of system expansion and economic allocation. Environmental impacts are assessed with Impact 2002+ and results are presented at the midpoint level for greenhouse gas emissions, non-renewable energy use, freshwater eutrophication and water use. Furthermore, results include impacts on human health and ecosystem quality at the damage level. Sensitivity analysis is also performed on key contributing parameters such as pesticides, stillage treatment and irrigation water use.

Results and discussion

It is found that, compared to Brazilian ethanol, Indian ethanol causes lower or comparable greenhouse gas emissions (0.09–0.64 kgCO_2eq/kg_ethanolIN, 0.46–0.63 kgCO_2eq/kg_ethanolBR), non-renewable energy use (?0.3–6.3 MJ/kg_ethanolIN, 1–4 MJ/kg_ethanolBR), human health impacts (3.6?·?10^?6 DALY/kg_ethanolIN, 4?·?10^?6 DALY/kg_ethanolBR) and ecosystem impairment (2.5 PDF?·?m²?·?year/kg_ethanolIN, 3.3 PDF?·?m²?·?year/kg_ethanolBR). One reason is that Indian ethanol is exclusively produced from molasses, a co-product of sugar production, resulting in allocation of the environmental burden. Additionally, Indian sugar mills and distilleries produce surplus electricity for which they receive credits for displacing grid electricity of relatively high CO₂ emission intensity. When economic allocation is applied, the greenhouse gas emissions for Indian and Brazilian ethanol are comparable. Non-renewable energy use is higher for Indian ethanol, primarily due to energy requirements for irrigation. For water use and related impacts, Indian ethanol scores worse due groundwater irrigation, despite the dampening effect of allocation. The variation on greenhouse gas emissions and non-renewable energy use of Indian mills is much larger for high and low performance than the respective systems in Brazil.

Conclusions

Important measures can be taken across the production chain to improve the environmental performance of Indian ethanol production (e.g. avoiding the use of specific pesticides, avoiding the disposal of untreated stillage, transition to water efficient crops). However, to meet the targets of the Indian ethanol blending programme, displacement effects are likely to occur in countries which export ethanol. To assess such effects, a consequential study needs to be prepared.     

Why going beyond standard LCI databases is important: lessons from a meta-analysis of potable water supply system LCAs

Purpose

Our aim is to assess the comparability and generic applicability of harmonized published lifecycle assessment (LCA) studies on water supply systems. In the absence of localized life cycle inventories for water systems, generic or country specific databases may be inadequate if applied elsewhere. The objectives of this paper are to calculate the potential magnitude of errors introduced by this practice and recommend ways to better account for sources of impact variability.

Methods

In this study, harmonization has been carried out rigorously, utilizing a systematic differentiation of the subsystems, functional units, and system boundaries referenced in over 100 candidate studies, resulting in a comparable subset of 34 LCA studies. Statistical techniques (cluster analysis and Welch’s analysis of variance) were used to isolate and validate the main sources of variation in impact scores and identify the sub-systems in which these are most pronounced. The significance of technology-specific contribution to the impacts was compared to the significance of electricity as a contributing factor to the global warming potential (GWP) by applying statistical correlation analysis.

Results and discussion

Our review revealed that most of the published LCAs analyzed water systems in well-developed countries. Large variation was found in the impacts of water supply systems (e.g., GWP between 0.16 and 3.4 kg CO2-eq/m³ of supplied water), with mean value of 0.84 kg CO2-eq/m3 and median of 0.57 kg CO2-eq/m3. The main contributor to GWP is water production and desalination in particular, making water production the most important differentiating factor. Cluster analysis also showed that production technology is the most important differentiating factor with respect to terrestrial acidification, ozone depletion, eutrophication, and abiotic depletion impacts of water production systems. There is a weak correlation between impact scores of electricity mixes and entire water supply systems.

Conclusions

An LCA of water-intensive products drawing from a standard life cycle inventory databases could be substantially inaccurate, especially in a region with desalination. More accurate results can be achieved by taking local water production technology into account. Meta-analysis is a useful tool to explore the sources of variance in the impacts of water systems. Applying harmonized results is a cost-effective way for obtaining more accurate LCA results as compared to applying generic databases only.

     

Vehicle manufacturing water use and consumption: an analysis based on data in automotive manufacturers’ sustainability reports

Purpose

The goal of this study is to develop an estimate of water use and consumption in automotive manufacturing to enhance the data quality of vehicle life cycle assessments that include life cycle water impacts. A benchmark is developed to compare water resources across manufacturing and nonproduction-related manufacturing processes, including an indication whether indirect water consumption due to electricity generation is significant.

Methods

Data from 12 original equipment manufacturers’ (OEM’s) sustainability reports are examined for the years 2006 to 2010. Distinctions are made between “water use” and “water consumption.” These factors are divided by total reported production to develop use and consumption values in cubic meter/vehicle for comparison. Additionally, total energy consumption is converted to indirect water consumption based on the water consumed in the generation of electricity for the electricity grid mix.

Results and discussion

Excluding outliers, average direct water use is 5.20 and 5.95 m³/vehicle for manufacturing and company-wide activities, respectively, with corresponding standard deviations of 1.42 and 1.20 m³/vehicle. Average direct water consumption was calculated to be 1.25 and 4.29 m³/vehicle for manufacturing and company-wide activities, respectively, with corresponding standard deviations of 0.52 and 1.56 m³/vehicle. Average indirect water consumption due to electricity consumption is found to be 2.21 m³/vehicle. Variability arises through different understandings on the words “consumption” and “use,” reporting continuity between years and in classification of data as it relates to manufacturing, nonmanufacturing, or company-wide activities.

Conclusions

These water values show that needs vary widely across OEMs. Additionally, the magnitude of the indirect water consumption results indicates that OEMs should focus on both indirect and direct water consumption to reduce their overall water footprint. The results also highlight the potential for significance and variability in indirect water consumption, in particular for “cradle-to-gate” type of impact assessments, dependent on electricity generation water consumption assumptions. It is hoped that with the introduction of water reporting standards like the International Organization of Standardization 14046, manufacturers will provide a more comprehensive summary of their water use and consumption in the future.     

A comparison of three methods to assess land use impacts on biodiversity in a case study of forestry plantations in New Zealand

Purpose

The aim of this study is apply available methods to assess impacts on biodiversity from the land use caused by plantation grown radiata pine in New Zealand in a life cycle assessment framework. This is done both to quantify the impact as well as compare the results obtained by different methods.

Methods

Data on location and productivity for wood supply regions in New Zealand was assessed using three methods identified as relevant for the purpose. All data were related to a functional unit of 1 m³ of timber production.

Results and discussion

The results show both a significant difference in impact on biodiversity from land use in the different wood supply regions and a significant difference in the results from the three applied methods. Although some of the results obtained from the three methods were correlated, this was not consistent through all the results. The methodological variation emanates from the treatment of the characteristics of the wood supply regions and underlying assumptions, e.g. reference vegetation. Compared to a case study in Norway, the impact on biodiversity from plantation forestry in New Zealand is found to be relatively low following the applied methods and assumptions taken.

Conclusions

The study shows a significant variation in how impacts on biodiversity are assessed following different approaches. Research to harmonize methods to quantify impact on biodiversity is recommended, as well as exploring effects of different weighting of crucial aspects of biodiversity, such as rarity, abundance and species richness.     

Nickel-enriched seed and externally supplied nickel improve growth and alleviate foliar urea damage in soybean

Background and aims

The importance of seed Ni reserves for plant growth and N metabolism is poorly understood. This study investigated the effects of both seed Ni and externally supplied Ni on the impact of foliarly-applied urea and N-nutritional status of soybean.

Methods

Soybean seeds were produced by growing plants in nutrient solutions containing different Ni levels, and their urease activities were measured. Plants were then grown from these seeds with or without external Ni. After treating half of the plants with foliar urea, the urea damage symptoms, elongation rates and chlorophyll concentrations were followed over one week. Biomass and mineral concentrations of different plant parts were determined.

Results

Nickel supply at increasing rates improved seed yield by up to 25 %. Seeds with Ni concentrations varying between 0.04–8.32 mg.kg^?1 were obtained. Depending on the Ni concentration, the seed urease activities differed up to 100-fold. Leaf damage due to foliar urea spray was significantly alleviated by higher seed Ni as well as external Ni supply. Higher Ni also promoted shoot elongation and improved chlorophyll concentrations. Nickel was 10-times more concentrated in the youngest part than in older leaves. In the absence of foliar urea, Ni enhanced the N concentration of the growing part of the shoot by up to 30 %.

Conclusion

A better utilization of foliarly-applied urea-N is achieved in soybean when adequate Ni is supplied to plants by seed reserves and/or externally. High seed Ni levels are also required for preventing foliar urea damage and improving N remobilization.     

Environmental assessment of air to water machines—triangulation to manage scope uncertainty

Purpose

Devices that condense and disinfect water vapour to provide chilled drinking water in office environments, so-called ‘air water generators’ (AWGs), are being marketed as environmentally friendly alternatives to the traditional bottled water cooler. We sought to examine this claim.

Methods

The approach adopted was a preliminary life cycle assessment with performance indicators for the use of energy and water and the emission of greenhouse gases. We compared an AWG with its main market competitor, the traditional bottled water cooler and a simple refrigerator containing a jug of water. Modelling was based on Australian conditions and energy supply. To manage possible scope uncertainty, we borrowed the idea of ‘triangulation’ as defined in the social sciences.

Results and discussion

We found that without a renewable energy supply, the claim of environmental superiority is not supported by quantitative analysis. For each indicator, the AWG's score was typically two to four times higher than the alternatives. Energy consumption was the key issue driving all three indicators.

Conclusions

Considering the principal environmental issues related to these systems, air-to-water machines significantly underperform bottled water coolers. A simple refrigerator has the capacity to perform multiple functions and therefore outperform both the bottled and atmospheric water options once allocation of burdens is considered. These conclusions are supported by all three perspectives examined to manage uncertainty.     

Life cycle assessment of cheese and whey production in the USA

Purpose

A life cycle assessment was conducted to determine a baseline for environmental impacts of cheddar and mozzarella cheese consumption. Product loss/waste, as well as consumer transport and storage, is included. The study scope was from cradle-to-grave with particular emphasis on unit operations under the control of typical cheese-processing plants.

Methods

SimaPro© 7.3 (PRé Consultants, The Netherlands, 2013) was used as the primary modeling software. The ecoinvent life cycle inventory database was used for background unit processes (Frischknecht and Rebitzer, J Cleaner Prod 13(13–14):1337–1343, 2005), modified to incorporate US electricity (EarthShift 2012). Operational data was collected from 17 cheese-manufacturing plants representing 24 % of mozzarella production and 38 % of cheddar production in the USA. Incoming raw milk, cream, or dry milk solids were allocated to coproducts by mass of milk solids. Plant-level engineering assessments of allocation fractions were adopted for major inputs such as electricity, natural gas, and chemicals. Revenue-based allocation was applied for the remaining in-plant processes.

Results and discussion

Greenhouse gas (GHG) emissions are of significant interest. For cheddar, as sold at retail (63.2 % milk solids), the carbon footprint using the IPCC 2007 factors is 8.60 kg CO₂e/kg cheese consumed with a 95 % confidence interval (CI) of 5.86–12.2 kg CO₂e/kg. For mozzarella, as sold at retail (51.4 % milk solids), the carbon footprint is 7.28 kg CO₂e/kg mozzarella consumed, with a 95 % CI of 5.13–9.89 kg CO₂e/kg. Normalization of the results based on the IMPACT 2002+ life cycle impact assessment (LCIA) framework suggests that nutrient emissions from both the farm and manufacturing facility wastewater treatment represent the most significant relative impacts across multiple environmental midpoint indicators. Raw milk is the major contributor to most impact categories; thus, efforts to reduce milk/cheese loss across the supply chain are important.

Conclusions

On-farm mitigation efforts around enteric methane, manure management, phosphorus and nitrogen runoff, and pesticides used on crops and livestock can also significantly reduce impacts. Water-related impacts such as depletion and eutrophication can be considered resource management issues—specifically of water quantity and nutrients. Thus, all opportunities for water conservation should be evaluated, and cheese manufacturers, while not having direct control over crop irrigation, the largest water consumption activity, can investigate the water use efficiency of the milk they procure. The regionalized normalization, based on annual US per capita cheese consumption, showed that eutrophication represents the largest relative impact driven by phosphorus runoff from agricultural fields and emissions associated with whey-processing wastewater. Therefore, incorporating best practices around phosphorous and nitrogen management could yield improvements.     

Risk of dietary magnesium deficiency is low in most African countries based on food supply data

Background

Dietary mineral deficiencies are widespread in Africa. Our previous studies in Malawi revealed population-level shortfalls in dietary calcium and selenium supply but adequate dietary magnesium (Mg) supply. Here we examine dietary Mg supply throughout Africa.

Methods

Food supply data from 1961 to 2007 were compiled using Food and Agriculture Organization (FAO) Food Balance Sheets (FBSs). Magnesium supply was estimated for each country using regional food Mg composition tables.

Results

Mean Mg supply in 2007 was 649 mg capita ^?1 d^?1, ranging from 188 mg d^?1 in Eritrea to 1,828 mg d^?1 in Burkina Faso. Magnesium supply was greater in West Africa than in other regions, was dominated by sorghum, maize and wheat and was correlated with calorie supply. The World Health Organization (WHO) Estimated Average Requirement (EAR) for Mg (217 mg capita ^?1 d^?1 for adult males) was exceeded in most countries. Using the EAR cut-point method, the risk of dietary Mg deficiency in Africa is <4 % and unlikely to be a major problem, assuming access to sufficient food and that phytic acid does not compromise Mg absorption.

Conclusions

Estimating Mg supply is highly sensitive to concentration data available for the primary staple crops. Given that soil factors profoundly affect crop Mg concentration, there is a need to increase the spatial resolution of food composition tables for the staple crops.     

Evaluation of water services system through LCA. A case study for Iasi City,Romania

Purpose

The main objective of this paper is to analyse through life cycle assessment (LCA), the entire water services system in Iasi City (Romania): a representative city for the problems faced by the water services sector in Romania. Furthermore, the study is aimed at demonstrating the usefulness of the LCA approach as a support instrument for water resources management.

Methods

The life cycle inventory (LCI) of the Iasi water system was organized considering the water system components, as well as their function related to the water use life cycle: before the tap system as production phase (water abstraction, transport, treatment and distribution) and after the tap section as post-use phase (wastewater collection, treatment and discharge). The foreground data describing the LCI processes were provided directly by the company operating the Iasi water system, while the data for the background processes were sourced or selected from Ecoinvent 2.0 database. The assessment considers the quantification of environmental impacts (according to the CML 2000 baseline and Ecological Scarcity 2006 methodologies) of water supply (abstraction, treatment and distribution) and wastewater disposal (collection and treatment) relative to 1 m³ of tap water.

Results and discussion

For this given system, the results have pointed out that the before the tap system generates higher impacts than the after tap system, mainly due to the energetic effort needed for water supply and the fairly high water losses in the distribution system. However, the after the tap system, specifically the discharge of treated wastewater is still responsible for many of the water-related impact such as Eutrophication (when using CML) or Emissions to surface waters (when using the Ecological Scarcity method). Apart from the LCA approach, this study presents several scenarios for the improvement of the environmental performance of the water services, such as: changing between water sources, improving the distribution system and upgrading the wastewater treatment plant.

Conclusions

This study has demonstrated the usefulness of LCA to describe, compare and predict the environmental performance of complex water services systems (and all its components). The results have provided a reference case for the environmental profile of Iasi city water system, and have enabled the identification of its improvement alternatives. Also, this study, which represents a premiere for Romania, has opened future research directions which may include the development perspectives of the Iasi water services system, as well as improvements of LCIA methodologies to better represent the local specific water-related impacts.     

Phenotypic seedling responses of a metal-tolerant mutant line of sunflower growing on a Cu-contaminated soil series: potential uses for biomonitoring of Cu exposure and phytoremediation

Background and aims

The potential use of a metal-tolerant sunflower mutant line for both biomonitoring and phytoremediating a Cu-contaminated soil series was investigated.

Methods

The soil series (21–1,170 mg Cu kg^?1) was sampled in field plots at control and wood preservation sites. Sunflowers were cultivated 1 month in potted soils under controlled conditions.

Results

pH and dissolved organic matter influenced Cu concentration in the soil pore water. Leaf chlorophyll content and root growth decreased as Cu exposure rose. Their EC₁₀ values corresponded to 104 and 118 μg Cu L^?1 in the soil pore water, 138 and 155 mg Cu kg^?1 for total soil Cu, and 16–18 mg Cu kg^?1 DW shoot. Biomass of plant organs as well as leaf area, length and asymmetry were well correlated with Cu exposure, contrary to the maximum stem height and leaf water content.

Conclusions

Physiological parameters were more sensitive to soil Cu exposure than the morphological ones. Bioconcentration and translocation factors and distribution of mineral masses for Cu highlighted this mutant as a secondary Cu accumulator. Free Cu²⁺ concentration in soil pore water best predicted Cu phytoavailability. The usefulness of this sunflower mutant line for biomonitoring and Cu phytoextraction was discussed.     

Irrigation mix: how to include water sources when assessing freshwater consumption impacts associated to crops

Purpose

Impacts of activities related to freshwater use are gaining interest among the life cycle assessment (LCA) community and several approaches are nowadays available in the literature. However, the general trend still is to ignore the assessment of its impact or, luckily, its inclusion on the inventory. This paper describes a procedure to incorporate water source information at the inventory level and evaluate the influence of that profile on the environmental impact assessment level.

Methods

The methodology lies on two main elements: the “irrigation mix” concept and the freshwater ecosystem impact indicator already defined in the literature. By doing so, the results obtained can be easily integrated in LCA studies of irrigated crops, or more complex studies with agricultural ingredients, where only information regarding the amount (but not the origin) of irrigation water is available.

Results and discussion

The results make more visible the benefits associated to the use of nonconventional, artificial water sources, by quantifying the improvement achieved on the water stress of a specific basin. Besides, the irrigation mix gives a better picture of the real contribution of irrigation to other impact categories (here, the global warming potential). Finally, the results were applied in a LCA study of lettuce production (an irrigated product cultivated in the studied region), and the method was analyzed against the criteria defined by the International Reference Life Cycle Data System handbook.

Conclusions

The inclusion of the water mix in the inventory level (irrigation profile) as well as in the impact assessment level (water stress index) is straightforward to apply by LCA practitioners, resulting in a more realistic assessment of the impacts of freshwater consumption associated to crops. The implementation on a case study allowed the quantification of promoting alternative water sources in a region suffering from significant water stress as well as to improve knowledge on the environmental impact associated to freshwater consumed by one of the irrigated crops grown there. We recommend using the approach defined here in order to check its applicability to other river basins and products.     

When consumer behavior dictates life cycle performance beyond the use phase: case study of inkjet cartridge end-of-life management

Purpose

Conventional wisdom suggests that product reuse can provide environmental savings. The purpose of this study is to first compare the environmental impacts of retail refilling and remanufactured inkjet cartridge alternatives to production of new inkjet cartridges, and then determine the extent to which consumer behavior can influence life cycle outcomes.

Methods

A life cycle inventory was developed for an inkjet cartridge with an integral print head using material composition data collected from cartridge disassembly and material processing, product manufacturing, and transportation inputs estimated from market data and the ecoinvent database in SimaPro 7.3. Although previous comparative life cycle assessment (LCA) studies for printer cartridges typically use “pages printed” or a variation thereof for the functional unit, “cartridge use cycles” is more suitable for examining reused inkjet cartridge alternatives that depend on the inkjet cartridge end-of-life (EOL) route chosen by the consumer. Since multiple reuse cycles achieved from refilling by a retailer was of specific interest, a functional unit defined in the form of “five use cycles” included the mode and manner in which consumers purchased inkjet cartridge use cycles.

Results and discussion

Cartridge refills present the lowest environmental impact, offering a 76 % savings in global warming potential (GWP) impact compared to production and purchase of a new inkjet cartridge alternative, followed by the remanufacturing case, which provided a 36 % savings in GWP impact compared to the new inkjet cartridge. However, results varied widely, even switching to favor new cartridge purchase, depending on how consumer transport was modeled, specifically the mode of travel, travel patterns (number of trips), and method of allocating impact to each trip.

Conclusions

Refilling an original equipment manufacturer (OEM) cartridge four consecutive times provides the best alternative for reducing environmental impact for those consumers that purchase inkjet cartridges one at a time. On the other hand, consumers that purchase multiple cartridges in a single trip to a retailer reduce environmental impact more by transport minimization than by refilling. Results reinforce the need for more comprehensive inclusion of consumer behavior when modeling life cycle environmental impact of product alternatives.