Analysis of iodine-129 in environmental materials: Quality assurance and applications

The long-lived radionuclide 129I (T 1/2 = 15.7 My) occurs in the nature in very low concentrations. Since the middle of our century the environmental levels of 129I have been dramatically changed as a consequence of civil and military use of nuclear fission. Its investigation in environmental materials is of interest for environmental surveillance, retrospective dosimetry and for the use as a natural and man-made fracers of environmental processes. We are comparing two analytical methods which presently are capable of determining 129I in environmental materials, namely radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS). Emphasis is laid upon the quality control and detection capabilities for the analysis of 129I in environmental materials. Some applications are discussed.

Iodine-129: Sample preparation, quality control and analyses of pre-nuclear materials and of natural waters from Lower Saxony, Germany

Sample preparation procedures for AMS measurements of 129I and 127I in environmental materials and some methodological aspects of quality assurance are discussed. Measurements from analyses of some pre-nuclear soil and thyroid gland samples and of a systematic investigation of natural waters in Lower Saxony, Germany, are described. Although the up-to-now lowest 129I/127I ratios in soils and thyroid glands were observed, they are still suspect to contamination since they are significantly higher than the pre-nuclear equilibrium ratio in the marine hydrosphere. A survey on all available 129I/127I isotopic ratios in precipitation shows a dramatic increase until the middle of the 1980s and a stabilization since 1987 at high isotopic ratios of about (3.6–8.3)×10−7. In surface waters, ratios of (57–380)×10−10 are measured while shallow ground waters show with ratios of (1.3–200)×10−10 significantly lower values with a much larger spread. The data for 129I in soils and in precipitation are used to estimate pre-nuclear and modern 129I deposition densities.

Ecological sustainable development: a study of the obstacles in Australia's construction industry

Ecological sustainable development (ESD), defined as that which meets the needs of the present without compromising the ability of future generations to meet their own needs, has much to offer in enhancing the quality of life of people and maintaining the environment for future generations by reducing the pollution of water, air and land, minimizing the destruction of irreplaceable ecosystems and cutting down the amount of toxic materials released. However, there is still much to do to achieve full implementation world-wide. This paper reports on three factors-design, attitudes and financial constraints - that are likely barriers to the implementation of ESD within the built environment in Australian industry. A postal questionnaire survey is described aimed at soliciting views on detailed aspects of the factors. This shows that ESD in the Australian built environment has also not been successfully implemented. The main reason is found to be due to the perceived costs involved - the cost of using environmental materials being a predominant factor. The design of ESD, being more sophisticated, also is perceived as involving stakeholders in more expense. There also appears to be a lack of knowledge and a lack of specialised and interdisciplinary design teams available in the Australian context.

Valutazione della mobilita' di contaminanti inorganici tramite test di cessione su matrici ambientali contaminate

La caratterizzazione di sedimenti contaminati è un problema complesso, in questo lavoro ci si è occupati di individuare una metodologia di caratterizzazione che tenesse conto sia delle caratteristiche della contaminazione, con analisi volte a determinare il contenuto totale di contaminanti, sia della mobilità degli inquinanti stessi. Una adeguata strategia di caratterizzazione può essere applicata per la valutazione di trattamenti di bonifica, a questo scopo si è valutato il trattamento di soil washing, andando ad indagare le caratteristiche dei sedimenti dragati e del materiale in uscita dal processo, sabbie e frazione fine, andando inoltre a confrontare le caratteristiche della sabbia in uscita con quelle delle sabbie comunemente usate per diverse applicazioni. Si è ritenuto necessario indagare la compatibilità dal punto di vista chimico, granulometrico e morfologico. Per indagare la mobilità si è scelto di applicare i test di cessione definiti sia a livello internazionale che italiano (UNI) e quindi si sono sviluppate le tecnologie necessarie alla effettuazione di test di cessione in modo efficace, automatizzando la gestione del test a pHstat UNI CEN 14997. Questo si è reso necessario a causa della difficoltà di gestire il test manualmente, per via delle tempistiche difficilmente attuabili da parte di un operatore. Le condizioni redox influenzano la mobilità degli inquinanti, in particolare l’invecchiamento all’aria di sedimenti anossici provoca variazioni sensibili nello stato d’ossidazione di alcune componenti, incrementandone la mobilità, si tratta quindi di un aspetto da considerare quando si individuano le adeguate condizioni di stoccaggio-smaltimento, si è eseguita a questo scopo una campagna sperimentale.

Identification of key environmental issues for building materials

Manufacture, construction and use of buildings and building materials make a significant environmental impact internally (inside the building), locally (neighbourhood) and globally. Life cycle assessment (LCA) methodology is being applied for evaluating the environmental impact of building/or building materials. One of the major applications of LCA is to identify key issues of a product system from cradle to grave. Key issues identified in an LCA lead one to the right direction in assessing the environmental aspects of a product system and help to identify the areas for improvement of the environmental performance of a product as well. The purpose of this paper is to suggest two methods for identifying key issues using an integrated tool (LCADesign), which has been developed to provide a method of determining the best alternative for reducing environmental impacts from a building or building materials, and compare both methods in the case study. This paper assists the designers or marketers related to building or building materials in their decision making by giving information on activities or alternatives which are identified as key issues for environmental impacts.

Analysis of environmental efficiency variation : a materials balance approach

Recent literature has argued that environmental efficiency (EE), which is built on the materials balance (MB) principle, is more suitable than other EE measures in situations where the law of mass conversation regulates production processes. In addition, the MB-based EE method is particularly useful in analysing possible trade-offs between cost and environmental performance. Identifying determinants of MB-based EE can provide useful information to decision makers but there are very few empirical investigations into this issue. This article proposes the use of data envelopment analysis and stochastic frontier analysis techniques to analyse variation in MB-based EE. Specifically, the article develops a stochastic nutrient frontier and nutrient inefficiency model to analyse determinants of MB-based EE. The empirical study applies both techniques to investigate MB-based EE of 96 rice farms in South Korea. The size of land, fertiliser consumption intensity, cost allocative efficiency, and the share of owned land out of total land are found to be correlated with MB-based EE. The results confirm the presence of a trade-off between MB-based EE and cost allocative efficiency and this finding, favouring policy interventions to help farms simultaneously achieve cost efficiency and MP-based EE.

Environmental efficiency of energy, materials, and emissions

This study estimates the environmental efficiency of international listed firms in 10 worldwide sectors from 2007 to 2013 by applying an order-m method, a non-parametric approach based on free disposal hull with subsampling bootstrapping. Using a conventional output of gross profit and two conventional inputs of labor and capital, this study examines the order-m environmental efficiency accounting for the presence of each of 10 undesirable inputs/outputs and measures the shadow prices of each undesirable input and output. The results show that there is greater potential for the reduction of undesirable inputs rather than bad outputs. On average, total energy, electricity, or water usage has the potential to be reduced by 50%. The median shadow prices of undesirable inputs, however, are much higher than the surveyed representative market prices. Approximately 10% of the firms in the sample appear to be potential sellers or production reducers in terms of undesirable inputs/outputs, which implies that the price of each item at the current level has little impact on most of the firms. Moreover, this study shows that the environmental, social, and governance activities of a firm do not considerably affect environmental efficiency.

Use of solvents and environmental friendly materials for applications in Green Chemistry

The present Thesis studies three alternative solvent groups as sustainable replacement of traditional organic solvents. Some aspects of fluorinated solvents, supercritical fluids and ionic liquids, have been analysed with a critical approach and their effective “greenness” has been evaluated from the points of view of the synthesis, the properties and the applications. In particular, the attention has been put on the environmental and human health issues, evaluating the eco-toxicity, the toxicity and the persistence, to underline that applicability and sustainability are subjects with equal importance. The “green” features of fluorous solvents and supercritical fluids are almost well-established; in particular supercritical carbon dioxide (scCO2) is probably the “greenest” solvent among the alternative solvent systems developed in the last years, enabling to combine numerous advantages both from the point of view of industrial/technological applications and eco-compatibility. In the Thesis the analysis of these two classes of alternative solvents has been mainly focused on their applicability, rather than the evaluation of their environmental impact. Specifically they have been evaluated as alternative media for non-aqueous biocatalysis. For this purpose, the hydrophobic ion pairing (HIP), which allows solubilising enzymes in apolar solvents by an ion pairing between the protein and a surfactant, has been investigated as effective enzymatic derivatisation technique to improve the catalytic activity under homogeneous conditions in non conventional media. The results showed that the complex enzyme-surfactant was much more active both in fluorous solvents and in supercritical carbon dioxide than the native form of the enzyme. Ionic liquids, especially imidazolium salts, have been proposed some years ago as “fully green” alternative solvents; however this epithet does not take into account several “brown” aspects such as their synthesis from petro-chemical starting materials, their considerable eco-toxicity, toxicity and resistance to biodegradation, and the difficulty of clearly outline applications in which ionic liquids are really more advantageous than traditional solvents. For all of these reasons in this Thesis a critical analysis of ionic liquids has been focused on three main topics: i) alternative synthesis by introducing structural moieties which could reduce the toxicity of the most known liquid salts, and by using starting materials from renewable resources; ii) on the evaluation of their environmental impact through eco-toxicological tests (Daphnia magna and Vibrio fischeri acute toxicity tests, and algal growth inhibition), toxicity tests (MTT test, AChE inhibition and LDH release tests) and fate and rate of aerobic biodegradation in soil and water; iii) and on the demonstration of their effectiveness as reaction media in organo-catalysis and as extractive solvents in the recovery of vegetable oil from terrestrial and aquatic biomass. The results about eco-toxicity tests with Daphnia magna, Vibrio fischeri and algae, and toxicity assay using cultured cell lines, clearly indicate that the difference in toxicity between alkyl and oxygenated cations relies in differences of polarity, according to the general trend of decreasing toxicity by decreasing the lipophilicity. Independently by the biological approach in fact, all the results are in agreement, showing a lower toxicity for compounds with oxygenated lateral chains than for those having purely alkyl lateral chains. These findings indicate that an appropriate choice of cation and anion structures is important not only to design the IL with improved and suitable chemico-physical properties but also to obtain safer and eco-friendly ILs. Moreover there is a clear indication that the composition of the abiotic environment has to be taken into account when the toxicity of ILs in various biological test systems is analysed, because, for example, the data reported in the Thesis indicate a significant influence of salinity variations on algal toxicity. Aerobic biodegradation of four imidazolium ionic liquids, two alkylated and two oxygenated, in soil was evaluated for the first time. Alkyl ionic liquids were shown to be biodegradable over the 6 months test period, and in contrast no significant mineralisation was observed with oxygenated derivatives. A different result was observed in the aerobic biodegradation of alkylated and oxygenated pyridinium ionic liquids in water because all the ionic liquids were almost completely degraded after 10 days, independently by the number of oxygen in the lateral chain of the cation. The synthesis of new ionic liquids by using renewable feedstock as starting materials, has been developed through the synthesis of furan-based ion pairs from furfural. The new ammonium salts were synthesised in very good yields, good purity of the products and wide versatility, combining low melting points with high decomposition temperatures and reduced viscosities. Regarding the possible applications as surfactants and biocides, furan-based salts could be a valuable alternative to benzyltributylammonium salts and benzalkonium chloride that are produced from non-renewable resources. A new procedure for the allylation of ketones and aldehydes with tetraallyltin in ionic liquids was developed. The reaction afforded high yields both in sulfonate-containing ILs and in ILs without sulfonate upon addition of a small amount of sulfonic acid. The checked reaction resulted in peculiar chemoselectivity favouring aliphatic substrates towards aromatic ketones and good stereoselectivity in the allylation of levoglucosenone. Finally ILs-based systems could be easily and successfully recycled, making the described procedure environmentally benign. The potential role of switchable polarity solvents as a green technology for the extraction of vegetable oil from terrestrial and aquatic biomass has been investigated. The extraction efficiency of terrestrial biomass rich in triacylglycerols, as soy bean flakes and sunflower seeds, was comparable to those of traditional organic solvents, being the yield of vegetable oils recovery very similar. Switchable polarity solvents as been also exploited for the first time in the extraction of hydrocarbons from the microalga Botryococcus braunii, demonstrating the efficiency of the process for the extraction of both dried microalgal biomass and directly of the aqueous growth medium. The switchable polarity solvents exhibited better extraction efficiency than conventional solvents, both with dried and liquid samples. This is an important issue considering that the harvest and the dewatering of algal biomass have a large impact on overall costs and energy balance.

THE USE OF LIFE-CYCLE ANALYSIS TO REDUCE THE ENVIRONMENTAL IMPACT OF MATERIALS IN MANUFACTURING

This thesis is composed of three life-cycle analysis (LCA) studies of manufacturing to determine cumulative energy demand (CED) and greenhouse gas emissions (GHG). The methods proposed could reduce the environmental impact by reducing the CED in three manufacturing processes. First, industrial symbiosis is proposed and a LCA is performed on both conventional 1 GW-scaled hydrogenated amorphous silicon (a-Si:H)-based single junction and a-Si:H/microcrystalline-Si:H tandem cell solar PV manufacturing plants and such plants coupled to silane recycling plants. Using a recycling process that results in a silane loss of only 17 versus 85 percent, this results in a CED savings of 81,700 GJ and 290,000 GJ per year for single and tandem junction plants, respectively. This recycling process reduces the cost of raw silane by 68 percent, or approximately $22.6 and $79 million per year for a single and tandem 1 GW PV production facility, respectively. The results show environmental benefits of silane recycling centered around a-Si:H-based PV manufacturing plants. Second, an open-source self-replicating rapid prototype or 3-D printer, the RepRap, has the potential to reduce the environmental impact of manufacturing of polymer-based products, using distributed manufacturing paradigm, which is further minimized by the use of PV and improvements in PV manufacturing. Using 3-D printers for manufacturing provides the ability to ultra-customize products and to change fill composition, which increases material efficiency. An LCA was performed on three polymer-based products to determine the CED and GHG from conventional large-scale production and are compared to experimental measurements on a RepRap producing identical products with ABS and PLA. The results of this LCA study indicate that the CED of manufacturing polymer products can possibly be reduced using distributed manufacturing with existing 3-D printers under 89% fill and reduced even further with a solar photovoltaic system. The results indicate that the ability of RepRaps to vary fill has the potential to diminish environmental impact on many products. Third, one additional way to improve the environmental performance of this distributed manufacturing system is to create the polymer filament feedstock for 3-D printers using post-consumer plastic bottles. An LCA was performed on the recycling of high density polyethylene (HDPE) using the RecycleBot. The results of the LCA showed that distributed recycling has a lower CED than the best-case scenario used for centralized recycling. If this process is applied to the HDPE currently recycled in the U.S., more than 100 million MJ of energy could be conserved per annum along with significant reductions in GHG. This presents a novel path to a future of distributed manufacturing suited for both the developed and developing world with reduced environmental impact. From improving manufacturing in the photovoltaic industry with the use of recycling to recycling and manufacturing plastic products within our own homes, each step reduces the impact on the environment. The three coupled projects presented here show a clear potential to reduce the environmental impact of manufacturing and other processes by implementing complimenting systems, which have environmental benefits of their own in order to achieve a compounding effect of reduced CED and GHG.

Characterization of the environmental performance of the insulating materials in the enveloping of the building.

Insulating materials in buildings are one of the main factors that should be taken into account when talking about sustainability since with a correct application it could imply important savings for the citizens. In the course of its life, a building requires a series of supplies to perform the duties it has been built for, generating an impact on the environment. The selection of one material or another will establish partly the global environmental impact of the building. Choosing the right insulating material will determine the building's general degree of sustainability, both in its heating savings (energy consumption) and in the environmental impacts caused by its LCA (greenhouse gas emissions). Therefore, we propose to establish guidelines to characterize the insulating material with a better environmental performance in all the stages of its life cycle, taking into account the construction system, the use of the building and its location.