Although zinc in the environment is generally considered to be beneficial or benign, excessive amounts can cause deterioration of environmental quality and toxicity problems for some plants and animals. High amounts of zinc in the environment are often associated with anthropogenic activities, mainly those involving zinc production and consumption and those related to the use and disposal of zinc-containing products. To obtain some upper limit parameters on the historical quantities of zinc that may have entered the U.S. environment from anthropogenic sources, the Bureau of Mines conducted a materials flow study of zinc from the earliest beginning of the domestic industry through 1990 and for the year 1989. For comparative purposes a generalized historical materials flow of zinc for the world was also prepared.The United States was the world's leading producer and consumer of zinc in the 1850–1990 period. In that period, U.S. mines and smelters produced 15% and 20%, respectively, of world output, and U.S. zinc consumption accounted for about one-fourth of the world total. Maximum zinc losses into the environment related to the above production, consumption, and disposal of end use products total about 63 million tons. Dissipative uses and landfill disposal have accounted for about 73% of the potential zinc losses to the environment, followed by mining and smelting 22%, and manufacturing, 5%. At the end of 1990, contained zinc in useful end-products in the United States was estimated to be about 23 million tons. In 1989 slightly more than 1 million metric tons of zinc in new zinc-containing products were added to the domestic pool of zinc in use but in the same year, an estimated 0.9 million tons was dissipated and discarded, indicating only small net gains to the zinc pool of use annually.
This paper reports on a historical materials and energy flow analysis of the UK steel sector. The flow of raw materials, steel, steel products and steel scrap are quantified for the period from 1954 to 1994. On the basis of this analysis, the authors calculate the consumption of exergy (or available energy) associated with the UK steel sector taking into account steel production, transport, generation of waste steel, trade and recycling. The study finds that overall exergy consumption in the sector has declined almost twofold from 700 to 380 PJ p.a. over the study period, indicating a similar reduction in resource consumption. This is mainly due to improvements in the exergetic efficiency of steel production and the phasing out of the less-efficient open hearth method. Contrary to the overall decline, the amount of waste steel and the transportation exergy consumption due to the import of raw materials has increased significantly. There appears to be considerable potential, therefore, to reduce resource consumption in the steel sector still further by increasing the recovery of post-use scrap.
This paper presents a detailed account of the supply chain for iron and steel in the UK, using material ﬂow analysis. Due to the lack of a universally agreed methodology of material ﬂow analysis, we include an explanation of the accounting methodology employed in the study. Data for the supply chain has been collected reaching back three decades, enabling analysis of trends in production and consumption of iron and steel over the years. This ﬁrst part of a series of two papers quantiﬁes the iron and steel ﬂows through the UK economy including the annual amount of iron and steel embodied in all ﬁnal goods that enter the use phase in the UK. The second part explores the more elusive ﬂows of scrap generation and recycling. In this ﬁrst paper we show that the UK no longer has the capacity to recycle the scrap it collects and is increasingly relying on foreign economies to do so. We also observe that trade in iron and steel products and ferrous metal containing ﬁnal goods has increased dramatically over the years, but remained relatively balanced. Today, one-half of UK's iron and steel production is exported, whereas one-half of the iron and steel entering the UK use phase comes from imported ﬁnal goods. The efficiency with which the UK iron and steel industry transforms iron ore and scrap into iron and steel products has increased substantially. However, there is no significant downward trend in the absolute level of iron and steel use in the UK. Between 1970 and 1981 the annual amount of steel put to use dropped from 16.4 to 10.7 million metric tonnes but climbed back up to 15 million metric tonnes twice since then.
Non-energy use of fossil fuels accounts for 7% of the Total Primary Energy Supply (TPES) of Germany and represents an important potential source of CO2 (carbon dioxide) emissions. To gain a better understanding of emissions associated with non-energy use in Germany, we conduct a bottom-up carbon flow analysis with the Non-energy use Emission Accounting Tables (NEAT) model for the period of 1990–2003. We calculate average yearly non-energy use emissions to be 25 ± 2 megatonnes (Mt) CO2, of which 77% are related to industrial processes, 17% to solvent and other product use, 2% to fertilizer use in agriculture, and 4% to wastewater treatment. The comparison of NEAT estimates and official data reveals gaps and errors in the German greenhouse gas (GHG) inventory. This research highlights the difficulties associated with non-energy use emissions accounting not only in Germany but in other countries as well. To ensure correct calculation of non-energy use emissions, we recommend that inventory experts (i) obtain detailed insight into the system boundaries of non-energy use data as stated in national energy statistics, (ii) allocate non-energy use emissions accordingly to the relevant emission source categories (i.e., energy, industrial processes, solvent and other product use, agriculture, or waste), (iii) ensure completeness of emission estimates, and (iv) be cautious with the use of default emission factors as given by the Intergovernmental Panel on Climate Change (IPCC).
This paper reports on a scenario analysis of material and energy flows through the UK iron and steel sector for the period from 1994 to 2019. Following an earlier paper looking at historical flows through the sector, the authors extrapolate a set of hypothetical scenarios for the future based on varying assumptions about critical parameters. These parameters include: the demand for steel goods, technological improvements within steel production processes, and changes in the ratio of primary (basic oxygen furnace) to secondary (electric arc furnace) steel production. The hypothetical scenarios are then used to forecast a range of possible values for the exergy consumption associated with the UK steel sector for the period between 1994 and 2019. The results indicate that exergy consumption from steel is likely to fall by 15–70% of 1994 levels by 2019. Technological improvement alone does not result in significant reductions.
Xiashan Reservoir is the largest reservoir in the Shandong peninsula and the major water supply source for urban, industry and agriculture in Weifang, Shandong Province. In the upstream region of Xiashan Reservoir, its industry development ranged in the top three among 12 districts and counties of Weifang from 1995 to 2004. This study investigated changes of water quality in Xiashan Reservoir and its upstream rivers, and analyzed the key industrial developments and industry structure in the upstream region of Xiashan Reservoir between 1995 and 2004, in order to provide potential implications for planning and conducting Xiashan Reservoir protection and the industry development in the upstream region in the future. Five key industries in the upstream region were investigated between 1995 and 2004, including industrial production, water usage, wastewater treatment, and the discharged pollutants. Results showed that the water quality of Xiashan Reservoir gradually improved between 1995 and 2004 and met the requirements of Class III in 2004. Industrial development in the upstream region has increased nearly 7 times, from US$ 163.67 million in 1995 to US$ 1283.69 million in 2004, and shifted in the past decade from food brewery processing industry as the major industry in 1995 to car manufacture and accessory processing as the major industry in 2004. The amounts of water used by the five key industries in 2004 were lower than that in 1995 because of improvements in water utilization and a shift in industry structure. Correspondingly, the total industrial wastewater discharged changed little from 1995 to 2004, but the total CODCr discharged was greatly reduced.
Environmental economics assumes that reliance on price signals, adjusted for externalities, normally leads to efficient solutions to environmental problems. We explore a limiting case, when market volatility created ‘mixed signals’: prices of waste paper and other recycled materials were suddenly extremely high in 1994–1995, then plummeted back to traditional low levels in 1996. These rapid reversals resulted in substantial economic and political costs. A review of academic and business literature suggests six possible explanations for abrupt price spikes. An econometric analysis of the prices of wood pulp and waste paper shows that factor which explained price changes in 1983–1993 contribute very little to understanding the subsequent price spike. From the econometric analysis and from other sources, we conclude that speculation must have played a major role in the price spike, perhaps in combination with modest effects from changes in government policy and in export demand. If speculatively driven price spikes can disrupt an environmentally important industry such as recycling, what is the appropriate role for public policy? When price volatility is sufficiently disruptive, then measures to control or stabilize prices, rather than interfering with the market, might help to make it more efficient.
The Packaging Directive approved by EU in 1994 (62/94) initiated national activities regarding packaging waste minimization, recycling and energy recovery. In Norway, a packaging covenant between the Ministry of Environment and the packaging sector was established, where one of the elements was a voluntary program for reducing waste from the total packaging sector, defined as all the users of packaging materials in Norway. Østfold Research Foundation has developed an indicator system to follow development in material efficiency and waste minimization in the packaging sector. The indicator system is based on an Eco-efficiency approach, with measurements of packaging consumption per 1000 NOK turnover in companies adjusted for changing in the total consumer price index. A total of about 40 companies from 15 sectors of packers and fillers have participated with data over 3 years (1998–2001), whereas two companies have been followed over a period of 6 years (1995–2001). In addition, two product groups (juice and lemonade) have been followed within a large share of the Norwegian market in the period 1995–2001. The results show minor changes in the total packaging sector over the four last years, with a reduction in intensity of consumer packaging and a parallel increase in intensity of retail and transport packaging. However, there seems to have been achieved significant efficiency gains in the two companies in the period 1995–1998, and also in the distribution of concentrated lemonade. The indicator system which is based on a representative sample of companies within economic important sectors in Norway is regarded as a promising approach for measuring material efficiency and waste minimization in national packaging sectors, and could be implemented on an European basis to follow up the Packaging Directive.
We present a material flow analysis (MFA) for polyethylene terephthalate (PET), a synthetic polymer, in the United States for the years 1996–2007. We model the industrial metabolism of PET as a network of flows linking stocks and processes. The most common worldwide use of PET is in textile production, but in the US it is increasingly used to make disposable beverage containers for transporting water, carbonated soda, and other beverages. Bottles made from PET are the most-recycled plastic product in the US by mass and by recovery rate, and thus the PET material flow system constitutes an ideal case study of polymer recycling. We find that total consumption of PET resin grew at 2.7% per year over the period of the study, reaching 5.01 million metric tons in 2007. This growth was driven largely by the beverage packaging market, which accounted for 55% of consumption in 2007. About a quarter of PET bottles are collected for recycling, a number that has fluctuated widely but kept pace with consumption. However, domestic capacity for reclamation of post-consumer PET has not grown as quickly, leading recyclers to export increasing amounts of post-consumer material. Manufacturers have also imported secondary PET in increasing amounts. Reclaimed PET accounted for 6–9% of total resin demand throughout the study. While polymer recycling appears to be viable, efforts to improve material efficiency are confounded by low collection rates and a lack of reclamation infrastructure.
The needs and problems existing in the field of cultivation systems and waste management concerning elements and energy, as well as pollution, health, environment, and economy are described. The lack of reproducible biofertilisers of high quality calls for an efficient use of organic waste as a renewable raw material. Each 100 000 inhabitants in Sweden generate organic waste with considerable economic values in terms of nitrogen, phosphorus, and potassium; US$ 600 000 from the organic fraction of municipal solid waste and US$ 900 000 from human excreta as liquid organic waste, meanwhile only US$ 160 000 is recovered from the sewage sludge after the wastewater has passed the wastewater treatment plants. Most of the existing systems for handling solid and liquid waste are of old-fashioned design and cause large losses of nutrient elements. Therefore, pollution of air, water, soil, and vegetation, mainly by emissions from organic uaste, continues. Bioconversion is microbial transformation and upgrading of various organic wastes to products of high value. The elements can be efficiently recycled in completely closed local bioconversion systems with subsystems for collection, pre-processing, processing, and application of end-products. Solid and liquid organic waste from the municipality can provide renewable raw material for manufacturing of reproducible biofertilisers and of biogas. Suggestions are made on how to improve the present situation by the re-orientation of technology. A scenario for bioconversion by the year 2010 is presented.
Samples of Indiana New Albany oil shale have been examined for their content of microorganisms and for the potential of using isolates to reduce the sulfur content prior to fluidized bed hydroretorting. Shale samples have been used as inocula for culture development. Standard microbial culture methods revealed the presence of 1 × 105 to 1 × 106 microorganisms/gram of shale. The organisms found appeared to be primarily a mixture of unidentified Gram-positive bacteria and several fungi. An electron microscope procedure was developed to quantitatively examine microparticulates and to obtain their X-ray spectra. Pieces of shale several hundred grams in weight were ground in a ball mill or by mortar and pestle and wet or dry sieved into three fractions designated +200, −200 and −325, based on the mesh size of the sieve used. Equal weight samples of the ground-sieved shale were taken up in distilled, demineralized water and passed through a 0.45 μM nitrocellulose filter. The dried filters were softened, coated with a thin layer of carbon, dissolved and recoated with carbon to prepare a carbon film sandwich which entraps microparticulates and is suitable for examination in the TEM. Results of the direct TEM examination of shale indicated that the ground material contained about 1 × 109 to 1 × 1010 microbial cells/gram of shale in a surprising variety of sizes and shapes. Examination of X-ray spectra from individual microparticulates was inconclusive but suggested variability in particulate content. Quantitative X-ray analysis of bulk sieved samples was also performed. Shale, used as a growth medium supplemented with glucose but limited in sulfur, was inoculated with shale isolates. Reduction in sulfur content was measured quantitatively using the X-ray spectrometer. Results suggest that about 63–65% of the total sulfur could be removed when you include a pretreatment with HNO3 acid.
During biological denitrification in Waste Water Treatment Plants (WWTPs), many parameters (chemical, physical and biological) are responsible for greenhouse gas emissions such as nitrous oxide (N2O) and nitric oxide (NO). The present study intends to investigate the impact of the carbon source more specifically on N2O emissions, but also on NO emissions. The experiments were done in a bioreactor performing batch denitrification at a laboratory scale. Three sources of carbon were tested: ethanol and acetate as short carbon chain compounds and a mixture composed of ethanol and acetate and two long carbon chain compounds: casein extract and meat extract. The nitrogen source was always nitrates (NO3−) and the ratio COD/N was set to three. Current nitrite and nitrate ions, nitric and nitrous oxide levels were monitored during experimentation. The results principally show that the acetate carbon source generates the highest N2O and NO emissions (74% and 19% of denitrified N-NO3−, respectively).The results of this work suggest that the type and length of the carbon source used are responsible for nitrogen emissions but not in the expected way. While the literature always focuses on the inhibitory effect of nitrites on N2O emissions, this work has singled out that NO may also exert inhibitory effects on the N2O reductase enzyme. These results may be explained by the diversity of denitrifying bacteria and their distinct metabolic pathways towards the added carbon substrates (influents).
This report summarises some of the discussions at the recently held international conference on biological waste treatment (Biowaste '95, 21–24 May). The conference took place in Aalborg, in the north of the Jutland peninsula (Denmark). Denmark is one of the countries in which biotreatments for household waste are more developed.
Numbers of abandoned vehicles in England have grown rapidly over the past 10 years. In 2001/2002, over 290 000 vehicles were reported abandoned. This paper examines how the abandoned vehicle problem is likely to develop in the future with the introduction of new laws and initiatives, after first establishing the current situation and the causes of abandoned vehicles. There are four main factors which seem likely to have created the conditions for the problem to grow. These are: the substantial decline in the price of scrap metal; weaknesses in the vehicle licensing and registration system; growth in the pool of cheap, second-hand vehicles; and increased motoring costs. In the near future, implementation of the End of Life Vehicles Directive (ELVD) is likely to push up numbers of abandoned vehicles even further, since this will increase the cost of legitimate vehicle disposal. At the same time, initiatives introduced both by central government and by local authorities should help to slow the upward trend in numbers of abandoned vehicles. These initiatives include increased enforcement against untaxed vehicles, continuous registration, surrender schemes for end of life vehicles and rapid removal of abandoned vehicles. The current research suggests that if all measures to counter abandoned vehicles are effectively implemented, it is possible that the number of vehicles abandoned per annum will rise to approximately 400 000 in 2007. However, a more realistic projection, based on the assumption that new loopholes will be found by motorists determined to dump their vehicles, suggests that the number of abandoned vehicles in 2007 could be around 560 000 i.e. about double the current number. From 2007 onwards under the ELVD, vehicle manufacturers will become responsible for vehicle disposal costs. It is hoped that the problem of abandoned vehicles will start to decline from this date.
The rapid increase in population and economic growth have led to an increase in energy demand. Coal reserves are distributed worldwide, and coal is now known to be the most stable and available energy source. However, utilization of coal as an energy source involves the generation of a great amount of coal ash, and the recycling rate of the ash is rather low. Coal ash is mainly used in civil construction materials, and there is a limit to the demand for coal ash by construction industries: therefore, the increasing amount of coal ash will be a serious problem in the near future. Different applications should be considered. In this paper, three environmentally-friendly methods for coal ash recycling are described. Firstly, alkali treatment can transform coal ash to zeolite, which is used in deodorant and for wastewater treatment and soil improvement. Secondly, potassium silicate fertilizer is produced from coal ash and has a higher retentivity in the soil than that of conventional fertilizers. Thirdly, emission of sulfur dioxide is controlled by flue gas desulfurization using coal ash. It is considered that environmentally-friendly use of coal ash is important from the viewpoints of energy, economy, and environmental strategy in order to realize the concept of sustainable development.
In this article, we apply the Non-energy Use Emission Accounting Tables (NEAT) model as an independent mass balance approach to Italy in order to estimate total non-energy use and related CO2 emissions for the year 1990 and the period 1995–1997. The model results are compared with official data according to the IPCC Reference Approach (IPCC-RA) and the IPCC Sectoral Approach (IPCC-SA) of the Italian National Inventory Report. The NEAT results for total non-energy use range between 25.0 and 27.6 Mt CO2 equivalents and are therefore clearly below the values used in the IPCC-RA (31.3–32.8 Mt CO2 equivalents). Our research revealed inconsistencies in the IPCC-RA regarding feedstock consumption (i) of steam crackers in 1990 and (ii) for ammonia production in the period of 1995–1997. The CO2 emissions as determined with NEAT correspond well with official IPCC-SA values for most individual industrial processes. However, the total industrial process emissions are underestimated in the IPCC-SA because CO2 released from methanol and carbon black production is not taken into account. Moreover, we calculate with NEAT 14–61% higher CO2 emissions from ‘solvent and other product use’ than the IPCC-SA. These deviations are caused to some extent by the fact that the IPCC-SA does not account for CO2 emissions from the consumption of lubricants. In total, we therefore conclude that emissions from the non-energy use of fossil fuels are currently underestimated in the IPCC-SA. Further research is recommended (i) to improve the general accuracy of emission estimates for ‘solvent and other product use’ in the IPCC-SA and (ii) to introduce a definition for non-energy use, which allocates feedstock consumption consistently to either energy use or non-energy use in the IPCC-SA and the IPCC-RA of the Italian National Inventory Report.
To contribute to a more accurate accounting of CO2 emissions originating from the non-energy use of fossil fuels, the non-energy use emission accounting tables (NEAT) model has been developed. The model tracks the final fate of the carbon embodied in this non-energy use by means of a carbon flow analysis for the relevant sectors. The model generates estimates for total non-energy use, carbon storage in synthetic organic chemicals and CO2 emissions resulting from non-energy use that are independent from energy statistics. This paper describes the basic methodology of the NEAT model. It is shown that the results obtained with the model can be used as an important addition to and crosscheck for the non-energy use emission accounting in official greenhouse gas (GHG) emission inventories prepared according to the guidelines of the Intergovernmental Panel on Climate Change (IPCC). The model can help to identify which definitions of non-energy use are applied in the energy statistics employed in national emission inventories and can help to improve national inventory methodologies based on this insight.
This study is a quantitative description of Brazil's copper life cycle, comprising mining, refining, manufacturing, use and waste generation in the year 2005. A substance flow analysis is presented and the results are compared with existing values for other countries and economic regions (Europe, Asia, Latin America, and Africa).The results show that Brazil is a net importer of copper both in concentrate and in the form of finished goods (total net weight 64 kt). Internal copper consumption is 1.44 kg per inhabitant per year and 0.52 kg/inhab/year is accumulated in the form of stock. Otherwise, the amount of waste generated (1.4 t/inhab/year) is close to that generated in Europe (1.9 t/inhab/year).The copper distribution profile in waste flow is characterized by similar values for waste flow from construction and demolition (27.8%) and from electrical and electronic equipments (27.7%), whilst municipal solid waste and non-dangerous and industrial waste present 19.7% and 13.2%, respectively. Waste from electrical and electronic equipment and motor vehicles sent to scrap, in spite of representing just 1% of all waste in terms of mass, contain almost 38% of all residual copper (28% and 10%, respectively).Brazil presents a secondary copper-recycling rate of around 25%, differing from that of other developing countries because it imports little scrap copper and releases 142 kt into the biosphere (0.75 kg/inhab).We make the case that Brazil's government can feasibly encourage reductions in demand for this metal while increasing copper recycling rates through a two-edged strategy based on education and public awareness on the one hand – making a case for the unsustainability of current copper production and consumption models – and on the other, implementing economic tools to transfer costs of post-use recovery to manufacturers and consumers.
The decontamination of soils and wastes polluted with heavy metals presents one of the most intractable problems for soil clean-up. Present technology relies upon metal extraction or immobilization processes, both of which are expensive and which remove all biological activity in the soil during decontamination. They may only be appropriate for small areas of valuable redevelopment land. In this paper the use of metal-accumulating plants is explored for the removal of metals from superficially-contaminated soils such as those resulting from the long-term application to land of metal-contaminated sewage sludges. Green remediation employs plants native to metalliferous soils with a capacity to bioaccumulate metals such as zinc and nickel to concentrations greater than 2% in the aerial plant dry matter (hyperaccumulators). Growing such plants under intensive crop conditions and harvesting the dry matter is proposed as a possible method of metal removal and for ‘polishing’ contaminated agricultural soils down to metal concentrations below statutory limits. Not only are the biological activity and physical structure of soils maintained but the technique is potentially cheap, visually unobtrusive and offers the possibility of biorecovery of metals. The limitations of the process are reviewed and the future requirements for the development of efficient phytoremediators are outlined.
Large quantities of xenobiotic phosphonates (Pn), which are used as pesticides, detergent additives, antibiotics, and flame retardants, are released into the environment. These C-P compounds are generally resistant to chemical hydrolysis and recalcitrant to biodegradation. We have cloned the Klebsiella aerogenes phn gene cluster which is required for degrading Pn and also for oxidizing phosphite (Pt) to phosphate (Pi). Recombinant plasmids containing the phn gene cluster allowed E. coli MV1184 to grow with aminoethylphosphonate (AEPn), ethylphosphonate (EPn), methylphosphonate (MPn) and Pt as a sole source of phosphorus. Pi, which is generated by Pn breakdown and Pt oxidation, is also a priority target for controlling the eutrophication in natural bodies of water. We examined the genetic improvement of bacterial Pi accumulation by manipulating the genes involved in the key steps of Pi transport and polyphosphate (polyP) formation.
Hydrogen is a clean energy alternative to fossil fuels. Photosynthetic bacteria produce hydrogen from organic compounds under anaerobic, nitrogen-limiting conditions through a light-dependent electron transfer process. In this study, the hydrogen production efficiency of phototrophic bacteria, Rhodobacter capsulatus and its Hup mutant strain (an uptake hydrogenase deleted strain) were tested on different initial acetate concentrations at fluctuating temperatures with indoor and outdoor photobioreactors. Acetate was effectively metabolized and H2 was produced at a high rate. Increasing the initial acetate concentration resulted in a shift in the utilization kinetics of acetate from first order to second order. The effects of fluctuating temperature and day/night cycles on hydrogen production were also studied in indoor and outdoor conditions using acetate as the carbon source. Temperature fluctuations and day/night cycles significantly decreased hydrogen production. It was found that the Hup mutant strain of R. capsulatus has better hydrogen productivity than the wild type parent in outdoor conditions.
Using residue biomass as feedstock for conversion to calcium magnesium acetate (CMA) as an alternative road salt has been investigated. This salt is less corrosive to bridge decks and vehicles than sodium chloride, the traditional road salt. CMA derived from residue biomass is expected to be less costly than that derived from petroleum or natural gas. The residue biomass may be woody biomass residues not suitable for lumber or paper pulp, industrial residues such as whey, municipal solid waste (MSW), or sewage sludge. This study focused on bioconversion of sewage sludge to CMA based on “suppressed methane” fermentation to produce acetic acid followed by liquid ion exchange to recover acetic acid from the fermenter broth prior to reaction with limestone. Overall feasibility was evaluated using results from laboratory work and cost estimates from a preliminary engineering process model. Percent bioconversion and kinetics to acetic acid were confirmed in small batch fermenters. Equilibrium constants for acetic acid recovery via liquid ion exchange were measured. Rates of conversion to CMA were determined.
An engineering study was conducted to evaluate the engineering economics of producing calcium magnesium acetate (CMA), using different kinds of residue biomass as feedstock (sewage sludge, biomass, municipal solid wastes, industrial wastes etc.). This study focused on bioconversion of cellulose (as a model organic) to CMA based on ‘suppressed methane’ fermentation of the organic residue to produce acetic acid, followed by liquid ion exchange to recover the acetic acid from the fermenter broth, with subsequent reaction with dolime to form CMA, which is dried to a white crystalline salt. Preliminary economic analysis revealed that the base line production cost for CMA was $358 (metric) tonne ($325 per US ton). However, with the assumption of a ‘credit’ for the disposal of the residue biomass, CMA can be more competitive. For example, it was found with a credit of $1210 per t ($1100 per US ton) for disposal of sewage sludge, the costs result in a plus $825 per t ($750 per US ton) CMA produced.
Comprehensive laboratory and field experiments were performed to determine the potential effects of the experimental deicing agent calcium magnesium acetate (CMA) on aquatic and terrestrial ecosystems. A companion paper covers the overall results of these experiments. This paper concentrates on the leading concern to emerge from the testing, the potential for CMA to deplete dissolved oxygen (DO) in water bodies. In laboratory biochemical oxygen demand (BOD) experiments, 100 mg CMA/1, at the high end of the concentration routinely expected in highway runoff, completely depleted oxygen within 2 days at 20°C. A concentration of 10 mg/1 caused a net depletion of about 4.5 and 7.0 mg O2/l for reagent-grade and corn-based CMA, respectively. This extra oxygen demand was created by the corn-based CMA even though the two products had equal acetate concentrations. Most of the extra demand can probably be attributed to the presence of butyrate as a contaminant in the corn-based CMA. The rate of DO depletion was strongly dependent on temperature. While the rate appeared to follow an Arrhenius relationship with temperature, the classic, first-order BOD equation did not represent initial DO depletion well at low temperatures. An alternative model was proposed for this region, where depletion better followed a logistic-type curve, probably in direct proportion to the growth of bacteria. Oxygen depletion after CMA additions was also observed in microcosm ecosystems and field ponds, although reaeration reduced net depletion compared to the BOD experiments. When ice covered one of the ponds, a large DO drop occurred following a relatively small CMA inflow. It is recommended that CMA applications be avoided in situations where receiving waters are close to the road, have a low dilution potential, or support populations of fish sensitive to low oxygen levels. Applications during late spring storms and where there is potential for CMA runoff to get into ice-covered water bodies are also discouraged.
Major environmental issues are now coming to the forefront in all parts of the globe with increased public awareness of the human health effects and the possible effects on our global environment. Modern control technologies, when implemented, have significantly reduced air pollution emissions that are a result of coal combustion during this century. However, the emissions have not been completely eliminated. On this basis, a study was conducted to determine the efficacy of carboxylic calcium and magnesium salts (e.g., calcium magnesium acetate or CMA, CaMg2 (CH3CO2)6) for the simultaneous removal of SO2 and NOx in oxygen-lean atmospheres. Experiments were performed in a high-temperature furnace that stimulated the post-flame environment of a coal-fired boiler by providing similar temperatures and partial pressures of SO2, NOx, CO2, and O2. When injected into a hot environment, the salts calcined and formed highly porous ‘popcorn’-like cenospheres. Residual MgO and/or CaCO3 and CaO reacted heterogeneously with SO2, and oxygen to form MgSO4 and/or CaSO4. The organic components — which can be manufactured from wastes such as sewage sludge — reduced NOx to N2 efficiently in a moderately fuel rich atmosphere. Dry-injected CMA particles at a ratio of 2, residence time of 1 s and bulk equivalence ratio of 1.3 removed over 90% of SO2 and NOx at gas temperatures ≥950°C. When the furnace isothermal zone was ≤950°C, CaO was essentially inert in the furnace quenching zone, while MgO continued to sorb SO2 as the gas temperature cooled at a rate of — 130°C/s. Hence, the removal of SO2 by CMA could continue for nearly the entire residence time of emissions in the exhaust stream of a power plant. The composition of the calcined salts was used to interpret the results of a cenosphere sulfation model. The sulfation kinetics of Ca-containing calcined residues were found to be bounded by those of pure CaO and pure CaCO3. The high solubility of the carboxylic acid salts makes them excellent candidates for wet injection. Fine mists of CMA sprayed in the furnace at temperatures between 850 and 1050°C, removed 90% of SO2 at a molar ratio of 1, about half of the amount used in the dry injection experiments to achieve a similar SO2 reduction. The NOx reduction chemistry was not affected by water when CMA was sprayed at a ratio of 1, i.e., the same reduction efficiency was achieved as with dry injection (25–30%). Thus, while a substantial degree of success has been achieved in controlling SO2 and NOx emissions, unfortunately, the emissions that are currently unable to be controlled include vapor and particulate emissions within the respirable range. The respirable particulates encompass heavy metals, polyaromatic hydrocarbons, and volatile organics and have the ability to penetrate into the lungs. The vapor phase emissions comprise mercury, arsenic, and selenium. Most of the mercury vapor emissions are unable to be controlled by the current technologies of the electrostatic precipitator or the baghouse. Some of the potential emissions are known to be carcinogens. Therefore, new or improved current technologies for emission control are being developed in hopes of reducing the potential effects. Because previous interest for control technology was directed toward the control of acid rain precursors (sulfur dioxide and nitrogen oxides emissions), and laboratory studies revealed that the injection of calcium magnesium acetate (CMA) into the combustion chamber significantly reduces both levels of emissions, the effect of this sorbent on mercury vapor capture was investigated suing CMA ash after combustion with the gases (SO2 and NOx). Also, the effect of calcium magnesium carbonate (dolomite, CMC), currently being injected into industrial furnaces, was investigated utilizing the same combustion conditions as CMA. In addition, CMA when calcined forms cenospheres which possess thin porous walls with blowholes that enable mercury vapor and respirable particulates to penetrate into the interior of the particle. Thus, these CMA-ash cenospheres have higher porosity and surface area that provides more area for capture and reactions to occur than CMC ash. Experiments for mercury capture have demonstrated that CMA ash combusted with the gases provided the greatest removal (40%); CMC at the same conditions exhibited only 4% removal. Furthermore, in separate experiments using a model particulate (FeSO4), CMA ash was able to capture more of these model air particulates than the CMC ash after combustion suggesting an even further role of CMA in particulate toxin capture. Analysis of ‘spent’ CMA or CMA ‘ash’ from the laboratory furnace, which was combusted with revealed substantial amounts of elemental sulfur, while no elemental sulfur was present on CMA ash which was combusted in the furnace without . These results suggest that CMA pyrolysis serves to reduce SO2 to elemental sulfur and indicating that HgS(s) formation is feasible, thus suggesting the scavenger value of CMA in capturing mercury vapor.
About 28 billion lbs of liquid whey produced from cheese manufacture are being wasted in the US. An anaerobic fermentation process is developed to produce calcium magnesium acetate (CMA) from whey permeate. CMA can be used to replace salt as a noncorrosive road deicer. A co-culture consisting of homolactic and homoacetic bacteria was used to convert whey lactose to lactate and then to acetate in continuous, immobilized cell bioreactors. The acetate yield from lactose was ∼ 95% (w/w), and the final concentration of acetic acid obtained from this homofermentative process was 4%. The acetic acid produced from fermentation can be readily recovered by solvent extraction with a tertiary amine and reacted with dolomitic lime (CA/MgO) to form a concentrated (>25%) CMA solution. This CMA solution can then be dried to form the granular CMA deicer. About 40 tons CMA can be produced from a plant processing 1.5 million lbs whey permeate per day, at a cost of $215/ton. The total capital investment is estimated at ∼ 7 million dollars, with a return rate of less than 1.5 years at the current market price of $600/ton.
Calcium magnesium acetate (CMA) was identified in the early 1980s as a material that is potentially effective for deicing highways, feasible to manufacture commercially, and environmentally acceptable. Its environmental acceptability required definitive testing prior to widespread application. This paper reports the results of comprehensive laboratory and controlled field plot experiments designed to determine CMA transport characteristics and environmental fate and its impacts on terrestrial and aquatic ecosystems. Preliminary modeling predicted routine and maximum CMA concentrations and mass loadings in highway runoff and spray as a basis for designing experimental treatments.
This research project demonstrates the potential for converting the materials present in partially digested sewage sludge to acetic acid for environmental protection purposes, e.g. use in production of calcium magnesium acetate for road deciding salt or scrubbing sulfur dioxide from atmospheric emissions to prevent acid rain problems.Thermal treatment at 121°C for diluted sewage sludge (5:1) in 0.1 N Ca(OH)2 proved to be successful for solubilizing the suspended volatile solids in the digested sewage sludge. The reduction of such solids reached 57% on a dry weight basis. The more soluble sewage sludge could then be treated in a flow-through, low hydraulic retention time, packed column anaerobic reactor to produce acetic acid. The laboratory pilot process first involved suppressing the methane producing bacteria using 0.0005 N bromo ethane sulfonic acid (BES), then feeding the 2.5-1 up-flow anaerobic reactor with thermally conditioned sludge broth in batch and then in continuous feed modes operated at hydraulic retention times of 24, 8 and 4 h.The effluent was monitored for acetic acid production, COD destruction, pH, alkalinity, ammonia, and total nitrogen. Electron scanning microscope photographs were taken to examine the attachment of the acid producing bacteria to the support media. The efficiency of the production of total volatile fatty acids (TVFA) from the treated sewage sludge was 80, 87 and 90% of the theoretical bioconversion possible based on the amount of COD reduced (40–62%). Acetic acid was the major volatile acid form produced.
In this paper, we present our results obtained during implementation of a recycling methodology for chromatographic solvent waste in the University of Bremen, Germany. The procedures are combined out of three principal areas of activity where the first covers logistics of waste collection, the second–proper recycling techniques and the third biodegradation of postprocessing residues. The overall procedures where developed for recovery of methanol and acetonitrile, the main solvents used extensively in reverse phase high performance liquid chromatography. Successful management of a total recycling system was transferred towards the University of Gdańsk in Poland, which is a very active academic institution in the field of the waste management of chemicals.
The article is a revised version of the findings from a research investigation carried out at the Interfaculty Department of Environmental Science, University of Amsterdam, for the Dutch Ministry of Environment (Sirkin and Ten Houten, 1993). The general aim of the research was to investigate the implications and applications of the concept and the principles of cascading (Sirkin, 1990) as a tool for the appropriate design of products and production processes; and furthermore, as a possible foundation for a sustainable resource management policy.Among the questions set out to be answered were the following: (1) What possibilities lie in the application of the cascade concept for the appropriate exploitation of the intrinsic and extrinsic properties of resources, substances, materials and products? (2) What does the appropriate use of resource potential and resource quality mean for the design of products? (3) What examples can be found in industrial practices, product design or in resource utilization systems where the principles of cascading are already applied? (4) Is it possible to apply the principles of cascading at the industrial or company level; and what kinds of problems arise when attempting to do so? How can they be solved? (5) What are the implications of cascading for the concept of integral chain control, and its applications for environmental policy? (6) What are the implications of cascading in relationship to an eventual sustainable resource management policy? And what strategic policy measures can be derived?Answering these questions, and attempting to set cascading into an operational framework within the context of sustainability, required revisions and further development of previously formulated cascade principles. The cascade chain concept, presented in this article, is the result of these revisions. The theoretical foundations of the cascade chain model as a tool for achieving resource sustainability are presented in Part I. Part II presents various examples of cascade systems and discusses the cascade chain implications related to product design, industrial practices and subsequent resource management policies. Part III consists of a summary and conclusions with policy recommendations and recommendations for further areas of investigation. A glossary of terms has been attached at the end of the article.
Spent acidic cupric chloride etchant waste and tin stripping waste from printed circuit board (PCB) industry are classified as hazardous wastes. They contain significant amounts of metals and acid. Usually, spent cupric chloride and tin stripping solutions are shipped off-site for reclamation. At the moment, a large proportion of acidic cupric chloride etchant waste and tin stripping waste are treated by neutralization, resulting in metal-bearing sludge that often ends up in special landfills. This wastes valuable natural resources, which could otherwise be recycled. This paper presents a review of some patented methods developed for the regeneration of acidic cupric chloride etchant waste and tin stripping waste. These methods are based on electrowinning, cementation, solvent extraction, precipitation and membrane technology. The advantages and disadvantages of these developed processes are summarized. It can be seen that there is still a need to develop more efficient and economical processes for the regeneration of acidic cupric chloride etchant waste and tin stripping waste.
The possibility of using the respiratory activity of microbial cells for the separate determination of acrylonitrile, acrylamide or acrylic acid in a mixture of these compounds has been demonstrated. The experiments were conducted using the two bacterial strains Brevibacterium sp. and Pseudomonas pseudoalcaligenes, possessing different enzyme systems of acrylonitrile and acrylamide metabolism. The conditions to obtain high respiratory activity of Brevibacterium sp. cells for acrylamide and/or for acrylic acid and of P. pseudoalcaligenes cells for acrylonitrile have been optimized. For the quantitation of the mentioned compounds, the concentration dependences of the cell respiratory activity were established. They were linear in the concentration diapason 0.14–1.4 mM for acrylic acid, 0.14–1.0 mM for acrylamide and 0.02–0.10 mM for acrylonitrile. The selectivity of the cell respiratory activity for various organic amides, nitriles and acids has been studied.
The reduction of household waste has been identified as a key component of waste management strategies throughout Europe. A number of theoretical approaches and research methods have been employed to investigate why people behave the way they do as the first step towards improving household waste behaviour. Typically these approaches have adopted some form of quantitative survey of attitudes and reported behaviour in order to generate statistical information on the relationship between values and actions and to identify the barriers and opportunities that mediate those relationships. However, within this body of work there has been little consideration of how particular methodologies themselves may act as a catalyst for improving waste management behaviour. Building on research findings from a study that investigated household attitudes and actions towards waste in Ireland, this paper considers an approach to investigating household waste management behaviour, and crucially behaviour change, through the active participation of householders in a waste minimisation exercise in the home. The paper evaluates the form and function of the exercise against criteria established for action research. While not a panacea for resolving household waste management dilemmas it is concluded that active techniques, such as the waste minimisation exercise, have the added value of offering enhanced learning opportunities for participating householders as well as nuanced information for policy makers. However, the ultimate impact of such active research techniques still relies on the commitment of waste service providers to respond to the findings of participants.
Video documenting is a powerful instrument used in participatory action research to promote social justice and to empower marginalised populations. The paper discusses results from research conducted in early 2005, on the experience of the recycling co-operative CooperPires in Ribeirão Pires, Brazil. The research shows the social and economic challenges of organized recycling groups, it demonstrates their vulnerability due to the dependency on local politics, and it underlines the need for inclusive waste management policies as a poverty reduction strategy enhancing environmental health. This co-op was created in 2004 and with the recent change in municipal politics had lost the previously conquered government support in infrastructure and capacity building. With the participants’ consent all interviews conducted with the recyclers, the local government, and the business community were videotaped. The edited film was presented during a local seminar on building partnerships, in 2006. This opportunity has contributed to actively engage local stakeholders to support the recyclers’ cause. The paper emphasises the need for inclusive and participatory public policies in waste management. It underscores the pressing demand for the recognition of the social, economic and environmental benefits from organized resource recovery.
This paper examines the main factors which link intended behaviour and actions to sustainably manage waste from, within a large organisational setting in the UK. A quantitative study of 566 employees from the Cornwall NHS and waste bin analyses were employed to examine the difference between intended behaviour and actions. Regression analyses demonstrated that the key factors that linked intended behaviour to actions were the beliefs about the priority of waste management as an issue and the benefits of recycling, as well as whether staff were concerned with recycling. The results also indicate the usefulness of the Theory of Planned Behaviour (TPB) as a framework for predicting actions. Recommendations for overcoming the gap between intended behaviour and actions are also suggested.
An assessment was made of biological phosphorus and nitrogen removal and related sludge bulking control in both intermittent cyclic and continuous activated sludge systems. Experimental results from a laboratory-scale investigation using fermented domestic sewage indicated the advantages of achieving high levels of P and N removal and good sludge-settling properties using the intermittent cyclic process, as compared to the continuous process. The modified intermittently fed and decanted system incorporating non-mixing sequences produced an effluent quality of NO3-N < 5 mg L−1, PO4-P < 1 mg L−1 and NH3-N < 2 mg L−1, with a non-bulking sludge having a sludge volume index < 120 mL g−1, despite unfavourable influent characteristics (TCOD : TKN < 7, TKN > 60 mg L−1, TP-9 mg L−1 and RBCOD < 30 mg L−1). In contrast, the modified 4-stage Bardenpho process could not achieve effluent NO3-N and PO4-P concentrations of < 10 and < 1 mg L−1, respectively. The sludge volume index (SVI) values were always higher than 250 mL g−1 and occasionally reached as high as 422 mL g−1. The causative filaments were low F:M growers - Types 0041/0675.
The removal of two reactive dyes (Black 5 and Orange 16) was investigated. The objective of this study was to investigate the removal of reactive dyes through a combined treatment process with coagulation/adsorption on activated carbon. Activated carbon derived from coconut shells was used as the adsorbent and aluminum chloride was used as the coagulant. In order to obtain the best conditions for the removal of the dyes, the influence of the following parameters was verified: coagulant and alkalizer dosage, aqueous solution pH, temperature of the mixture and salt addition (sodium chloride). Spectrophotometry was the analysis technique used to measure the concentration of dye remaining in the fluid phase. The results for the adsorption of the reactive dyes were fitted to the models of the Langmuir, Freundlich and Radke-Prausnitz isotherms and showed good correlation. The removal efficiencies were approximately 90% and 84% for the Black 5 and Orange 16, respectively. In order to evaluate the final effluent obtained after the coagulation and adsorption process, acute toxicity tests were carried out with Artemia salina and Daphnia magna, which verified that the effluent was atoxic. The combined coagulation/adsorption process was shown to be an excellent option for the removal of reactive dyes.
This paper is a critical overview on fly ash utilisation with emphasis on mechanical activation of fly ash in developing processes for medium to high volume utilisation of fly ash. Applications of mechanical activation that are particularly highlighted include blended cement containing high volume (50–60%) of fly ash, and geopolymer materials, such as high compressive strength (up to 120 MPa) geopolymer cements and self glazed tiles. The schemes for the utilisation of fly ash involving mechanical activation are worked out that have potential to evolve as sustainable solutions.
This paper summarises the basic methodology of life cycle analysis, and aims to show that without clear understanding of the technique, life cycle inventories (LCI) can be easily misused to give preferred results, or misunderstood to give erroneous results which could lead to detrimental environmental decisions. It highlights areas where most errors are likely to exist, namely through the definition of system boundaries and the collection of data, and shows through examples how these can drastically affect LCI results. The paper also touches briefly on life cycle assessment techniques, which are aimed at evaluating environmental damage, and concludes with a brief summary of the properties of an ideal LCI which would provide a comprehensive data base for life cycle assessment.
This study examines the Swedish debate on the sustainability of using sewage sludge as fertiliser in agriculture. Although the use of sludge as fertiliser presents potential resource and environmental advantages, it can have negative effects on people and soil productivity. Both proponents and opponents of agricultural application of sludge use environmental arguments to support their positions. By 1990, the Swedish parliament stressed the importance of recycling nutrients from wastewater; however, despite low levels of contamination, compared to other countries, little sludge is used in agriculture today.During the last few decades, a large amount of research has addressed the risks and benefits of using sludge as fertiliser, but the central actors have not been able to reach lasting agreements. This study, which is based on document analysis, direct observations, and interviews, analyses the beliefs, preferences, and arguments of major actors in the national debate on sludge. The study investigates how actors define problems and interpret the risks and benefits of sludge use. Specifically, the study concentrates on the role of science in the sludge controversy. Two distinct ways of thinking—a precautionary frame and a proof-first frame—are identified. These frames are shown almost immune to factual claims and arguments from opponents. It is concluded that actors in the controversy need to address explicitly value judgements and beliefs that go beyond scientific information. In addition, the study concludes that there is a need for policy makers to further develop process leadership skills.
This paper demonstrates the development of a methodology for systematically analysing radioactive waste generation and disposal in an acute general hospital setting in the UK. Low level radioactive waste occurs in research centres and hospitals as the result of the use of radiopharmaceuticals for a range of diagnostic and therapeutic procedures. There is specific legislation regarding the disposal of radioactive waste which overrides any attempt to minimise the quantity of waste going to final disposal. This means that any efforts to minimise the cost of radioactive waste disposal must be taken prior to the final disposal. This research systematically investigated the generation and movement of radioactive sources and wastes in from the perspective of the Medical Physics and Nuclear Medicine Departments. Waste flow diagrams have been used to document the flows of radioactive sources and waste streams. A range of quantitative and qualitative methods have been utilised in order to represent the interactions between systems in place both within and outside the site being analysed. This research has shown that by systematically analysing the waste generation and flow of waste around the hospital, opportunities for implementing best practice can be identified.
In the last decade, climate change has been one of the major concerns with regard to the health of the earth’s ecosystem. The problem of a changing climate is related to not only climate, energy consumption and emissions of greenhouse gases, but also effects of such a change on the earth’s ecosystems, resources and human settlements, as well as the need to reduce or avoid these effects. In this study, an inexact-fuzzy multiobjective programming model was proposed for adaptation planning of land resources management in the Mackenzie Basin under changing climate. This integrated adaptation planning enables the inclusion of systems interaction and feedback mechanisms and can therefore yield insights that scattered information cannot offer. Many sectors were considered, including agriculture, forest, wildlife habitat preservation, wetland preservation, hunting, recreation, and soil conservation, as well as their interactive relationships. The results indicate that uncertain, multiobjective, dynamic and interactive features of the study system have been effectively reflected. Temporal variations of land characteristics and land-use activities exist due to changes in climatic, economic and environmental conditions. However, through effective systems analysis and planning, the desired land-use patterns for adapting to the changing climate and compromising objectives from different stakeholders could be obtained.
In south-eastern Sicily, one of the greatest greenhouse tomato production areas in Italy, fresh tomato packinghouse waste stream was characterized for content of carotenoids (lycopene and β-carotene, biologically active compounds, highly valuable) and waste composition (vegetative matter, green fruits, turning fruits, red unmarketable fruits, and miscellaneous materials) in relation to their source (four packinghouses) and to the month in which they were produced (from December to July). Source and month both affected the characteristics of the wastes. The wastes were almost entirely putrescible, since miscellaneous materials were rarely observed. The highest proportion of red fruits (RF) and the highest lycopene and β-carotene contents were recorded in summer (836 kg Mg−1 and 57.5 and 8.3 g Mg−1, respectively, based on the average of the July and June values). Moreover, the proportion of RF was significantly correlated with the lycopene content (R = 0.839, P < 0.001), and this relation, when low incidence of RF in the total waste occurred, suggests the possibility of obtaining the same quantity of extractable lycopene by means of the selection of the carotenoid richest fraction that, consequently, minimizes the amount of waste involved in the extraction activities. These results suggest the potential for environmentally friendly and economically profitable waste management that integrates anaerobic or aerobic biotransformation processes with the extraction of carotenoids for an additional recovery of value from wastes.
The disposal of fly ash from coal-fired power stations causes significant economic and environmental problems. A relatively small percentage of the material finds application as an ingredient in cement and other construction products, but the vast majority of material generated each year is held in ash dams or similar dumps. This unproductive use of land and the associated long-term financial burden of maintenance has led to realization that alternative uses for fly ash as a value-added product beyond incorporation in construction materials are needed. Utilization of fly ash in such areas as novel materials, waste management, recovery of metals and agriculture is reviewed in this article with the aim of looking at new areas that will expand the positive reuse of fly ash, thereby helping to reduce the environmental and economic impacts of disposal.
The swine industry in China has grown rapidly over last two decades. Great amount of pig manure is generated in China, which can be used as organic fertilizers on agricultural lands. Meanwhile, the organic arsenic compounds have been used as feed additives for swine disease control and weight improvement. Once the excessive additives are released in the environment, arsenic may compromise food safety and environmental quality. There is a growing public concern about the arsenic residues accumulation in pig manure, however, little work has been done to investigate the exact arsenic content in pig feed and the residues in manure in China This study investigates the concentrations of arsenic in 29 pig feed samples and 29 manure samples collected from eight pig farms in the Chaoyang district, Beijing city. The detected rate of arsenic in 29 couples of samples was 100%. The concentrations of arsenic in pig feeds and manures ranged from 0.15 to 37.8 mg/kg and 0.42 to 119.0 mg/kg, respectively. The result showed that arsenic concentration in pig manure will be greatly elevated when the arsenic in pig feed was largely increased. The loading rates of pig manure in fourteen Beijing counties and districts were in the range of 2.7–57.2 t/ha yr. Accordingly, the potential soil arsenic increase rates resulting from land application of pig manure might range between 11.8 and 78.9 μg/kg yr. Despite these findings, it is too early to draw the conclusion that arsenic pollution from pig manure is serious in Beijing farmland; therefore, longitudinal studies about the chemical form transformation and the environmental behaviors of pig manure arsenic are required in order to come up with more definitive conclusions.
The finiteness of many resources made it necessary to think about how to save them by developing resource-saving technologies, e.g. to recycle materials. To execute the idea of recycling, it is necessary to think about a material recycling of the used products when designing them. This means that all additives of the process have to be designed in the way they do not disturb the later material recycling. Today, adhesives play a decisive role in the production of almost every good, especially for mass-produced articles and therefore it is important to choose adhesives that do not disturb the recycling of the primary materials. In recycling processes which take place at high temperatures (e.g. glass or metal recycling), the influence of the adhesives usually formed by organic polymers can be ignored. In the field of low temperature recycling technologies, the question whether an adhesive is recycling-friendly or not can only be answered by knowing its application and the recycling process. If the recycling processes are known, it is easy to chose suitable adhesives. For plastic and paper recycling, there are a lot of adhesives today that fulfill the requirements of recyclers. In order to simplify recycling for the future, adhesives with “switches enclosed” are being developed which will allow us to disbond system components into separate parts after use for reuse or material recycling.
Due to increasing pressure from the European Union to meet recycling and recovery targets, (e.g. the packaging waste, waste electronic equipment and landfill directives), both the Irish and England's governments’ policy on waste management is changing to meet these pressures, with major emphasis upon the management of biodegradable municipal waste (BMW). In particular, the EU landfill directive requires reductions in the rate of biodegradable waste going to landfill to 35% by 2016. The objective of this paper is to examine how Ireland plans to meet this challenge and to compare the Irish strategy to that being adopted in England. The approach in England is driven by a clear understanding that the practice in the late 1990s was unlikely to ensure compliance with EU targets by the set dates. England has therefore developed a discrete, programme (Waste Implementation Programme) to drive a new approach, based on rigorous science and international best practice, which includes a Demonstrator Programme for new technologies. The dynamic, high cost, large scale programme in England stands in sharp contrast to that for Ireland and only future, detailed analysis of outcomes will be able to evaluate the cost effectiveness of each.
Both consultants and scientists would agree that even if their own work provided a solution to a landuser's problem, then that solution is unlikely to be adopted if the landuser is unwillign to pay for it Financial incentives, while enabling factors in technology transfer and adoption, are usually not the only limiting factors. In reality, adoption is more complex. This complexity resides within the interrelationship between human endeavours, economics and the environment. Although there is a global consensus on the need for sustainability, the means of achieving the core values and principles of sustainable development, on the ground, remains a challenge. This paper discusses some of the fundamental reasons why sustainable land use practices and innovations are not always adopted, providing a perspective from industry.
The impact of technology adoption (advanced irrigation technologies and anticipated biotechnological advances) on the sustainability of agricultural activities in the Texas High Plains of the US is evaluated in this study. Specifically, a county-wide dynamic optimization model is used to (a) determine optimal ground water use levels and cropping patterns, and (b) evaluate the impacts of irrigation technology and biotechnology adoption on ground water use. The results indicate that current cropland allocation and levels of advanced irrigation technology adoption are not close to optimal. Approaching the issue of sustainability, the results show that the net present value of returns trade-off to achieve ground water conservation, in terms of what producers would have to give up to achieve ground water supply stability, would be relatively small.