Environmental impact of incineration of calorific industrial waste: Rotary kiln vs. cement kiln

Rotary kiln incinerators and cement kilns are two energy intensive processes, requiring high temperatures that can be obtained by the combustion of fossil fuel. In both processes, fossil fuel is often substituted by high or medium calorific waste to avoid resource depletion and to save costs. Two types of industrial calorific waste streams are considered: automotive shredder residue (ASR) and meat and bone meal (MBM). These waste streams are of current high interest: ASR must be diverted from landfill, while MBM can no longer be used for cattle feeding. The environmental impact of the incineration of these waste streams is assessed and compared for both a rotary kiln and a cement kiln. For this purpose, data from an extensive emission inventory is applied for assessing the environmental impact using two different modeling approaches: one focusing on the impact of the relevant flows to and from the process and its subsystems, the other describing the change of environmental impact in response to these physical flows. Both ways of assessing emphasize different aspects of the considered processes. Attention is paid to assumptions in the methodology that can influence the outcome and conclusions of the assessment. It is concluded that for the incineration of calorific wastes, rotary kilns are generally preferred. Nevertheless, cement kilns show opportunities in improving their environmental impact when substituting their currently used fuels by more clean calorific waste streams, if this improvement is not at the expense of the actual environmental impact.     

A roadmap for ladybird conservation and recovery

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.     

The role of human capital,motivation and supervisor sponsorship in predicting career success

Based on Turner's (1960) contest‐ and sponsored‐mobility systems, a comprehensive model of the determinants of career success was examined. Human capital and motivational variables represented the contest‐mobility system whereas leader–member exchange and supervisor career mentoring represented the sponsored‐mobility system. Results based on data from 245 supervisor–subordinate dyads indicated limited support for the contest‐mobility system and strong support for the sponsored‐mobility system. Interestingly, the two forms of sponsorship were differentially related to career outcomes. Specifically, leader–member exchange was positively related to salary progression, promotability, and career satisfaction. Career mentoring, however, was only related to promotability. Copyright © 1999 John Wiley & Sons, Ltd.     

Symptomatic profile and health‐related quality of life of persons affected by the Prestige catastrophe

This study analyses the impact of the Prestige oil spill on the mental health and the perception of physical health and functional capacity in the affected population. The sample comprised 926 residents from the section of the Spanish coast affected by the oil spill. The data was collected slightly more than one year after the accident. Scales referring to clinical symptoms (SCL‐36) and health‐related quality of life (SF‐36) were administered. The results suggest that individuals with higher degrees of exposure or residing in areas closest to the spill show lower levels of mental health in comparison to those with lower levels of exposure or living in areas farther away from the spill. This study also finds that women and fishermen tend to suffer more from the consequences of these types of disaster.     

An empirically tested overlap between indigenous and scientific knowledge of a changing climate in Bolivian Amazonia

Regional Environmental Change - Existing climate data for Bolivian Amazonia rely on observations from a few sparse weather stations, interpolated on coarse-resolution grids. At the same time, the...     

Silica removal in industrial effluents with high silica content and low hardness

High silica content of de-inked paper mill effluents is limiting their regeneration and reuse after membrane treatments such as reverse osmosis (RO). Silica removal during softening processes is a common treatment; however, the effluent from the paper mill studied has a low hardness content, which makes the addition of magnesium compounds necessary to increase silica removal. Two soluble magnesium compounds (MgCl₂?6H₂O and MgSO₄?7H₂O) were tested at five dosages (250–1,500 mg/L) and different initial pH values. High removal rates (80–90 %) were obtained with both products at the highest pH tested (11.5). With these removal efficiencies, it is possible to work at high RO recoveries (75–85 %) without silica scaling. Although pH regulation significantly increased the conductivity of the waters (at pH 11.5 from 2.1 to 3.7–4.0 mS/cm), this could be partially solved by using Ca(OH)₂ instead of NaOH as pH regulator (final conductivity around 3.0 mS/cm). Maximum chemical oxygen demand (COD) removal obtained with caustic soda was lower than with lime (15 vs. 30 %). Additionally, the combined use of a polyaluminum coagulant during the softening process was studied; the coagulant, however, did not significantly improve silica removal, obtaining a maximum increase of only 10 %.     

Solar photovoltaic investments and economic growth in EU: Are we able to evaluate the nexus?

A core question in energy economics may be stated as follows: Is the cost–benefit analysis being correctly applied when we encourage investments in renewables, as an alternative to the traditional energy sources? The relationship between energy consumption and economic growth has been extensively treated within economics literature. Yet, literature on the nexus between specific energy sources and GDP is almost inexistent. In this article, we intend to explore the relationship between a certain type of renewable generation technology (solar PV) and GDP. The present and above all the planned energy mix might differ widely from one country to another. Thus, the analysis by source of energy generation becomes a helpful instrument for policy-making. Using a fixed effects panel data methodology and a sample of eighteen EU countries, we find that a 1 % increase in solar PV installed capacity and in electricity production from renewable sources has a positive impact on GDP of 0.0248 and 0.0061 %, respectively. We also conclude that a 1 % growth on greenhouse gas emissions positively affects GDP by 0.3106 %. Further evidence reveals that, in terms of country-specific analysis, Germany, France, Italy and the UK have the most significant estimations for fixed effects. In fact, Germany is a solar PV technology producer, France has a very active nuclear sector, with little pressure for both renewables development and CO₂ reductions, Italy had in this period a strong governmental support to this sector, and the UK has a strong connection between the solar PV and the industry sectors.     

Molecular biodiversity. Case study: Porifera (sponges)

Biological diversity--or biodiversity--is the term given to the variety of life on Earth and the natural patterns it forms. The biodiversity we see today is the fruit of billions of years of evolution, shaped by natural processes and, increasingly, by the influence of humans. It forms the web of life of which we are an integral part and upon which we so fully depend. The research on molecular biodiversity tries to lay the scientific foundation of a rational conservation policy that has its roots in various disciplines including systematics/taxonomy (species richness), present day ecology (diversity of ecological systems), and functional genetics (genetic diversity). The results of ongoing genome analyses (genome projects and expressed sequence tag projects) and the achievements of molecular evolution may allow us not only to quantitate the diversity of the present biota but also to extrapolate to their diversification in the future. A link between biodiversity and genomics/molecular evolution will create a platform which we hope may facilitate a sustainable management of organismic life and ensure its exploitation for human benefit. In the present review we outline possible strategies, using the Porifera (sponges) as a prominent example. On the basis of solid taxonomy and ecological data, the high value of this phylum for human application becomes obvious, especially with regard to the field of chemical ecology and the desire to find novel potential drugs for clinical use. In addition, the benefit of trying to make sense of molecular biodiversity using sponges as an example can be seen in the fact that the study of these animals, which are "living fossils", gives us a good insight into the history of our planet, especially with respect to the evolution of Metazoa.     

UASB performance for bleached and unbleached kraft pulp synthetic wastewater treatment

This paper presents the performance of two bench scale Upflow Anaerobic Sludge Blanket reactors (UASB) used for the treatment of synthetic substrates that simulate bleached and unbleached cellulose pulp plant wastewaters. The control reactor was fed with diluted black liquor and the treatment reactor with the same substrate plus a mixture of chlorinated organics. The total concentration of the chlorinated compounds was gradually increased from 2.5 mg l-1 to 15.0 mg l-1. The average COD removal efficiency during the last phase of the experiment was 81% in the control reactor and 76% in the treatment reactor. These results indicate the capability of UASB reactors to treat this kind of wastewater and the low impact of the chlorinated organics on COD removal efficiency. The minimum overall chlorinated organics removal efficiency was 71% and the maximum was 99.7%. The experiment indicates that under the conditions used in this research the presence of chlorinated organics does not negatively impact the treatment process.     

Predicting emissions from oil and gas operations in the Uinta Basin,Utah

In this study, emissions of ozone precursors from oil and gas operations in Utah’s Uinta Basin are predicted (with uncertainty estimates) from 2015–2019 using a Monte-Carlo model of (a) drilling and production activity, and (b) emission factors. Cross-validation tests against actual drilling and production data from 2010–2014 show that the model can accurately predict both types of activities, returning median results that are within 5% of actual values for drilling, 0.1% for oil production, and 4% for gas production. A variety of one-time (drilling) and ongoing (oil and gas production) emission factors for greenhouse gases, methane, and volatile organic compounds (VOCs) are applied to the predicted oil and gas operations. Based on the range of emission factor values reported in the literature, emissions from well completions are the most significant source of emissions, followed by gas transmission and production. We estimate that the annual average VOC emissions rate for the oil and gas industry over the 2010–2015 time period was 44.2E+06 (mean) ± 12.8E+06 (standard deviation) kg VOCs per year (with all applicable emissions reductions). On the same basis, over the 2015–2019 period annual average VOC emissions from oil and gas operations are expected to drop 45% to 24.2E+06 ± 3.43E+06 kg VOCs per year, due to decreases in drilling activity and tighter emission standards.

Implications: This study improves upon previous methods for estimating emissions of ozone precursors from oil and gas operations in Utah’s Uinta Basin by tracking one-time and ongoing emission events on a well-by-well basis. The proposed method has proven highly accurate at predicting drilling and production activity and includes uncertainty estimates to describe the range of potential emissions inventory outcomes. If similar input data are available in other oil and gas producing regions, then the method developed here could be applied to those regions as well.