Mass,energy and material balances of SRF production process. Part 1: SRF produced from commercial and industrial waste

This paper presents the mass, energy and material balances of a solid recovered fuel (SRF) production process. The SRF is produced from commercial and industrial waste (C&IW) through mechanical treatment (MT). In this work various streams of material produced in SRF production process are analyzed for their proximate and ultimate analysis. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. Here mass balance describes the overall mass flow of input waste material in the various output streams, whereas material balance describes the mass flow of components of input waste stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. A commercial scale experimental campaign was conducted on an MT waste sorting plant to produce SRF from C&IW. All the process streams (input and output) produced in this MT plant were sampled and treated according to the CEN standard methods for SRF: EN 15442, EN 15443. The results from the mass balance of SRF production process showed that of the total input C&IW material to MT waste sorting plant, 62% was recovered in the form of SRF, 4% as ferrous metal, 1% as non-ferrous metal and 21% was sorted out as reject material, 11.6% as fine fraction, and 0.4% as heavy fraction. The energy flow balance in various process streams of this SRF production process showed that of the total input energy content of C&IW to MT plant, 75% energy was recovered in the form of SRF, 20% belonged to the reject material stream and rest 5% belonged with the streams of fine fraction and heavy fraction. In the material balances, mass fractions of plastic (soft), plastic (hard), paper and cardboard and wood recovered in the SRF stream were 88%, 70%, 72% and 60% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC), rubber material and non-combustibles (such as stone/rock and glass particles), was found in the reject material stream.     

The lay system in commercial fisheries: Origin and implications

In most commercial fisheries, the crew is remunerated via some form of the lay system. Under the lay system, the crew is paid with a share of revenues or a share of revenues less costs. Naturally, the presence and the functioning of the lay system are well known and accepted as one of fishery's important institutions. Compared with share contracts in agriculture, however, the lay in fisheries has garnered relatively little research. This article has two goals. First, we provide an explanation for the existence of the lay system as an incentive mechanism to alleviate a potential team agency problem. This explanation of the lay system explains anomalies, such as the presence of wages in some fisheries, that are odds with the theory of pure risk sharing. Second we show the implications of the lay system for econometric modeling of fisheries and for understanding firm behavior. In general we conclude that models that fail to account explicitly for the incentive properties of shares are likely to provide poor representations of fishing firm behavior. The thrust of the paper is that the formation and working of the lay system are a fundamental force in fisheries influencing firm behavior and research results in a way that has been largely ignored.     

Injury-severity analysis of lane change crashes involving commercial motor vehicles on interstate highways

Introduction: One of the challenging tasks for drivers is the ability to change lanes around large commercial motor vehicles. Lane changing is often characterized by speed, and crashes that occur due to unsafe lane changes can have serious consequences. Considering the economic importance of commercial trucks, ensuring the safety, security, and resilience of freight transportation is of paramount concern to the United States Department of Transportation and other stakeholders. Method: In this study, a mixed (random parameters) logit model was developed to better understand the relationship between crash factors and associated injury severities of commercial vehicle crashes involving lane change on interstate highways. The study was based on 2009–2016 crash data from Alabama. Results: Preliminary data analysis showed that about 4% of the observed crashes were major injury crashes and drivers of commercial motor vehicles were at-fault in more than half of the crashes. Acknowledging potential crash data limitations, the model estimation results reveal that there is increased probability of major injury when lane change crashes occurred on dark unlit portions of interstates and involve older drivers, at-fault commercial vehicle drivers, and female drivers. The results further show that lane change crashes that occurred on interstates with higher number of travel lanes were less likely to have major injury outcomes. Practical Applications: These findings can help policy makers and state transportation agencies increase awareness on the hazards of changing lanes in the immediate vicinity and driving in the blind spots of large commercial motor vehicles. Additionally, law enforcement efforts may be intensified during times and locations of increased unsafe lane changing activities. These findings may also be useful in commercial vehicle driver training and driver licensing programs.     

Superior CO2 uptake on nitrogen doped carbonaceous adsorbents from commercial phenolic resin

In this study, N-doped porous carbons were produced with commercial phenolic resin as the raw material, urea as the nitrogen source and KOH as the activation agent. Different from conventional carbonization-nitriding-activation three-step method, a facile two-step process was explored to produce N-incorporated porous carbons. The as-obtained adsorbents hold superior CO₂ uptake, i.e. 5.01 and 7.47 mmol/g at 25?°C and 0?°C under 1 bar, respectively. The synergistic effects of N species on the surface and narrow micropores of the adsorbents decide their CO₂ uptake under 25?°C and atmospheric pressure. These phenolic resin-derived adsorbents also possess many extremely promising CO₂ adsorption features like good recyclability, quick adsorption kinetics, modest heat of adsorption, great selectivity of CO₂ over N₂ and outstanding dynamic adsorption capacity. Cheap precursor, easy preparation strategy and excellent CO₂ adsorption properties make these phenolic resin-derived N-doped carbonaceous adsorbents highly promising in CO₂ capture.     

Shifting regime shifted policy—interplay of interests in sustainability discourses of forest land use

This study investigates the influence of policy interests on resource sustainability. Information on ‘colonial interest’ of the British regime and the ‘commercial interest’ of the post-colonial regimes on forest land use of Bangladesh have been drawn on to show the interplay of interests on sustainability impacts. The findings show that both colonial and commercial interests have caused intensification of forest land use for production of economic crops like teak (Tectona grandis) and cash crops like tea (Camellia sinensis), cotton (Gossypium herbaceum and G. arboreum) and tobacco (Nicotiana tabacum). The ‘colonial interest’ has also initiated the dispute of ownership, rights and tenure of forest land and resources. The post-colonial regimes have utilized colonial legacy as the privilege for implementing ‘commercial interests’. In both the cases traditional interests of people were disregarded. As a result, peoples’ participation in forestry was discouraged and the sustainability of forest land use was impeded.     

Effects of Altered Offshore Food Webs on Coastal Ecosystems Emphasize the Need for Cross-Ecosystem Management

By mainly targeting larger predatory fish, commercial fisheries have indirectly promoted rapid increases in densities of their prey; smaller predatory fish like sprat, stickleback and gobies. This process, known as mesopredator release, has effectively transformed many marine offshore basins into mesopredator-dominated ecosystems. In this article, we discuss recent indications of trophic cascades on the Atlantic and Baltic coasts of Sweden, where increased abundances of mesopredatory fish are linked to increased nearshore production and biomass of ephemeral algae. Based on synthesis of monitoring data, we suggest that offshore exploitation of larger predatory fish has contributed to the increase in mesopredator fish also along the coasts, with indirect negative effects on important benthic habitats and coastal water quality. The results emphasize the need to rebuild offshore and coastal populations of larger predatory fish to levels where they regain their control over lower trophic levels and important links between offshore and coastal systems are restored.     

Reducing commercial fishing deck hazards with engineering solutions for winch design

INTRODUCTION: The majority (67%) of hospitalized injuries among Alaska commercial fishermen are associated with deck machinery. This paper describes the "Prevention Through Design" process to mitigate one serious machinery entanglement hazard posed by a capstan deck winch. METHODS: After observing that the capstan winch provides no entanglement protection and the hydraulic controls are usually out of reach of the entangled person, NIOSH personnel met with fishermen and winch manufacturers to discuss various design solutions to mitigate these hazards. RESULTS: An emergency-stop ("e-stop") system was developed that incorporated a momentary contact button that when pushed, switches a safety-relay that de-energizes the solenoid of an electro-hydraulic valve stopping the rotating winch. The vessel owners that had the e-stop installed enthusiastically recommend it to other fishermen. NIOSH entered into a Proprietary Technology Licensing Agreement with a company to develop the system for commercial use. CONCLUSIONS: This is an example of a practical engineering control that effectively protects workers from a hazardous piece of equipment by preventing injuries due to entanglement. This solution could reduce these types of debilitating injuries and fatalities in this industry.     

Not drowning, waving!: Safety management and occupational culture in an Australian commercial fishing port

An ethnographic study of safety management was conducted in a commercial lobster fishing industry, in a small fishing town in Southern Australia. The objectives were to test the utility of the ethnographic method for exploring the nature of the relationship between occupational culture, workplace social organization, and safety management.Available accident data suggests this particular fishery may not have the same high incidence of occupational trauma normally attributed to commercial fishing. Changes in licensing laws and improved management of fish stocks have significantly reduced risk exposure. Participants in this study had a good understanding of their physical workplace risks, but accepted some of these with too few defences. Wear rates of personal flotation devices (PFDs) were below 1% for the study period.The paper suggests that participants do not have a strong learning culture, and links this to occupation-wide cultural assumptions, other external issues and safety management issues. Assessment of the social and cultural context of safety management can offer policy makers a ‘road-map’ to guide their interventions. The utility of ethnographic methods for this type of analysis is significant, and will be enhanced by improving the transparency of the research method.     

Flocculation behaviors of a novel papermaking sludge-based flocculant in practical printing and dyeing wastewater treatment

•PSBF performed better than PAC and PAM in CODCr removals. •PSBF was more insensitive to changing pH than PAC and PAM. •PAC could remove humic acid-like pollutants and dye particles. •PSBF was efficient in removing tryptophan-like pollutants from PPDW. •A secondary coagulation-flocculation process (PAC→PSBF) is proposed here. In our previous studies, several papermaking sludge-based flocculants (PSBFs) were synthesized from wood pulp papermaking sludge. The structure-activity relationships of the PSBFs have been investigated in simulated dye wastewater treatment, but their efficiencies in practical printing and dyeing wastewater (PPDW) treatment are unknown. Herein, an PSBF was prepared, and its performance is discussed in comparison to polyaluminium chloride (PAC) and polyacrylamide (PAM) in PPDW treatment. The PSBF was used in three ways: as an independent flocculant, as a PAC aid, or used to treat the effluent of the PAC system. The results indicated that adding PSBF alone produced similar color and chemical oxygen demand (COD_Cr) removals as the PAC system alone, but PSBF performed better than PAC when the pH of PPDW was higher than 7.0. Adding PSBF as a PAC aid improved the color, COD_Cr and turbidity removals, but the elimination efficiencies were slightly lower than those of the PAC+ PAM system. However, when PSBF was used as a flocculant to treat the effluent of the PAC system (PAC→PSBF), the effluent qualities were enhanced. Compared with the PAC system, the color and COD_Cr removals of PAC→PSBF system increased by 16.21% and 13.26%, respectively. The excitation and emission matrix fluorescence results indicated that PSBF removed tryptophan-like pollutants more efficiently than PAC. Considering the pH requirements of the subsequent bioreactor treatment in practice, the PAC→PSBF system were also investigated at the PPDW pH level of 7.0. Its maximum removal efficiencies of color, COD_Cr and turbidity were 90.17%, 32.60% and 82.50%, respectively.