Injection-Molded Bioblends from Lignin and Biodegradable Polymers: Processing and Performance Evaluation

This paper investigates the effects of the incorporation of lignin and small quantities of epoxidized natural rubber (ENR) as an impact modifying agent on blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL). The addition of lignin resulted in a slight improvement of flexural strength and modulus of the ternary blending system. Incorporation of ENR into the blend resulted in an increase in notched Izod impact strength from 40 to 135% depending on the concentration of ENR. The addition of lignin into the blend resulted in an improvement of thermal stability of the ternary blend system. Morphological analysis showed a good dispersion of PHBV phases and lignin within the PCL matrix. Rheological characterization revealed that the presence of lignin resulted in increased storage modulus of the bioblend.     

Evaluation of the waste heat discharged from the Di-ammonium Phosphate production plant: a case study

Journal of Material Cycles and Waste Management - This work presents an energy analysis of an industrial plant of production of Di-ammonium Phosphate (DAP plant). It aims to evaluate the important...     

Research priorities for managing the impacts and dependencies of business upon food,energy, water and the environment

Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the ‘nexus’ of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation.     

Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Delayed reporting reduces the usefulness of such data for nature conservation where timely information about animal movements is required. To counter this problem, we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (based on radial and angular velocity calculated from fixes) allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data. Automating the detection of both excursions and home-range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal. The automated analysis, interpretation, and communication of satellite-tag and other ecological data offer clear benefits to nature conservation research and practice.     

Evaluating the phytoremediation potential of Phragmites australis grown in pentachlorophenol and cadmium co-contaminated soils

Pot-culture experiments were conducted to evaluate the phytoremediation potential of a wetland plant species, Phragmites australis in cadmium (Cd) and pentachlorophenol (PCP) co-contaminated soil under glasshouse conditions for 70 days. The treatments included Cd (0, 5 and 50 mg kg^?1) without or with PCP (50 and 250 mg kg^?1). The results showed that growth of P. australis was significantly influenced by interaction of Cd and PCP, decreasing with either Cd or PCP additions. Plant biomass was inhibited and reduced by the rate of 89 and 92 % in the low and high Cd treatments and by 20 and 40 % in the low and high PCP treatments compared to the control. The mixture of low Cd and low PCP lessened Cd toxicity to plants, resulting in improved plant growth (by 144 %). Under the joint stress of the two contaminants, the ability of Cd uptake and translocation by P. australis was weak, and the BF and TF values were inferior to 1.0. A low proportion of the metal is found aboveground in comparison to roots, indicating a restriction on transport upwards and an excluding effect on Cd uptake. Thus, P. australis cannot be useful for phytoextraction. The removal rate of PCP increased significantly (70 %) in planted soil. Significant positive correlations were found between the DHA and the removal of PCP in planted soils which implied that plant root exudates promote the rhizosphere microorganisms and enzyme activity, thereby improving biodegradation of PCP. Based on results, P. australis cannot be effective for phytoremediation of soil co-contaminated with Cd and PCP. Further, high levels of pollutant hamper and eventually inhibit plant growth. Therefore, developing supplementary methods (e.g. exploring the partnership of plant–microbe) for either enhancing (phytoextraction) or reducing the bioavailability of contaminants in the rhizosphere (phytostabilization) as well as plant growth promoting could significantly improve the process of phytoremediation in co-contaminated soil.     

Distribution and ecological risk of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in surface sediments from the Bizerte lagoon,Tunisia

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 18 surface sediment samples collected from Bizerte lagoon, Tunisia. The total concentrations of ten PCBs (∑PCBs) and of four OCPs (∑OCPs) in the sediments from this area ranged from 0.8 to 14.6 ng g^?1 dw (average value, 3.9 ng g^?1 dw) and from 1.1 to 14.0 ng g^?1 dw (average value, 3.3 ng g^?1 dw), respectively. Among the OCPs, the range of concentrations of dichlorodiphenyltrichloroethane and its metabolites (DDTs) and hexachlorobenzene (HCB) were 0.3–11.5 ng g^?1 dw (1.9 ng g^?1 dw) and 0.6–2.5 ng g^?1 dw (1.4 ng g^?1 dw), respectively. Compositional analyses of the POPs indicated that PCB 153, 138 and 180 were the predominant congeners accounting for 60 % of the total PCBs. In addition, p,p′-DDT was found to be the dominant DDTs, demonstrating recent inputs in the environment. Compared with some other regions of the world, the Bizerte lagoon exhibited low levels of PCBs and moderate levels of HCB and DDTs. The high ratios ΣPCBs/ΣDDTs indicated predominant industrial versus agricultural activities in this area. According to the established guidelines for sediment quality, the risk of adverse biological effects from such levels of OCPs and PCBs, as recorded at most of the study sites, was insignificant. However, the higher concentrations in stations S1 and S3 could cause biological damage.     

Statistical thermodynamics of adsorption of dye DR75 onto natural materials and its modifications: double-layer model with two adsorption energies

In this article, adsorption modelling was presented to describe the sorption of textile dye, Direct Red 75 (DR75), from coloured wastewater onto the natural and modified adsorbent, Posidonia oceanica. The formulation of the double-layer model with two energy levels was based on statistical physics and theoretical considerations. Thanks to the grand canonical ensemble in statistical physics some physico-chemical parameters related to the adsorption process were introduced in the analytical model expression. Fitting results show that the dye molecules are adsorbed in parallel position to the adsorbent surface. The magnitudes of the calculated adsorption energies show that the DR75 dye is physisorbed onto Posidonia. Both Van der Waals and hydrogen interactions are implicated in the adsorption process. Despite its simplicity, the model fits a wide range of experimental data, thereby supporting the underlying data that the grafted groups facilitate the parallel anchorage of the anionic dye molecule. Thermodynamic parameters, such as adsorption energy, entropy, Gibbs free adsorption energy and internal energy were calculated according to the double-layer model. Results suggested that the DR75 adsorption onto Posidonia was a spontaneous and exothermic process.     

浊漳河山西省潞城市境内段河流生态健康评价研究

浊漳河山西省潞城市境内干流段及南源段河道生态环境目前最突出的问题在于水质恶化、水量减少以及生物多样性衰退。本文从水质、水量、生物状况三个要素出发,通过建立浊漳河潞城市境内河段的水生态健康评价体系,对浊漳南源及干流段进行了生态健康诊断。结果显示,浊漳干流段生态健康总指数36.74,呈生态病态状;南源段生态健康总指数60.03,呈基本健康状态。据此,浊漳河潞城境内段目前的核心问题是生态恢复问题,应当针对其存在的问题选择适当的生态修复模式,采取相应的生态环境管理方法,把生态系统的恢复和重建作为其流域治理的最终目标。     

Influence of Suwannee River humic acid on particle properties and toxicity of silver nanoparticles

Adsorption of natural organic matter (NOM) on nanoparticles can have dramatic impacts on particle dispersion resulting in altered fate and transport as well as bioavailability and toxicity. In this study, the adsorption of Suwannee River humic acid (SRHA) on silver nanoparticles (nano-Ag) was determined and showed a Langmuir adsorption at pH 7 with an adsorption maximum of 28.6 mg g⁻¹ nano-Ag. It was also revealed that addition of <10 mg L⁻¹ total organic carbon (TOC) increased the total Ag content suspended in the aquatic system, likely due to increased dispersion. Total silver content decreased with concentrations of NOM greater than 10 mg TOC L⁻¹ indicating an increase in nanoparticle agglomeration and settling above this concentration. However, SRHA did not have any significant effect on the equilibrium concentration of ionic Ag dissolved in solution. Exposure of Daphnia to nano-Ag particles (50 μg L⁻¹ and pH 7) produced a linear decrease in toxicity with increasing NOM. These results clearly indicate the importance of water chemistry on the fate and toxicity of nanoparticulates.     

Integrating Environmental and Socio-Economic Indicators of a Linked Catchment–Coastal System Using Variable Environmental Intensity

Can we develop land use policy that balances the conflicting views of stakeholders in a catchment while moving toward long term sustainability? Adaptive management provides a strategy for this whereby measures of catchment performance are compared against performance goals in order to progressively improve policy. However, the feedback loop of adaptive management is often slow and irreversible impacts may result before policy has been adapted. In contrast, integrated modelling of future land use policy provides rapid feedback and potentially improves the chance of avoiding unwanted collapse events. Replacing measures of catchment performance with modelled catchment performance has usually required the dynamic linking of many models, both biophysical and socio-economic—and this requires much effort in software development. As an alternative, we propose the use of variable environmental intensity (defined as the ratio of environmental impact over economic output) in a loose coupling of models to provide a sufficient level of integration while avoiding significant effort required for software development. This model construct was applied to the Motueka Catchment of New Zealand where several biophysical (riverine water quantity, sediment, E. coli faecal bacteria, trout numbers, nitrogen transport, marine productivity) models, a socio-economic (gross output, gross margin, job numbers) model, and an agent-based model were linked. An extreme set of land use scenarios (historic, present, and intensive) were applied to this modelling framework. Results suggest that the catchment is presently in a near optimal land use configuration that is unlikely to benefit from further intensification. This would quickly put stress on water quantity (at low flow) and water quality (E. coli). To date, this model evaluation is based on a theoretical test that explores the logical implications of intensification at an unlikely extreme in order to assess the implications of likely growth trajectories from present use. While this has largely been a desktop exercise, it would also be possible to use this framework to model and explore the biophysical and economic impacts of individual or collective catchment visions. We are currently investigating the use of the model in this type of application.