Biphasic production of hydrogen and methane from waste lactose in cyclic-batch reactors

The biphasic production of the energy gases hydrogen and methane was possible in a fed batch culture resulting in a volumetric mix of approximately 20% H₂ and 80% CH₄ and an energy conversion efficiency of 95%, based on the measured Chemical Oxygen Demand and theoretical calculations assuming that the substrate (a dairy waste permeate) was lactose. Gas production showed a rapid initial phase over 0–20 h in which the composition was up to 50% hydrogen with the balance mainly carbon dioxide. This was accompanied by the accumulation of volatile fatty acids (VFA) in which butyric was predominant. A slower second phase of gas production produced a mixture of methane and carbon dioxide with a reduction in the accumulated acids. The duration of this second phase depended on the initial load applied to the reactor, and in the experiments carried out lasted between 6 and 12 days. Where the applied initial load led to an acid accumulation such that the pH fell below 5.5, the second phase of gas production was inhibited. Where pH control was exerted to prevent the pH dropping below 6.5, ethanol accumulated alongside VFA as a first phase product, with the gas comprised entirely of carbon dioxide. Despite the excellent energy conversion and the production of biogas fuel elements matching those for hythane (a mixture of hydrogen and methane, with improved combustion characteristics), the overall process loading was considered too low for efficient volumetric conversion of the feedstock to energy. The concept could be further developed based on high rate reactor systems with granular or immobilised biomass either as a single tank biphasic system or in a split tank two phase production process.     

Oceanic variability and coastal topography shape genetic structure in a long-dispersing sea urchin

Understanding the scale of marine population connectivity is critical for the conservation and sustainable management of marine resources. For many marine species adults are benthic and relatively immobile, so patterns of larval dispersal and recruitment provide the key to understanding marine population connectivity. Contrary to previous expectations, recent studies have often detected unexpectedly low dispersal and fine-scale population structure in the sea, leading to a paradigm shift in how marine systems are viewed. Nonetheless, the link between fine-scale marine population structure and the underlying physical and biological processes has not been made. Here we show that patterns of genetic structure and population connectivity in the broadcast-spawning and long-distance dispersing sea urchin Centrostephanus rodgersii are influenced by physical oceanographic and geographic variables. Despite weak genetic differentiation and no isolation-by-distance over thousands of kilometers among samples from eastern Australia and northern New Zealand, fine-scale genetic structure was associated with sea surface temperature (SST) variability and geography along the southeastern Australian coast. The zone of high SST variability is characterized by periodic shedding of eddies from the East Australian Current, and we suggest that ocean current circulation may, through its influence on larval transport and recruitment, interact with the genetic consequences of large variance in individual reproductive success to generate patterns of fine-scale patchy genetic structure. If proven consistent across species, our findings suggest that the optimal scale for fisheries management and reserve design should vary among localities in relation to regional oceanographic variability and coastal geography.     

What does team–member exchange bring to the party? A meta‐analytic review of team and leader social exchange

Both leader–member exchange (LMX) and team–member exchange (TMX) measure the quality of reciprocal exchange among employees in the workplace. Although LMX focuses on supervisor–subordinate relationships while TMX examines the relationships among team members, both have theory‐based and empirically proven relations with workplace outcomes such as job performance, organizational commitment, job satisfaction, and turnover intentions. However, it is not yet known which has more of an impact on such workplace outcomes—specifically, it is not clear if an employee's time is best spent developing vertical relationships among supervisors and subordinates (LMX) or on the horizontal relationships among team members (TMX). Accordingly, this meta‐analysis explores the incremental validity and relative importance of these two social exchange‐based constructs. The theoretical logic underlying LMX and TMX is clarified, and the parameter estimates between LMX, TMX, and work outcomes are reported. Results demonstrate that TMX shows incremental validity above and beyond LMX for some outcomes (organizational commitment and job satisfaction), but not others (job performance and turnover intentions). Also, LMX shows greater relative importance across all four outcomes. In sum, the clarification of the theoretical and empirical landscape lays a foundation for recommendations for future research. Copyright © 2013 John Wiley & Sons, Ltd.     

Still some way to go: institutionalisation of sustainability in German local governments

There is a widespread consensus among sustainability experts about the need for ambitious transformative practices in order for a sustainable development to progress. Agenda 21 emphasised the need for multilevel and multi-actor governance and explicitly focused on the local level. The conceptual and analytical preference of governance beyond government has directed attention towards the interaction between state and non-state actors. The present article focuses on the role of (local) state institutions in sustainability governance. We argue that an effective implementation of sustainability in government institutions is a precondition for a successful multi-stakeholder governance of a sustainable development. The guiding question of this article is: How has sustainability been institutionalised in local governments in Germany in the last 20 years after Agenda 21 was adopted? Based on a conceptual framework, we are presenting the empirical results of a survey of 371 German cities and municipalities in this article, which primarily aims at providing empirical evidence on to what extent sustainability has been institutionalised in German local governments. The article ends with discussing the potential reasons for the institutionalisation deficit observed and gives an outlook on the potential for developing a sustainability state, that is, a state dedicated to institutionalising sustainability.     

Biodegradation of disodium cocoamphodiacetate by a wastewater microbial consortium.

Biodegradation of an amphoteric surfactant commonly used in personal care products, disodium cocoamphodiacetate (DSCADA), was evaluated. Results from respirometry experiments indicated that high levels of DSCADA (>216 mg/L) may be toxic to bacteria in wastewater treatment processes. Limited biodegradation, with 50% dissolved organic carbon (DOC) removal and 80% chemical oxygen demand removal was observed in batch assays, while complete removal of the parent compound, DSCADA, was noted. Oxygen biosensors were used to evaluate biodegradability of the metabolites present in the batch samples. Additional aerobic microbial activity was not detected in these samples, even with a residual DOC of approximately 45 mg/L. Results from this research indicate that biodegradability of DSCADA is limited and recalcitrant metabolites may be formed. Because DSCADA is a commonly used surfactant and is present in domestic and industrial wastewater, the associated risk posed by residual compounds should be carefully evaluated.     

Verification of the "first flush" phenomenon in mine water from coal mines in the Upper Silesian Coal Basin, Poland

Case studies of Grodziec and Siersza mines in the Upper Silesian Coal Basin confirm that mine water accumulating in and over-flowing from abandoned coal mines is subject to a "first flush" phenomenon. The accumulated products of sulphide oxidation are dissolved in the rising mine water and flushed out at concentrations several times those observed during mine operation. Following the first overflow, sulphate concentration and hydrogen ion activity decay exponentially. In the case of workings in Siersza, decay constants of -0.003 to -0.005 day(-1) are observed, corresponding to flushing times of 480 to 820 days, some 10-20 times the period required for the workings to flood. Quantities of leachable sulphur in the abandoned workings of 0.02-0.03% are adequate to explain the observed concentrations of sulphate in the first flush, and this figure is tentatively supported by laboratory analyses.     

Digital technology and human development: A charter for nature conservation

The application of digital technology in conservation holds much potential for advancing the understanding of, and facilitating interaction with, the natural world. In other sectors, digital technology has long been used to engage communities and share information. Human development—which holds parallels with the nature conservation sector—has seen a proliferation of innovation in technological development. Throughout this Perspective, we consider what nature conservation can learn from the introduction of digital technology in human development. From this, we derive a charter to be used before and throughout project development, in order to help reduce replication and failure of digital innovation in nature conservation projects. We argue that the proposed charter will promote collaboration with the development of digital tools and ensure that nature conservation projects progress appropriately with the development of new digital technologies.     

Associations of Forest Cover,Fragment Area,and Connectivity with Neotropical Understory Bird Species Richness and Abundance

Theoretical and empirical studies demonstrate that the total amount of forest and the size and connectivity of fragments have nonlinear effects on species survival. We tested how habitat amount and configuration affect understory bird species richness and abundance. We used mist nets (almost 34,000 net hours) to sample birds in 53 Atlantic Forest fragments in southeastern Brazil. Fragments were distributed among 3 10,800‐ha landscapes. The remaining forest in these landscapes was below (10% forest cover), similar to (30%), and above (50%) the theoretical fragmentation threshold (approximately 30%) below which the effects of fragmentation should be intensified. Species‐richness estimates were significantly higher (F= 3715, p = 0.00) where 50% of the forest remained, which suggests a species occurrence threshold of 30–50% forest, which is higher than usually occurs (<30%). Relations between forest cover and species richness differed depending on species sensitivity to forest conversion and fragmentation. For less sensitive species, species richness decreased as forest cover increased, whereas for highly sensitive species the opposite occurred. For sensitive species, species richness and the amount of forest cover were positively related, particularly when forest cover was 30–50%. Fragment size and connectivity were related to species richness and abundance in all landscapes, not just below the 30% threshold. Where 10% of the forest remained, fragment size was more related to species richness and abundance than connectivity. However, the relation between connectivity and species richness and abundance was stronger where 30% of the landscape was forested. Where 50% of the landscape was forested, fragment size and connectivity were both related to species richness and abundance. Our results demonstrated a rapid loss of species at relatively high levels of forest cover (30–50%). Highly sensitive species were 3‐4 times more common above the 30–50% threshold than below it; however, our results do not support a unique fragmentation threshold. Asociaciones de la Cobertura Forestal, Superficie del Fragmento y Conectividad con la Riqueza y Abundancia de Aves Neotropicales de Sotobosque