Combining Ion‐exchange (IX) technology and biological reduction for perchlorate removal

Ion‐exchange (IX) resin is perhaps the most promising technology to remove the contaminant perchlorate (ClO₄^?) from waters. However, ion exchange is only a separation technology that transfers the perchlorate from waters to the waste solutions used to regenerate the resins. The waste solutions contain high perchlorate concentrations, and treatment technologies for these regenerant solutions are needed. In this article, we review the latest knowledge on perchlorate removal by ion‐exchange resins; propose three systems that combine ion‐exchange resins (for perchlorate removal) and biological reduction for treating the waste solutions resulting from resin regeneration; and discuss the challenges and research needed to fully develop the proposed technology. © 2002 Wiley Periodicals, Inc.     

Seasonal nitrogen fluxes of the Lena River Delta

The Arctic is nutrient limited, particularly by nitrogen, and is impacted by anthropogenic global warming which occurs approximately twice as fast compared to the global average. Arctic warming intensifies thawing of permafrost-affected soils releasing their large organic nitrogen reservoir. This organic nitrogen reaches hydrological systems, is remineralized to reactive inorganic nitrogen, and is transported to the Arctic Ocean via large rivers. We estimate the load of nitrogen supplied from terrestrial sources into the Arctic Ocean by sampling in the Lena River and its Delta. We took water samples along one of the major deltaic channels in winter and summer in 2019 and sampling station in the central delta over a one-year cycle. Additionally, we investigate the potential release of reactive nitrogen, including nitrous oxide from soils in the Delta. We found that the Lena transported nitrogen as dissolved organic nitrogen to the coastal Arctic Ocean and that eroded soils are sources of reactive inorganic nitrogen such as ammonium and nitrate. The Lena and the Deltaic region apparently are considerable sources of nitrogen to nearshore coastal zone. The potential higher availability of inorganic nitrogen might be a source to enhance nitrous oxide emissions from terrestrial and aquatic sources to the atmosphere.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01665-0.     

Perceptions of Prescribed Burning in a Local Forest Community in Victoria, Australia

The general perceptions of prescribed burning were elicited from forest users for an area that has been subject to this form of land management for at least 20 years. The largest group consisted of local residents living in and around the Wombat State Forest with two smaller groups of students from a nearby university campus and local professional land managers. A questionnaire was given to each participant in order to explore how the forest was used, to determine the level of knowledge of burning in the targeted forest and Victoria and the perception of the appearance, effectiveness of protection, and accessibility to the forest after prescribed burning. Generally all groups had similar responses with community members having stronger views on the effectiveness and practicalities of prescribed burning, whereas students were more neutral in their opinions. All participants claimed knowledge of prescribed burning activities within Victoria, but fewer had experience of planned fires in the Wombat State Forest. All groups agreed that areas that had not been recently burned had a better appearance than those that had, but this result may have included a range of value judgments. Land managers had a greater understanding of the ecological importance of season and timing of burning; however, some students and community members were equally knowledgeable. Prescribed burning did not impede access to the forest, nor did smoke from prescribed burns pose any great problem. The majority of the participants felt that the amount of prescribed burning done in the forest was adequate for engendering a feeling of protection to life and property, yet many were still suspicious of this management practice. These initial findings indicate several areas in which further research would be useful including the efficacy of education programs for community members and improved communication of burn plans by land managers.     

Transformation of Particle-Bound Phosphorus at the Land–Sea Interface in a Danish Estuary

Danish rivers carry >50% of the phosphorus (P) transport as particulate P (PP). In five of six rivers sampled in November 1998 iron-bound P made up > 59% of PP and loosely adsorbed P ranged between 2% and 13%. This fraction could potentially be released in 14‰ seawater. The behaviour of dissolved and particulate P fractions was studied during seven month in a 2 km long estuary with low freshwater retention time and low tidal range. The river carried ∼10% of PP as loosely adsorbed P but increased concentrations of dissolved inorganic P (DIP) relative to the estuarine mixing line was only observed in the summer month with low freshwater flow and was more likely due to DIP release from the bottom sediment. Instead estuarine particles were always enriched with oxidized iron (ox.Fe) and iron-bound P as well as loosely adsorbed P and during May–September this coincided with increasing concentration of PP in estuary. We suggest that flocculation of ox.Fe and adsorption of DIP onto the particles with subsequent transport seawards is a major loss process for P during the summer month. During winter month where 85% of the run-off occurs the dominant process in the estuary is sedimentation of larger particles, however, a comparison of river particles with surface sediment clearly reveals that most PP is mobilized again from the bottom sediments.     

Chemisch-analytische Charakterisierung technischen tierischen Fettes aus einer Tierkörperbeseitigungsanstalt

Aims and Scope

German rendering plants produce 300,000 tons of animal fat per year. Until recently, these raw products have been in wide use as nutritional additive for cattle and other animals fodder but now they have been banned due to their assumed role in BSE infection. Therefore, alternative fields of usage are required. In this context the Deutsche Bundesstiftung Umwelt (DBU) is sponsoring a joint research project which deals with the production and testing of cooling lubricants based on animal fat esters.

Methods

In a first step, characteristics and quality of the animal fat were analyzed and monitored for a whole year in order to identify e.g. seasonal variations. The investigations covered the following fat specific and trace analytical parameters: total contamination, sulfates ash, water content, peroxide number, iodine value, kinematical viscosity, neutralisation number (free fatty acids), fatty acid spectra, elements / heavy metals (Al, B, Ca, Cd, Cr, Cu, Fe, K, Mo, Mn, Na, Ni, P, Pb, S, Sn, V, W and Zn), polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

Results

Valuable hints on the design of the technical process of fatty acid methylesters production were gained by regarding the fat specific parameters. For example, filtration and dewatering of the fats proved necessary. Small variations of iodine value, viscosity and fatty acid spectrum pointed at a quite constant composition of the raw material in the course of the year. Clues to the degree of hydrolysis and decay of the fat were given by the share of free fatty acids. The saturated fatty acids, most interesting for the production of the cooling lubricants, were present in the fatty acid spectra in the rage of 36.4% to 54.6%. Trace analytical investigations concerning inorganic and organic pollutants proved a low basic contamination of the technical animal fats.

Outlook

Next step will be to present the pilot plant for the production of the cooling lubricants and further analytical results in context with the production process.     

Collaborative environmental governance and transaction costs in partnerships: evidence from a social network approach to water management in France

Several studies attempt to explain how collaborative environmental governance processes operate, but the question of why collaboration relationships form has received much less attention. Motivated by this need, this paper provides insights to the broad question: why does collaborative river basin management in France depend so heavily on partnerships made up around a few actors? Accordingly, our analytical framework develops a transaction cost explanation for the extent to which participatory procedures help stakeholders to identify partners and initiate collaboration, and for the causal link between the attributes of these stakeholders and their partnerships. The p2 model is implemented to investigate partnership networks of the key actors that govern the management of the Gironde estuary, the study case. The results provide evidence that environmental institutions bring together heterogeneous actors who might not be ready for collaboration, thereby actors’ perceived power similarity; their geographical proximity and co-presence in formal fora limit transaction costs.