From traditional to modern fee systems

This paper deals with the environmentally important issue regarding how best to motivate citizens to reduce their individual waste production. The paper discusses the pros and cons of the various financial incentives incorporated into the waste charging mechanism, pay-as-you-throw (PAYT). Pay-as-you-throw breaks with the tradition of paying for waste services through general blanket taxes or levies in the form of flat rates in that households are required to pay individually adjusted fees in the same way as water and electricity bills are calculated on an individual consumption basis. This difference is achieved through the interplay of three principal components which mark the technical implementation of PAYT: identification as a vehicle to attain accountability, measurement of the generated waste and/or corresponding services, and unit pricing as the basis for individual charges proportional to the extent of the obtained services. However, any motivating factor for inducing citizens to dispose of their recyclable discards and residual waste must be supported by a well developed collection infrastructure, good media information and an appropriate, transparent charging policy. Of particular importance is the use of a multi-tiered charge model, i.e., the charging of a fixed minimum fee plus certain variable components payable in respect of the service structure. The introduction of a basic charge, albeit reducing the intensity of the incentives created by the PAYT system, ensures that certain fixed costs for the provision of waste services will be covered independently from the actual waste developments and, at the same time, minimises the temptation to attempt to bypass the system. Such an arrangement for the waste charges neither contradicts the principle of pay-as-you-throw nor does it impair the waste diversion for which it is implemented. Waste statistics and figures representing the waste charging situation in Germany indicate that there is a relatively good correlation between the level of recycling and the amount of perceived financial motivation provided by PAYT. Waste stream developments in areas using such charging schemes generally suggest that the reduction goals are being achieved. Single figures on decreasing quantities of collected residual waste, however, say little about the actual efficiency of differentiated waste charging models and deliver little in the way of reasoned explanation as to why the diffusion of variable rate pricing is progressing painstakingly slowly. To evaluate the success, feasibility and problems of PAYT schemes, one needs to consider the various ways for technically implementing this approach in practice, and must take a broader look into the wide spectrum of available waste services and into more factors that influence their efficiency and acceptance. Urban structure settings assume a particular importance here as do the specific goals of social policy which, among others, are reflected in the charging mechanisms applied. Practical experience, however, shows that solutions can be found which allow most of the concerns and area specifics to be accommodated and waste streams to be influenced in the desired way. Aside from this, positive effects as to waste collection efficiency can also be achieved, which contribute towards long-term environmental improvements and countervail the incremental costs of implementing PAYT.     

Das Biologische System der Elemente (BSE): Eine modelltheoretische Betrachtung zur Essentialität von chemischen Elementen

The correlation of data on the elements obtained by instrumental chemical analysis of highly representative plant samples led to the establishment of a first Biological System of Elements (BSE) in 1994. Including other physiological parameters like availability of chemical elements, transport, storage, etc. it is clear, that aside from the bioinorganic aspects of coordination chemistries of given elements, features of essentiality or toxicity depend on their interference with enzymatic processes. Notably, the latter are not to be considered as purely catalytic transformations, but are instead related to the reproduction of organisms in a direct or indirect manner — as autocatalytic: a process whereby a protein containing some metal or burdened in function by its presence is indirectly involved in its own reproduction. Stoichiometric Network Analysis (SNA) explicitly deals with the general dynamics of such autocatalytic systems. Given there is a relationship between the kinds of metal or metalloid species and the key biological/biochemical transformations to be promoted using them — a relationship which is the topic of bioinorgnaic chemistry-, and that biochemistry is in effect about systems which can reproduce and thus behave autocatalytically, one can expect SNA to yield statements on the basic features of biology and biochemistry as well.     

Biomonitoring zur wirkungsbezogenen Ermittlung der Schadstoffbelastung in terrestrischen Ökosystemen

Biomonitoring programmes provide relevant information, which may supplement ambient air pollution monitoring or modelling around emission sources. As a prerequisite, assessment scales for biomonitoring data have to be derived based on an objective evaluation of available data, as well as on a scheme of presentation, which is suggestive and easily understandable even for laymen. Based on an evaluation of numerous monitoring programmes, assessment scales for biomonitoring results are derived for plant biomonitoring, which also serve as a basis for the graphical presentation of monitoring results. This study is focussed on bioindicator plants like mosses (passive biomonitoring) and exposed lichens (active biomonitoring), in which 14 metal elements are investigated. As an example, data from a local biomonitoring network around a cement plant were used to demonstrate the use of the assessment scales derived and the presentation scheme developed. Data sets from about 15 moss and 24 lichen biomonitoring programmes, comprising more than 1000 specimens, were sorted by their pollutant characteristics in order to form the database. Data on the metal contents of species demonstrating similar values with respect to growth characteristics and habit, and representing background or low pollution levels, are aggregated and their statistical distributions are evaluated. Spacing of the assessment scales and their colour designations are derived from the 50-, 75-, 90- and 95-percentile values. Graphical presentation allows a comparison of the absolute values of metal contents and a relative association of measured values. Exemplary results from moss and lichen monitoring around a cement plant are generally below or slightly above the median values at background and low-pollution sites. Metal contents are higher in lichens compared to mosses for 7 elements (Cd, Cu, Hg, Pb, Sb, Sn, Zn), and are lower in lichens only for thallium. The assessment scheme presented is mainly aimed at the practitioner in the field of biomonitoring in order to provide a reliable and sound scale of assessment by comparison on an absolute scale rather than presenting the basis of ecological risk assessment. Differences in metal content of co-located samples of various moss species and possible correction procedures are briefly discussed- as well as the consequences of pooling monitoring data across various moss species for the quality of assessment scales. Further evaluations shall focus on species-specific rather than on pooled databases and will investigate the consequences of the use of correction factors when extrapolating metal data from one monitoring species to another.     

Drought frequency in the Volta Basin of West Africa

According to various reports, climate change is responsible for the change in rainfall amount and pattern accompanied by the various degrees of extreme events in Sahelian West Africa in recent years. Other reports also suggest that there has been a “recovery” of the rainy season (Nicholson 2005). In this study, temporal characteristics of meteorological droughts in the Volta basin, a semi-arid region in West Africa, are investigated in order to provide a guide for sustainable water resource management. For this purpose, drought intensity, areal extent and recurrence frequency is analysed using the standardised precipitation index (SPI) for a time series between 1961 and 2005 from 52 meteorology stations across the Volta basin. Using this analysis the severity of the historical droughts of 1961, 1970, 1983, 1992 and 2001 that occurred in the region are assessed and their intensity, areal extent and return periods are obtained. The drought intensity is lower than −2.0 over nearly 75% of the region, meaning that a major part of the region was under extreme drought conditions during this year. The drought of 1983/1984 has a probability of occurrence of up to 0.1 from records spanning 44 years. The areal extent of extreme drought conditions is about 90% during this drought period.     

Ein Moosbiomonitoring zur Ermittlung atmosph?rischer Elementeintr?ge in die Euroregion Nei?e (D, PL, CZ)

Zusammenfassung  Durch ein Moosbiomonitoring sollte die H?he und die Verteilung der atmosph?rischen Deposition von 37 Elementen in der Euroregion Nei?e (ERN) nach den politischen und wirtschaftlichen Ver?nderungen erfasst und mit anderen Regionen verglichen werden. Weiterhin sollten die Akkumulationseigenschaften vonPleurozium schreberi undPolytrichum formosum, den in dieser Studie verwendeten Moosarten, miteinander verglichen werden. Bis Anfang der 90er Jahre war diese Region Teil des “Schwarzen Dreiecks”, das sich durch eine extrem hohe atmosph?rische Staubbelastung auszeichnete. Durch die Schlie?ung zahlreicher Betriebe, der Ausrüstung der Kraftwerke mit Filteranlagen, der abnehmenden Bedeutung der Braunkohle als h?uslicher Energietr?ger ver?nderte sich die Situation drastisch. Die Elementkonzentrationen in den Moosen der ERN lassen sich heute mit denen der alten Bundesl?nder vergleichen. Lediglich für Fe und Ti konnten deutlich h?here Gehalte ermittelt werden. Dies ist auf den h?heren Anteil der Braunkohle als Energietr?ger zurückzuführen. In der Region um Katowice in Oberschlesien konnten für einige Elemente mehr als 10 fach h?here Gehalte in den Moosen als in der ERN ermittelt werden. Das Oberschlesische Industrierevier weist eine derart hobe atmosph?rische Belastungen auf, dass hier ein dringender Handlungsbedarf besteht. Online-First: 21. Juni 2000     

Handling the phosphorus paradox in agriculture and natural ecosystems: Scarcity,necessity, and burden of P

This special issue of Ambio compiles a series of contributions made at the 8th International Phosphorus Workshop (IPW8), held in September 2016 in Rostock, Germany. The introducing overview article summarizes major published scientific findings in the time period from IPW7 (2015) until recently, including presentations from IPW8. The P issue was subdivided into four themes along the logical sequence of P utilization in production, environmental, and societal systems: (1) Sufficiency and efficiency of P utilization, especially in animal husbandry and crop production; (2) P recycling: technologies and product applications; (3) P fluxes and cycling in the environment; and (4) P governance. The latter two themes had separate sessions for the first time in the International Phosphorus Workshops series; thus, this overview presents a scene-setting rather than an overview of the latest research for these themes. In summary, this paper details new findings in agricultural and environmental P research, which indicate reduced P inputs, improved management options, and provide translations into governance options for a more sustainable P use.     

The influence of EDDS on the uptake of heavy metals in hydroponically grown sunflowers

Phytoextraction is an environmentally friendly in situ technique for cleaning up metal contaminated land. Unfortunately, efficient metal uptake by remediation plants is often limited by low phytoavailability of the targeted metals. Chelant assisted phytoextraction has been proposed to improve the efficiency of phytoextraction. Phytoremediation involves several subsequent steps: transfer of metals from the bulk soil to the root surfaces, uptake into the roots and translocation to the shoots. Nutrient solution experiments address the latter two steps. In this context we investigated the influence of the biodegradable chelating agent SS-EDDS on uptake of essential (Cu and Zn) and non-essential (Pb) metals by sunflowers from nutrient solution. EDDS was detected in shoots and xylem sap for the first time, proving that it is taken up into the above ground biomass of plants. The essential metals Cu and Zn were decreased in shoots in the presence of EDDS whereas uptake of the non-essential Pb was enhanced. We suggest that in the presence of EDDS all three metals were taken up by the non-selective apoplastic pathway as the EDDS complexes, whereas in the absence of EDDS essential metal uptake was primarily selective along the symplastic pathway. This shows that synthetic chelating agents do not necessarily increase uptake of heavy metals, when soluble concentrations are equal in the presence and absence of chelates.     

Analysis of perfluorooctanoate (PFOA) and other perfluorinated compounds (PFCs) in the River Po watershed in N-Italy

C7-C11 perfluorinated carboxylates (PFACs) and perfluorooctansulfonate (PFOS) were analysed in selected stretches of the River Po and its major tributaries. Analyses were performed by solid-phase extraction (SPE) with Oasis HLB cartridges and methanol elution followed by LC-MS-MS detection using 13C-labelled internal standards. High concentration levels ( approximately 1.3 microg l(-1)) of perfluorooctanoate (PFOA) were detected in the Tánaro River close to the city Alessandria. After this tributary, levels between 60 and 337 ng l(-1) were measured in the Po River on several occasions. The PFOA concentration close to the river mouth in Ferrara was between 60 and 174 ng l(-1). Using the river discharge flow data in m3 s(-1) at this point (average approximately 920 m3 s(-1) for the year 2006), a mass load of approximately 0.3 kg PFOA per hour or approximately 2.6 tons per year discharged in the Adriatic Sea has been calculated. PFOS concentration levels in the Po River at Ferrara were approximately 10 ng l(-1).