Mari Ivask

Presence of fluoroquinolones and sulfonamides in urban sewage sludge and their degradation as a result of composting

The concentrations of some widely used pharmaceuticals, namely fluoroquinolones (ciprofloxacin C17 H18FN3O3, norfloxacin C17 H18FN3O3 and ofloxacin C18 H20FN3O4 and sulfonamides (sulfadimethoxine C12 H14N4O4s and sulfamethoxazole C10 H11N3O3S were determined in urban sewage sludge utilized for making compost. The levels of degradation of these pharmaceuticals resulting from sludge treatment were assessed. The concentrations of the studied pharmaceuticals sufficiently varied both in sewage sludge and in compost and due to this phenomenon the possible danger resulting from the presence of pharmaceuticals in sewage sludge, used for composting, can not be ignored. The concentrations of the studied pharmaceuticals were lower in compost, if compared to the relevant concentrations in sewage sludge. The highest pharmaceutical concentration in sewage sludge — 426 μg/kg — was detected in the case of ciprofloxacin. The highest concentrations present in compost were 22 μg/kg of norfloxacin and 20 μg/kg of ciprofloxacin. Results show that before using the sewage sludge for making compost or before using the compost a fertilizer for food plants, they should be carefully tested against the content of commonly used pharmaceuticals.

Domestic organic waste treatment through vermitechnology

Vermitechnology has become a popular method for the safe and cost-effective treatment of domestic and agricultural solid wastes. Since 2010, a remarkable number of excellent papers have been published in Waste Management & Research on this environmentally friendly transformation of energy-rich organic matter into humus-like product. Among these, the work of Rajpal et al. (2010), is of special interest, as the indigenous earthworm species Perionyx sansibaricus and Perionyx excavates are successfully used in India instead of exotic species for vermicomposting. These authors claim that the vermicomposting process is limited, because the users have to purchase non-native earthworm species (usually Eisenia fetida) and if they are lost for some reason, they have to be purchased again. In this study it was shown that the performance of indigenous species was comparable with that of the exotic species, although the exotic species degraded the organic matter faster. However, after continuous application of vermicompost produced by Eisenia fetida, the local earthworm species vanished from that area. Kurian and Velmourougane (2010) have shown in India, that both exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species can be used in vermicomposting, and that the efficiency of composting with indigenous species was found to be higher in their study. In Estonia, Eisenia fetida is one of the native earthworm species inhabiting manure and compost piles. Vermicomposting has not found wide usage in Nordic countries, due to insufficient efficiency at low and moderate temperatures. However, on-site small-scale vermicomposting of kitchen waste could be a reasonable way of obtaining valuable fertilizer for the gardens and small fields of private households. We conducted a comparable on-site vermicomposting experiment in the range of temperatures from 16 to 31 °C, using kitchen waste that consisted of fresh and boiled fruits, vegetables and plants, coffee grounds and teabags, eggshells, kitchen paper, milk and meat, etc. As a result of this study, it may be concluded that on-site vermicomposting using Eisenia fetida is a beneficial way of treating kitchen waste in Estonia. The biomass of the earthworms doubled during 120 days, the pH increased from 5.4 to 8.3, the change in the content of total phosphorous increased from 0.3 to 0.7%, and a two-fold reduction of organic carbon was observed. These results are in good agreement with the results obtained by Rajpal et al. and they clearly show that there is no need to adapt non-native earthworm species for vermicomposting in Estonia. Moreover, the legislation of Estonia determines that the release of non-native species into the wild should be fully excluded. Vermicomposting is an efficient way of reusing organic waste materials and indigenous earthworm species should be preferably used for this purpose. Most of the relevant studies have been carried out in countries with a warm climate. Novel intelligent protocols should be developed, so that this attractive approach could also be widely applied in regions with a moderate climate. We propose that the editors encourage the scientists dealing with vermicomposting to publish the results of their studies in Waste Management & Research more actively.

Distribution of Octolasion cyaneum (Savigny, 1826) in Estonia 1993–2008

Abstract The aim of the paper is to give an overview about distribution of the endogeic species Octalasion cyaneum (Savigny, 1826) in Estonia. First time, this endogeic species was found in 1980s in the Tallinn Botanical Garden (Northern-Estonia). The new results show that O. cyaneum is slowly expanding into Estonian territory and becoming more abundant.

Ground-Dwelling Spider Fauna of Flooded Meadows in Matsalu, Estonia

Traditionally managed and unregulated floodplain meadows are characterised by high and habitat-specific biodiversity. In most parts of Europe, however, these habitats are almost completely lost. Despite possessing high importance in conservation, little is known about the dynamics of important species groups in those valuable communities. Here, we studied the diversity and composition of ground-dwelling spider fauna in ten sites of temporarily flooded semi-natural grasslands in the Matsalu Bay, Western Estonia. As fluctuation of aquatic and terrestrial phases is the strongest factor determining the environmental conditions in flooded coastal and floodplain meadows, we estimated the effect of floods on spider diversity and composition. Studied grasslands were characterized by opportunistic, eurytopic and hydrophilic spider species that are also abundant in other disturbed habitats. Most species belonged to families characterised by species with good dispersal ability (Linyphiidae and Lycosidae). Average ecological flexibility of spiders (i.e. number of preferred habitats) increased, while activity density of spiders declined towards the sea, where floods are more frequent and more saline. Our results indicate that the spider fauna of floodplain meadows is dependent on flooding regime and is likely re-structured after major flooding events via colonisation from nearby habitats.