Influence of pH on the toxicity of nitrophenols to Microtox and Spirotox tests

The toxicity of mononitrophenols and dinitrophenols (DNP) to luminescent bacteria Vibrio fischeri (Microtox test) and ciliated protozoan Spirostomum ambiguum (Spirotox test) was evaluated. Spirotox was more sensitive to the tested nitrophenols (NPs) than the Microtox test. 2,5-DNP was the most toxic and 2-NP was the least toxic to the both bioindicators. The toxicity depended greatly on the pH of the medium. The highest changes were observed for DNPs, where the toxicity decreased more than 20-times when the pH increased from 6 to 8. No significant decrease of the toxicity was found for NPs, when the pH increased from 6 to 7. Greater increase of the pH to 8 caused from 1.5 to 4-fold decrease of the toxicity.     

Location of noise sources in fluid power machines.

This paper discusses noise generation mechanisms and techniques for noise reduction in fluid power units. Major noise sources in fluid power units can be identified with a sound intensity method. It has been proved that components of power units with larger sound radiating surfaces such as an electric motor and an oil reservoir produce a major part of global noise radiation.     

The complexity of nectar: secretion and resorption dynamically regulate nectar features

In this paper, we review the phenomenon of nectar resorption, focusing on its physiological and ecological meaning. Nectar resorption is a phenomenon that has long been known but was rarely reported until the1990s. It has more recently been demonstrated in several species by various direct and indirect methodologies. It has generally been demonstrated in senescent flowers as a phenomenon separate in time from, and independent of, nectar secretion. The significance of this type of resorption is generally recognized as a resource-recovery strategy, recycling at least some materials invested in nectar production. Nevertheless, nectar resorption can occur concomitantly with nectar secretion. Nectar production is therefore best considered as a unified process comprising nectar secretion and resorption. The modulation of these two opposite phases allows nectar concentration to be maintained in a range suitable for pollinators (nectar homeostasis). The mechanism of nectar resorption at the cell level has received little attention, and its molecular basis can only be hypothesized on the basis of recent studies concerning sugar sensing.     

Growth of non-English-language literature on biodiversity conservation

English is widely recognized as the language of science, and English-language publications (ELPs) are rapidly increasing. It is often assumed that the number of non-ELPs is decreasing. This assumption contributes to the underuse of non-ELPs in conservation science, practice, and policy, especially at the international level. However, the number of conservation articles published in different languages is poorly documented. Using local and international search systems, we searched for scientific articles on biodiversity conservation published from 1980 to 2018 in English and 15 non-English languages. We compared the growth rate in publications across languages. In 12 of the 15 non-English languages, published conservation articles significantly increased every year over the past 39 years, at a rate similar to English-language articles. The other three languages showed contrasting results, depending on the search system. Since the 1990s, conservation science articles in most languages increased exponentially. The variation in the number of non-English-language articles identified among the search systems differed markedly (e.g., for simplified Chinese, 11,148 articles returned with local search system and 803 with Scopus). Google Scholar and local literature search systems returned the most articles for 11 and 4 non-English languages, respectively. However, the proportion of peer-reviewed conservation articles published in non-English languages was highest in Scopus, followed by Web of Science and local search systems, and lowest in Google Scholar. About 20% of the sampled non-English-language articles provided no title or abstract in English; thus, in theory, they were undiscoverable with English keywords. Possible reasons for this include language barriers and the need to disseminate research in countries where English is not widely spoken. Given the known biases in statistical methods and study characteristics between English- and non-English-language studies, non-English-language articles will continue to play an important role in improving the understanding of biodiversity and its conservation.     

Mechanical,Thermal and Microstructural Characteristic of 3D Printed Polylactide Composites with Natural Fibers: Wood,Bamboo and Cork

Journal of Polymers and the Environment - In the study, polylactide-based (PLA) composites modified with natural particles (wood, bamboo, and cork) and with different levels of infilling (100%,...     

Potential toxicity of leachate from the municipal landfill in view of the possibility of their migration to the environment through infiltration into groundwater

Environmental Geochemistry and Health - Leachate from landfills is a product of complex biological and physicochemical processes occurring during waste storage. In the present study, the toxicity...     

Toxicity and biodegradability of sulfonamides and products of their photocatalytic degradation in aqueous solutions

The photocatalytic degradation of sulfacetamide, sulfathiazole, sulfamethoxazole and sulfadiazine in water solutions during their illumination of UV radiation (lambda(max) 366 nm) with TiO2 catalyst was examined. The growth-inhibition effect of sulfonamides and intermediate products theirs photodegradation was investigated in aqueous solution with the green alga Chlorella vulgaris. The biodegradability of the investigated compounds was determined in the illuminated solutions and is expressed as Biochemical Oxygen Demand. It was found that all of the investigated sulfonamides in the initial solutions were resistant to biodegradation and were toxic relative to C. vulgaris. The toxicity (EC50 values) relative to C. vulgaris increased in the following order sulfacetamide, sulfathiazole, sulfamethoxazole, sulfadiazine. All of the investigated sulfonamides undergo photocatalytic degradation. The toxicity of intermediate products of the sulfonamides degradation was significantly lower than the toxicity of sulfonamides in the initial solutions and was dependent on illumination time and degradation rate. The intermediate products of photocatalysis in contrast to the initial sulfonamides, might be mineralized using biological methods.     

Vitrification as an alternative to landfilling of tannery sewage sludge

Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling.The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification.The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives.One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with flotation sewage sludge, and 45% v/v and 5% v/v, respectively, for precipitation sewage sludge. These combinations allowed for obtaining products with negligible heavy metal leaching levels and hardness similar to commercial glass, which suggests they could be potentially used as construction aggregate substitutes. Incineration of sewage sludge before the vitrification process lead to increased hardness of the vitrificates and reduced leaching of some heavy metals.