Sequential Extraction and Determination of Chemical Forms of Zinc in Sulfate Sludge

Total content of zinc and other metals has been assayed in thesludge that remained after leaching zinc-bearing smelting losswith sulfuric acid. The paper also presents zinc speciationcarried out by means of the sequential extraction by Rudd and an analysis of chemical forms of zinc. It has been found thatzinc occurs mainly in the mobile, bioavailable, soluble form and in the moderately mobile, carbonate form. The speciationcarried out showed that zinc occurred in the sludge in the following forms (mg kg^-1): sulfate 143 000, oxide 79 000,metallic 68 200, siliceous 35 500, sulfide 20 800 and ferrate18 500. Preparatory extraction of zinc from the sludge usingwater, sodium salt of ethylenediaminetetraacetic acid (EDTA)and acetic acid has also been conducted.     

Interference of Chironomus in an open culture system for Tubifex tubifex

In an outdoor culture of Tubifex tubifex, occurrence of the larvae of Chironomus pulcher and C. calligaster was recorded. An increase in the density of Chironomus larvae reduced the standing biomass of tubifex and made the harvest impossible.     

Triterpene saponins from aerial parts of Medicago arabica L

Eight major triterpene saponins have been isolated from the aerial parts of Medicago arabica and their structures elucidated by FAB-MS and NMR analysis. Three of them are new compounds and are identified as 3-O-(alpha-L-arabinopyranoside) bayogenin, 3-O-(alpha-L-arabinopyranosyl), 28-O-(beta-D-glucopyranoside) bayogenin, and 3-O-[alpha-L-arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl], 28-O-beta-D-glucopyranoside 2-beta-hydroxyoleanolic acid. Two saponins, identified as 3-O-(alpha-L-arabinopyranoside) hederagenin and 3-O-(alpha-L-arabinopyranosyl), 28-O-(beta-D-glucopyranoside) hederagenin are known compounds but not previously reported as saponin constituents of Medicago species, while three other saponins, being mono- and bidesmosides of hederagenin, have been previously isolated from roots of M. sativa.     

Phenolic acid profiles in some small berries

The composition of phenolic acids in several small berries grown in Northeastern Poland, namely, low-bush blueberries, black mulberries, European juneberries, black currants, fruits of blue-berried honeysuckle, and blackberries, was determined by gas chromatography (GC) and mass spectrometry (MS). The total content of phenolic acids, identified by GC-MS, ranged from 2845.8 +/- 141.0 (black mulberries) to 5418.2 +/- 228.0 (blue-berried honeysuckle). Twenty phenolic acids were identified in the berries. Of these, hydroxycaffeic, m- and p-coumaric, and 3,4-dimethoxycinnamic acids were the major phenolic acids in blackberries and blueberries, m-coumaric acid was the major phenolic acid in blue-berried honeysuckle and black currant fruits, while salicylic, caffeic, and m- and p-coumaric acids were the predominant phenolic acids in European juneberries. Syringic and veratric acids were detected only in blueberries, while p-hydroxybenzoic and sinapic acids were present only in black currants and o-coumaric acid was present in blueberries and black mulberries. The phenolic acids liberated from esters and glycosidic bonds were the major fractions of phenolic acids in the berries.     

Research needs in relation to the conservation of biodiversity in the UK

A number of key agreements and pieces of legislation within the UK have provided an important ‘framework' for the conservation of our national biological diversity. In this paper an overview of the framework is provided and the associated research requirements classified into three broad themes: autecology and synecology, populations and environment. Evidence, for a deficiency between research need and the provision of this information from dedicated research programmes is discussed in relation to four key factors: (1) inadequate public sector funding, (2) gaps in knowledge within the research community of the existence of a statutory conservation framework and associated research needs, (3) a poor perception of conservation-oriented research and internal organisational pressures, and (4) a lack of an integrated government approach resulting in conflicts between national biodiversity obligations and support for conservation-oriented research. The paper also suggests that the required research provides a wealth of new strategic opportunities for the research community, and discusses the need to embrace new research processes as part of this work.     

Photoinduced oxidation of the insecticide phenothrin on soil surfaces

Photodegradation profiles of the pyrethroid insecticide phenothrin on a moistened U.S. soil thin layer was investigated by using its predominant component, the 1R-trans-isomer (I), under continuous exposure to light at >290 nm from a xenon arc lamp. Its degradation was moderately accelerated by irradiation with half-lives of 5.7-5.9 days (dark control 21-24 days), mainly via successive oxidation of the 2-methylprop-1-enyl group and ester cleavage followed by mineralization to carbon dioxide. Spectroscopic and cochromatographic analyses showed that the major degradates were the alcohol and ketone derivatives of I formed via photoinduced oxidation of the 2-methylprop-1-enyl group by singlet oxygen. The photoinduced generation of singlet oxygen in/on the soil surface was confirmed by using chemical trapping reactions together with ESR spectroscopy.     

Helium/oxygen atmospheric pressure plasma treatment on poly(ethylene terephthalate) and poly(trimethylene terephthalate) knitted fabrics: Comparison of low-stress mechanical/surface chemical properties

Helium-oxygen plasma treatments were conducted to modify poly(trimethylene terephthalate)(PTT) and poly(ethylene terephthalate) (PET) warp knitted fabrics under atmospheric pressure. Lubricant and contamination removals by plasma etching effect were examined by weight loss (%) measurements and scanning electron microscopy (SEM) analysis. Surface oxidation by plasma treatments was revealed by x-ray photoelectron spectroscopy (XPS) analyses, resulting in formation of hydrophilic groups and moisture regain (%) enhancement. Low-stress mechanical properties (evaluated by Kawabata evaluation system) and bulk properties (air permeability and bust strength) were enhanced by plasma treatment. Increasing interfiber and interyarn frictions might play important roles in enhancing surface property changes by plasma etching effect, and then changing low-stress mechanical properties and bulk properties for both fabrics.