Measuring the antioxidant activity of olive oil mill wastewater using chemiluminescence

A sensitive and simple procedure is described for determining the total phenolic/antioxidant levels of olive oil mill wastewater (OMW), using for the first time Co(II)/ethylenediaminetetracetic acid (EDTA)-induced luminol chemiluminescence. Olive oil wastewater samples were tested for their composition in simple phenolic compounds as a function of the extraction system (two- and three-phase centrifugation systems). The results revealed that the three-phase system had a stronger antioxidant activity and a higher total phenolic content than the two-phase system. The relationship between antioxidant values and total phenolic content is also discussed.     

Integral assessment of climate impact on the transboundary Mesta River flow formation in Bulgaria

The present work considers the section of the Mesta River on Bulgarian territory using the integral method for evaluation of climate and anthropogenic impact on the river flow. The level of this impact is determined by the index K _i (flow module), the coefficient C _i for the deviation of the average annual water volume Q _i from the flow norm Q _o and the index h _i for the deviation of the average annual rainfall volume H _i from the average multi-annual rainfall volume H _o . The dynamics of the average annual flow Q _i at two typical hydrometric stations – Yakoruda and Khadzhidimovo, as well as the dynamics of the average annual rainfall for the Yakoruda station was examined for the period 1955–2003. The data for the considered period 1955–2003 exhibit a decreasing trend of the average annual water volumes dynamics for both stations due to the impact of climate changes in the Mesta River catchment.     

Sonochemical reduction of the antioxidant activity of olive mill wastewater

The use of ultrasonic irradiation to reduce the antioxidant activity of olive oil mill wastewaters (OMWs) originating from two-phase and three-phase decanters was examined. Sonication of diluted OMW samples was conducted at ultrasonic frequencies of 24 and 80 kHz, an applied power varying between 75 and 150 W, and liquid bulk temperatures varying between 25 and 60 degrees C. At the conditions in question, the reduction in antioxidant activity was found to increase with decreasing temperature and increasing power and frequency. Addition of NaCl in the samples also appeared to enhance reduction. Antioxidant activity of OMW samples was assessed using the recently developed Co(II)/ethylenediaminetetraacetic acid (EDTA)-induced luminol chemiluminescence analytical protocol, while the total phenolic load was measured according to the Folin-Ciocalteu method.     

The environment and Britain's aid programme

Summary Some of the environmental and developmental activities assisted by Britain's Programme of Overseas Aid are outlined. In particular, the article draws attention to a new booklet published by the Overseas Development Administration to mark the European Year of the Environment which, in the Minister's words, shows how through British aid, programme improvements are possible by a combination of sound scientific research and a sensitivity to people's needs.Mr Christopher Patten, Member of Parliament for Bath, is the UK's current Minister for Overseas Development. He also serves as Minister of State for Foreign and Commonwealth Affairs. The Minister may be contacted through the offices of the Overseas Development Administration, Eland House, Stag Place, London SW1E 5DH, UK.     

Adsorption and desorption of Cu at high equilibrium concentrations by soil and clay samples from Bulgaria

Studies were carried out on the adsorption and desorption of added copper (from 100 to 600 microg g(-1)) to whole soils with contrasting properties: a Podzol (Godech A and Godech B) and a Chernozem (Gramada). Adsorption resulted in high Cu concentrations for the Podzol. The adsorbed copper, especially that in the B-horizon, is also potentially mobile, as judged by its ease of desorption on treatment with 0.01 m CaCl(2). A higher proportion of the added adsorbed copper is retained in Godech A soil (4% clay), than in Godech B soil (41% clay). Clay minerals are the principal adsorbent in the Podzol (Godech B), because of the high desorption observed at a low site coverage (7% CEC). The Godech B clay fraction (<0.001 mm) simulates the behaviour of the whole soil. The clay fraction from the Chernozem (Gramada) shows contrasting behaviour, as compared to the whole soil. Copper in the Chernozem is specifically (non-exchangeably) adsorbed, even at pH 2.7. A Langmuir model is appropriate for describing Cu-adsorption for the systems investigated at the acid pH values.