Detoxification of olive mill wastewaters by zinc–aluminium layered double hydroxides

Disposal of olive mill waste waters (OMWW) represents a serious problem due to its elevated toxicity and pollution risk for environmental and aquatic bodies, which is mainly related to its polyphenol content. The use of layered double hydroxides (LDHs) or anionic clays for OMWW detoxification may represent an effective remediation process. In the current study, OMWW was treated with cold methanol to obtain a dark humic acid-like precipitate made of high molecular weight organic compounds named polymerin and a supernatant made of low molecular weight organics named OMWW-S. After precipitation with methanol, phenol content decreased from 2.14 g L^?1 to 0.80 and 1.20 g L^?1, in polymerin and OMWW-S, respectively. The chemical oxygen demand of OMWW-S decreased by about 30% with respect to raw OMWW, from 62.2 to 40.2 g L^?1. A phenolic concentrate, named OMWW-E was also obtained by ethyl acetate extraction of OMWW-S at pH 2.0. LDHs of zinc and aluminium (LDH) were obtained at room temperature and after calcination at 450 °C (LDH-450). An organo-mineral complex of LDH with polymerin (LDH-Pol) was also synthesised. Phenols from OMWW-E were sorbed preferentially on three matrices according to the following order: LDH-450 > LDH > LDH-Pol, with percent sorption of up to 73% for LDH-450. Repeated cycles of sorption of OMWW-S onto LDH-450 decreased phenol concentration by about 90%. Use of remediated water in a phytotoxicity bioassay revealed scant inhibition of germination and coleoptile elongation rate in tomato seeds and seedlings. Thus, OMWW-S after sorption onto LDH-450 could represent a low cost source of irrigation water for arid soil of the Mediterranean region.     

Structural and electrical investigation of BLT films deposited at different times using electron beam evaporation technique

Thin films Bi4Ti3O12 (BLT) were deposited using electron beam evaporation on silicon substrate at several times, also on AlN/Si and SiO2/Si substrates. Thin films morphology and thickness were measured via scanning electron microscopy (SEM). The crystallography was studied using X-ray diffraction (XRD) technique for films which have a (0010) preferred orientation in all substrate types. The capacitance values were contingent on frequency value in C-V measurement. The ferroelectric characterization was investigated for BLT film deposited on isolator layer (SiO2 or AlN) for Al/Bi4Ti3O12/SiO2/Si devices. Memory effect value varied from 1 V to 3 V depending on the thin films isolator on substrate.     

Potent antioxidant biophenols from olive mill waste

Olive mill waste (OMW) is rich in biophenols that can be extracted and applied as natural antioxidants for the food and pharmaceutical industries. Bioactivity-guided fractionation combines the use of bioassay and chromatographic separation for isolation of potent bioactive compounds from highly complex plant extracts, such as OMW, and avoids tedious purification and identification of inactive phytochemicals. Antioxidant activity-guided fractionation and sub-fractionation of Correggiola variety OMW extract, using semi-preparative HPLC and multidimensional antioxidant screening, followed by isolation of the screening hits are described. Activity-guided fractionation using four different bioscreens revealed verbascoside and 3,4-dihydroxyphenylethyl alcohol–deacetoxyelenolic acid dialdehyde (3,4-DHPEA–DEDA) as the most potent antioxidants in Correggiola OMW extracts.     

Fraudulent and malicious sites on the web

Fraudulent and malicious web sites pose a significant threat to desktop security, integrity, and privacy. This paper examines the threat from different perspectives. We harvested URLs linking to web sites from different sources and corpora, and conducted a study to examine these URLs in-depth. For each URL, we extract its domain name, determine its frequency, IP address and geographic location, and check if the web site is accessible. Using 3 search engines (Google, Yahoo!, and Windows Live), we check if the domain name appears in the search results; and using McAfee SiteAdvisor, we determine the domain name’s safety rating. Our study shows that users can encounter URLs pointing to fraudulent and malicious web sites not only in spam and phishing messages but in legitimate email messages and the top search results returned by search engines. To provide better countermeasures against these threats, we present a proxy-based approach to dynamically block access to fraudulent and malicious web sites based on the safety ratings set by McAfee SiteAdvisor.