Reuse of spent bleaching earth by polymerisation of residual organics

Spent bleaching earth (SBE) is a waste generated by the edible oil industry that currently has limited options for beneficial reuse. In excess of ～2 million tonnes per year of SBE is generated world-wide with major quantities available in the middle-east where significant volumes of edible oils are produced. Low pressure compaction followed by heat treatment at 150 °C causes polymerisation of the residual organic components in SBE and this produces monolithic samples with high unconfined compressive strengths (54 MPa). SBE can therefore be used to manufacture novel clay blocks for use in construction that are bonded by polymerised vegetable oil. This represents a new, innovative and resource efficient application for SBE. In this research, commercial SBE has been characterised and the effects of key processing variables (temperature and compaction pressure) on the compressive strength, porosity and density of the SBE clay blocks are reported and the mechanisms responsible for strength development are discussed.     

Study of aflatoxin B1 as a risk factor that impairs the reproductive performance in females – Egypt

Infertility among couples in Egypt is causing increasing concern. Investigations showed a relationship between ovulatory disorders and the incidence of female factor-mediated fertility difficulties in couples. However, the factors responsible for the sudden increase in ovulatory disorders are not fully understood. The aim of this study was to assess the presence of aflatoxin in sera of infertile women and to correlate this with ovarian functions and hormonal parameters. Blood samples were collected from 70 adult Egyptian females comprising 50 infertile and 20 fertile control individuals, and screened for the presence of aflatoxin B₁ (AFB₁). Ovarian function was examined by measuring mean ovarian volume, and the umber and size of ovarian follicles. Blood hormonal levels were determined. All blood samples (patients and controls) showed negative results as regards AFB₁ analysis. However, there was a significant enlargement in the mean ovarian volume but a significant decrease in follicular size. In addition, there were significant higher levels of lutinizing hormone (LH) and significant lower levels of mid-luteal progesterone in infertile females. Although blood samples were negative with respect to AFB₁, the role of aflatoxin cannot be excluded as a contributing factor to female infertility, since the toxin was found to produce deleterious effects on the reproductive system in animals. More studies including aflatoxin analysis in ovarian biopsies are recommended to ascertain involvement of this toxin.     

Study on the sensitivity to cadmium of marine fish Salaria basilisca（Pisces： Blennidae）

The present study tested the sensitivity of Salaria basilisca to water-cadmium (Cd) contamination. For this purpose, liver somatic index (LSI), Cd concentrations and the activities of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured in the liver of S. basilisca exposed to Cd-contaminated water (2 mg Cd/L as CdCl2) for 14 and 28 d. The results showed that the LSI decreased significantly after 14 and 28 d of Cd-exposure. Cd bioaccumulation in the liver resulted in an increasing uptake up to 42 g/g dry weight after 28 d of exposure. Activities of CAT and SOD were significantly increased with increasing exposure time. A significant increase in GSH-Px activity, under Cd influence, was observed during 14-day exposure period (p < 0.0001). However, a significant decrease (p < 0.05) in this activity with respect to control fish was registered after 28 d of Cd-exposure. These results showed that Cd accumulation in the liver of S. basilisca could induce oxidative stress as demonstrated by changes in the antioxidant enzyme activities. Results also emphasized that S. basilisca may considered as a sensitive species to Cd exposure.     

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca,Zosterisessor ophiocephalus and Solea vulgaris collected from the Guff of Gabes in Tunisia

To select a marine teleost fish which can be used as a bioindicator of cadmium (Cd) pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination: the industrialized coast of Sfax (S1), the coast of Douar Chart (S2) and the coast of Luza ($3). The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher (p<0.0001) than those from S2 and $3. For each species, Cd concentrations, in both liver and gill, showed the decreasing order: S1>S2>S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors (BAF) greater than 1 in all studied sites. In S1 and S2, BAF values respect the following order: S. basilisca>Z. ophiocephalus>S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccamulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gahes.     

Adsorption of 60Co and 154+152Eu Using Graft Copolymer of Starch-Polyacrylic Acid-Polyvinylsulfonic Acid

Journal of Polymers and the Environment - Starch-polyacrylic acid-polyvinylsulfonic acid (St-g-PAA-PVSA) graft copoymer was synthesized by gamma radiation as an initiator. The chemical structure,...     

Novel Composite Films Based on Acrylic Fibers Waste/Nano-chitosan for Congo Red Adsorption

Journal of Polymers and the Environment - The current research aimed to use waste to treat waste; to recycling of acrylic fibers waste combined with nano-chitosan for use as an adsorbent to remove...