Electrochemical profiles of bacteria isolated from crude oil on simple benzene compounds detection

Five polyaromatic hydrocarbons (PAHs) degrading bacterial species had been isolated from crude oil samples. All bacteria were positive Gram-stained, except one; and had positive results on the catalase test. After sequencing bacterial DNA, three bacterial genera were obtained with 99-100% certainty, namely: Pseudomonas sp., Staphylococcus sp., and Bacillus sp. All bacteria were known strongly to form a biofilm, thus can be applied for biosensing and/or bioremediation techniques. Using minimal mineral media growth assay as media culture, all bacteria were able to degrade naphthalene and anthracene, Staphylococcus sp. shown the strong degradation affinity. Meanwhile, Bacillus sp. tended to form strong biofilm. Electrochemical data were obtained with the cyclic voltammetry method, with a scan rate of 100 mV/s. Voltammogram profiles of all bacteria against simple benzene compounds (benzene, toluene, and xylene; concentration for each compound 1μL/mL) showed irreversible oxidation peaks at 0.20-0.40 V ppm of the analyte, producing current 50-100 μA. The measurements were taken when the solution was more stable (±10 seconds) after vigorous shaking to homogenize benzene compounds and introducing O2 into the solution. The peaks were decreasing over the next cycles, indicating the lower bioavailability of benzene compounds to be degraded with O2.

CHANGES IN ONTOGENETIC PARAMETERS IN DAPHNIA MAGNA INFLUENCED BY SOLUTIONS OF BENZENE COMPOUNDS

The article presents the research results of biological parameters of Daphnia magna development at the critical stages of ontogenesis influenced by the aqueous solutions of ecotoxicants: nitrobenzene and trichlorobenzene. The periods of reproduction and development in Daphnia magna are stated to be decisive, among other parameters (physiological, biochemical). In fact, the entire period of embryogenesis in Daphnia is quite vulnerable, compared to the further stages of development. Under the action of solutions of ecotoxicants taken for the research Daphnias have a decreased fertility and a delayed oogenesis. The next stage of sensitivity is the number of cast carapaces. The least sensitive parameter is the survival rate of adults. Increasing the remote toxic effect in three generations of Daphnias was not detected in the course of research. The Daphnia magna test object showed high sensitivity to nitrobenzene and trichlorobenzene acting as water environment pollutants in all the experiments. For the main ontogenetic parameters in the assessment of water quality it is preferable to take fecundity and violation of development processes at the pre-natal stages of Daphnia magna. According to the survival parameter, the maximum permissible concentration of the studied benzene compounds was 0.01 mg/l, which was determined by the most sensitive parameters and critical stages of ontogenesis

Synthetic Organic Compounds From Paper Industry Wastes: Integrated Biotechnological Interventions

Synthetic organic compounds (SOCs) are reported as xenobiotics compounds contaminating the environment from various sources including waste from the pulp and paper industries: Since the demand and production of paper is growing increasingly, the release of paper and pulp industrial waste consisting of SOCs is also increasing the SOCs’ pollution in natural reservoirs to create environmental pollution. In pulp and paper industries, the SOCs viz. phenol compounds, furans, dioxins, benzene compounds etc. are produced during bleaching phase of pulp treatment and they are principal components of industrial discharge. This review gives an overview of various biotechnological interventions for paper mill waste effluent management and elimination strategies. Further, the review also gives the insight overview of various ways to restrict SOCs release in natural reservoirs, its limitations and integrated approaches for SOCs bioremediation using engineered microbial approaches. Furthermore, it gives a brief overview of the sustainable remediation of SOCs via genetically modified biological agents, including bioengineering system innovation at industry level before waste discharge.

Optical Studies of Binary Mixture of Chloro Substituted Benzene and n-Hexane or Cyclohexane or 1,4-Dioxane

Thermophysical properties of binary liquid mixtures are highly beneficial for getting information about the intermolecular interactions and geometrical effects in the system. The chloro-substituted benzene compounds like 2-chlorotoluene, 4-chlorotoluene, 1,3-dichlorobenzene also have wide range of industrial and biomedical areas. In present work, the refractive indices (n) of haloarenes, hydrocarbons, ether, and respective possible binary mixtures were experimentally determined over the entire compositions at T= (298.15-318.15) K. The mixtures selected were 2-chlorotoluene or 4-chlorotoluene or 1,3-dichlorobenzene (1) + n-hexane or cyclohexane or 1,4-dioxane (2) with its possible combinations. The Δn is positive for all binary mixtures at all investigated compositions. Different rules of mixing like Lorentz-Lorentz, Erying-John, Arago-Biot, etc. were also used to predict n values. The Δn values were also analyzed in terms of ongoing intermolecular interactions among the components of the selected system.

COMPARATIVE STUDY OF THE EFFECT OF GAMMA-RADIATION ON THE STRUCTURAL AND THERMOPHYSICAL PROPERTIES OF NITRILE-BUTADIENE RUBBER FILLED WITH DIFFERENT NANOMETAL OXIDES

In the present work, the structure and thermal properties of nanocomposites based on nanometal oxides (ZnO, Al2O3, ZrO2) and aromatic disulphochloride benzene compounds in a butadiene nitrile rubber (NBR) matrix that are obtained by gamma-rays processing have been investigated. Structural changes of nanocomposites depend on the type of used nanoparticles which have been identified by Fourier Transform Infrared (FTIR) spectroscopy and Electron Paramagnetic Resonance (EPR). Analysis by Scanning Electron Microscope (SEM) was used to study the morphology phase of the nanoparticles in the polymer matrix and the interface between the polymer-filler. In addition, the results of the samples based on NBR were obtained by thermogravimetric analysis (TGA)/differential thermal analysis (DTA). The results show that, the thermal stability of nanocomposites significantly decreased after irradiation, but with the addition of a certain amount of benzene-1,3-disulfonyl chloride (DSChB) and nanometal oxides to rubber blend the thermal stability could be improved.