Enhanced photocatalytic oxidation of reactive dye using manganese catalyst complex

In this work, the treatment efficiency of advanced oxidation processes H2O2/UV enhanced by the addition of a manganese catalyst complex (MnTACN) was investigated on a model dye solution and a real dye-house effluent. The experimental results were evaluated in terms of absorbance (A) and total organic carbon (TOC) reduction. The major degradation products of the model dye solution were identified by high resolution gas chromatography/mass spectrometry analyses. In addition, the toxicity of the final reaction solution after H2O2/UV/MnTACN treatment to Vibrio fischeri bacteria was determined. The results showed that the addition of the H2O2/UV/MnTACN system at in different concentrations of the catalyst solution increased enhance the decolourization rate compared to H2O2/UV for both the model dye solution and real dye-house effluent.

The Essential Oils-bearing Plant Containing Eugenol in Vietnam

Aim and Objectives: Eugenol is widely used in the pharmaceutical and aromatic industries, so the task of surveying to find essential oils containing eugenol is very important. The purpose of this study is to investigate essential oil-bearing plants containing eugenol in Vietnam for pharmaceutical and aromatic industries. Materials and Methods: By the method of fresh sampling of essential oil plants, essential oils are extracted by steam distillation and then analyzed by high-resolution gas chromatography (HRGC) to identify eugenol sources. Results: We have found that a lot of plants containing high eugenol content mostly grow wild in forests such as Hiptis suaveolens Poit. containing 62-67% eugenol, Cinnamomum verum Prest: 75-80%, Camellia sasanqua Thumb.: 90-95% can be used to exploit essential oils and extract eugenol. We also pointed out that essential oil plants containing high eugenol as Cestrum nocturnum L.: 50-55%, Ocimum sanctum L.: 60-65%, Ocimum gratissimum L.: 65-75% can be cultivated to obtain eugenol for the pharmaceutical and aromatic industry. Conclusions: During the survey, we discovered and made a list of 10 plants as a source of essential oils containing eugenol in Vietnam. The rainy season in Vietnam is from June to September. During this season, the essential oil content in the fresh leaves is lower than in the dry season, therefore, the eugenol content in the essential oils is low. However, due to the strong-growth of plants in the rainy season, a lot of fresh leaves can be harvested, which mean there are more essential oils presented to be extracted.

Production of glycolipid biosurfactant during crude oil degradation by the novel indigenous isolated Achromobacter kerstersii LMG3441

This study aimed to find biosurfactant producing and crude oil-degrading bacteria able to decontaminate crude oil from wastewater. The bacteria that were isolated from contaminated sites in an oil refinery plant in Isfahan, Iran, were identified by 16S rDNA sequencing as Achromobacter kerstersii strain LMG3441, Klebsiella pneumonia strain SKBA6, and Klebsiella variicola strain SKV2. According to the results obtained from different tests for the production of biosurfactant among three strains, only Achromobacter kerstersii strain LMG3441 was selected for further study. The pattern of residual hydrocarbons was analyzed by high-resolution gas chromatography-mass spectrometry (GC-MS). This novel and indigenous strain was capable of producing the highest amount of a glycolipid biosurfactant (7.81 g/L) in MSM (mineral salt medium) with 1% (v/v) crude oil as the only source of carbon and energy. The compound showed high surface activation capacity with reduction of surface tension from 40 mN m–1 in the control to 23.3 mN m–1 by the bacterium. The results of GC-MS for assessment of residual hydrocarbons in the MSM and comparison with crude oil as a control showed that 53% of the hydrocarbons in the crude oil were consumed by this novel strain.

Environmental exposure to persistent organic pollutants measured in breast milk of lactating women from an urban area in central Poland

Mothers’ milk is considered a channel by means of which new-borns are exposed to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs), environmental pollutants entering food chain and accumulating in fat-rich tissues. In this study, the concentrations of selected PCDDs, PCDFs, and dl-PCBs (a total of 29 substances) in milk samples of 110 breast-feeding women from an urban area were analyzed using the high-resolution gas chromatography/high-resolution mass spectrometry method. Environmental exposure to these substances was expressed by means of the World Health Organization Toxicity Equivalent (WHO-TEQ2005) using the Toxicity Equivalent Factor values from van der Berg et al. (Toxicol. Sci. 93: 223-241, 2006). Concentrations and WHO-TEQ2005 values were then searched for plausible relationships with selected demographic and diet-related factors. The total WHO-TEQ2005 toxicity equivalent for all 29 substances was (mean ± SD) 10.57 ± 4.57 pg/g fat, while the WHO-TEQ2005 levels of PCDDs/PCDFs and dl-PCBs were 7.90 ± 4.17 pg/g fat and 2.67 ± 1.36 pg/g fat, respectively. The concentration and WHO-TEQ2005 toxicity equivalent of dl-PCBs correlated significantly with the mothers’ age (rP = 0.3814, p < 0.00005; rP = 0.2817, p < 0.005, respectively). The total WHO-TEQ2005 toxicity equivalent for all analyzed substances was found to be positively associated with the frequency of consumption of fish and dairy products (p < 0.05 for both associations). These outcomes must, however, be interpreted cautiously due to limited size of the study. The results of this paper may provide a basis for further studies on the exposure to PCDDs, PCDFs, and dl-PCBs, and mechanisms underlying their action.