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Response surface methodology and Plackett-Burman experiments were applied to optimize the biodegradation of carbofuran by using Enterobacter sp. stain BRC05 isolated from selected agricultural areas in peninsular Malaysia. The significant factors influencing the degradation of carbofuran were assessed using two-level Plackett–Burman Design (PBD) with five variables. Plakett Burman experiment showed that the following four variables were significant for carbofuran degradation including, carbofuran concentration, temperature, pH and nitrogen sources. Significant variables obtained in Plackett-Burman Design were further optimize using Central Composite Design (CCD). The outcome of the design for carbofuran degradation for each runs of the PBD experiment base on the design matrix, showed that the minimum and the maximum carbofuran degradation percentage were found to be 6.7% and 79.77% as presented in runs 4 and 1, respectively. Results obtained using Central Composite Design showed that the relations between the factors affect carbofuran degradation with significant response. The predicted results in CCD indicated that highest carbofuran degradation of 95.40% could be realized with carbofuran concentration of 92.50 mg/L, pH of 6.0, temperature 27.50 °C, nitrogen sources of 0.45 g/L and reaction period of 6 days. The predicted values were in agreement with the actual values with coefficient of determination with R2 0.9719. Partial 16S rRNA sequence analysis showed that the carbofuran degrading isolate was closely related to members of the genera Enterobacter sp. The morphological and biochemical characteristics of the isolate also confirmed the phylogenetic signature. This study would provide an effective approach that could be beneficial for the bioremediation of carbofuran insecticide in polluted environment. [ABSTRACT FROM AUTHOR]

Industrial effluent limitations should be established regarding the special characteristics of each sector with emphasis given to the local context, whereas, in Iran, a uniform “Wastewater Effluent Standard” is employed throughout the country in which no specific industrial effluent limitations have been considered. This gap highlights the essential need for a transparent and scientifically proven methodology for determining effluent emission limit values (ELVs) at the sector level. In this research, an integrated approach is proposed based on the application of the Best Practicable Control Technology Currently Available (BPT) concept. The modelling framework includes a series of sequential steps comprising two main sections: 1. identifying the effluent emission datasets, and 2. computing the emission levels associated with the BPT (BPT-AELs). To identify the datasets, the methodology follows two different procedures: 1. a detailed analysis of the environmental performance of this sector in the country to determine the plants reflecting BPT, and 2. screening their emission datasets through statistical analysis. The Best Available Techniques (BAT) principle is employed as a reference element for determining the best representative plants, and the results indicate that corrective measures in accordance with the BAT considerations should be implemented in many of the plants under consideration. The comparison of the derived BPT-AELs with the existing standards show that they are mainly lower than the standard levels and are reasonable estimations for the involved parameters. Conclusively, this methodology presents a reliable and practical stepwise process at the sector level, which can be developed for other industries. [ABSTRACT FROM AUTHOR]

In this study, we isolated two indigenous hydrocarbon-degrading bacteria from tarball found in Rhu Sepuluh beach, Terengganu, Malaysia. These bacteria were identified based on their physiological characteristic and 16S rRNA gene sequence analysis, and they showed 99% similarity with Cellulosimicrobium cellulans DSM 43879 and Acinetobacter baumannii ATCC 19606 respectively. Their hydrocarbon-degrading capabilities were tested using diesel-oil as sole carbon source. Results analysed using GC–MS, showed diesel-oil alkanes were degraded an average 64.4% by C. cellulans and 58.1% by A. baumannii with medium optical density reaching 0.967 ( C. cellulans ) and 1.515 ( A. baumannii ) in minimal salt media at 32 °C for 10 days. Individual diesel-oil alkanes were degraded between 10%–95.4% by C. cellulans and 0.2%–95.9% by A. baumannii . Both strains utilized diesel-oil for growth. The study suggests both strains are part of indigenous hydrocarbon-degrading bacteria in tarball with potential for bioremediation of oil-polluted marine environment. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs) were used as anthropogenicmarkers of organic chemical pollution of sediments in the Selangor River, Peninsular Malaysia. This study was conducted on sediment samples from the beginning of the estuary to the upstream river during dry and rainy seasons. The concentrations of .PAHs and .LABs ranged from203 to 964 and from23 to 113 ng g-1 dry weight (dw), respectively. In particular, the Selangor River was found to have higher sedimentary levels of PAHs and LABs during the wet season than in the dry season,whichwas primarily associatedwith the intensity of domesticwastewater discharge and high amounts of urban runoffwashing the pollutants from the surrounding area. The concentrations of the toxic contaminantswere determined according to the Sediment Quality Guidelines (SQGs). The PAH levels in the Selangor River did not exceed the SQGs, for example, the effects range low(ERL) value, indicating that they cannot exert adverse biological effects. [ABSTRACT FROM AUTHOR]

Different mixture ratio of household organic waste (HOW) and cow manure (CM) were investigated for biogas production. The objective was to explore possible significant synergistic effect obtained from the combination of these different substrates in Reactor 1 – 4 (R 1 – 4 ) batch experiment. The highest methane yield, 247 mL/g VS was obtained from R 3 and 243 mL/g VS in R 4 . Co-digestion in R 4 increased to 9% for CM and 78% for HOW in methane production. The results clearly demonstrate synergistic effect from nutrient balanced that improves the stability of anaerobic process. [ABSTRACT FROM AUTHOR]

Treatment of acid mine drainage (AMD) has been tested in batch experiments to evaluate the efficiency of both single and mixed substrates for mine-impacted waters. Synthetic mine water was used in all experiments. The single treatment was performed using limestone (LS), activated sludge (AS), and spent mushroom compost (SMC). In addition, different ratios of treatment media combined as mixed substrates were also tested for AMD in an anoxic condition. Physico-chemical parameters and heavy metals (Mn, Fe, Cu, Pb, Zn) were analyzed throughout 120 h. Hence, SMC showed great contribution in the process of AMD treatment in this study. The results showed that the mixed substrates were effective in removing heavy metals and sulfate i.e. uncrushed limestone mixed with AS, SMC and woodchips at 12 hours contact time with 88.15% of removal efficiency. [ABSTRACT FROM AUTHOR]

Heavy metals tolerant bacteria were isolated from electroplating industry. The activities of electroplating and metal processing industries are regarded as one of the major source of heavy metal pollution. This paper present about the role of microorganisms in heavy metal removal from industrial waste water. In this study 21 bacterial colonies were isolated and tested in the presence of different metals. After screening five best isolates which showed high resistances were selected. The result reveals that all isolates MH1, MH4, MH6 MH15 and MH21 were able to tolerate 50 mg/l of cr, cu, pb and cd. Isolates MH1 and MH21 tolerate 200 mg/l of cadmium while isolate MH4 also showed high degree of resistance to copper. These indicated that the isolates can be used efficiently in removal of heavy metals in contaminated industrial effluents. [ABSTRACT FROM AUTHOR]

Objective To examine whether earthworms of Eisenia fetida, Lumbricus rubellus and Eudrilus eugeniae extracts have elastase, tyrosinase and matrix metalloproteinase-1 (MMP-1) inhibitory activity. Methods The earthworms extract was screened for elastase, tyrosinase and MMP-1 inhibitory activity and compared with the positive controls. It was also evaluated for whitening and anti-wrinkle capacity. Results The extract showed significantly ( P <0.05) good elastase and tyrosinase inhibition and excellent MMP-1 inhibition compared to N-Isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid. Conclusions Earthworms extract showed effective inhibition of tyrosinase, elastase and MMP-1 activities. Therefore, this experiment further rationalizes the traditional use of this worm extracts which may be useful as an anti-wrinkle agent. [ABSTRACT FROM AUTHOR]