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A consortium of bacteria capable of decomposing oily hydrocarbons was isolated from tarballs on the beaches of Terengganu, Malaysia, and classified as Pseudomonas stutzeri, Cellulosimicrobium cellulans, Acinetobacter baumannii and Pseudomonas balearica. The Taguchi design was used to optimize the biodegradation of diesel using these bacteria as a consortium. The highest biodegradation of diesel-oil in the experimental tests was 93.6%, and the individual n-alkanes decomposed 87.6—97.6% over 30 days. Optimal settings were inoculum size of 2.5 mL (1.248 OD600nm); 12% (v/v) the initial diesel-oil in a minimal salt medium of pH 7.0, 30.0 gL−1 NaCl and 2.0 gL−1 NH4NO3 concentration, incubated at 42 °C temperature and 150 rpm agitation speed. Parameters significantly improved diesel-oil removal by consortium as shown by the model determination coefficient (R2 = 90.89%; P < 0.001) with a synergistic effect of agitation speed significantly contributing 81.03%. Taguchi design determined the optimal settings for the parameters under study, which significantly improved diesel-oil removal by consortium. This can be used to design a novel bioremediation strategy that can achieve optimal decontamination of oil pollution in a shorter time. Highlights: Hydrocarbon-degraders in Tarball were isolated and identified by their 16S rRNA gene sequence as Pseudomonas stutzeri, Cellulosimicrobium cellulans, Acinetobacter baumanniiand Pseudomonas balearica. Taguchi method was applied to optimize effects of parameters such as initial diesel concentration, salinity (NaCl concentration), nitrate (NH4NO3) concentration, pH, temperature, agitation speed and inoculum size on diesel-oil removal in 30 days. Maximum diesel-oil biodegradation by experimental runs was 93.6% with individual n-alkanes degraded between 87.6% – 97.6% in 30 days Optimal settings were 2.5 mL (1.248 OD600nm) inoculum size; 12% (v/v) initial diesel-oil in MSM media with 7.0 pH, 30.0 gL−1 NaCl and 2.0 gL−1 NH4NO3 concentration, incubated at 42 °C temperature and 150 rpm agitation speed Parameters significantly improved diesel-oil removal by this consortium as indicated by model determination coefficient (R2 = 90.89%; P < 0.001) with synergistic effect of agitation speed significantly contributing 81.03% Taguchi design established optimal settings of investigated parameters that produced significant improvement on diesel-oil removal by consortium [ABSTRACT FROM AUTHOR]

Background: Environmental policies should be developed in a contextual decision-making process regarding local environmental concerns emphasizing the economic, technical, social and institutional considerations. Establishing emission limit levels, especially in the industrial sector, is one of the most problematic environmental issues in developing countries, for which it is essential to include several criteria that reflect their country-specific constraints and capacities. Since Best Available Technology (BAT) is acknowledged to be the reference element for sustainable development and a basis for Emissions Limit Values (ELVs), the objective of this study is to present a reliable methodology for establishing ELVs thresholds with an emphasis on the BAT concept for national regulation at the sector level. Methods: A hybrid fuzzy multiple-criteria decision-making (FMCDM) process, consisting of the Analytic Hierarchy Process (AHP) and fuzzy Technique for Order of Preference by Similarity to Ideal Solution (fuzzy TOPSIS) method, is structured to aggregate the different criteria and rank different ELV alternatives in this complicated evaluation. In order to use the most profound knowledge and judgment of a professional expert team, this qualitative assessment highlights the importance of supportive information. Results: The results obtained indicate that experts have considered the country-specific information as a reliable reference in their decisions. Among different key evaluation criteria in effluent standard setting, the highest experts' priority is "Environmental protection". For both the conventional and toxic pollutants, the influence of all other criteria namely "Economic feasibility", "Technology viability" and "Institutional capacity", as constraining criteria in developing countries, have not reduced the responsibility towards the environmental objectives. In ELVs ranking, experts have made their decisions with respect to the specific characteristics of each pollutant and the existing capacities and constraints of the country, without emphasizing on any specific reference. Conclusions: This systematic and transparent approach has resulted in defensible country-specific ELVs for the Iron and Steel industry, which can be developed for other sectors. As the main conclusion, this paper demonstrates that FMCDM is a robust tool for this comprehensive assessment especially regarding the data availability limitations in developing countries. [ABSTRACT FROM AUTHOR]