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Developing countries consist of nearly 80% of the total world population where urea fertilizer is extensively used. Fertilizer is applied mainly in the regions where environmental conditions are suitable for plant growth and irrigation is available. It plays a crucial role in the economy and food production of a developing country like Bangladesh, where around half of the total agricultural production is solely dependent on urea fertilizer. Bangladesh government has seven urea fertilizer industries with a capacity of 3.37 million metric tons per year. Their production is currently not up to the mark due to facing some difficulties that are very common for any developing country. This article studied the current scenario of Bangladesh fertilizer sector, production parameters and major challenges with recommendations accordingly. The study revealed that the natural gas crisis is one of the significant problems. Frequent cutting off supply restricted the average yearly stream days of individual industry to 152 days only. Around 3.56% of urea consumption increased per unit of arable lands in 10 years due to the reduction of soil fertility. At present, Bangladesh needs to be self-reliant in the fertilizer sector to retain food autarky and economic growth. Some valuable recommendations to attain this goal have been discussed further that can help Bangladesh as well as most of the developing countries.

Water-soluble dyes are common persistent organic pollutants present in textile wastewater, which are associated with environmental pollution and health hazards. The conventional effluent treatment methods are not efficient to remove these dyes from textile wastewater. Heat activated persulfate based wastewater treatment is a promising advanced oxidation process (AOP) for the treatment of textile wastewater. Therefore, the main objective of the present work was to study the degradation of Sudan Black B (SBB) dye in aqueous solution by varying activation temperature (40–60 °C), KPS dosage (250–750 ppm), and initial dye concentration (20–50 ppm). The dye degradation was found in a range of 35%−100% for varied experimental conditions. Removal percentages were improved by the increase of temperature, time, and persulfate concentration but decreased with the increase of initial dye concentration. The kinetic study indicated that the degradation of SBB dye using KPS followed first order model with rate constants varied in a range of 0.15 × 10-2 − 40.5 × 10-2 min-1. Standard reaction enthalpies (ΔH˚), standard Gibbs free energies (ΔG˚), activation energies (Ea), standard entropies (ΔS˚) were found in a range of 190 − 505 kJ.mole-1, -33.0 − 0.6 kJ, 73 − 222 kJ.mole-1, 0.6–1.6 kJ/K for different sets of experimental conditions, respectively. Degradation reactions of SBB dye were endothermic (ΔH˚ +ve); non-spontaneous (ΔG˚ +ve) at 40 °C, but spontaneous (ΔG˚ −ve) at other temperatures (50 °C and 60 °C). Therefore, it can be predicted that heat-activated persulfate is an efficient method to achieve faster degradation of dye in the treatment of industrial wastewaters containing SBB dye.

Water pollution from textile industries is a great concern in developing countries. To address the textile wastewater treatment, this study investigated the removal of chemical oxygen demand (COD), color, dye, and turbidity from synthetic textile wastewater containing remazol black B (RBB) dye under electro-coagulation (EC) and electro-Fenton (EF) processes by using an electrochemical cell comprising two stainless steel electrodes. The impacts of the addition of Fe2+ concentration, H2O2 concentration and their dual effect on the process performances and operating costs of the processes were also assessed. Over 76 %, 94 %, 95 % and 95 % of COD, color, dye, and turbidity removals were observed, respectively, from the EF process after 50 min of treatment. The EC process was efficient to degrade dye (86.5 %) and to remove color (91 %), however, the process was not effective to remove turbidity (60.4 %) and to mineralize the dye (19.8 %). About 4 times higher dye mineralization was observed in the EF process as compared to the EC process. The kinetics analysis demonstrated that the degradation process of RBB dye followed first order kinetic model and the value of reaction rate constant was 1.5 times higher in the EF treatment process than achieved in the EC treatment process. The analysis of operating costs suggested that the EF processes had about 3 times lower operating costs than the operating cost evaluated for the EC process. Therefore, the outcome of this study revealed that the EF process can be a good option for the treatment of textile wastewater for the sustainable development of textile industries.