Sustainable Production Environment Research Articles

Reinforcement Learning-Based Optimization for Sustainable and Lean Production within the Context of Industry 4.0

The manufacturing industry often faces challenges related to customer satisfaction, system degradation, product sustainability, inventory, and operation management. If not addressed, these challenges can be substantially harmful and costly for the sustainability of manufacturing plants. Paradigms, e.g., Industry 4.0 and smart manufacturing, provide effective and innovative solutions, aiming at managing manufacturing operations, and controlling the quality of completed goods offered to the customers. Aiming at that end, this paper endeavors to mitigate the described challenges in a multi-stage degrading manufacturing/remanufacturing system through the implementation of an intelligent machine learning-based decision-making mechanism. To carry out decision-making, reinforcement learning is coupled with lean green manufacturing. The scope of this implementation is the creation of a smart lean and sustainable production environment that has a minimal environmental impact. Considering the latter, this effort is made to reduce material consumption and extend the lifecycle of manufactured products using pull production, predictive maintenance, and circular economy strategies. To validate this, a well-defined experimental analysis meticulously investigates the behavior and performance of the proposed mechanism. Results obtained by this analysis support the presented reinforcement learning/ad hoc control mechanism’s capability and competence achieving both high system sustainability and enhanced material reuse.

EFFECTS OF WATER STRESS AND QUALITY ON RESIDUAL SOIL MACRONUTRIENTS AND ROOT-ZONE SALINITY FOR TOMATO PRODUCTION IN A PROTECTED CROPPING ENVIRONMENT

Improvement of water productivity from irrigated tomatoes while maintaining yield and soil health is a global challenge. This study aimed to examine the effect of varying water quality and water stress (deficit irrigation) scenario on different soil parameters of tomatoes in a greenhouse setting to establish an optimum soil-water-plant environment for sustainable production. The study was completed by simulating tomato growing conditions in the Northern Adelaide Plains of South Australia in two consecutive years (2017-2018 and 2018-2019). Three water sources selected as varying water quality were: groundwater, recycled wastewater and mixed of both. Water was applied via drip irrigation system in four irrigation scenarios maintaining irrigation frequency of two days. The results showed that irrigation with recycled wastewater had the highest residual nutrients accumulated in soil after completion of a crop growth season. The study also indicated that the residual soil macronutrients in the 80% FC treatment were not significantly different to that of the 100% FC regardless of water quality. The results thus suggested that a considerable amount of water and fertilizer can be saved through application of DI technique - especially at 80% FC level without having a significant difference of soil macronutrient compared to full irrigation. This study also found that salt accumulation in the effective root-zone was affected by both water quality and irrigation scenarios and was highest in the case of recycled wastewater.

Crop Rotation: A Sustainable Practice for the Management of Diseases

The management and environmental impacts influence agricultural production, diseases, in turn, can interfere and cause damage to the crop at different times and parts of the plant, due to economic loss, it is necessary to use disease control methods. To maintain sustainable agricultural production, disease management is necessary. Many methods are adopted in agriculture during its development, and led to the implementation of various production systems, including the no-till system, which helped boost production. However, no-tillage was found to have several soil conservation problems, making it necessary to adopt another practice in this system, which is crop rotation, which emerged as a sustainable means of soil conservation, bringing several benefits. Crop rotation is the planned and orderly alternation of different crops in a given period of time and in the same area, making the development and survival of pests and pathogens that affect crops difficult. Along with sustainable disease management using biological control and methods plant-based, allowed for better disease management in agriculture and provided a more sustainable production environment. Crop rotation is important in disease control because it can be a preventive practice to provide diversity to the system through breakage cycles. The control of these diseases can be done through the biological control of pests and plant extracts.

Cultural Control: A Sustainable Method of Pest and Disease Control

Agriculture is composed of many factors that alter its production, are of an environmental and management nature, and in terms of management, pests and diseases are of great importance, as they cause a lot of damage to the crop, at different times, and the control of these is essential. pests and diseases to ensure that the plant can reach its production potential. With the concern for a more sustainable production, agriculture has diversified through transformations in the technological and information scopes, which helped to increase the production of production systems. However, only biological and plant-based controls did not guarantee such a large control of pests and diseases, and to complement the control, and to reduce the use of chemicals in agriculture, cultural control was used. This cultural control, together with its sustainable management of pests and diseases, using biological control methods and the base of plant origin, brought new forms of pest and disease control, helping in management, and providing a more sustainable production environment. In addition to these benefits, cultural control is of great importance in the control of pests and diseases, as its control comes as a preventive practice, providing a diversity of the system, and a better control of pests and diseases by breaking cycles, culture, pests and diseases.

Cleaner production of basic chromium sulfate – with a review of sustainable green production options

Ferrochromium and chromium based compounds are produced worldwide from chromite ore. Chrome chemicals are from chromium based compounds. Basic-chromium-sulfate (BCS) is a chrome chemical mostly required as main tanning agent in chrome tanning process in leather industry and also to synthesize other chromic compounds. During the preparation of basic-chromium- sulfate, sodium dichromate containing chromium (VI) is reduced to chromium (III) by sulfur-di-oxide in a packed tower at a chemical process industry (B&M Chemicals, India) where the BCS is produced at suboptimal efficiency due to inefficient (suboptimal) absorption of sulfur-di-oxide (as the gas enters the tower at a higher temperature) followed by reaction. Improper reduction leads to the presence of unconverted chromium (VI) that imparts toxicity, not only through product basic-chromium- sulfate but also through leather and articles produced using this chemical. Design and operating conditions of the packed bed absorber were found and effects of pH, temperature and concentration of SO2 on the performance of absorption were studied. The reaction is favored at pH 4. The overall efficiency of conversion in the tower is increased from 70% to 80% by operating the column at optimal operating conditions obtained using response surface method. Dispersion is achieved by random packing that provides complex countercurrent flow path resulting in greater probability of entraining gas inside the tower. Profiles of basic chromium sulfate are obtained along the height of the tower by solving mathematical models of the reactive absorption process. Chromium (VI) is 99% reduced to chromium (III) in the product. Leached residues and liquid wastes are treated with either ferrous sulfate or sodium sulfide to convert chromium (VI) to chromium (III) to provide sustainable technology. Treated solid waste is stored before safe disposal in hazardous landfill facility. As chromium (VI) is highly toxic, several sustainable methods are suggested to eliminate it from effluent to provide cleaner and sustainable production environment in the industry.