The water hyacinth (WH), also known as Eichhornia crassipes, is Bangladesh’s fast-growing and rapidly expanding sustainable aquatic bioenergy feedstock. The WH, as an energy crop, has been harnessed as a phytoremediation agent to purify contaminated water and produce fuel and environmentally friendly products. A country’s economy relies on the availability of raw materials for energy production, cleaning life-supporting abiotic resources for consumption, and the innovation of cost-effective, eco-friendly products. The present study focuses on a three-in-one nexus using the WH to purify polluted water, the (post-purification) biomass to produce clean energy fuels (biogas and bioethanol), and for the manufacture of daily-use products. The ability of the WH, an aquatic macrophyte, to act as a phytoremediator to improve the quality of eutrophic lake water in a laboratory setting was investigated. Water samples were collected from four lakes surrounding the urban community in Dhaka, Bangladesh. The potential to remove salts and solutes and improve the physio-chemical properties of water, including pH, dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDSs), turbidity, and NaCl concentration, were assessed. During the aquatic macrophyte treatment, a 100% WH survival rate was shown, with no visible toxicity symptoms observed in the biomass. The WH improved water quality after one week, as determined by a significant decrease in turbidity, EC, NaCl, and TDSs, and improved pH and DO levels. Here, we establish the WH’s proficiency in removing nutrients/solutes and improving water quality. In addition, we discuss the utilization of this invasive aquatic biomass to produce energy after remediation of water including cost-effective and eco-friendly products to incur daily life with environmental and socioeconomic benefits in Bangladesh.

Purpose: The purpose of the paper is to set out ideas regarding the use of both first- and second-order cybernetics in reducing global energy-based emissions through energy technology innovation at multiple levels and to discuss necessary production and consumption patterns to facilitate such changes over time.Design/methodology/approach: The paper uses a conceptual framework to estimate a national model of energy consumption and production, conceived as embedded hypercubes for different actor levels. The author has developed a model that elaborates on a multi-level ecosystem for low-carbon technology adoption and innovation, embedded within a sustainability transition framework.Findings: The paper reviews product–process relationships at multiple levels and grounds the framework in a transition approach. With more contextually conceptualized framework grounded in theory, this research aims to inform future development in the topic area, given the embryonic emergence of advanced cybernetic technologies, by viewing such capabilities at the subsystem level as a unit of analysis.Originality/value: The paper will be of interest to firm managers, ecologists and policymakers with a particular interest in system sciences. The framework can be applied for facilitating discussions or for scenario planning.