Water is life, and clean-water demand is increasing daily as a result of rapid population growth and industrial evolution. Nevertheless, due to the inadequate supply and availability of new water sources, there is a need for effective, sustainable removal of contaminants for wastewater reuse. Several treatment approaches that include chemical, physical, and biological methods have been thoroughly tested, with biological treatment being regarded as the most cost-effective and environmentally friendly method. However, the presence of heavy metals and complicated chemicals that are nonbiodegradable limits the use of this cost-effective approach. In this paper, we review the sustainable application of a cheap, water-stable metal-organic framework, the zeolitic imidazolate framework (ZIF-8), with an easier synthesis approach for heavy-metal removal in aqueous solutions. In this review, we discuss the removal efficiency in terms of adsorption capacity, describe the underlying mechanism behind the adsorption capacity of ZIF-8, present a sustainable synthesis approach, and make vital suggestions to aid in the future application of ZIF-8 for the removal of heavy metals.

CWMFC is a novel technology that has been used for almost a decade for concurrent wastewater treatment and electricity generation in varying scopes of domestic, municipal, and industrial applications since its implementation in 2012. Its advantage of low-cost enhanced wastewater treatment and sustainable bioelectricity generation has gained considerable attention. Nevertheless, the overall efficiency of this novel technology is inclined by several operating factors and configuration strands, such as pH, sewage composition, organic loading, electrode material, filter media, electrogens, hydraulic retention time, and macrophytes. Here, we investigate the effect of the wetland plant component on the overall performance of CWMFCs. The macrophyte’s involvement in the oxygen input, nutrient uptake, and direct degradation of pollutants for the required treatment effect and bioelectricity production are discussed in more detail. The review identifies and compares planted and unplanted CWMFC with their efficiency on COD removal and electricity generation based on previous and recent studies.