Environmental Engineering Science

Phytoremediation is a green technology that utilizes plants to remove pollutants from contaminated soil, water, and air. It is a promising and sustainable alternative to traditional remediation methods. This review will explore the patent landscape related to phytoremediation for water pollution. This patent landscaping examined the patent on phytoremediation from PATENTSCOPE (World Intellectual Property Organization database), Scopus Patents, Google Patents, and Lens (a public patent knowledge database). This landscaping reviewed around 190 patent records related to phytoremediation belongs to the International Patent Classification (IPC) C02F class for treatment and removal of pollutants from contaminated water. Out of 190 applications, 142 applications (75%) were granted, while 48 applications (25%) were published and await examinations. The analysis identified emerging innovations, key patent holders, and trends in IPC classifications. Innovative phytoremediation strategies for water pollution include: (1) plant species and genetic modification: engineering plants with improved pollutant uptake, especially for heavy metals or organic compounds; (2) hydroponic and aquatic systems: designing hydroponic tanks and nutrient solutions for effective aquatic plant cultivation methods of pollutant removal; (3) rhizofiltration and phytodegradation: enhancing root-based pollutant absorption and optimizing plant metabolism for pollutant breakdown; (4) combined approaches with bioaugmentation: phytoremediation enhanced by adding beneficial microorganisms; and (5) monitoring and assessment using sensors: utilizing sensors for effective phytoremediation. Additionally, phytoremediation is discussed for addressing the challenges of climate change and achieving sustainable development goals. At last, the policy recommendation is described to significantly enhance the efficiency and applicability of phytoremediation techniques.

Fullerenols (PHFs) are emerging pollutants with health risks, yet conventional adsorbents suffer from small pore sizes, limited effective pore quantities, and low unit area adsorption capacities. This study used cuttlebone (CB), a fishery waste, to prepare carbonized CB (CCB), acid-modified CB (HCB), and a combined carbonized and acidified CB (HCCB) as adsorbents for PHF. These modified adsorbent materials showed increases in effective pores (50–200 nm) for PHF adsorption: 33% (CCB), 23% (HCB), and 41% (HCCB). The initial adsorption rate and adsorption capacity of CCB for PHF increased with higher pyrolysis temperatures due to reduced electrostatic repulsion, increased π–π interactions, and the transformation of aragonite into calcite of CB calcium carbonate skeleton. Acid modification enhances pore filling and thus capacity but slows kinetics via longer intraparticle diffusion; both effects intensify with higher acid concentration and longer treatment. The unit area adsorption capacities of CCB, HCB, and HCCB for PHF were 3.11, 1.18, and 2.11 mg/m², much higher than traditional materials. This research effectively removes PHF and upgrades marine waste into a high-value adsorbent, practicing “pollution control through waste utilization.” The results have both pollution control and circular economy value, expanding sustainable and low-cost material paths, promoting the integration of multiple disciplines such as environmental engineering, materials science, and marine science, and providing new ideas for the treatment of nanomaterial pollutants.

Lake eutrophication and harmful algal blooms (HABs) have emerged as paramount concerns in the global aquatic environment. Microcystis aeruginosa is a kind of common harmful algae in fresh water. In this study, the surface of TiO₂ was modified by incorporating molybdenum disulfide (MoS₂) and zeolitic imidazolate framework-67 (ZIF-67), resulting in the formation of a novel titanium dioxide (TiO₂) photocatalyst (MoS₂@ZIF-67/TiO₂). MoS₂@ZIF-67/TiO₂ photocatalyst was also used to investigate the inactivation of M. aeruginosa under visible light. After doping with MoS₂@ZIF-67, the energy bandgap of MoS₂@ZIF-67/TiO₂ was reduced to 2.4 eV, while exhibiting an increase in the average pore diameter. The inactivation efficiency of 10% MoS₂@ZIF-67/TiO₂ composite photocatalyst for M. aeruginosa was 86.08%. The content of photosynthetic pigment, soluble protein, and various antioxidant indexes also continued to decline during the experiment, dropping to the lowest level on the fifth day. Based on the comprehensive data analysis, it was evident that the 1030% MoS₂@ZIF-67/TiO₂ photocatalyst exhibited remarkable potential for advancements in the realm of photocatalytic algae removal and mitigation of HABs.