https://www.selleckchem.com/products/FK-506-(Tacrolimus).html Adsorption capacities varied between 9.0 and 68 mg g-1 with biosludge HTC at 220 °C adsorbing the highest amount. Adsorption also dropped drastically at the highest temperature (260 °C), indicating a correlation between adsorption capacity and HTC conditions. This was attributed to the loss of oxygen functional groups, which can contribute to adsorption. These results suggest that adsorption properties can be tailored both by selection of HTC temperature and feedstock.Due to the rapid growth in the heavy metal-based industries, their effluent and local dumping have created significant environmental issues. In the past, typically, removal of heavy metals was handled by reverse osmosis and ion exchange techniques, but these methods have many disadvantages. Therefore, extensive work into the development of improved techniques has increased, especially for heavy metal removal. Many countries are currently researching new materials and techniques based on nanotechnology for various applications that involve extracting heavy metals from different water sources such as wastewater, groundwater, drinking water and surface water. Nanotechnology provides the possibility of enhancing existing techniques to tackle problems more efficiently. The development in nanotechnology has led to the discovery of many new materials such as magnetic nanoparticles. These nanoparticles demonstrate excellent properties such as surface-volume ratio, higher surface area, low toxicity and easy separation. Besides, magnetic nanoparticles can be easily and efficiently recovered after adsorption compared with other typical adsorbents. This review mainly emphasises on the efficiency of heavy metal removal using magnetic nanoadsorbent from aqueous solution. In addition, an in-depth analysis of the synthesis, characterisation and modification approaches of magnetic nanoparticles is systematically presented. Furthermore, future opportunities a