The COVID-19 pandemic is the largest global public health outbreak in the 21st century so far. Based on World Health Organization reports, the main source of SARS-CoV-2 infection is transmission of droplets released when an infected person coughs, sneezes, or exhales. Viral particles can remain in the air and on the surfaces for a long time. These droplets are too heavy to float in air and rapidly fall down onto the surfaces. To minimize the risk of the infection, entire surrounding environment should be disinfected or neutralized regularly. Development of the antiviral coating for the surface of objects that are frequently used by the public could be a practical route to prevent the spread of the viral particles and inactivation of the transmission of the viruses. In this short review, the design of the antiviral coating to combat the spread of different viruses has been discussed and the technological attempts for minimizing the coronavirus outbreak have been highlighted.

The technology of additive manufacturing, especially 3D concrete printing (3DCP), has been recently adopted in the construction industry as a viable alternative to traditional construction methods. Although the technology offers a wide variety of structural, economic, and environmental benefits, it is still restricted in use due to certain limitations that are still under research. This paper explains the fundamentals of the 3D printing process, its potential, challenges, as well as the different 3D printing systems. The recent literature is explored for recommended materials that possess the required properties for 3D printing, as well as reinforcement methods and techniques. This paper also reviews 3D printing extrusion using concrete and foam and explores the effect of both materials and extruding systems on the final product. The application of different additive construction systems with Building Information Modeling (BIM)-integrated algorithms are also discussed in this paper. It is believed that with providing a comprehensive knowledge of 3D printing for concrete construction, there is a huge potential to change the way cementitious materials are formulated and sustainability aspects are implemented, especially for complicated designs.

Biochar utilization for adsorption seems to be the most cost-effective, easy/fast approach for pollutants removal from water and wastewater. Due to the high adsorption properties, magnetic biochar proved to be efficient in the sorption of heavy metals and nutrients. Although there are several studies on development of magnetic biochars, there is a lack of research on development of high-performance magnetic biochar from food waste for removal applications. This study aimed at preparing new classes of magnetic biochar derived from tea waste (TBC) for removal of heavy metals (Ni²⁺, Co²⁺), and nutrients (NH₄⁺ and PO₄³⁻) from water and effective fertilizer (source of NH₄⁺ and PO₄³⁻). Standard carbonization process and ultrafast microwave have been used for fabrication of TBCs. The removal of nickel, cobalt as the representatives of heavy metals, and over-enriched nutrients (NH₄⁺ and PO₄³⁻) from water were tested and the removal kinetics, mechanism, and the effect of pH, dissolved organic matter and ionic strength were studied. Simultaneously, possible fertilizing effect of TBC for controlled release of nutrients (NH₄⁺ and PO₄³⁻) in soil was investigated. Up to 147.84 mg g⁻¹ of Ni²⁺ and 160.00 mg g⁻¹ of Co²⁺ were adsorbed onto tested biochars. The process of co-adsorption was also efficient (at least 131.68 mg g⁻¹ of Co²⁺ and 160.00 mg g⁻¹ of Ni²⁺). The highest adsorbed amount of NH₄⁺ was 49.43 mg g⁻¹, and the highest amount of PO₄³⁻ was 112.61 mg g⁻¹. The increase of the solution ionic strength and the presence of natural organic matter affected both the amount of adsorbed Ni²⁺+Co²⁺ and the reaction mechanism. The results revealed that magnetic nanoparticle impregnated onto tea biochar, can be a very promising alternative for wastewater treatment especially considering removal of heavy metals and nutrients and slow-release fertilizer to improve the composition of soil elements.