Rapidly increasing industrialisation has human needs, but the consequences have added to the environmental harm. The pollution caused by several industries, including the dye industries, generates a large volume of wastewater containing dyes and hazardous chemicals that drains industrial effluents. The growing demand for readily available water, as well as the problem of polluted organic waste in reservoirs and streams, is a critical challenge for proper and sustainable development. Remediation has resulted in the need for an appropriate alternative to clear up the implications. Nanotechnology is an efficient and effective path to improve wastewater treatment/remediation. The effective surface properties and chemical activity of nanoparticles give them a better chance to remove or degrade the dye material from wastewater treatment. AgNPs (silver nanoparticles) are an efficient nanoparticle for the treatment of dye effluent that have been explored in many studies. The antimicrobial activity of AgNPs against several pathogens is well-recognised in the health and agriculture sectors. This review article summarises the applications of nanosilver-based particles in the dye removal/degradation process, effective water management strategies, and the field of agriculture.

The foamed geopolymers are promising alternative to other foamed materials. The article presents the method of its production and the results of the research on such materials produced from fly ash from CHP plant. It provides and analyses the strength and thermal conductivity of the expanded geopolymers. It also determines the relationship between the thermal conductivity and density of foamed geopolymers. The density of the obtained materials ranged from approx. 400kg/m3 to 650kg/m3. The research results confirm that the foamed geopolymers produced from fly ash from CHP plant have reasonable mechanical properties and performance of a construction product

Transformation of waste into resources is an important part of the circular economy. Nowadays, the recovery of materials in the most effective way is crucial for sustainable development. Composite materials offer great opportunities for product development and high performance in use, but their position in a circular economy system remains challenging, especially in terms of material recovery. Currently, the methods applied for recycling composites are not always effective. The aim of the article is to analyse the most important methods of material recovery from multilateral composites. The manuscript presents three case studies related to the recycling of products manufactured from composites: used tyres, wind turbine blades, and solar panels. It shows the advantages and disadvantages of currently applied methods for multilateral composite utilisation and presents further trends in composite recycling. The results show that increasing volumes of end-of-life composites have led to increased attention from government, industry, and academia.

In buildings and in civil engineering structures, both active and passive fire protection are used. Active fire protection includes automatic fire detection and fire suppression systems while the passive fire protection's main purpose is to attempt to contain fires or slower their spread. The aim of fire protection system's usage is to maintain the temperature of the building component (structural steel element, electrical installation) bellow the critical temperature during fire but also is intended to contain a fire in the origin fire compartment for a limited period of time. In this paper the passive fire protection material solutions were described and their action mode explained. Starting with thermal insulation barrier, endothermic building materials including concrete and gypsum and also novel solution based on alkali activated binders. Concrete is considered to be fire protective, however, in some specific cases, dense and low permeable concrete (i.e. high performance concrete) has a tendency to spall in explosive way under fire. Several fires in structures have caused the spalling of concrete elements that jeopardized the structure stability. In this specific case polypropylene fibres (PP) added to the concrete mix act as a passive protection system. Another group of passive fire protection materials, described in this document, are the intumescent and ablative materials for steel structure protection. The present manuscript describes also the techniques of passive fire protection testing in fire conditions

Fly ash-based geopolymers can be considered as a greener alternative to ordinary Portland cement, featuring comparable properties and cost yet with lower CO₂ emissions. New wood fiber reinforced geopolymer composites with sand addition (WFSGC) have been synthesized at room temperature by mixing powder (fly ash, sand and randomly reinforced wood fiber) with sodium silicate and sodium hydroxide as alkaline activators. New WFSGC were cured at 90°C for 24 h. The design and investigation of WFSGC were based on a fix 5 wt.% percentage of sand, with variable wood fiber (5, 10, 15, 20, 25, 30 and 35 wt.%) and fly ash percentages. These WFSGC showed decreasing mechanical properties with increasing wood fiber addition as measured by the compressive strength at the cylindrical test (21.76–42.52 MPa), the compressive strength at the cubic test (31.79–39.17 MPa), the force load at upper yield at the cylindrical test (1.27–3.58KN), the flexural strength (7–10.76 MPa), compressive modulus at the cylindrical test (590,75–1021.17 MPa), the compressive modulus at cubic test (787.92–1059.79 MPa) and the flexural modulus (298.03–737.83 MPa). The density of WFRGC decreases with the addition of wood fiber (1.49–1.71 g/cm³). WFSGC with addition wood fibers up to 15 wt.% could be the limit for a promising green material for construction.