Adsorption Properties of Waste Building Sludge for Environmental Protection

Abstract

Waste building sludge (WBS) originating in the production of concrete prestressed poles (CSW) and technical stone (TSW) used in original and Fe-modified forms (CSWFe, TSWFe) was tested as an environmentally friendly and cheap sorbent of selected cations (Cd2+, Pb2+, Cs+) and anions (AsO43−, PO43−, CrO42−) from water. The experiments were performed with 0.1 and 0.5 mmol·L−1 model solutions in a batch manner at laboratory temperature. Adsorption data were fitted with the Langmuir model. The adsorption of cations (Pb2+ and Cd2+) ran almost quantitatively (>97%) on both CSW and TSW. Cesium (Cs+) adsorption on TSW reached 80%, while in the case of CSW, it was ineffective. The modification of CSW and TSW with FeII (CSWFe and TSWFe) improved their adsorption selectivity to anions by up to 70%. The adsorption of PO43− and AsO43− ran quantitatively (>98%) on modified CSWFe and TSWFe and also on initial CSW, while CrO42− was effectively adsorbed (≈80%) on TSWFe only. The adsorption affinity of tested ions in terms of adsorption capacity and sorbent consumption declined in order as follows: Pb2+ ≈ Cd2+ >> Cs+ for cations and AsO43− ≈ PO43− > CrO42− for anions.

Kaolin–Fly Ash Composite for Pb2+ and AsO43− Adsorption from Aqueous System

“…Model solutions of the tested toxic ions (Pb 2+ and AsO 4 3− ) were prepared from analytical-grade inorganic salts (Pb(NO 3 ) 2 and KH 2 AsO 4 , respectively) in distilled water at a concentration of 0.5 mmol L −1 and their natural pH values (≈4.5 for Pb 2+ and ≈5.7 for AsO 4 3− ). This concentration was selected as appropriate for simulating a heavily contaminated water system [26,27].…”

Adsorption of Phosphate and Ammonium on Waste Building Sludge

“…Concrete is one of the most widely used building materials, with an annual global consumption of 25 billion tons [ 3 ]. At present, various separation and recycling processes are used in its production, enabling the reuse of water and coarse aggregates [ 2 , 4 , 5 ]. The remaining concrete sludge (fine aggregates and cement particles) can be used in the production of ceramic materials [ 6 ], synthesis of geopolymers [ 7 ], or in the production of new concrete to reduce the required amount of cement [ 1 , 3 , 5 ].…”

“…All of these processes are relatively effective but insufficient for modern sustainable development. This is because the remaining concrete sludge (B) is landfilled without further use, along with several other wastes from the construction industry, such as powder waste from the production and treatment of technical stone (TS), which currently has no other application [ 4 ]. However, sewage sludges have a large specific surface area (S BET ), suitable structural properties and chemical composition (Si, Ca, Al and Fe content), which predetermine their possible applications in environmental technologies, for example, as adsorbents for removing toxic ions from contaminated waters [ 4 , 8 , 9 ].…”

Electrically conductive composite materials with incorporated waste and secondary raw materials

“…Thanks to the use of secondary raw materials, it is possible to reduce the consumption of primary raw materials, which are in most cases non-renewable 22 . Secondary raw materials equally replace and at the same time facilitate technological processes in the production of various materials, thus reducing the energy and material demand of products 23 .…”