Abstract
High amount of orthophosphate will accelerate the growth of autotrophs and eutrophication will occur. This phenomenon decreases the water quality and as a result may increase the cost of water treatment for drinking water. The overabundance of orthophosphate occurs when untreated or inadequately-treated wastewater from domestic and industrial activities is released into water bodies. Conventional treatment has been developed to treat wastewater. However, it is not effective for phosphorus removal, hence, high-cost advanced treatment is needed to remove phosphorus. Thus, alternative low-cost treatments for phosphorus removal are needed. Therefore, this study was conducted to understand and investigate the mechanisms of phosphorus removal using two different setups of steel slag filter, Set 1 for high Fe and Set 2 for high Ca. The study was operated at different pH values of 3, 5, 7, 9 and 11 under aerated and unaerated conditions. The samples of steel slag from 12 filters that has been run for three months for each set were semi-quantitatively analysed using scanning electron microscope-energy dispersive X-ray (SEM-EDX) to identify the adsorption of phosphate ion on the surface of the steel slag. The results of SEM-EDX studies showed that adsorption mechanism of phosphate removal takes place on the surface of the steel slag. The precipitates in the steel slag filters were collected and analysed for X-ray diffraction (XRD) for chemical compound identification and the precipitates were confirmed to be Fe3O4, a precursor of iron phosphate related compound.
Highlights
Wastewater from domestic, industrial and agricultural activities contains high amount of chemical by-products and nutrients
Phosphorus removal systems are commonly installed in wastewater treatment plants as an advanced treatment system, depending on the type of wastewater being treated
Steel slag filter system has emerged as an alternative method to the conventional treatment system
Summary
Wastewater from domestic, industrial and agricultural activities contains high amount of chemical by-products and nutrients. Multiple studies have been conducted on the removal of phosphorus in wastewater using safe, non-toxic materials as a substrate in phosphorus removal in water treatment plants. The ideal phosphorus sorbing materials (PSMs) for use in various practices should be free, non-toxic, industrial by-products and are generated locally They should be widely available and potentially useful as soil amendments once saturated with phosphorus.[4,5] The presence of ferum, calcium, aluminium and magnesium in the materials used are expected to promote the phosphate removal. Under neutral to acidic condition, the removal of phosphate is probably due to the ion exchange between phosphate hydrolysis products 24(HPO,−HPO)−2 as well as the precipitation of the metallic salts of Al3+, Ca2+ and Fe3+ released by slag with phosphate in the solution, which form stable phosphate precipitates such as hydroxyapatite. Steel slag contains high amount of Fe2+, Ca2+ and Mg2+ which make them have high affinities in removing phosphorus
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
