Chemical phosphorus (P) removal during aerobic wastewater treatment induced by iron salt addition in sewer systems for sulfide control is investigated. Aerobic batch tests with activated sludge fed with wastewater containing iron sulfide precipitates showed that iron sulfide was rapidly reoxidised in aerobic conditions, resulting in phosphate precipitation. The amount of P removed was proportional to the amount of iron salts added, and for the sludge used, ratios of 0.44 and 0.37 mgP/mgFe were obtained for ferric and ferrous dosages, respectively. The hydraulic retention time (HRT) of iron sulfide in sewers was found to have a crucial impact on the settling of iron sulfide precipitates during primary settling, with a shorter HRT resulting in a higher concentration of iron sulfide in the primary effluent and thus enabling higher P removal. A mathematical model was developed to describe iron sulfide oxidation in aerated activated sludge and the subsequent iron phosphate precipitation. The model was used to optimise FeCl(3) dosing in a real wastewater collection and treatment system. Simulation studies revealed that, by moving FeCl(3) dosing from the WWTP, which is the current practice, to a sewer location upstream of the plant, both sulfide control and phosphate removal could be achieved with the current ferric salt consumption. This work highlights the importance of integrated management of sewer networks and wastewater treatment plants.
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http://dx.doi.org/10.1016/j.watres.2010.03.023 | DOI Listing |
J Hazard Mater
December 2024
Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China; Anhui Provincial Engineering Laboratory of Water and Soil Pollution Control and Remediation, Anhui Normal University, Wuhu 241002, China. Electronic address:
Iron reduction impacts the mobilization and thionation of diphenylarsinic acid (DPAA) in soil, but the contribution of crystalline and non-crystalline iron remains unknown. A paddy soil deficient in non-crystalline iron (P-Fe), crystalline and non-crystalline iron (P-Fe) were incubated with sulfate-plus-lactate, and the results were compared with paddy soil (P) in our previous study. For treatments without ferrous sulfide (FeS) precipitation, the solution-to-solid ratio (R) of DPAA increased slightly and dramatically with iron reduction, respectively, for P-Fe and P, suggesting that the reduction of non-crystalline iron contributes more to DPAA mobilization than crystalline iron.
View Article and Find Full Text PDFNat Commun
December 2024
Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, 2052, Australia.
ACS Omega
November 2024
College of Energy Environment and Safety Engineering, China Jiliang University, Hangzhou 310018, China.
To more accurately grasp the current status and trends in the density functional theory (DFT) study of iron sulfur compounds, this paper presents a bibliometric analysis of 821 documents from 2000 to 2023. The literature source is the Web of Science (WOS) core data set. The results show that China is the country with the highest publication volume (247, 30.
View Article and Find Full Text PDFNat Commun
November 2024
Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, 2052, Australia.
Nat Food
December 2024
Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA.
Carbon removal from the atmosphere is needed to keep global mean temperature increases below 2 °C. Here, we develop a model to explore how alkalinity production through enhanced iron sulfide formation in low-oxygen aquatic environments, such as aquaculture systems, could offer a cost-effective means of CO removal. We show that enhanced sulfide burial through the supply of reactive iron to surface sediments may be able to capture up to a hundred million tonnes of CO per year, particularly in countries with the highest number of fish farms, such as China and Indonesia.
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