Extraction of heavy metal from sewage sludge using ultrasound-assisted nitric acid

Citric acid and ethylene diamine tetra-acetic acid as effective washing agents to treat sewage sludge for agricultural reuse

“…As shown in previous studies, large doses and frequent applications of additives are typically needed to remove high concentrations of metals from sewage sludge (Deng et al, 2009;Zhu et al, 2009Zhu et al, , 2013. However, such a large number of washings results in high processing costs and can even be detrimental to the environment because of the loss of nutrients (e.g., total nitrogen (TN), total phosphorus (TP), available-N, Olsen-P, and organic matter).…”

“…These include chemical treatments (Lo and Chen, 1990;Stylianou et al, 2007), thermal treatments (Zorpas et al, 2001), ion exchange methods (Dabrowski et al, 2004;de Villiers et al, 1995), chlorination methods (Fraissler et al, 2009), electrochemistry methods (Hanay et al, 2009), membrane separation methods (Chaudry et al, 1998), and bioleaching methods (Chen et al, 2005;Pathak et al, 2009). Chemical treatments have received extensive attention due to the simplicity of operation processes, short operation times, and high efficiency for metal removal (Deng et al, 2009). Various inorganic acids, organic acids, and strong complexing reagents have been proposed as effective additives to remove toxic metals from sludge or soil.…”

Mild Acid Ultrasonic Assisted Extraction of Arsenic Residues in Different Parts of Hot Chilli Prior to Ultra-Trace Determination by Flow Injection-Hydride Generation Atomic Absorption Spectrometry

“…Nitric acid is frequently reported in studies of the extraction of metals using ultrasonic energy. However, other acid solutions and their mixture have also been reported 18 . In this work, different acid solutions: HCl, HNO 3 and two kinds of mixing ratio of HCl : HNO 3 (1:1, 3:1, 1:3, by volume) each at 1.0 Mconcentration were chosen to investigate in details.…”

Optimalization of Metals Ions Extraction from Industrial Wastewater Sludge with Chelating Agents / Optymalizacja Procesu Ekstrakcji Jonów Metali Z Przemysłowych Osadów Ściekowych Za Pomocą Roztworów Związków Chelatujących

“…Recently different chemicals have been reported as an effective agents for extraction of metals from sewage sludge, e.g. nitric acid [4], sulfuric acid [10], ferric sulfate [8]. But chelating agents such as EDTA (ethylenediaminetetraacetic acid) and citric acid seem to be very promising.…”