Novel combination of bioleaching and persulfate for the removal of heavy metals from metallurgical industry sludge.

The objective of this study was to remove heavy metals from metallurgical industry sludge by bioleaching alone and bioleaching combined with persulfate (PDS). The results showed that the removal of Cu, Zn, Pb, and Mn reached 70%, 83.8%, 25.

Cattail fibers as source of cellulose to prepare a novel type of composite aerogel adsorbent for the removal of enrofloxacin in wastewater.

In this study, cattail was researched as a natural cellulose source to extract cellulose. Dewaxing, alkali and bleaching treatments were carried out for the cattail fibers (CFs). The FTIR, SEM and XRD results indicated that hemicellulose and lignin were successfully removed from the CFs, and the content of cattail cellulose increased from 41.

[One-step Preparation of Lanthanum-Magnesium Ferrite and Its Phosphate Adsorption Capacity in Aqueous Solutions].

Due to the shortage of phosphate and the eutrophication caused by phosphorus pollution, it is urgent to recover phosphate from wastewater. Given their high adsorption capacity and convenient separation from water to which a magnetic field is applied, ferrite composites have received increasing attention for phosphate recovery. In this study, Spinel La@MgFeO was prepared using a one-step co-precipitation method.

[Experiment on Recovery of Phosphorus from Aqueous Solution by Calcium Doped FeO].

Adsorption is an economical and effective method for recovering phosphate from wastewater. In order to improve the adsorption capacity of FeO for phosphate and for easy separation from water under the action of an external magnetic field, CaO was used in this study as an oxidant to partially oxidize Fe. A phosphorus recovery adsorbent, Ca doped FeO (CMIO), was prepared and was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) and vibrating sample magnetometer (VSM) techniques.

Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites.

This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO-modified FeO (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH), Ce (OH), and FeO, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity.

Highly efficient enhancement of municipal sludge dewaterability using persulfate activation with nZVI/HA.

This study presents a sulfate radical-based oxidation method for improving municipal sludge dewaterability by combining persulfate and nanoscale zero-valent iron supported on humic acid (nZVI/HA-PS). Sludge dewaterability using persulfate activation with nZVI/HA was assessed for specific resistance to filterability (SRF), time to filter (TTF), settling volume percentage (SV) and water content (Wc). The influencing factors, such as mass ratios of nZVI to HA, initial pH, PS dosage and nZVI/HA nanocomposite dosage, were investigated.

[Influencing Mechanism of Calcium Peroxide Pre-treatment on Dewatering Performance of Waste Activated Sludge].

The evolution of sludge filteration dewaterability, floc structure and hydrolytic kinetics with calcium peroxide oxidation pre-treatment was investigated in this study. The effect of sludge characteristics with combined process of ferrous ion and calcium peroxide was deeply analyzed and the result suggested that the sludge dewatering performance was improved first and then worsened after CaO addition. When the dosage was 20 mg·g, sludge reached its optimal dewaterability.

Enhancement of waste activated sludge dewaterability using calcium peroxide pre-oxidation and chemical re-flocculation.

The effects of combined calcium peroxide (CaO2) oxidation with chemical re-flocculation on dewatering performance and physicochemical properties of waste activated sludge was investigated in this study. The evolutions of extracellular polymeric substances (EPS) distribution, composition and morphological properties were analyzed to unravel the sludge conditioning mechanism. It was found that sludge filtration performance was enhanced by calcium peroxide oxidation with the optimal dosage of 20 mg/gTSS.

Enhancement of activated sludge dewatering performance by combined composite enzymatic lysis and chemical re-flocculation with inorganic coagulants: Kinetics of enzymatic reaction and re-flocculation morphology.

The feasibility of combined process of composite enzymatic treatment and chemical flocculation with inorganic salt coagulants was investigated in this study. The evolution of extracellular polymeric substances (EPS) distribution, composition and morphological properties were analyzed to unravel the sludge conditioning mechanism. It was found that sludge filtration performance was deteriorated due to release of a large amount of biopolymers after enzymatic treatment.