Sludge-derived iron-carbon material enhancing the removal of refractory organics in landfill leachate: Characteristics optimization, removal mechanism, and molecular-level investigation.

Mature landfill leachate is a refractory organic wastewater, and needs physical and chemical pretreatments contemporaneously, e.g. iron-carbon micro-electrolysis (IC-ME).

Enhanced silicon bioavailability of biochar derived from sludge conditioned with Fenton's reagent and lime.

Biological wastewater treatment generates a large quantity of sewage sludge that requires proper treatments. In this study, the biochar pyrolyzed by sludge conditioned with Fenton's reagent and lime (referred to as Fenton-lime system) was first used as an efficient silicon fertilizer for rice cultivation. When the pyrolysis temperature was 750 °C, the dissolved silicon and available silicon contents in biochar derived from sludge conditioned with Fenton-lime system were much higher than those in raw sludge derived biochar without conditioning (3.

Recirculation of reject water in deep-dewatering process to influent of wastewater treatment plant and dewaterability of sludge conditioned with Fe/HO, Fe/Ca(ClO), and Fe/NaSO: From bench to pilot-scale study.

Deep dewatering of sewage sludge pretreated with advanced oxidation processes (AOPs) is a strategy for efficient sludge reduction and subsequent disposal. The pretreatment and dewatering performance of sludge conditioned with three types of AOPs (Fe/HO, Fe/Ca(ClO), and Fe/NaSO), compared with sludge conditioned with traditional conditioner (Fe/CaO), were investigated in both bench and pilot-scale tests. All of those conditioner systems could reduce the water content of dewatered sludge cake to below 60 wt% in bench-scale (about 16 kg raw sludge per round) and pilot-scale (approximate 800 kg raw sludge per round) diaphragm filter press dewatering.

Enhancing waste activated sludge dewaterability by reducing interaction energy of sludge flocs.

How to efficiently improve waste activated sludge (WAS) dewaterability is a common challenge in WAS treatment and management throughout world. The interaction energy of sludge flocs is of great importance for sludge dewaterability. In this study, the relationship among the repulsive force of sludge flocs, hydrophilic/hydrophobic characteristics of sludge flocs, and sludge dewaterability have been quantitatively and qualitatively investigated based on extended Derjaguin-Landau-Verwey-Overbeek theory for the first time.

Improvement of sludge dewaterability by ammonium sulfate and the potential reuse of sludge as nitrogen fertilizer.

A novel method to enhance sludge dewaterability with ammonium sulfate ((NH)SO) was proposed, and the potential reuse of dewatered sludge cake and filtrate as nitrogen fertilizers was evaluated. Compared with raw sludge, 87.91% reduction of capillary suction time (CST) and 88.

Enhanced sludge dewaterability with sludge-derived biochar activating hydrogen peroxide: Synergism of Fe and Al elements in biochar.

Reuse of sludge-derived Fe-rich biochar as sludge conditioner is an attractive route for management of waste activated sludge at source. Homogeneous and heterogeneous Fenton reactions have been proved in sludge conditioning with Fe-rich biochar activating HO to enhance sludge dewaterability. The FeAlO phase in Fe-rich biochar was first identified during pyrolysis of sewage sludge after adding both FeO and AlO, since Fe and Al elements are two of major metal elements in Fe-rich sludge.

Sludge-derived biochar with multivalent iron as an efficient Fenton catalyst for degradation of 4-Chlorophenol.

Fe-rich biochar with multivalent iron compounds (Fe, FeC, FeO, and FeAlO) pyrolyzed from sludge cake conditioned with Fenton's reagent and red mud was utilized as an efficient Fenton catalyst for the degradation of 4-chlorophenol (4-CP). Effects of pyrolysis temperature and sludge conditioner composition on the transformation of iron compounds were studied. Both homogeneous Fenton reaction initiated by Fe leached from both low-valent Fe and FeC, and heterogeneous Fenton reaction initiated by solid iron phases of FeO and FeAlO were revealed to contribute to the degradation of 4-CP.

Profiling of amino acids and their interactions with proteinaceous compounds for sewage sludge dewatering by Fenton oxidation treatment.

During advanced oxidation treatment for enhancing sludge dewaterability, the peptide chains of protein can be decomposed into amino acids. Protein exhibits a great impact on sewage sludge dewaterability. However, the role of amino acids in sludge dewatering remains unclear.

A one-step acidification strategy for sewage sludge dewatering with oxalic acid.

Sewage sludge dewatering is an efficient approach to reduce the volume of sludge for the subsequent disposal. In this study, a novel one-step acidification sludge dewatering method was developed with using oxalic acid as a conditioner. In laboratory-scale experiments with the dosage of 200 mg/g dry solid (DS), the normalized capillary suction time and the specific resistance to filtration were respectively decreased by 78.

A comparison between sulfuric acid and oxalic acid leaching with subsequent purification and precipitation for phosphorus recovery from sewage sludge incineration ash.

Wet chemical approach is widely applied for P extraction from incinerated sewage sludge ash (ISSA) due to the relatively simple process and low lost. In this study, HSO and HCO were compared to recover P from ISSA through three steps of acid leaching, cation exchange resin (CER) purification and precipitation. Transformations of P speciation and mineral phases in ISSA from 600 to 900 °C were studied.

Correlation between oxidation-reduction potential values and sludge dewaterability during pre-oxidation.

Pre-oxidation is effective in enhancing sludge dewaterability. Different types and doses of oxidants are used to improve sludge dewaterability in pre-oxidation. Rapid evaluation of the sludge dewaterability is vital for optimizing the type and dose of oxidants in pre-oxidation.

Unraveling oxidation behaviors for intracellular and extracellular from different oxidants (HOCl vs. HO) catalyzed by ferrous iron in waste activated sludge dewatering.

Cell lysis in sludge pretreatment by advanced oxidation process (AOP) has a great effect on sludge dewaterability. Cell lysis caused by reactive radicals (e.g.

Visible Light Driven Organic Pollutants Degradation with Hydrothermally Carbonized Sewage Sludge and Oxalate Via Molecular Oxygen Activation.

Converting sewage sludge into functional environmental materials has become an attractive sewage sludge disposal route. In this study, we synthesize a sewage sludge-based material via a facile one-pot hydrothermal carbonization method and construct a visible light molecular oxygen activation system with hydrothermally carbonized sewage sludge (HTC-S) and oxalate to degrade various organic pollutants. It was found that iron species of HTC-S could chelate with oxalate to generate HO via molecular oxygen activation under visible light, and also promote the HO decomposition to produce OH for the fast organic pollutants degradation.

A comparatively optimization of dosages of oxidation agents based on volatile solids and dry solids content in dewatering of sewage sludge.

Organic content of sludge is a major factor influencing its dewaterability. Conditioning sewage sludge with oxidation reagents (Fenton's reagent or Fe/persulfate) can effectively improve sludge dewaterability. In traditional conditioning process of sewage sludge, the optimization of conditioner dosage were commonly based on volume of sludge (referred as mg/L) or mass of dry solid (DS) of sludge (referred as mg/g DS).