scholarly journals Removal behavior and chemical speciation distributions of heavy metals in sewage sludge during bioleaching and combined bioleaching/Fenton-like processes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chunsheng Qiu ◽  
Shangyu Xie ◽  
Nannan Liu ◽  
Kequan Meng ◽  
Chenchen Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Chemical Speciation ◽  
Speciation Analysis ◽  
Residual Fraction ◽  
Combined Process ◽  
Capillary Suction ◽  
Ph Values ◽  
Mobile Forms ◽  
Removal Efficiencies

AbstractThe removal and chemical speciation changes of heavy metals in the sewage sludge during the single bioleaching and combined bioleaching/Fenton-like processes were compared in this study. The improvement in the dewaterability of the treated sludge was also investigated. The single bioleaching led to a removal of Zn, Cu, Cd, Cr, Mn, Ni, As and Pb of 67.28%, 50.78%, 64.86%, 6.32%, 56.15%, 49.83%, 20.78% and 10.52% in 10 days, respectively. The chemical speciation analysis showed that the solubilization of heavy metals in mobile forms (exchangeable/acid soluble and reducible forms) and oxidizable form was the main reason for their removal. Subsequent Fenton-like treatment was carried out at different bioleaching stages when the bioleached sludge dropped to certain pH values (4.5, 4.0 and 3.0), by adding H2O2 at different dosages. The highest removal ratio of Zn, Cu, Cd, Cr, Mn and Ni could reach 75.53%, 52.17%, 71.91%, 11.63%, 66.29% and 65.19% after combined bioleaching/Fenton-like process, respectively, with appropriate pH and H2O2 dosages in less than 6 days. The solubilization efficiencies of these heavy metals in mobile forms were further improved by Fenton-like treatment. The removal efficiencies of As and Pb decreased due to their transformation into insoluble forms (mostly residual fraction) after Fenton treatment. The capillary suction times (CST) of the raw sludge (98.7 s) decreased by 79.43% after bioleaching and 87.44% after combined process, respectively.

Speciation of heavy metals in sewage sludge after mesophilic and thermophilic anaerobic digestion

2012 ◽  
Vol 66 (6) ◽  
Author(s):  
Lidia Dąbrowska
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Metal Ions ◽  
Metal Speciation ◽  
Speciation Analysis ◽  
Chromium Concentration ◽  
Residual Fraction ◽  
Stabilization Process

AbstractTwo types of sewage sludge anaerobic digestion were carried out: mesophilic and thermophilic. Metal speciation analysis was performed revealing some changes in the chemical form of the metals during the stabilization process of sludge. After both methane fermentation processes, a comparable level of organic matter distribution was obtained (≈ 40 %). The amount of produced methane during thermophilic and mesophilic digestion was 560 mL of CH4 and 580 mL of CH4 from 1 g of removed organic matter, respectively. Low concentration of heavy metal ions in the liquid phase of sludge was observed. Metal ions precipitated and remained bound throughout the stabilization process. No accumulation of heavy metals in the mobile fractions of sludge (exchangeable and carbonate) was observed for either digestion process. The highest increase of zinc, copper, nickel, cadmium, and chromium concentration was observed in the organic-sulfide fraction, whereas the highest increase of lead was found in the residual fraction.

scholarly journals Chemical Speciation and Potential Mobility of Heavy Metals in the Soil of Former Tin Mining Catchment

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
M. A. Ashraf ◽  
M. J. Maah ◽  
I. Yusoff
Keyword(s):  
Chemical Speciation ◽  
Extraction Procedure ◽  
Optical Emission ◽  
Residual Fraction ◽  
Emission Spectrometry ◽  
Trophic Chain ◽  
Toxic Risk ◽  
Mobile Forms ◽  
Average Potential ◽  
Potential Mobility

This study describes the chemical speciation of Pb, Zn, Cu, Cr, As, and Sn in soil of former tin mining catchment. Total five sites were selected for sampling and subsequent subsamples were collected from each site in order to create a composite sample for analysis. Samples were analysed by the sequential extraction procedure using optical emission spectrometry (ICP OES). Small amounts of Cu, Cr, and As retrieved from the exchangeable phase, the ready available for biogeochemical cycles in the ecosystem. Low quantities of Cu and As could be taken up by plants in these kind of acidic soils. Zn not detected in the bioavailable forms while Pb is only present in negligible amounts in very few samples. The absence of mobile forms of Pb eliminates the toxic risk both in the trophic chain and its migration downwards the soil profile. The results also indicate that most of the metals have high abundance in residual fraction indicating lithogenic origin and low bioavailability of the metals in the studied soil. The average potential mobility for the metals giving the following order: Sn > Cu > Zn > Pb > Cr > As.

Influence of Decreasing Supplementation to Transformation of Chemical Forms of Ni, Zn and Cu During Composting of Sewage Sludge

2021 ◽  
Vol 23 ◽  
pp. 580-593
Author(s):  
Robert Sidełko
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Organic Carbon ◽  
Ion Exchange ◽  
Beneficial Effect ◽  
Sequential Extraction ◽  
Nitrogen Concentration ◽  
Chemical Forms ◽  
N Value ◽  
Mobile Forms

This paper pertains to the influence of decreasing supplementation to transformation of chemical forms of Ni. Zn and Cu during composting of sewage sludge. A universally used supplementing material constituting a rich source of organic carbon is straw. Addition of straw to sewage sludge is aimed at increasing C/N proportion up to at least 15 due to the risk of formation of toxic forms of nitrogen, concentration of which in sewage sludge is exceptionally high. We have presented in this paper the results of speciation research of three elements applying Tessier’s sequential extraction. It’s been proven that decreasing of straw share in the composted mixture with sewage sludge down to the level of C/N value below the admissible value, has a beneficial effect on the allocation of tested heavy metals towards the forms that are permanently bound in compost matrix. A systematic increase of organic (IV) and residual (V) fractions share and decrease of mobile forms of heavy metals content in bioavailable fractions i.e. ion-exchange (I) and carbonate (II) has been ascertained.

Total concentrations and chemical speciation of heavy metals in liquefaction residues of sewage sludge

2011 ◽  
Vol 102 (5) ◽  
pp. 4104-4110 ◽  
Author(s):  
Xingzhong Yuan ◽  
Huajun Huang ◽  
Guangming Zeng ◽  
Hui Li ◽  
Jingyu Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Chemical Speciation ◽  
Total Concentrations

Influence and Mechanism of Different pH Values of Extractant on the Leachability of Heavy Metals in Industrial Sewage Sludge

2011 ◽  
Vol 197-198 ◽  
pp. 1000-1004 ◽  
Author(s):  
Jing Yong Liu ◽  
Shui Yu Sun ◽  
Yan Bin Xu ◽  
Li Zheng ◽  
Shao Song Huang
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Extraction Procedure ◽  
Leaching Tests ◽  
Ph Values ◽  
Leaching Toxicity ◽  
Co Precipitation ◽  
Adsorption Desorption ◽  
Industrial Sewage ◽  
Industrial Sewage Sludge

The leaching tests of heavy metals in industrial sewage sludge were carried out under different pH of extractant by the solid waste extraction procedure for leaching toxicity (GB5086.2-1997) of China on the base of the contents and fractions of Zn, Cu, Pb, Cr, Mn and Ni elements. The results showed that the sludge was with higher levels of Mn and Zn, followed by Cu and Ni, while the higher toxicity of Pb and Cr was lower. The fractions of different elements in the sewage sludge had very different forms. The potential migration and biological toxicity were a concern for the active forms of Zn, Mn, Ni, Cr because their active proportions were more than 50%. The pH of extraction solutions had an important impact on the leaching of heavy metals in sewage sludge. The largest concentrations of Zn, Mn, Ni, Cu were appeared when the pH of extractant was about 7, but that of Fe had a greater fluctuation at the same pH. The concentrations of heavy metals had very different at different pH values, which may be related with the process of adsorption/desorption, complexation/dissociation, the dissolution/precipitation/co-precipitation and other chemical reactions in the extractant process.

scholarly journals Chemical Speciation, Bioavailability and Risk Assessment of Potentially Toxic Metals in Soils Around Petroleum Product Marketing Company as Environmental Degradation Indicators

2021 ◽  
Author(s):  
D. A Ayeni ◽  
Festus Mayowa ADEBIYI
Keyword(s):  
Risk Assessment ◽  
Ecological Risk ◽  
Chemical Speciation ◽  
Contamination Factor ◽  
Speciation Analysis ◽  
Residual Fraction ◽  
Potentially Toxic Metals ◽  
Analytical Technique ◽  
Accumulation Index ◽  
Product Marketing

Abstract The study aims at investigating chemical speciation, bioavailability and risk assessment of some selected metals in soils around refined petroleum depot using the concentrations of the metals as variables to ascertain the impacts of the activities within the petroleum depot. Surface-soils were got from within the premises of Pipelines and Product Marketing Company, Ibadan, Nigeria, while control samples were got at 200 m away from the study location. Electrical conductivity and pH were measured using a calibrated dual purpose meter, while elemental analysis was done using Atomic absorption spectroscopy analytical technique. The results showed that the soils exhibited low ecological risk; minor enrichment for Mn, moderately severe enrichment for Ni and Co, severe enrichment for Cr and extremely severe enrichment for Pb, Zn and Cd; low contamination factor by Pb, Ni, Mn, Cr, Co, and Fe and moderate contamination by Zn and Cd. Geo - accumulation index results indicated unpolluted with Ni, Mn, Cr, Co, and Fe, unpolluted to moderately polluted with Pb and Zn and moderately to strongly polluted with Cd. Inter-element clustering results indicated chemical affinity and/or similar genetic origin among the elements. Speciation analysis suggested that Fe, Co, Cr, Cd, and Ni occurred in the residual fraction; Pb, and Zn in the carbonate fraction, while Mn have its highest percentage in the Fe-Mn oxides fraction. Percentage mobility and bioavailability showed that most of the metals are immobile and non-bioavailable. Study concluded that the oil-impacted soils were contaminated with most of the metals, but with low ecological risk.

Removal of Trace Heavy Metals from Sewage Using the Lime-Magnesium Process

1978 ◽  
Vol 13 (1) ◽  
pp. 149-160
Author(s):  
W.K. Oldham ◽  
B.H. MacLean
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Removal Efficiency ◽  
The Other ◽  
Lime Treatment ◽  
Trace Heavy Metals ◽  
Ph Values ◽  
Treatment Conditions ◽  
Removal Efficiencies

Abstract The research described in this paper is directed toward optimizing conventional lime precipitation of heavy metals by the addition of small quantities of magnesium. Specifically, jar tests were performed to evaluate the effectiveness of adding various concentrations of Mg2+ to both raw sewage and primary effluent to improve the precipitation of metal ions at various reaction pH values. The desired pH levels (10.0, 10.6 and 11.4) were obtained by the addition of lime. General results of the study, using Cr3+, Cu2+, Pb2+, Ni2+ and Zn2+ in concentrations of 0.5, 2.5 and 5.0 mg/l, indicated the following: 1. as expected, the higher the reaction pH, the greater the removal efficiency; 2. for a given reaction pH, the presence of some added Mg++ increased the removal efficiency for all metals tested except Ni2+; 3. on the average, a lime dosage of 220 mg/l (reaction pH=10.6) coupled with an Mg2+ concentration of 30 mg/l, give equivalent removals to high lime treatment at 400 mg/l (reaction pH=11.4); 4. the removal efficiencies varied between 10% and 35% for Ni2+, while the other metals gave results of 35% to 95%, depending upon treatment conditions. It can be concluded that the addition of Mg2+ does indeed enhance the removal of many heavy metals although more work is needed to optimize the combinations for a given type of sewage and to subsequently investigate relative economics.

Enhanced heavy metals removal without phosphorus loss from anaerobically digested sewage sludge

2008 ◽  
Vol 58 (1) ◽  
pp. 201-206 ◽  
Author(s):  
A. Ito ◽  
K. Takahashi ◽  
J. Aizawa ◽  
T. Umita
Keyword(s):  
Heavy Metals ◽  
Hydrogen Peroxide ◽  
Sewage Sludge ◽  
Ferric Hydroxide ◽  
Ferric Sulphate ◽  
Combined Process ◽  
Phosphorus Loss ◽  
Heavy Metals Removal ◽  
Metals Removal ◽  
Digested Sewage Sludge

Heavy metals removal without phosphorus loss from anaerobically digested sewage sludge was investigated by conducting batch experiments using hydrogen peroxide and/or iron sulphate under acidified conditions at pH 3. The addition of hydrogen peroxide to the sludge improved the elution efficiencies of As, Cd, Cu and Zn with phosphorus loss from the sludge. The optimum initial concentrations of hydrogen peroxide were. Respectively. 0.1% for As, Cd, Mn and Zn and 0.5% for Cu and Ni. The combined process of 0.1% hydrogen peroxide and 1 g Fe/L ferric sulphate enhanced the initial elution rate of Cu and Cr compared to the addition of either ferric sulphate or hydrogen peroxide, indicating that oxidants stronger than hydrogen peroxide were produced in the sludge. Furthermore, the combined process immobilised phosphorus in the sludge due to co-precipitation with ferric hydroxide or precipitation as ferric phosphate. It was concluded that there is a possibility that the combined process could remove heavy metals effectively without phosphorus loss from anaerobically digested sewage sludge.

Heavy metals and its chemical speciation in sewage sludge at different stages of processing

2015 ◽  
Vol 37 (7) ◽  
pp. 899-908 ◽  
Author(s):  
Malwina Tytła ◽  
Kamila Widziewicz ◽  
Ewa Zielewicz
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Chemical Speciation
Sign in / Sign up

Export Citation Format

Share Document