scholarly journals Effect of temperature on pyrolysis of sewage sludge: biochar properties and environmental risks from heavy metals

2021 ◽  
Vol 237 ◽  
pp. 01040
Author(s):  
Zhipu Wang ◽  
Shun Liu ◽  
Kai Liu ◽  
Shibo Ji ◽  
Mingming Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Pyrolysis Temperature ◽  
Environmental Risks ◽  
Effect Of Temperature ◽  
Ecological Risks ◽  
Average Pore ◽  
Leaching Potential ◽  
Ph Values ◽  
Increasing Temperature

Biochars were prepared via the pyrolysis of sewage sludge at temperatures ranging from 350–550 °C. The properties and behaviors of heavy metals in the biochars were investigated. The results indicated that the pH values and ash contents of the biochars increased, while biochar yield and C, H, and N contents decreased with the increasing temperature. A high pyrolysis temperature contributed to a developed biochar pore structure. The specific surface area and pore volume of the biochars increased, while the average pore width decreased, with the increasing temperature. Heavy metals in the biochars were further enriched with the increasing temperature. TCLP tests demonstrated that the leaching potential of heavy metals from the biochars significantly decreased with the increasing temperature, indicating the decrease of potential ecological risks of heavy metals to the environment. Additionally, BCR tests confirmed the transformation of heavy metals from mobile fractions (F1 and F2) to stable fractions (F3 and F4). The evaluation results showed that a high pyrolysis temperature can effectively inhibit the ecological risks of heavy metals in the biochars. Thus, the conversion of sewage sludge into biochar via pyrolysis is a promising method for the safe disposal of sewage sludge.

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 Sorption of Selected Heavy Metals with Different Relative Concentrations in Industrial Effluent on Biochar from Human Faecal Products and Pine-Bark

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1768 ◽  
Author(s):  
Koetlisi Andreas Koetlisi ◽  
Pardon Muchaonyerwa
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Industrial Effluent ◽  
Pine Bark ◽  
Sorption Data ◽  
Removal Of Heavy Metals ◽  
Maximum Sorption ◽  
Batch Sorption Experiment ◽  
Increasing Temperature ◽  
Waste Sewage Sludge

The removal of heavy metals from effluents at source could reduce contamination of soil and water bodies. A batch sorption experiment was performed to determine the effects of feedstock of biochars pyrolysed at increasing temperature on sorption capacities of Cu, Cr and Zn from industrial effluent and aqueous solutions. Sewage sludge, latrine faecal waste and pine-bark biochars were used. The sorption data were fitted to the Langmuir isotherm. Maximum sorption capacities of latrine waste, sewage sludge and pine-bark biochar (350 °C) were, respectively, 313, 400 and 233 mg kg−1 for Zn, 102, 98.0 and 33.3 mg kg−1 for Cu, and 18.9, 13.8 and 67.1 mg kg−1 for Cr from industrial effluent. Conversely, sorption capacities from single metal solutions were 278, 227 and 104 mg Zn kg−1, 97.1, 137 and 21.3 mg Cu kg−1, 122, 106 and 147 mg Cr kg−1 on latrine waste, sewage sludge and pine-bark biochar, respectively. Step-wise regression analysis showed that the combined effects of ash, fixed C, pH influenced Zn sorption, ash and fixed C affected Cu sorption, and Cr sorption by ash and specific surface area of the biochar. The findings of the study imply that biochar from human faecal waste, particularly sewage sludge, has the potential to be utilized as sorbents of heavy metals from multiple metal effluent and that the sorption is affected by relative concentrations.

Effects of pyrolysis temperature on properties of swine manure biochar and its environmental risks of heavy metals

2020 ◽  
Vol 152 ◽  
pp. 104945
Author(s):  
Feiyue Li ◽  
Xuan Wu ◽  
Wenchao Ji ◽  
Xiangyang Gui ◽  
Yihan Chen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Pyrolysis Temperature ◽  
Swine Manure ◽  
Environmental Risks

Characteristics of Pollutants Removal by Carbonized Porous Media Made from Sewage Sludge

2014 ◽  
Vol 804 ◽  
pp. 99-102
Author(s):  
Yeong Seok Yoo ◽  
Jun Ho Jo ◽  
Gyu Tae Seo
Keyword(s):  
Heavy Metals ◽  
Porous Media ◽  
Sewage Sludge ◽  
Average Pore Size ◽  
Sewage Treatment ◽  
Pollutant Removal ◽  
Equilibrium Equations ◽  
Average Pore ◽  
Metals Removal ◽  
Pollutants Removal

In this study, carbonized porous media was manufactured using sewage sludge and analyzed for pollutants removal characteristics. Sewage sludge produced by activated sludge sewage treatment contained much organics to be carbonized, so it was mixed with other mixtures, extruded and formed in ∅ 5~10 mm ball shape, and sintered at 900°C and 1 hour in furnace for carbonization under N2 purge. The characteristics of the porous media was BET 35 m2/g and average pore size 39.3Å, pore volume 0.0092 cm3/g, Iodine number 45.9 and bulk density 0.91 cm3/g. Experiments were performed for SS, phosphate, nitrate and heavy metals (Cu, Zn). Its removal characteristics of SS and fertilizer components were compared with gravel’s used in filtration and its heavy metals removal was characterized by derivation of its adsorption equilibrium equations. In result, the carbonized porous media could be utilized as massive adsorption media for pollutant removal or fertilizer adsorption in fields of roof planting or non-point source pollutants control.

Removal of Heavy Metals from Aqueous Solution Using Biochar Derived from Biomass and Sewage Sludge

2015 ◽  
Vol 768 ◽  
pp. 89-95 ◽  
Author(s):  
Han Qiao Liu ◽  
Xian Xu ◽  
Zhen Hua Wu ◽  
Guo Xia Wei ◽  
Lei Sun
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Sewage Sludge ◽  
Heating Rate ◽  
Pyrolysis Temperature ◽  
Optimum Conditions ◽  
Solution Ph ◽  
Adsorption Time ◽  
Mixed Aqueous Solution ◽  
Removal Of Heavy Metals

Biochar, a production of cotton/sludge pyrolysis, was used as an adsorbent for the removal of heavy metals from aqueous solutions. In this paper, it was assessed that the effect of biochar produced parameters including pyrolysis temperature and heating rate, adsorption time, solution pH and biochar modification on removal of Cd from aqueous solution, and the removal effect of heavy metals from mixed aqueous solution was also studied. The results showed that the optimum conditions were pyrolysis temperature of 550°C, heating rate of 5°C/min, adsorption time of 90min, biochar dosage of 10g/L and solution pH=6, respectively. And the effect was a little increased when the biochar were impregnated with chemicals. About 99% Cd, Pb and Zn were removed from aqueous solution using biochar under the optimum conditions.

scholarly journals Influence of Temperature on Characteristics of Particulate Matter and Ecological Risk Assessment of Heavy Metals during Sewage Sludge Pyrolysis

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5838
Author(s):  
Binbin Li ◽  
Haihong Fan ◽  
Songxiong Ding ◽  
Yixuan Luan ◽  
Yiming Sun
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Particulate Matter ◽  
Sewage Sludge ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
Pyrolysis Temperature ◽  
Inorganic Particles ◽  
Different Temperatures ◽  
Influence Of Temperature On

The formation process of Particulate Matter (PM) during sludge pyrolysis at different temperatures (300–700 °C) and the ecological risks of heavy metals were studied. The results showed that the particulate matter is mainly condensed on the quartz film in a carbon-based organic matter when the pyrolysis temperature was between 200–500 °C in a volatilization process. Inorganic particles was found in the particulate matter when the temperature was raised to 500–700 °C in a decomposition stage. Heavy metals were enriched in particulate matter with increase in pyrolysis temperature. When the temperature reached 700 °C, the concentration of Pb and Cd in the particulate matter significantly increased. The ecological risk assessment showed that heavy metals in the sewage sludge had considerable ecological toxicity. When the pyrolysis temperature reached 700 °C, the ecological toxicity of those heavy metals enriched in the particulate matter decreased considerably.

scholarly journals PENGARUH SUHU, WAKTU, DAN KADAR AIR PADA PIROLISIS PELEPAH KELAPA SAWIT

2017 ◽  
Vol 6 (2) ◽  
pp. 14-18
Author(s):  
Frist Silia ◽  
Seri Maulina
Keyword(s):  
Processing Time ◽  
Pyrolysis Temperature ◽  
Ph Value ◽  
Gas Production ◽  
Effect Of Temperature ◽  
Pyrolysis Process ◽  
Liquid Smoke ◽  
Yield And Quality ◽  
Increasing Temperature

Palm plantations in Indonesia began to grow rapidly since the early 80s. The area of ​​Indonesia's oil palm in 2013 was 10.4 million ha and increased 4.69% annually.  The production of palm midrib was about 22 midribs per tree per year with the weight of midrib meat ranging from 2.2 kg. The palm midrib is composed of cellulose, hemicellulose, and lignin, which can be used as liquid smoke. The purpose of this study was to analyze the effect of temperature and time of pyrolysis on the yield and quality of liquid smoke produced. The pyrolysis process of fractured palm was performed at 150 ºC, 200 ºC, and 250 ºC for 30 minutes, 60 minutes, 90 minutes. The results indicated that the yield of liquid smoke tends to decrease with increasing pyrolysis temperature, and tends to increase with increasing pyrolysis time in which the difficult condensed gas production increases with increasing temperature and time of pyrolysis. The highest yield of liquid smoke pyrolysis temperature of 150 OC with pyrolysis time 120 minutes that is equal to 43.47%. In this study, obtained the best results for a pH value of 3.1 is done at process temperatures of 250 ° C with processing time 60 minutes

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.

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