The fate of heavy metals in excess sludge during disintegration by discharge plasma

2021 ◽  
Vol 277 ◽  
pp. 119433
Author(s):  
Tengfei Li ◽  
Yuxuan Zhang ◽  
Zhiyin Ren ◽  
Xiwen Cheng ◽  
Hu Li ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Discharge Plasma ◽  
Excess Sludge

Research on the stability of heavy metals (Cu, Zn) in excess sludge with the pretreatment of thermal hydrolysis

2015 ◽  
Vol 73 (4) ◽  
pp. 890-898 ◽  
Author(s):  
Huimin Wu ◽  
Meng Li ◽  
Lei Zhang ◽  
Chao Sheng
Keyword(s):  
Heavy Metals ◽  
Anaerobic Digestion ◽  
Chemical Speciation ◽  
Stable Form ◽  
Thermal Hydrolysis ◽  
Excess Sludge ◽  
The Stability ◽  
Cu And Zn

Thermal hydrolysis (TH) has been used to improve anaerobic digestion performance as well as the stability of heavy metals in sludge. Because the toxicity of heavy metals is closely related to both the concentration and the chemical speciation, more exhaustive studies on speciation distribution are urgently needed. This research aimed to investigate the effects of TH treatment (especially the time and temperature) on the concentration and stability of heavy metals in sludge, and to define the optimal TH conditions. The TH experiment indicated that the content of the stable form of Cu and Zn reached 83% and 47.4%, respectively, with TH at 210°C and 30 min. Compared with the raw sludge, the proportion of Cu and Zn increased by 11.88% and 7.3%, respectively. Results indicated that the heavy metals were combined with sludge in a more stable form with the pretreatment of TH, which improved the stability of heavy metals.

scholarly journals Optimizing Heavy Metals Removal of Excess Sludge by Biodegradable Chelants GLDA Using a Response Surface Methodological Approach

2018 ◽  
Vol 27 (4) ◽  
pp. 1841-1850 ◽  
Author(s):  
Xu Da-Yong ◽  
Hong Ya-Jun ◽  
Yao Qiao-Feng ◽  
Cao Pei-Pei ◽  
Zhan Ling-Ling ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Response Surface ◽  
Methodological Approach ◽  
Excess Sludge ◽  
Heavy Metals Removal ◽  
Metals Removal

Transformation and Migration of Heavy Metals by Aquatic Worms in Wastewater Treatment

2012 ◽  
Vol 573-574 ◽  
pp. 526-533
Author(s):  
Wei Fei Huang ◽  
Ying Gang Shu ◽  
Lu Cai ◽  
Sheng Liang Si
Keyword(s):  
Heavy Metals ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Environmental Risk ◽  
Sludge Reduction ◽  
Excess Sludge ◽  
Safe Disposal ◽  
Waste Sludge ◽  
And Migration ◽  
Sludge Settleability

L. hoffmeisteri was inoculated in reactor to investigate the effects on waste sludge and wastewater to reduce excess sludge and reduce the environmental risk of heavy metals in sludge and effluent in this study. The result showed a gravimetric sludge reduction of 53.8% and modification in the texture of the sludge. The residual form of heavy metals (As, Cd, Cr, Cu, Ni, Pb and Zn) was increased, which reduced the risk of the phytoaccumulation. An evident concentration of heavy metals in worm faece and a bioaccumulation of heavy metals in aquatic worms were also observed. Activated sludge is reduced significantly, sludge settleability is improved and the bioavailability of heavy metals in waste sludge is minimized, which are beneficial to wastewater treatment and safe disposal of waste sludge.

scholarly journals Residual and ecological risk assessment of heavy metals in fly ash from co-combustion of excess sludge and coal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yao Tang ◽  
Jingshi Pan ◽  
Biqing Li ◽  
Suying Zhao ◽  
Liguo Zhang
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Ecological Risk ◽  
Fine Particles ◽  
Total Concentration ◽  
Excess Sludge ◽  
Leaching Toxicity ◽  
Main Fraction ◽  
Total Concentrations

AbstractCo-combustion of municipal excess sludge (ES) and coal provides an alternative method for disposing ES. The present study aims to investigate the residual and ecological risk of heavy metals in fly ash from co-combustion of ES and coal. The total concentration and speciation distribution of heavy metals, characterization of SEM, EDX, XRD and leaching test were carried out to assess the fly ash in this study. The results showed that the total concentrations of Cu, Zn and Mn were higher than others in fly ash, and most heavy metals were concentrated in fine particles. For Cd, Cr and Pb, the percentages of speciation of F4 and F5 were all over 90%, suggesting the relatively lower leaching toxicity. The leaching percent of all heavy metals was lower than 5% by two diluted HNO3 solutions for fly ash. The potential ecological risks increased with the decrease of particle size of fly ash, and Cd accounted for the main fraction for ecological risk despite of lower concentration in comparison to other measured heavy metals.

Excess sludge disintegration by discharge plasma oxidation: Efficiency and underlying mechanisms

2021 ◽  
Vol 774 ◽  
pp. 145127
Author(s):  
Tengfei Li ◽  
Yanhui Fan ◽  
Hu Li ◽  
Zhiyin Ren ◽  
Liqing Kou ◽  
...  
Keyword(s):  
Discharge Plasma ◽  
Plasma Oxidation ◽  
Excess Sludge ◽  
Underlying Mechanisms ◽  
Oxidation Efficiency

Treatment of Excess Sludge Containing Heavy Metal by Chemical Ways

2012 ◽  
Vol 178-181 ◽  
pp. 507-511
Author(s):  
Zhi Min Zhang
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Wastewater Treatment Plants ◽  
Heavy Metal Removal ◽  
Municipal Wastewater Treatment ◽  
Excess Sludge ◽  
Municipal Wastewater Treatment Plants

The concentration of heavy metals in excess sludge from municipal wastewater treatment plants has restricted its convertion to soil fertilizer, so it is necessary to remove the heavy metals from sludge. In this article, the effects of heavy metal removal by some mineral acids such as HCl, H2SO4, H3PO4, HNO3 were analysed, when treating excess sludge from a second sediment tank in municipal wastewater treatment plants. To improve the treatment, a combination of H2O2 and acid was also investigated. Consequently, the difference of heavy metal removal among those acids was showed. Its removal of Hg by HNO3 was better than by other acids. Lower pH enhanced the dissolving of heavy metal, yet the removal of Cr was insensitive to the pH. Aided by H2O2, the removal by the acid was enhanced. The suitable dosage of H2O2 was specially related to the solid content of sludge, pH and the acid kind.

Metal Removal by Waste Biomass to Upgrade Wastewater Treatment Plants

1990 ◽  
Vol 22 (7-8) ◽  
pp. 319-320 ◽  
Author(s):  
C. Venkobachar
Keyword(s):  
Heavy Metals ◽  
Ganoderma Lucidum ◽  
Waste Treatment ◽  
Metal Removal ◽  
Wastewater Treatment Plants ◽  
Domestic Wastewater ◽  
Waste Biomass ◽  
Excess Sludge ◽  
Tannery Effluents ◽  
Biological Waste Treatment

As a pretreatment, biosorption is evaluated for its ability to remove heavy metals from electroplating and chrome tannery effluents before these are mixed with domestic wastewater for biological waste treatment. The biosorptive capacities of Cu(II) and Cr(VI) by waste biomass like excess sludge from activated sludge unit (S), Ganoderma lucidum (M)–a wood-rotting fungus, and Asperigillus niger (A) from fermentation industry are evaluated.

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