scholarly journals Chemical forms and risk assessment of heavy metals in sludge-biochar produced by microwave-induced low temperature pyrolysis

RSC Advances ◽  
2016 ◽  
Vol 6 (104) ◽  
pp. 101960-101967 ◽  
Author(s):  
Xingxin Liu ◽  
Yawei Wang ◽  
Chengmin Gui ◽  
Ping Li ◽  
Junya Zhang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Sewage Sludge ◽  
Low Temperature ◽  
Chemical Forms ◽  
Low Temperature Pyrolysis

Microwave-induced low temperature pyrolysis can reduce the risk of most heavy metals in biochar prepared from sewage sludge, except the Cd and Pb.

scholarly journals Identification of the Chemical Forms of Heavy Metals in Municipal Sewage Sludge as a Critical Element of Ecological Risk Assessment in Terms of Its Agricultural or Natural Use

2020 ◽  
Vol 17 (13) ◽  
pp. 4640 ◽  
Author(s):  
Malwina Tytła
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Sewage Sludge ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
Municipal Wastewater ◽  
Risk Index ◽  
Municipal Sewage Sludge ◽  
Critical Element ◽  
Chemical Forms

The present study aimed to demonstrate that identification of the chemical forms of heavy metals in sewage sludge produced in municipal Wastewater Treatment Plants (WWTPs) is a critical element of ecological risk assessment, especially in terms of its agricultural or natural use. The concentrations of seven heavy metals (Cd, Cr, Cu, Ni, Pb, Zn and Hg) were determined using inductively coupled plasma optical spectrometry (ICP-OES) and cold vapor atomic absorption spectrometry (CV-AAS). The chemical forms of heavy metals were analyzed in accordance with the sequential extraction method proposed by the Community Bureau of Reference (BCR). Sludge samples were collected at the five municipal WWTPs located in the largest industrial area in the country, i.e., the Upper Silesian Industrial Region (southern Poland, central Europe). The ecological risk was assessed by calculating the Potential Ecological Risk Factor (ER), Risk Index (RI), Risk Assessment Code (RAC), Individual Contamination Factor (ICF), Global Risk Index (GRI) as well as the author’s indices, i.e., Individual Ecological Risk (IER) and Global Ecological Risk (GER). To demonstrate the differences between the level of ecological risk posed by the different heavy metals, sludge samples were collected at two specific points of the processing line. Considering the chemical forms of heavy metals, the highest ecological risk was posed by Zn, Cd and Ni, while in the case of their total concentrations, by Cd and Hg. The obtained results confirm that quantitative determination of the total content of heavy metals in sewage sludge is not a sufficient criterion in assessment of the ecological risk that these elements pose to the natural environment and living organisms. Moreover, multivariate statistical analysis revealed a significant correlation between the concentrations of heavy metals, which indicates that they plausibly originate from the same source of pollution.

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.

Migration and risk assessment of heavy metals in sewage sludge during hydrothermal treatment combined with pyrolysis

2016 ◽  
Vol 221 ◽  
pp. 560-567 ◽  
Author(s):  
Xingdong Wang ◽  
Chunxing Li ◽  
Bin Zhang ◽  
Jingjiang Lin ◽  
Qiaoqiao Chi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Sewage Sludge ◽  
Hydrothermal Treatment

Research Progress of Oil Making from Sewage Sludge

2016 ◽  
Vol 851 ◽  
pp. 232-236
Author(s):  
Jiang Long Lu ◽  
Guo Ri Dong ◽  
Fang Chen ◽  
Ji Bin Wang
Keyword(s):  
High Temperature ◽  
Sewage Sludge ◽  
Low Temperature ◽  
Hot Spots ◽  
Energy Utilization ◽  
Research Progress ◽  
Treatment And Disposal ◽  
Low Temperature Pyrolysis

the treatment and disposal of sewage sludge is one of the hot spots in recent years, and the value of its energy utilization has gradually received attention by researchers. In this paper, the concept, yield, harm as well as the conventional disposal methods of sewage sludge are described, three kinds of main technologies of oil making from sewage sludge are introduced, including high temperature pyrolysis, low-temperature pyrolysis and direct thermo chemical liquefaction, and the research progress of these three technologies is reviewed.

Release of organic sulfur as sulfur-containing gases during low temperature pyrolysis of sewage sludge

2015 ◽  
Vol 35 (3) ◽  
pp. 2767-2775 ◽  
Author(s):  
Shuai Liu ◽  
Mengmeng Wei ◽  
Yu Qiao ◽  
Zhenle Yang ◽  
Ben Gui ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Low Temperature ◽  
Organic Sulfur ◽  
Low Temperature Pyrolysis ◽  
Sulfur Containing

scholarly journals Assessment of Heavy Metal Pollution and Potential Ecological Risk in Sewage Sludge from Municipal Wastewater Treatment Plant Located in the Most Industrialized Region in Poland—Case Study

2019 ◽  
Vol 16 (13) ◽  
pp. 2430 ◽  
Author(s):  
Malwina Tytła
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Wastewater Treatment ◽  
Risk Factor ◽  
Sewage Sludge ◽  
Ecological Risk ◽  
Treatment Plant ◽  
Potential Ecological Risk ◽  
Pollution Level ◽  
Chemical Forms

This study aimed to assess the pollution and potential ecological risk of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in the sewage sludge collected from a wastewater treatment plant (WWTP), located in the most industrialized region of Poland (Silesian Voivodeship). The concentrations of heavy metals were determined using inductively coupled plasma optical spectrometry (ICP-OES) and cold vapor atomic absorption spectrometry (CVAAS). The chemical forms (chemical speciation) of heavy metals were determined using the three-step chemical sequential extraction procedure, developed by the Community Bureau of Reference (BCR). To assess the pollution level and potential ecological risk, the following indices were used: Geoaccumulation Index (Igeo), Potential Ecological Risk Factor (ER), Individual Contamination Factor (ICF), Risk Assessment Code (RAC), and Ecological Risk Factor (ERF)—the author’s index. Sludge samples were collected at successive stages of processing. The results revealed that the activated sludge process and sludge thickening have a significant impact on heavy metal distribution, while anaerobic digestion and dehydration decrease their mobility. The most dominant metals in the sludge samples were Zn and Cu. However, the content of heavy metals in sewage sludge did not exceed the permissible standards for agricultural purposes. The concentrations of heavy metals bound to the immobile fractions exhibited higher concentrations, compared to those bound to mobile fractions (except Zn). The values of the total indices indicated that sludge samples were moderately to highly contaminated with Zn, Hg, Cd, Cu, and Pb, of which only Hg, Cd, and Cu posed a potential ecological risk, while according to the speciation indices, sludge samples were moderately to very highly polluted with Zn, Cu, Cd, Cr, and Ni, of which Zn, Ni, and Cd were environmentally hazardous. The obtained results proved that assessment of the pollution level and potential ecological risk of heavy metals in sewage sludge requires knowledge on both their total concentrations and their chemical forms. Such an approach will help prevent secondary pollution of soils with heavy metals, which may influence the reduction of health risks associated with the consumption of plants characterized by a high metal content.

Effect of alkali addition on sulfur transformation during low temperature pyrolysis of sewage sludge

2017 ◽  
Vol 36 (2) ◽  
pp. 2253-2261 ◽  
Author(s):  
Shan Cheng ◽  
Yu Qiao ◽  
Jingchun Huang ◽  
Liwen Cao ◽  
Huaizhou Yang ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Low Temperature ◽  
Sulfur Transformation ◽  
Low Temperature Pyrolysis ◽  
Alkali Addition
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