Influence of the Addition of Cotton Stalk during Co-pyrolysis with Sewage Sludge on the Properties, Surface Characteristics, and Ecological Risks of Biochars

Wang, Zhipu; Wang, Jian; Xie, Lipeng; Zhu, Henan; Shu, Xinqian

doi:10.1007/s11630-019-1100-1

Cited by 29 publications

(9 citation statements)

References 24 publications

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“…As shown in Figure 3, the concentration of Ni increased after microwave treatment. This phenomenon was also observed in the conventional thermal hydrolysis treatment process of sewage sludge (Zhang et al 2016;Wang et al 2019). Ni mainly existed in acid-soluble/exchangeable fraction in the raw sludge (Figure 3).…”

Section: Migration and Transformation Of Heavy Metals In The Sewage Sludgesupporting

confidence: 56%

“…Over 65% (more than twice of the initial content) of Ni was presented in oxidizable fraction (metal sulfide and organic bound form) in the treated sludge (160°C), which was the main reason for the increase of the total Ni concentration. Previous study had concluded that the enrichment of Ni might be due to its higher thermal stability compared with organic materials (Wang et al 2019).…”

Section: Migration and Transformation Of Heavy Metals In The Sewage Sludgementioning

confidence: 97%

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Migration and transformation of heavy metals during the microwave-assisted thermal hydrolysis of sewage sludge

Qiu

Zheng

Wang

et al. 2021

Water Science and Technology

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The migration, transformation and ecological risk of heavy metals (Cr, As, Ni, Cu, Zn, Cd and Pb) in the sewage sludge during the microwave-assisted thermal hydrolysis process were investigated under different temperatures (80 °C, 100 °C, 120 °C, 140 °C, and 160 °C). The potential relationship between the bio-availability of heavy metals and the variables of microwave treatment, including pH, ammonium-nitrogen, soluble chemical oxygen demand, pH, soluble protein, soluble polysaccharide and volatile solid, was also explored. The results showed that the migration of heavy metals between solid-liquid phase mainly depended on the temperature. The percentage of all heavy metals (except Cu) in mobile (acid-soluble/exchangeable and reducible) forms decreased after microwave-assisted thermal hydrolysis treatment. The solubilization of compounds with C = O and O-H accompanied with the generation of organic and inorganic metal halides were also observed in the treated sludge through fourier transform infrared spectroscopy analysis. NH4+-N showed the highest negative correlation to the bio-availability of most heavy metals (except Cu and Cr) with coefficients (absolute value) over 0.87 (P < 0.05). VS showed a positive correlation to the bio-availability of most heavy metals (except Cu). The total potential ecological risk index (RI) decreased by 46.65% after microwave treatment at 160 °C.

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Section: Migration and Transformation Of Heavy Metals In The Sewage Sludgesupporting

confidence: 56%

Section: Migration and Transformation Of Heavy Metals In The Sewage Sludgementioning

confidence: 97%

Migration and transformation of heavy metals during the microwave-assisted thermal hydrolysis of sewage sludge

Qiu

Zheng

Wang

et al. 2021

Water Science and Technology

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“…The above results indicate that generally these two heavy metals posed from a low to a moderate ecological risk. In contrast to the above findings, other scientists indicated that the sewage sludge collected from WWTP in Urumqi (Xinjiang Province, China) were slightly polluted by Cd, Cr, Cu, Ni, Pb and Zn (GRI: 132.9), which means that these elements did not pose a serious threat to the environment and living organisms [ 33 ]. However, it should be emphasized that, so far, both ICF and GRI have rarely been used in relation to sewage sludge.…”

Section: Resultsmentioning

confidence: 89%

“…For example, both ER and RI focus on the total quantity of heavy metals and their toxicity; RAC, ICF, IER and GER focus on heavy metal mobility, while GRI includes both mobility and toxicity [ 2 ]. The most commonly used indices are ER, RI and RAC [ 2 , 9 , 31 , 32 ], while ICF and GRI are rarely applied [ 2 , 33 ]. The above-listed indices (except for IER and GER) were also used to assess the ecological risk in other environmental samples, like soils and sediments [ 5 , 30 , 34 ].…”

Section: Introductionmentioning

confidence: 99%

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

Tytła

2020

IJERPH

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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.

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“…Since the industrial revolution, the concentration of carbon dioxide in the atmosphere has increased by nearly 30% [4], which is widely considered to be the main cause of the greenhouse effect [5]. The biomass utilization for bioenergy can help to reduce the emission of greenhouse gases and other toxic and harmful gases [6,7], and reduce the dependence of social development on fossil energy [8,9]. As a representative renewable biomass, woody biomass is anticipated to take on an increasingly significant role in the production of bioenergy (such as biochar and biogas) and chemical feedstocks [10,11].…”

Section: Introductionmentioning

confidence: 99%

Comparative Thermal Degradation Behaviors and Kinetic Mechanisms of Typical Hardwood and Softwood in Oxygenous Atmosphere

Pan

Chen

2021

Processes

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In order to utilize woody biomass effectively for bioenergy and chemical feedstocks, the comparative thermal degradation behaviors and kinetic mechanisms of typical hardwood (beech wood) and softwood (camphorwood) were studied at various heating rates in air. The Kissinger-Akahira-Sunose approach combined with the Coats-Redfern approach was employed to estimate the kinetic triplet. Softwood degradation began and ended at lower temperatures than hardwood. Compared with softwood, the maximal reaction rate of hardwood was greater and occurred in the higher temperature region. Two decomposition regions were determined by the variation of activation energy, and the dividing point was α = 0.6 and α = 0.65 for hardwood and softwood, respectively. Moreover, the average activation energy of hardwood was larger than that of softwood during the whole decomposition process. The thermal degradation process occurring in region 1 was dominated by the Avrami-Erofeev and 3D diffusion models for hardwood and softwood, respectively. Furthermore, the kinetic modeling results showed good consistency between the experimental and simulated curves under 5, 15, 20, and 40 K/min. It is noted that the thermogravimetric experimental profile under 20 K/min was not used for estimating the kinetic triplet. Besides, the combustion performance of hardwood is superior to softwood under the same external conditions (heating rate and atmosphere).

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Influence of the Addition of Cotton Stalk during Co-pyrolysis with Sewage Sludge on the Properties, Surface Characteristics, and Ecological Risks of Biochars

Cited by 29 publications

References 24 publications

Migration and transformation of heavy metals during the microwave-assisted thermal hydrolysis of sewage sludge

Migration and transformation of heavy metals during the microwave-assisted thermal hydrolysis of sewage sludge

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

Comparative Thermal Degradation Behaviors and Kinetic Mechanisms of Typical Hardwood and Softwood in Oxygenous Atmosphere

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