scholarly journals Assessment of Heavy Metals Inactivation in Contaminated Soil by Coal Fly and Bottom Ashes

Mineralogia ◽  
2017 ◽  
Vol 48 (1-4) ◽  
pp. 127-143
Author(s):  
Jean Diatta ◽  
Edward Fojcik ◽  
Leszek Drobek ◽  
Tomasz Spiżewski ◽  
Włodzimierz Krzesiński

Abstract The study compared coal fly and bottom ashes for their ability to inactivate metals and lead to soil remediation. Soil was artificially contaminated with Cu, Zn, Pb and Cd at five degrees. Next, both ashes were added at five rates: 0, 0.5, 1.0, 1.5 and 2.0% and all treatments incubated. Data showed that for moderately contaminated soils, ash rates of 0.5 - 1.0% were efficient from 40 to 70% for Zn and Cd, and raised markedly to between 70 and 93% for Cu and Pb. For extremely contaminated soils, the rates of ashes at 1.0, 1.5 and 2% were much more efficient (60 - 80%). The use of fly and bottom ashes for metal inactivation and soil remediation should give greater consideration to the effect of pH and the type of heavy metals than the content of SiO2and Al2O3. Fly ash displayed superior inactivation and remediation effects to the bottom ash.

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 448
Author(s):  
Mahrous Awad ◽  
Zhongzhen Liu ◽  
Milan Skalicky ◽  
Eldessoky S. Dessoky ◽  
Marian Brestic ◽  
...  

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.


2011 ◽  
Vol 194-196 ◽  
pp. 2365-2375
Author(s):  
Jai Houng Leu ◽  
Li Fong Wu ◽  
Ay Su

This research investigated and explored the overall technical and legal suggestions on mixed ash (bottom ash + fly ash) from the first BOT(built-operation then transfer) incineration plant in south Taoyuan of Taiwan, with the hope of serving as the reference for treating ash from urban refuse incinerator and making sustainable operation management policies in Taiwan. Both bottom ash and fly ash contain high-content harmful metals like lead, chrome, and cadmium, with the lead content exceeding standard value. Plasma fusing technology may effectively settle toxic heavy metals and reduce their dissolution rate. The results show that the increase in percentage of bottom ash could maintain post-fusing strength and produce solidification effect, but this reduced the stability of toxic heavy metals and raised their dissolution rate. Suitable mixture ratio of bottom ash and fly ash was 2:1, volume reduction ratio 0.349, and weight reduction ratio 0.4936. The mixture was fulvous and dense with gloss and adequate strength. The dissolution test of lava products complied with national standards, and they might be used for recycling aggregates and solidifying cement.


2020 ◽  
Vol 10 (17) ◽  
pp. 6075
Author(s):  
Ahmad Assi ◽  
Fabjola Bilo ◽  
Alessandra Zanoletti ◽  
Laura Borgese ◽  
Laura Eleonora Depero ◽  
...  

This study presents an innovative stabilization method of fly ash derived from co-combustion of municipal solid waste and sewage sludge. Bottom ash, obtained from the same process, is used as a stabilizing agent. The stabilization method involved the use of two other components—flue gas desulfurization residues and coal fly ash. Leaching tests were performed on stabilized samples, aged in a laboratory at different times. The results reveal the reduction of the concentrations of heavy metals, particularly Zn and Pb about two orders of magnitude lower with respect to fly ash. The immobilization of heavy metals on the solid material mainly depends on three factors—the amount of used ash, the concentrations of Zn and Pb in as-received fly ash and the pH of the solution of the final materials. The inert powder, obtained after the stabilization, is a new eco-material, that is promising to be used as filler in new sustainable composite materials.


Chemosphere ◽  
2020 ◽  
Vol 240 ◽  
pp. 124845 ◽  
Author(s):  
Mehr Ahmed Mujtaba Munir ◽  
Guijian Liu ◽  
Balal Yousaf ◽  
Muhammad Ubaid Ali ◽  
Qumber Abbas ◽  
...  

2019 ◽  
Vol 112 ◽  
pp. 03020
Author(s):  
Mihaela Niţu ◽  
Augustina Pruteanu ◽  
Despina Maria Bordean ◽  
Carmen Popescu ◽  
Gyorghy Deak ◽  
...  

Heavy metals in contaminated soils have benefited from a considerable attention due to the possible risks for the human body. The current study has investigated the accumulation and transfer coefficient for three heavy metals (Cu, Pb, Zn) found in the contaminated soil with three concentrations (c1=1.5%, c2=3.0%, c3=4.5%, c4=6.0%), obtained by mixing the three metals, in the tomato fruit. The highest accumulation in the tomato fruits was recorded for zinc, then copper and the smallest for lead, for all four concentrations used. The transfer coefficient decreases as the concentration of heavy metals increases, so that for high heavy metals concentrations, the values of the transfer coefficient are very low, and for small heavy metals concentrations in the soil, the values for the transfer coefficient are higher. The assessment of accumulation and transfer of heavy metals in the fruits of tomatoes grown in the contaminated soil has concluded that all concentrations of the copper, lead and zinc mix have shown a low risk for human consumption.


Author(s):  
Kanghee Cho ◽  
Eunji Myung ◽  
Hyunsoo Kim ◽  
Cheonyoung Park ◽  
Nagchoul Choi ◽  
...  

In this study, we investigated the feasibility of using a solution of sulfuric acid and phosphoric acid as an extraction method for soil-washing to remove Cu, Pb, Zn, and As from contaminated soil. We treated various soil particles, including seven fraction sizes, using sulfuric acid. In addition, to improve Cu, Pb, Zn, and As removal efficiencies, washing agents were compared through batch experiments. The results showed that each agent behaved differently when reacting with heavy metals (Cu, Pb, and Zn) and As. Sulfuric acid was more effective in extracting heavy metals than in extracting As. However, phosphoric acid was not effective in extracting heavy metals. Compared with each inorganic acid, As removal from soil by washing agents increased in the order of sulfuric acid (35.81%) < phosphoric acid (62.96%). Therefore, an enhanced mixture solution using sulfuric acid and phosphoric acid to simultaneously remove heavy metals and As from contaminated soils was investigated. Sulfuric acid at 0.6 M was adopted to combine with 0.6 M phosphoric acid to obtain the mixture solution (1:1) that was used to determine the effect for the simultaneous removal of both heavy metals and As from the contaminated soil. The removal efficiencies of As, Cu, Pb, and Zn were 70.5%, 79.6%, 80.1%, and 71.2%, respectively. The combination of sulfuric acid with phosphoric acid increased the overall As and heavy metal extraction efficiencies from the contaminated soil samples. With the combined effect of dissolving oxides and ion exchange under combined washings, the removal efficiencies of heavy metals and As were higher than those of single washings.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Chen-Yao Chu ◽  
Tzu-Hsing Ko

Heavy metal-contaminated soils were leached with various acid reagents, and a series of treatments was assessed to understand soil fertility after acid leaching. Aqua regia digestion and a five-step sequential extraction procedure were applied to determine heavy metal distribution. The average total concentrations of Zn, Cd, Cu, and Pb for contaminated soil were 1334, 25, 263, and 525 mg·kg−1 based on the ICP/AES quantitative analysis. Other than Pb extracted by H2SO4, over 50% removal efficiency of other heavy metals was achieved. A five-step sequential extraction revealed that the bound-to-carbonate and bound-to-Fe-Mn oxides were the major forms of the heavy metals in the soil. The addition of organic manure considerably promoted soil fertility and increased soil pH after acid leaching. Seed germination experiments demonstrated that after acid leaching, the soil distinctly inhibited plant growth and the addition of manure enhanced seed germination rate from 35% to 84%. Furthermore, the procedure of soil turnover after acid leaching and manure addition greatly increased seed germination rate by 61% and shortened the initial germination time. Seed germination in untreated soil was superior to that in acid-leached soil, illustrating that the phytotoxic effect of acid leaching is more serious than that of heavy metals.


2015 ◽  
Vol 773-774 ◽  
pp. 1261-1265 ◽  
Author(s):  
Aeslina Abdul Kadir ◽  
Mohd Ikhmal Haqeem Hassan ◽  
Syed Khairul Hafizi bin Syed Mohamad

The growing demand for electricity resulted in the construction of many coal fired power plants. The increment of the consumption of coal by power plants lead up to production of coal ash. Coal ash contains a range of toxic elements that may have negative effects to human and environmental health. Fly ash (FA) and bottom ash (BA) are the solid residues and mostly arise from coal combustion that being disposed in large quantities every year. The focus of the study is to determine the leachability of Self-Compacting Concrete (SCC) incorporated with FA and BA by using Static Leachate Test (SLT) method. In this study, FA and BA were collected from Kapar Energy Ventures Coal Power Plant in Selangor. The characteristics of Ordinary Portland cement (OPC), FA and BA were determined by using X-Ray Fluorescent (XRF) technique. The different percentages of FA (replace cement) and BA (replace sand) which is 0%, 10%, 20% and 30% were incorporated respectively into SCC. Ten reactors were set up for the leachability test for each solid specimen by using SLT method. The concentrations of leachate samples were analyzed for selected heavy metals content by using Atomic Absorption Spectroscopy (AAS) method. After 40 days conducting the test, the concentrations of selected heavy metals (As, Mn, Cu, Cr, Zn, Ni, Fe and Pb) in the synthetic acid rain leachates from the SCC specimens were significantly lower than the limit specified by the USEPA and EPAV. Therefore, incorporating of FA and BA up to 30% into SCC is potentially feasible.


Author(s):  
Y. Xiao ◽  
M. Oorsprong ◽  
Y. Yang ◽  
J. H. L. Voncken

During incineration of municipal solid waste (MSW), various environmentally harmful elements and heavy metals are liberated either into bottom ash, or carried away with the off-gases and subsequently trapped in fly-ash. If these minor but harmful elements are not properly isolated and immobilized, it can lead to secondary environmental pollution to the air, soil and water. The stricter environmental regulations to be implemented in the near future in the Netherlands require a higher immobilization efficiency of the bottom ash treatment. In the present study, MSW incinerator bottom ash was vitrified at higher temperatures and the slag formed and metal recovered were examined. The behaviour of soluble elements that remain in the slag is evaluated by leaching extraction. The thermodynamics of slag and metal formation is discussed. The results obtained can provide a valuable route to treat the ashes from incinerators, and to make recycling and more efficient utilization of the bottom ash possible.


2020 ◽  
Vol 166 ◽  
pp. 01007
Author(s):  
Vasyl Savosko ◽  
Aleksandr Podolyak ◽  
Irina Komarova ◽  
Aleksey Karpenko

Object of research: to systematize (taking into account the possible consequences to biosphere) the known technologies for ecological restoration of soils contaminated by heavy metals and radionuclides. Only a healing technology should be recognized as one possible methodology for solving any soil problems. For soils contaminated by heavy metals and radionuclides healing patterns is conceptually ordered into the following levels: mission, strategy, technology. The mission of healthy soil should be aimed at maintaining the chemical elements content within the optimum interval. The strategy of healthy soil involves the regulation of individual elements content in the soil. Ex-situ a soil healing technology is implemented outside the original pollution site. In-situ, a soil healing technology is carried out directly on the original pollution site. Excavation of the contaminated soil layer is the first stage for ex-situ soil restoration. In the future it will be possible: 1) storage of contaminated soil at special landfills, 2) treatment of contaminated soil at a special reactor. All technologies for in-situ healthy of heavy metals contaminated soils can be ordered as: 1) localization, 2) deconcentration, 3) inactivation, 4) extraction.


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