Use of Soluble Phosphates to Stabilize Lead Contaminated Soils

2014 ◽  
Vol 692 ◽  
pp. 161-166
Author(s):  
Zhong Zhong ◽  
Ying Jun Sun ◽  
Hui Min Lao ◽  
Chi Zhang

Lead pollution, commonly found in lead-acid battery plants or electroplating manufactures, has drawn more and more attention due to its intrinsic toxicity to human health and potential disturbances to local ecological system. Soluble phosphates showed great advantages over other inorganic stabilizers and could provide a rapid, cost-effective approach for lead contaminated sites, despite of complex contaminants presence and heterogeneity distribution of contamination. Chemical stabilization using soluble phosphates was demonstrated by immobilize both lab samples and on-site samples from a local lead contaminated site in this study. The soil samples were mixed with soluble phosphates and stabilized for selected intervals, while adding supplements for the purpose of pH control and solidification. Experiments for treatment duration and immobilization rate in comparison with other stabilizers were also investigated to provide guidance for following demonstration project. Soil samples were analyzed before and after the treatments to compare lead immobilization rates under different circumstances. The results suggested that 90% of lead in lab soil samples was stabilized after one day treatment with phosphates, while on-site soil samples took another 30 to 50 days due to their complexity. Phosphates treatment showed great consistence over all the soil samples after 50 days in contrast with the performance of lime treatment and ferrous sulfate stabilization. It is recommended that the stabilization duration for the specific site should be longer than 30 days, at an average cost of stabilization per ton of soil around 300 RMB. This study demonstrated the use of soluble phosphates in pilot-scale lead pollution remediation, as well as the possibility of extending the remediation concept for other heavy metal contamination scenarios. In addition, chemical stabilization could also be combined with other remediation technology in future due to its simplicity and convenience.

2021 ◽  
Author(s):  
Michel Rodrigo Zambrano Passarini ◽  
Júlia Ronzella Ottoni ◽  
Paulo Emílio Santos Costa ◽  
Denise Cavalvante Hissa ◽  
Raul Maia Falcão ◽  
...  

Abstract The inappropriate disposal of toxic compounds generated by industrial activity has been impacting to the environment considerably. Microbial communities inhabiting contaminated sites may represent interesting ecological alternatives for the decontamination of environments. The present work aimed to investigate the fungal diversity inhabiting sediments from industrial waste containing heavy metals by using metagenomic approach. A total of twelve fungal orders were retrieved from datasets and, at phylum level, Ascomycota was the most abundant, followed by Basidiomycota, Chytridiomycota and Blastocladiomycota. Higher abundance of sequences was encountered within the less contaminated site, while the lower abundance was found in the sample with the higher contamination with lead. Gene sequences related to DNA repair and heavy metals biosorption processes were found in the four samples analyzed. The genera Aspergillus and Chaetomium, and Saccharomycetales order were highly present within all samples, showing their potential to be used for bioremediation studies. The present work demonstrated the importance of using the metagenomic approach to understand the dynamics of fungal communities and their behavior under heavy metal contamination, aiming the use in bioremediation processes of environments contaminated with heavy metals.


2021 ◽  
Vol 13 (15) ◽  
pp. 8165
Author(s):  
Valer Micle ◽  
Ioana Monica Sur

The soil samples were taken from the site of a former oil products depot from an industrial area (Romania). The soil samples taken were analyzed from a physical and chemical point of view: texture, pH, soil micronutrient content, metals concentration and petroleum hydrocarbon concentration (PHCs). The soil contaminated with total petroleum hydrocarbon (TPH (4280 mg kg−1) was disposed in the form of a pile (L × W × H: 3000 × 1400 × 500 mm). Experiments on a pilot-scale were conducted over 12 weeks at constant pH (7.5–8), temperature (22–32 °C), nutrient contents C/N/P ratio 100/10/1, soil aeration time (8 h/day) and moisture (30%). Samples were taken every two weeks for the monitoring of the TPH and the microorganisms content. During the experiment, microorganisms were added (Pseudomonas and Bacillus) every two weeks. Results of the analyses regarding the concentration of PHCs were revealed a linear decrease of the concentration of PHCs after only two weeks of treatment. This decrease in concentration was also achieved in the following weeks. Following the analysis performed on the model at the pilot scale regarding the depollution process, it can be concluded that a soil contaminated with petroleum hydrocarbons can be efficiently depolluted by performing an aeration of 8 h/day, adding microorganisms Pseudomonas and Bacillus to ensure the conditions for increasing in the total number of germs (colony forming units–CFU) from 151 × 105 to 213 × 107 CFU g−1 soil, after 12 weeks of soil treatment—the depollution efficiency achieved is 83%.


2013 ◽  
Vol 651 ◽  
pp. 109-114 ◽  
Author(s):  
Zhen Yu Gu ◽  
Zhong Zhong ◽  
Zhi Qiu ◽  
Fu Cheng Sun ◽  
Zong Lin Zhang

Semi Volatile Organic Compounds (SVOCs) are common contaminants found in brownfield sites that used to be agrochemical plants, chemical storage sites, and industrial areas. Chemical oxidation showed great potential to provide a rapid, cost-effective approach for SVOCs contaminate sites. Chemical oxidation using persulfate was demonstrated by degrading both lab samples and on-site samples from a local o-ansidine contaminated site in this study. The soil samples were mixed with persulfate at different ratios, while adding supplements for the purpose of persulfate thermal activation and pH control. Experiments for optimal usage and treatment duration were also investigated to provide guidance for following demonstration project. Soil samples were analyzed before and after the treatments to compare the o-ansidine concentration changes. The results suggested an optimal ratio of persulfate at 0.5% (in w/w) for this study, with 90% or more removal of most samples in 3 days, at an average cost of oxidants per ton of soil around 800 RMB. This study demonstrated the potential of persulfate oxidation as a novel and reliable approach for o-ansidine contaminated soil, as well as the possibility of extending the remediation concept for other organic contamination scenarios. In addition, persulfate oxidation could also be combined with other remediation technology in future due to its simplicity and convenience.


2021 ◽  
Author(s):  
Valer Micle ◽  
Ioana Sur

Abstract The soil samples were taken from the site of a former oil products depot from an industrial area (Romania). The soil samples taken were analyzed from a physical and chemical point of view: texture, ph, soil micronutrient content, metals concentration and petroleum hydrocarbon concentration (PHCs). The soil contaminated with TPH (4280 mgkg-1) was disposed in the form of a pile (LxWxH:3000x1400x500 mm). Experiments a pilot-scale were conducted over 12 weeks at constant pH (7.5–8), temperature (22–32oC), nutrient contents C/N/P ratio 100:10:1, soil aeration time (8 hour/day) and moisture (30%). Samples were taken every two weeks for the monitoring of the TPH and the microorganisms content. During experiment every two weeks were added microoganisms (Pseudomonas and Bacillus). Results of the analyzes regarding the concentration of PHCs were revelead a linear decrease of the concentration of PHCs after only two weeks of treatment. This decrease in concentration was also achieved in the following weeks. Following the analysis performed on the model at the pilot scale regarding the depollution process, it can be concluded that a soil contaminated with petroleum hydrocarbons can be efficiently depolluted by performing an aeration of 8 h/day, adding microorganisms Pseudomonas and Bacillus to ensure the conditions for increasing in the total number of germs (colony forming units–CFU) from 151x105 to 213x107 CFU/gram of soil, after 12 weeks of soil treatment - the depollution efficiency achieved is 83%.


2021 ◽  
Vol 11 (15) ◽  
pp. 7099
Author(s):  
Inkyeong Moon ◽  
Honghyun Kim ◽  
Sangjo Jeong ◽  
Hyungjin Choi ◽  
Jungtae Park ◽  
...  

In this study, the geochemical properties of heavy metal-contaminated soils from a Korean military shooting range were analyzed. The chemical behavior of heavy metals was determined by analyzing the soil pH, heavy metal concentration, mineral composition, and Pb isotopes. In total, 24 soil samples were collected from a Korean military shooting range. The soil samples consist of quartz, albite, microcline, muscovite/illite, kaolinite, chlorite, and calcite. Lead minerals, such as hydrocerussite and anglesite, which are indicative of a transformation into secondary mineral phases, were not observed. All soils were strongly contaminated with Pb with minor concentrations of Cu, Ni, Cd, and Zn. Arsenic was rarely detected. The obtained results are indicated that the soils from the shooting range are contaminated with heavy metals and have evidences of different degree of anthropogenic Pb sources. This study is crucial for the evaluation of heavy metal-contaminated soils in shooting ranges and their environmental effect as well as for the establishment of management strategies for the mitigation of environmental risks.


2015 ◽  
Vol 8 ◽  
pp. ASWR.S22465 ◽  
Author(s):  
Diane Saint-Laurent ◽  
Francis Baril ◽  
Ilias Bazier ◽  
Vernhar Gervais-Beaulac ◽  
Camille Chapados

This research combines a hydrological and pedological approach to better understand the spatial distribution of contaminated soils along the Massawippi River (southern Québec, Canada). This river crosses through former mines, which were some of the largest copper mining areas in North America from 1865 to 1939. To determine the spatial distribution and concentration of the metal elements, soil samples were taken in each flood recurrence zone appearing on official flood zone maps. The maximum values obtained for Cu and Pb are 380 and 200 mg kg−1, respectively, for the soils in the frequent flood zones (FFzs), while the values for soils in the moderate flood zones (MFzs) range from 700 to 540 (Cu) and 580 to 460 mg kg−1 (Pb). Contamination extends through several kilometers of the former mining sites (Eustis and Capleton), and concentration of metals in alluvial soils is slightly higher near the mine sites.


2018 ◽  
Vol 3 (1) ◽  
pp. 414-426
Author(s):  
A.O. Adekiya ◽  
A.P. Oloruntoba ◽  
S.O. Ojeniyi ◽  
B.S. Ewulo

Abstract The study investigated the level of heavy metal contamination in plants {maize (Zea mays) and tomato (Solanum lycopersicum L.)} from thirty soil samples of three locations (Epe, Igun and Ijana) in the Ilesha gold mining area, Osun State, Nigeria. Total concentrations of As, Cd, Co, Cr, Cu, Ni, Pb and Zn were determined using atomic absorption spectrophotometry. Spatial variations were observed for all metals across the locations which was adduced to pH and the clay contents of the soils of each location. The results showed that heavy metals are more concentrated in the areas that are closer to the mining site and the concentrations in soil and plants (maize and tomato) decreased with increasing perpendicular distance from the mining site, indicating that the gold mine was the main sources of pollution. The mean concentrations of heavy metals in plants (tomato and maize) samples were considered to be contaminated as As, Cd and Pb respectively ranged from 0.6 - 2.04 mg kg-1, 0.8 - 5.2 mg kg-1, 0.8 - 3.04 mg kg-1 for tomato and respectively 0.60 - 2.00 mg kg-1, 1.50 - 4.60 mg kg-1 and 0.90 - 2.50 mg kg-1 for maize. These levels exceeded the maximum permissible limits set by FAO/WHO for vegetables. In conclusion, monitoring of crops for toxic heavy metals is essential for food safety in Nigeria.


2020 ◽  
Vol 58 (5A) ◽  
pp. 22
Author(s):  
Dao Thanh Son ◽  
Van Tai Nguyen ◽  
Thuy Nhu Quynh Vo ◽  
Vinh Quang Tran ◽  
Thi My Chi Vo ◽  
...  

Heavy metal contamination is among the globally environmental and ecological concerns. In this study we assessed the development of the two green algae Schroederia setigera and Selenastrum bibraianum under exposures to 5 – 200 µg/L of Ni, Zn, and Cd in the laboratory conditions. Heavy metal removal efficiency of S. setigera was also tested in 537 µg Ni/L, 734 µg Zn/L, and 858 µg Cd/L. We found that the exposures with these heavy metals caused inhibitory on the growth of S. bibraianum. The S. bibraianum cell size in the 200 µg Zn/L treatment was around two times smaller than the control. However, Zn and Cd at the concentration of 200 µg/L did not inhibit the growth of S. setigera over 18 days of exposure. The S. setigera also grew well during 8 days exposed to Ni at the same concentration. Besides, the alga S. setigera could remove 66% of Zn, 18% of Cd and 12% of Ni out of the test medium after 16 days of incubation. The Vietnam Technical Regulation related to metals should be considered for ecological protection. We recommend to test the metal removal by the alga S. setigera at pilot scale prior to apply it in situ


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