Leaching of heavy metals from monolithic waste

2023

Sci Rep

Self Cite

One of the parameters affecting the leachability of heavy metals from waste is their contact time with the leachant. In this paper, the leaching behaviour of Zn, Cu, Pb and Ni was evaluated in relation to the liquid to solid ratio (L/S), which is a reflection of time after which a certain volume of water permeates the material, e.g. in slag heaps or landfills. A leaching study was carried out by different leaching methods with using three test materials, i.e. hazardous zinc slag, lump copper slag and mineral-organic composite. It was found that the highest amount of metals leached in the long term in the maximum availability test, under the following leaching conditions: L/S = 50 dm3/kg, reduced pH of the leachant, fragmentation of the materials to particle size < 0.125 mm. Comparing the results obtained in the batch test and the percolation test, no strict trend was observed in the release of a given metal from different test materials. The analysis using the tank test showed that processes controlling leachability can result in the release of the highest metal loads immediately after contact between the material and the leachant, but can also contribute to the release of metals only after prolonged contact.

Section: Resultsmentioning

confidence: 89%

The importance of time and other determinants in the assessment of heavy metals release during solid waste management

2023

Sci Rep

Self Cite

“…The basis for verifying the model assumptions were results published in (Bożym et al, 2021;Król and Mizerna, 2015;Mizerna et al, 2017;Mizerna and Król, 2018) on the leachability of heavy metals Zn, Pb, Cu, Ni, Cd and Cr from metallurgical slags and mineral-organic composites.…”

Section: Methodsmentioning

confidence: 99%

“…The batch test requires the least expenditure in economic terms, however, the results obtained by this test are incomplete and insu cient, as they do not allow determining the actual rate of leaching of heavy metals with the consideration of the in uence of various external conditions and factors on the level of release of contaminants. Based on the authors' previous studies (Bożym et al, 2021;Król and Mizerna, 2015;Mizerna et al, 2017;Mizerna and Król, 2018), it was found that even a small change in the conditions of the leaching process, such as a change in the pH of the leachant or the contact time of the material with the liquid, can cause the release of heavy metals into the aqueous phase at different levels. Therefore, efforts should be made to characterize the leachability of contaminants using a variety of comprehensive methods, as has been advocated since the 1990s (Hage and Mulder, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, efforts should be made to characterize the leachability of contaminants using a variety of comprehensive methods, as has been advocated since the 1990s (Hage and Mulder, 2004). Previous studies (Bożym et al, 2021;Mizerna, 2015, 2016;Mizerna et al, 2017;Mizerna and Król, 2018) and scienti c reports on various materials, both construction materials and waste materials, show a variety of trends in the release of individual heavy metals depending on changes in a given factor using a given test method (Engelsen et al, 2017;Loncnar et al, 2022;Sun et al, 2019;van der Sloot et al, 2018). Consequently, there are di culties in unambiguous assessment of the leaching behaviour of heavy metals.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multi-criteria Decision Making Models in assessment of heavy metals leaching from waste

Jurczyk-Bunkowska

2023

Preprint

Self Cite

The paper presents a specific model used for the assessment and selection of the method of heavy metals leaching from waste materials. A recommendation for the rational selection of leachability method was made, taking into account the crucial parameters affecting the leaching process derived from the authors' research experience. The assessment models were supplemented with characteristics relating to the cost and time required to perform the tests. An approach was developed that makes the weights of the assessment criteria dependent on the degree of environmental risk from particular heavy metals and waste types. Using multiple-criteria decision analysis four models were developed for the assessment and selection of a test method for the leaching of heavy metals from waste, differing in the way in which the weights of the assessment criteria depend on the potential threat the waste poses to the environment. A key element of the proposed approach is assigning the weights of the criterion to the toxicity of the heavy metal and the kind of wastes and their management scenario. The results obtained indicate that the current practice of only imposing a batch leaching test is inappropriate. The choice of method should be justified in terms of environmental safety and reasonable in terms of time and costs. The results of the paper indicate the possibility of using the proposed model in practice as a recommendation for the method for heavy metals leaching from waste materials and their further treatment in accordance with the principles of sustainable waste management.

“…The classification method consists of a comparison of the pollution leaching result (liquid to solid ratio as L/S, 1/10) from waste with limits for one of the classes. The evaluation of leaching pollutants from landfilled waste may be carried out using several methods (e.g., TCLP, SPLP and ASTM) (Mizerna and Kuterasińska 2016;Bożym 2017;Mizerna et al 2017;Mizerna and Król 2018;Bożym 2019). These methods are also used to assess the leaching of heavy metals from solidified hazardous waste in concrete (Król and Jagoda 2012;Halim et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Leachate and contact test with Lepidium sativum L. to assess the phytotoxicity of waste

Bożym

Int. J. Environ. Sci. Technol.

2020

The study evaluated the use of Lepidium sativum L. to assess the phytotoxicity of three types of waste such as hazardous waste (slags from zinc to copper smelters) and nonhazardous waste (mineral–organic composite). Previous studies evaluated heavy metal leaching and the environmental impact of the tested waste. The purpose of phytotoxicity studies was to increase knowledge about this waste. Two types of tests were used to assess the phytotoxicity of wastes: germination index and accumulation test. Both tests were carried out for leachate (leachate test) and waste (contact test). The results of both tests were compared to assess the phytotoxic effects of tested waste. Phytotoxicity tests have shown that the mineral–organic composite leachate was stimulated plant growth, copper smelter slag leachate was characterized by no phytotoxicity and zinc slag leachate inhibited the growth of plants. In contrast, contact test showed inhibitory effects from all tested waste. Wherefore, the contact test was indicated as more sensitive in the assessment of phytotoxicity. However, this is not a clear assessment, because the germination index values for both tests were a result of differences of root length for both control samples (deionized water and sand). The study confirmed the usefulness of L. sativum for the assessment of phytotoxicity of various types of waste. Additionally, it was found that L. sativum was resistant to high concentrations of heavy metals in the leachate, without causing any negative physiological effects.