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1

Use Fry of Cyprinus Carpio as Biomarker for Lead and Cadmium

Aljaryan Sara Khalid, Al-Amari Moayed J. Y., Al-Rezzaq Adi Jassim Abd

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 3

64--69

EN

Fishes are considered a good biomarker, and bioindicator of pollution, Our current research aims to investigate the magnification of (Pb and Cd) and how both affect antioxidants and use fry carp Cyprinus carpio as a bioindicator. The samples were analyzed to find the possible biomagnification of metals in fish. The highest concentration in fry fish fed with Artemia used Dunaliella salina as food treated with Pb in Food type 1 for 28 days, with a significant difference. The highest concentration of Cd in fry fish fed with Artemia used D. salina as food treated with Cd in food type 1 for 28 days, with a significant difference. The activity of the enzyme (SOD - GSH - CAT– GST) U/gm is affected by toxicity in fry fish mussels. The investigation has proved that exposure of fish to (lead and cadmium) induced a significant increase in content and increased activity of GST U/gm. For this purpose, an aquarium-based trial was conducted with two different types of food treated with Cd and Pb. The highest concentration of SOD U/gm enzyme of fry fish fed with Artemia used D.salina treated with Pb in food type 1 for 28 days when fry fish fed on Artemia used food treated with Pb the results show a strong positive significant correlation between (GPX, with SOD and CAT) U/gm and (SOD, with CAT) U/gm. While the concentration has a positive significant correlation with all enzymes, With Cd the highest concentration was in the SOD U/gm enzyme in fry fish fed with Artemia that used D. salina as food treated with Cd in food type 2 for 28 days.

2

Ecological and health risk assessment of soil heavy metal contamination along National Highway 107 in China

Jin Xiaohua, Tong Xinru, Hua Shunheng, Xu Yang

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 2

155--175

EN

This study investigates soil heavy metal contamination behind the green belts along National Highway 107 in China. Soil samples were collected from both sides of the highway to determine the concentrations of heavy metals such as copper, cadmium, chromium, lead, and zinc. The distribution patterns, ecological risks, and health hazards associated with these heavy metals were analysed. In order to provide more sample examples and data support for soil heavy metal pollution control. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was employed to detect the concentrations and speciation of these five heavy metals in the soil samples. The Geo-Accumulation Index method, the Nemerow pollution index method, and a health risk assessment model were used to evaluate the ecological and health risks of heavy metal pollution adjacent to the highway. Results indicated that: (1) The concentrations of Cu, Cd, Cr, Pb, and Zn in the soil decreased with the increasing number of protective forest layers, highlighting the significant role of protective belts in impeding the migration of heavy metals from the highway. (2) In terms of pollution assessment, the Geo-accumulation index method revealed prominent Cd contamination, the Geo-accumulation index of Cd peaked at 1.95 indicating a moderate to mild pollution level overall. Conversely, the Nemerow index method suggested a medium to extremely high risk of soil heavy metal Cd contamination. Specifically, the peak value of Cd single-factor pollution index in the study area reached 5.78, and the mean value of its Nemerow index (P) was 4.67. (3) In health risk assessment, it was found that children are more susceptible to heavy metal threats. The non-carcinogenic risk indices of all five heavy metals were less than 1, implying minimal risk. However, the total carcinogenic risk index for Cr ranged between 10–6 and 10–4, posing a certain level of carcinogenic risk to humans.

3

Use of magnetic nanoparticles in an Ionic liquid (BMIM-PF6) based vortex‐assisted dispersive liquid-liquid microextraction (VSLLME) for measuring the traces amounts of cadmium in environmental, biological and nutritional samples

Payab Meghdad, Maleki Fatemeh Yousefnezhad, Sheikhloie Hossein, Baghban Ali

Scientiae Radices

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2023

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Vol. 2, Iss. 4

359--377

EN

In the present project, the magnetic nanoparticles were used in a type of an ionic liquid based micro-extraction to measure trace amounts of cadmium in different real samples containing environmental water samples, saliva and human hair. In the optimum condition, the recovery percentages for the real sample were about 94.5% to 101.3%, showing the designed method is suitable to be used for analyzing the real environmental and biological samples. The main parameters were evaluated and optimized as follows: pH was 2.5, the volume of ionic liquid was 150 μl, the amount of Fe3O4 magnetic nanoparticles was 50mg, the volume of the complexing agent was 12 μl, and the vortex time was 1 min and 2 min for ionic liquid, and magnetic nanoparticle distribution steps, respectively. Also, the volume of the medium was 10 to 20 ml.

4

Ecological risk assessment of heavy metals in the Sidi Boughaba Lake, Morocco

Najy Mohamed, Talbi Fatima Z., Ech-Chafay Hassan, Akkaoui Omar, Lachhab Mohamed, Achhar Abderrahman, Nouayti Nordine, Belghyti Driss

Journal of Water and Land Development

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2023

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no. 56

215--219

EN

The goal of the research was to evaluate the heavy metal detection and potential ecological risks in lake’s water. Geological formations consisting essentially of sandstone and quaternary marine or dune sands characterize the study area. With a climate of the Mediterranean type winters are mild and humid, whereas summers hot and dry. At the analysis center of the Faculty of Sciences, the monitoring of ETMs is carried out by ICP-MS, the processing of data and the validation of the analysis method have been drafted according to the NF T 90-120 standard applicable to the analysis in a laboratory. The analysis covers concentrations of heavy metals, which include Cu, Zn, Mn, Fe, Pb and As, in the water. Pollution load index (PLI) values were above one (>1) which indicates progressive deterioration of the water quality. However, contamination factor (CF) values of Pb and Cu, ranging from 8.31 to 15.68 and from 5.5 to 28.05 respectively, show that the studied water remains under a strong impact by Pb and Cu. Considering the severity of the ecological risk (Er) for a single metal, the descending order of contaminants is Cu > Pb > Mn > Fe > Zn. In relation to the total ecological risk index (RI), water from the lake shows low to considerable ecological risk.

5

Wastewater Treatment Using Activated Carbon Produced from Oil Shale

Hamdan Mohmmad Ahmad, Sublaban Esraa Taha, Al-Asfar Jamil Jawdat, Banisaid Mai Abdullah

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

131--139

EN

In recent years, many researchers have expressed interest in wastewater treatment using activated carbon produced from cheap raw materials. In this work, an activated carbo-aluminosilicate (ACS) – supported zero-valent iron (ZVI) composite was produced from Um AL-Rasa oil shale mine and examined to eliminate Chromium (VI) from contaminated water. Activation of raw oil shale fine particles (< 212 μm) was chemically performed using 95 and 5% wt of H2SO4 and HNO3, respectively, as activating agents. The activated material was further treated with caustic soda, named ACS, and modified with fine zero-valent iron particles < 212 μm), called ZVI/ACS composite. Kaolin was added to the composite with the ratio: (50 % wt. light kaolin: 50 % wt. ACS), named as ZVI/ACS/K. The XRD analysis for both composites confirmed iron dispersion at 45°. Adsorption experiments were carried out using the two adsorbents ZVI/ACS & ZVI/ACS/K under different values of pH, and adsorbent dosage. The results indicated that the reduction of Chromium was maximum under the 3 pH value and 2.0 gm amount of ZVI/ACS/K. Furthermore, it was found the removal rate was enhanced by 17% and 24.7% when ZVI/ACS & ZVI/ACS/K adsorbents were used, respectively, compared to that when only ACS adsorbent was used alone. Finally, the dependency of Chromium removal on its initial concentration by ZVI/ACS/K adsorbent was also investigated at two different temperatures of 27° and 50°. The results indicated a decrease in the removal rate of the Chromium as the concentration increased at 27°; however, the removal rate previously enhanced at 50° at all initial concentrations.

6

Thermal Recycling of Bentonite Waste as a Novel and a Low-Cost Adsorbent for Heavy Metals Removal

Shubber Mukhtar D. H., Kebria Daryoush Yousefi

Journal of Ecological Engineering

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2023

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Vol. 24, nr 5

288--305

EN

The objectives of this study are the thermal remediation of bentonite waste to convert non-hazardous material, and the use of the obtainedthermal recycling bentonite waste (TRBW) as a novel low-cost adsorbent for the removal of heavy metals from aqueous solution using the batch system. The origin of bentonite waste is a by-product from plants of spent engine oil recycling [PSEOR]. It was remediated in two stages, directly burning and in the electrical furnace at 700 °C for 100 minutes to eliminate oil residues and impurities. The tests of XRD, BET, FTIR, EDX, and SEM were accomplished to identify the chemical and physical characteristics of TRBW. After then, the examination of the ability of TRBW to adsorption of the fiveheavy metals (Zn, Ni, Cd, Cr, and Pb) with different experimental parameters such as initial concentration, adsorbent dose, temperature, pH, and contact time. Different models of isotherm, kinetic, and thermodynamic were utilized andthe results indicate that the nature of heavy metals adsorption onto TRBW was homogeneous. According to the maximum adsorption capacities, the metals ranked as Pb> Cd> Zn> Cr> Ni, and adsorption capacities were 94.97, 73.85, 39.56, 38.34, and 36.33 mg/g, respectively.

7

The Removal Performance of Bio-Sorption on Sunflower Seed Husk for Copper and Lead Ions from Aqueous Solutions

Abdulhusain Noor Alaa, Mokif Layla Abdulkareem

Journal of Ecological Engineering

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2023

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Vol. 24, nr 5

110--117

EN

This study was concerned with the feasibility of using sunflower seed husk (waste material from the food industry) as a low-cost and available sorbent material to remove copper and lead ions. Sunflower seed husk was used for the biosorption of heavy metal ions (Pb(II) and Cu(II)) from aqueous solutions. The properties of natural adsorbent were characterized using Fourier transform infrared spectroscopy (FTIR). Pb(II) and Cu(II) adsorption were investigated in batch experiments through several influencing operating parameters, including contact time, sorbent dosage, initial pH, and initial concentration. The Pseudo-first-order and pseudo-second-order models were also applied to the experimental data to determine the adsorption kinetics. The results showed that adsorption of both ions fitted well by pseudo-Second-order, with determination coefficient R2 = 0.99, for both ions with SSE (1.628, 1.345) for Pb(II) and Cu(II), respectively.

8

The Potential Biosorption of Copper and Manganese by Bacterial Cellulose in the Environment

Kroeksakul Patarapong, Ngamniyom Arin, Chongkolnee Boonsong

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

190--196

EN

This study investigated the efficiency of copper and manganese adsorption by bacterial cellulose (BC) produced from Komagataeibacter intermedius BE073. BC was collected from production processes in a village in Nakhon Nayok province. BC had high moisture content of 91.15±3.68%, an average water absorption index (WAI) of 5.30±0.362, an average tensile strength of 99.1 ±6.18 MPa, average elongation at break of 6.41±0.67%, and an average Young modulus of 1445±177 MPa. Structural analysis of the BC material shows that it is a cellulose powder with a main group. Measurements show that the Mn content in BC rapidly decreased after soaking in solution, and that the highest Cu absorption efficiency of BC during a 120 minute period was 15469 mg kg-1. The results of this study show that BC may be successfully used to absorb various heavy metal residues from leachate, particularly Cu solutions. BC cannot absorb Mn from solution, so it cannot be used to absorb Mn from leachate. However, studies have shown that BC can release Mn into solution. Therefore, BC may be effective for use in agriculture, as Mn is a micronutrient for plants.

9

Spatiotemporal Variation of Heavy Metals and Pollution Indices in Groundwater Around Al-Diwaniyah Open Dump

Aziz Fatin F., Hussain Entessar Kareem

Journal of Ecological Engineering

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2023

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Vol. 24, nr 8

106--117

EN

Potential environmental hazards associated with heavy metals have been reported at Al-diwaniyah open dump in Iraq. Therefore, the levels of heavy metals and their spatial and temporal variability have been studied, in addition to pollution indices (HPI, HEI, Cd) to achieve environmental management and sustainability. Concentrations of seven heavy metals in groundwater wells at various distances around dumpsite were analyzed for the period 2022–2023 using atomic absorption spectrophotometer. Results revealed that heavy metals levels in samples examined decreased with the distance from the dumpsite W1>W2>W3 and it followed this pattern: Cd < Ni < Cr < Pb < Cu < Fe < Zn, with average concentrations in dry and rainy seasons were Zn (0.641,0.305), Fe (0.199,0.375), Cu (0.208,0.068), Pb (0.035,0.117), Cr (0.031,0.073), Ni (0.106,0.055), Cd (0.023,0.0095). On one hand, seasonal variation showed that 57.14% of heavy metals were raising in the dry season, and on the other, pollution indices showed that the groundwater taken from the W1 site was heavily polluted and unfit for consumption, while the other two sites were in low pollution category, which showed little impact of waste dumps on groundwater in these sites. Analysis results indicated that groundwater is appropriate for drinking purposes compared to the permissible limits of WHO/IQS, apart from those taken from site W1. All wells also provide water suitable for irrigation purposes based on the guidelines of the Food and Agriculture Organization (FAO). The Statistical analysis demonstrated a strong correlation between some heavy metals, in addition to the influence of sampling sites on heavy metal levels. It is recommended to expand this study to include additional regions in order to provide more environmental monitoring for groundwater and examine its potential human health risks in the study region, construct an engineering landfill equipped with leachate collector system, moreover, systematic treatment of heavy metals concentrations should be carried out regularly.

10

Soil Pollution with Heavy Metals in the Turkestan Region

Salim Yerbol, Yerimbetova Aizhan, Baiduisenova Togzhan, Uspabayeva Aigul, Abildayeva Roza, Balgabekova Aigerim, Ashirbayeva Saltanat, Tleukeyeva Assel

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

31--38

EN

Toxic pollutants of industrial origin can be dangerous for professionals who come into contact with them at work, and also for the people who live near the sources of environmental hazards. There is a known relationship between the soil pollution with heavy metals and the morbidity of the population. This paper reports a study of the soil pollution with ions of heavy metals in the Turkestan region, Kazakhstan. The study found technogenic geochemical anomalies of various size, intensity and origin in the soils of the Turkestan region. The distribution of lead, copper, barium, zinc, molybdenum, phosphorus and arsenic was mapped based on the ecological and geochemical survey of the upper soil layer. The most polluted city is Kentau, where concentrations of Pb, Mo, Cu, Zn, As, Cd, Mn, Cr, Ni in the soil exceed the allowable level. The cause of pollution is erosion that occurs in the areas of technogenic waste storage. In some communities, the concentration of only one metal exceeded its MAC or the Clarke number, for example, only scandium exceeded its Clarke number by 1.1 in Lenger and only exceeded its Clarke number by 2.75 in Sholakkorgan.

11

Evaluation of Pesticide and Heavy Metal Contamination on Soil Properties and Microbiota in Thailand’s Mountainous Region

Kroeksakul Patarapong, Ngamniyom Arin, Silprasit Kun, Sutthisaksopon Phanom, Sriyapai Thayat, Phowan Naphat, Singhaboot Pakjirat

Journal of Ecological Engineering

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2023

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Vol. 24, nr 7

331--344

EN

The article aims to investigate the state of soil elements in upland agriculture and the state of pesticide contamination in the environment of differing highland agricultural areas in Thailand. The number of heavy metals present was Fe > Mn > Zn > Pb > Ni > Cu > Cd, dominant pesticide contamination in the carbamate group is methomyl (0.11 mg/kg), and the organochlorine group is triazophos (0.02 mg/kg). Pesticide contamination was found to positively and significantly correlate with the soil’s total N and Fe content (p < 0.01). In the soil microbes, the dominant genera of Aquabacterium were found at the highland agriculture site H1, Massilia at H2, and Sphingomonas at H3.

12

The impact of land set-aside on the chemical and physical properties of the soil and the composition of vegetation species. Case study

Petryk Agnieszka

Geomatics, Landmanagement and Landscape

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2023

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no. 3

121--133

EN

The study aimed to evaluate the effect of soil use in the Młoszowa and Bolęcin villages on the species composition of the overgrown vegetation. Additionally, the study compared the chemical and physical properties of the soils that were not being used for agriculture. The soils of Młoszowa and Bolęcinvillages did not exceed the permissible concentrations of copper, lead, and zinc for agricultural land, as outlined by the national regulations in [Journal of Laws 2016]. In Młoszowa, the concentration of cadmium exceeded the limit values as per national regulations in [Journal of Laws 2016] for agriculturally utilised land (land group II-2) (<3 g · 10–3 · kg–1 DM). The set-aside of both villages consisted of species typical of ruderal areas, fresh grassland, and thermophilous species. The granulometric composition of the soils, mainly their silt and sand content, were the primary factors that impacted the species composition of the set-aside vegetation. Ruderal and thermophilous species were discovered in the set-aside areas, which are their natural habitats. The occurring ruderal plants typical of post-mining heaps and postindustrial areas, including hemicryptophytes, testify to the long-term process of fallowing and adaptation to the existing ecosystem with a predominance of the most common species.

13

The Study of Heavy Metal Impacts on Biotic Processes in the Soils of the Urban Ecosystem of the City of Rivne (Ukraine)

Melnyk Vira, Malovanyy Myroslav, Lukіanchuk Nelia, Sternik Vita

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 1

143--153

EN

The paper deals with investigating the impact of heavy metals on biotic processes in the soils of the urban ecosystem of the city of Rivne. The territories of the northern part of the city, where the main industrial enterprises are concentrated, and the southern part of the city, with a significant impact of fugitive emissions from the railway and road transport, are characterized by the highest level of soil contamination. The soils are assigned to class III of hazard of contamination with heavy metals with "medium impact level" on biological processes, soil contamination category is "hazardous". The western and central parts of the city are marked by a significant level of contamination, the soils belong to class IV of hazard with "moderate impact level" on biological processes, the soil contamination category is "moderately hazardous". The eastern part of the city is the least contaminated and is assigned to class V of hazard. The contamination level is "low", the soil contamination category is "permissible".

14

Protective Disposable Face Masks Used During the COVID-19 Pandemic as a Source of Pollutants in the Aquatic Environment – A Study of Short-Term Effects

Loboichenko Valentyna, Leonova Nataliia, Shevchenko Olga, Blyashenko Oleg, Soshinskiy Alexander, Servatyuk Vasyl, Tregub Nataliia, Khmyrov Ihor, Burmenko Oleksandr

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 1

84--92

EN

The paper examines the impact of protective equipment used during the COVID-19 pandemic on the environment. The impact of protective face masks on the aquatic environment was analyzed in more detailed way. The amount of protective face masks penetrated into the environment as a result of the COVID-19 pandemic and their role in the increase of plastic and microplastic things in the environment was noted. The aim of the work was to study the migration of a number of metals from disposable protective masks into the aquatic environment in the short term. Using the method of atomic absorption spectroscopy, the value of Cu, Pb, Mn, Zn, Fe in the investigated model systems containing protective disposable face masks was obtained by varying the pH of the aqueous medium. It was found that for manganese, lead and iron there is a permanent (Mn) or temporary (Pb, Fe) excess of these metals in the aquatic environment according to national and European standards. The probable possibility of sorption effects and the need for further research in this direction were noted.

15

GIS and Index-Based Methods for Assessing the Human Health Risk and Characterizing the Groundwater Quality of a Coastal Aquifer

Foufou Atif, Haied Nadjib, Azlaoui Mohamed, Khadri Samira, Boussaid Adel, Kechiched Rabah

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 8

36--53

EN

The massive dune aquifer of Bouteldja is one of the most exploited aquifers in Algeria; as a result, its piezometric level has declined. Such pressure on the dune aquifer, in addition to its moderate-to-severe vulnerability to pollution, may lead to deterioration of groundwater quality. This study is intended to assess the quality of aquifer groundwater for drinking, irrigation and industrial purposes, and also to evaluate health risks. To this end, we analyzed data of 16 physicochemical parameters collected from 25 groundwater samples. Using the Durov diagram, principal component analysis (PCA), and Pearson’s correlation matrix, we found that most major ions show similar origins related to ion exchange and the proximity of the sea. Our results showed that, overall, the groundwater intended for drinking purposes was of good or excellent quality over most the aquifer, where the majority of wells are located. However, the groundwater is mostly unsuitable for irrigation purposes according to the Kelly index (KI), percentage of sodium (Na %), magnesium hazard (MH), and irrigation water quality index (IWQI). Further, calculations of corrosivity ratios (CRs) indicated that the groundwater is unsuitable for industrial uses. Finally, a health risk assessment of iron heavy metal related to the hazard index (HI) for both ingestion and dermal exposure in children and adults showed negligible-to-low risk from iron exposure.

16

Właściwości produktów powstałych w procesie zestalania i stabilizacji popiołów lotnych powstałych z termicznego przekształcania osadów ściekowych

Wichowski Piotr, Kalenik Marek, Rutkowska Gabriela, Malarski Maciej, Czajkowska Justyna, Franus Wojciech

Cement Wapno Beton

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2023

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R. 28, nr 6

389--408

PL

W artykule przedstawiono analizę wyników badań składu popiołów lotnych z termicznego przekształcania osadów ściekowych [SSA z ang. sewage sludge ash], pobranych z trzech spalarni zlokalizowanych w Warszawie, Krakowie i Łodzi oraz oznaczono wymywania wybranych metali ciężkich z badanych popiołów lotnych i betonów zwykłych klasy C20/25 z częściową zamianą - do 20% cementu na popiół lotny. Wykonane badania laboratoryjne wykazały, że mają porównywalny skład granulometryczny, natomiast właściwości fizyko-chemiczne badanych popiołów lotnych różnią się od tradycyjnie stosowanych w technologii betonu popiołów ze spalania węgla. SSA charakteryzują się przeciętnie mniejszą zawartością tlenków krzemu, żelaza i aluminium przy wielokrotnie większej zawartości fosforu. Badania wymywania wskazują na małą mobilność metali ciężkich spełniającą polskie przepisy dotyczące możliwości wykorzystania SSA w budownictwie do określonych zastosowań. Jednocześnie nie stanowią istotnego zagrożenia dla zdrowia ludzi i nie szkodzą środowisku. Odpady budowlane zawierające SSA mogą być składowane na składowiskach odpadów obojętnych.

EN

The article presents an analysis of the results of research on the composition of fly ash from the thermal processing of sewage sludge [SSA] collected from three incineration plants located in Warsaw, Cracow and Łódź. It determines the leaching values of selected heavy metals from the tested fly ash and ordinary class concrete C20/25 with partial replacement - up to 20% of cement with fly ash. The laboratory tests performed showed that they have a comparable granulometric composition. In contrast, the physico-chemical properties of the tested fly ashes differ from ashes from coal combustion traditionally used in concrete technology. SSA is characterized by an average lower content of silicon, iron, and aluminium oxides with a much higher content of phosphorus oxides. Leaching tests indicate low mobility of heavy metals, meeting Polish regulations regarding the possibility of using SSA in construction for specific applications. At the same time, they do not pose a significant threat to human health or the environment. Construction waste containing SSA may be disposed of in inert waste landfills.

17

Interfacial enhancement technology in high‑volume fly ash foam concrete: microscopic mechanism and heavy metal safety assessment

Huang De‑ming, Liu Ke, Wang Chao-qiang, Shen Bo-hong, Zhao Hui, Huang Qi-cong, Zhu Yu, Shui Zhong‑he

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e17, 2023

EN

Applying a large amount of fly ash to foam concrete can greatly reduce the engineering cost, but the proportion of fly ash is limited due to insufficient pozzolanic activity and heavy metal pollution. Therefore, this study used fly ash, portland cement, fly ash ceramsite, foaming agent, etc. as raw materials to design the mix ratio of large-volume fly ash foam concrete. The micro-interface enhancement mechanism was deeply analyzed, and a multi-method pollution assessment system was finally established for the risk assessment of heavy metals. The dry bulk density of the fly ash foam concrete prepared in this study was 894.5 kg/m3, the compressive strength was 4.22 MPa, and the thermal conductivity is 0.2213 W/(m K). These parameters all met the requirements of the Chinese standard “Foam Concrete” (JG/T 266-2011). The microscopic analysis results showed that, compared with the fly ash content of 60%, the foam concrete with 40% fly ash content had more rodlike ettringite at the interface of the pore wall, and its hydration products were distributed more uniformly. Similarly, the interface between the ceramsite mixed with 40% fly ash and the cement stone was more closely combined, the distribution of hydration products between the interfaces was more uniform, and the interface quality was higher. After adding thickener, the pore distribution of fly ash foam concrete was tight, and there were a lot of small pores between the pores, and the pore structure had better connectivity than when no thickener was added. The evaluation results of foamed concrete with 40% fly ash content with the aid of the multi-method pollution assessment system showed that the harmful heavy metals in fly ash were stably solidified in the silicate structure, resulting in low leaching efficiency. Finally, the performance of the high-volume fly ash foamed concrete slab produced according to the mix ratio designed in this study met the requirements of “Light weight panels for partition wall used in buildings” (GB/T 23,451-2009). Therefore, it is a safe and environmentally friendly high-performance building product.

18

Basic performance, heavy metal leaching mechanism and risk assessment analysis of waste concrete

Wang Chao-qiang, Cheng Lin-xiao, Huang Qi-cong, Shui Zhong-he, Liu Yan-yan, Zhao Hui, Zhang Zhao-ji

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e122, 2023

EN

With the acceleration of urbanization, the production of waste concrete is getting higher and higher. A large amount of outdoor accumulations of waste concrete will leach heavy metals, not only causing harm to the soil, but also posing a risk to human health. Based on this, this paper systematically studies the basic physical properties and microstructure (XRF, XRD, and SEM-EDS) of outdoor natural accumulation waste concrete, and analyzes the heavy metals in waste concrete from the aspects of existing state, leaching mechanism, human health risk analysis, and summarized the direction of resource utilization of waste concrete, calculated the carbon emission reduction during recycling. The study found that heavy metals in waste concrete mainly exist in hydration products in the form of precipitation, adsorption, and replacement, summarized the leaching mechanism from the micro- and macro-aspects. The leaching mechanism of heavy metals can be assigned to chemical (mineral dissolution and effective amount of components) and physical (advection, surface erosion, and diffusion) processes from the macro-perspective. From the micro-analysis, it can be assigned to the following five processes: acid migrates from solution to liquid-solid surface, acid migration through leaching layer, rapid dissolution reaction controlled by diffusion at leaching boundary, heavy metal through leaching layer, and heavy metals through the solid/liquid surface to the solution. In addition, the concentration and the leaching rate of heavy metals in waste concrete were analyzed. It was found that the concentration of Cr was the highest reached to 4.7 mg/kg and the leaching rate of Cd was the highest, its leaching coefficient was calculated as a result of 1.713 × 10–6. However, there was no obvious regularity in the leaching of heavy metals in different accumulate particle sizes. Through the establishment of risk assessment system was found the concentration of heavy metals in waste concrete will not cause significant harm to human health. The effective limit of heavy metals after 3 months of accumulation of waste concrete was calculated as: Cr < 0.09 mg/kg, Cd < 0.00715 mg/kg, As < 0.392 mg/kg, and Pb < 0.732 mg/kg. And the carbon emission reduction of waste concrete recycling was calculated to be 28.764kgCO2/t. All the results of this study can promote the safe and environmentally friendly utilization of waste concrete.

19

Ocena i próby zestalania szlamów z oczyszczania ścieków poligraficznych układami Fentona

Rauckyte-Żak Terese

Przemysł Chemiczny

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2022

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T. 101, nr 8

580--586

PL

Ciśnieniowo odwodnione szlamy z wstępnego oczyszczania ścieków poligraficznych w instalacji przemysłowej za pomocą wariantów układu Fentona oceniano z wykorzystaniem procedury TCLP (toxicological characteristic leaching procedure) i analizy składu frakcyjnego wg metodyki Tessiera. Zestalone (przez 28 dni) w kształtki kompozycje odwodnionych szlamów z cementem i piaskiem poddano oznaczeniu wymywalności metali ciężkich wg TCLP. Suma stężeń metali ciężkich (Cr, Cu, Ni i Zn) zawartych w ekstraktach z TCLP po końcowym zestalaniu była poniżej 0,1 mg/kg s.m.

EN

Pressure-dehydrated slimes from pre-treatment of printing wastewater in an industrial plant with variants of the Fenton system were assessed using the TCLP (toxicological characteristic leaching procedure) and fractional compn. anal. according to the Tessier’s methodology. The dehydrated slimes pressed in a chamber press were then mixed with cement and sand, as well as solidified for 28 days. In TCLP extracts from final solidified samples, the sum of heavy metal concns. (Cr, Cu, Ni and Zn) was below 0.1 mg/kg d.m.

20

Treatment of Laboratory Wastewater by Using Fenton Reagent and Combination of Coagulation-Adsorption as Pretreatment

Arita Susila, Agustina Tuty Emilia, Ilmi Nurul, Pranajaya Violanda Dwi Wulandari, Gayatri Rianyza

Journal of Ecological Engineering

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2022

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Vol. 23, nr 8

211--221

EN

Laboratory wastewater contains organic and inorganic compounds that are harmful to the environment when disposed of without prior treatment. Besides the high COD and BOD values, the laboratory wastewater also contains metals such as iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), and lead (Pb) which is categorized as dangerous waste material and can pollute the groundwater. Although the quantity of wastewater produced by the laboratory is relatively small, it has a real impact on the environment around the laboratory. However, the wastewater has to be treated properly before being discharged into the environment. The aim of the research was to study the laboratory wastewater treatment by using Fenton’s reagent with coagulation and adsorption pretreatment. In the pretreatment with coagulation, three types of coagulants are used, namely PAC (Poly Aluminum Chloride), ACH (Aluminum Chlorohydrate) and Aluminum Sulfate (AS) with their respective concentrations of 10–80 ppm. The highest percentage of average pollutant removal of 58.21% was found when 80 ppm of AS was applied. The pretreatment was continued by adsorption with activated carbon and zeolite adsorbents within 60–120 minutes of mixing time. It was detected that the most optimum adsorbent was activated carbon with average pollutant removal of 50.22% within 1 hour of mixing time. Processing was extended by utilized Fenton’s reagent using a variation of the molar ratio between 1:100 and 1:400. It was obtained that the best molar ratio to degrade the laboratory wastewater is 1:300 with an average removal of pollutant of 43.45%. As a result of laboratory wastewater treatment using combine Fenton’s reagent and coagulation-adsorption pretreatment, an average pollutant removal of 90.81% was obtained. The final content of COD, BOD, TSS, as well as Cu and Pb metal has met the environmental quality standard.