Fly Ash as an Ingredient in the Contaminated Soil Stabilization Process

Fly ash is the main by-product of coal combustion characterized by a large specific surface area. In addition to oxides, it also contains unburned coal and trace elements. This study aimed to investigate the possibility of using fly ash from pit-coal combustion (CFA) for the treatment of benzene-contaminated soil (S). The CFA was used as a mixture with Portland cement (PC) (70% PC + 30% CFA). The soil was treated with a PC-CFA mixture in amounts of 40, 60, and 80% of soil mass. During the process, the concentration of benzene was monitored with the flame-ionization detector. Produced monoliths (S+(PC-CFA)x) were tested for compressive strength and capillary water absorption. The experiment confirmed that the PC-CFA mixture limited benzene emission. The highest reduction in benzene concentration (34–39%) was observed for samples treated with the PC-CFA mixture in an amount of 80% (S+(PC-CFA)80). The average compressive strength of monoliths S+(PC-CFA)40, S+(PC-CFA)60, and S+(PC-CFA)80 was 0.57, 4.53, and 6.79 MPa, respectively. The water absorption values were in the range of 15–22% dm

Household E-Waste Management: A Case Study of Wroclaw, Poland

Improper collection and processing of waste electrical and electronic equipment (WEEE) pose a serious threat to the environment and prevent the recovery of valuable materials. Due to the decreasing availability of resources and production materials, the relevance of WEEE recycling has increased. WEEE should be seen as an important source of raw materials for European economies. Moreover, e-waste recycling has a positive impact on the environment by limiting energy use and CO2 emissions during ore processing. The objective of this study was the analysis of the product use times, the reasons for purchasing new devices, and the consumers’ behavior, knowledge, and awareness concerning WEEE collection and treatment. This study discusses these issues based on a survey on electronic waste management in Wroclaw (Poland). The results from 495 questionnaire respondents indicated a shortening use time of many types of electronic and electric equipment (EEE). The “failure of the device” was the primary reason respondents replaced their products. It was indicated by 90% of the respondents. In many cases, the repair of devices was unprofitable. The most important factor determining the purchase of new devices was their price. The environmental factors, mainly those giving economic benefits, were also considered. Despite the implementation of the extended producer responsibility, the functioning model of WEEE collection has proven to be ineffective. A significant amount of small WEEE ended up in waste bins. For this reason, the willingness of residents to pay an additional fee for WEEE collection was also estimated. The results indicated that campaigns to increase residents’ awareness of WEEE management should continue

Use of cement-fly ash-based stabilization techniques for the treatment of waste containing aromatic contaminants

Research on evaluation of evaporation rate of volatile organic compounds from soil beds during processing is presented. For the experiment, soil samples were prepared with the same amounts of benzene and stabilized using a mixture of CEMI 42.5R cement and fly ash from pit-coal combustion. Solidification of soils contaminated with BTEX hydrocarbons using hydraulic binders involves a risk of releasing vapours of these compounds during homogenization of waste with stabilizing mixture introduced and its dilution with water. The primary purposes of the research were: analysis of benzene volume emitted from soil during stabilization/solidification process and characterization of factors that may negatively affect the quality of measurements/the course of stabilization process. Analysis of benzene emission intensity during the process was based on concentration (C6H6) values, recorded with flame-ionization detector above the surface of reacting mixture. At the same time, gaseous contaminants emitted during waste stabilization were passed through pipes filled with activated carbon (SCK, Anasorb CSC). Benzene vapours adsorbed on activated carbon were subjected to analysis using gas chromatograph Varian 450-GC. Evaporation characteristics of benzene during processing contaminated soils revealed the stages creating the highest danger to workers’ health, as well as a need for actions connected with modification of technological line

BTEX compounds identification by means of gas sensors arrays

BTEX compounds can cause a threat to environment and human health. For this reason measurement devices are needed for rapid identification of such pollutants. The paper presents the results of recognition of mixtures of benzene, toluene, ethylbenzene and xylenes in humid air by means of two gas sensor arrays and linear discriminant analysis. Measurements were conducted during stabilization/solidification processes of contaminated soils. High classification ratios were obtained for both arrays (I: 88%–94%; II: 94%–96%). Improvement of identification was achieved when two copies of every sensor were included in analysis – classification rates reached 97.1–100%

BTEX compounds identification by means of gas sensors arrays

BTEX compounds can cause a threat to environment and human health. For this reason measurement devices are needed for rapid identification of such pollutants. The paper presents the results of recognition of mixtures of benzene, toluene, ethylbenzene and xylenes in humid air by means of two gas sensor arrays and linear discriminant analysis. Measurements were conducted during stabilization/solidification processes of contaminated soils. High classification ratios were obtained for both arrays (I: 88%–94%; II: 94%–96%). Improvement of identification was achieved when two copies of every sensor were included in analysis – classification rates reached 97.1–100%

SELECTIVE WASTE COLLECTION IN THE DETACHED HOUSING AREA

When it comes to waste management, the main objective of the European Union is to prevent waste production. Produced waste should be primarily recycled or other recovery should be applied. Introduction of an effective waste collection system is a basic activity that guarantees achieving European Union agenda including the minimal level of recycling and preparation for reuse. The aim of the research was the analysis of the selective waste collection in the detached housing area (before 1st July 2013). The evaluation was prepared on the basis of an opinion research conducted among the residents. One hundred respondents, living in one of the housing estates in Wrocław, took part in the survey

Household E-Waste Management: A Case Study of Wroclaw, Poland

Improper collection and processing of waste electrical and electronic equipment (WEEE) pose a serious threat to the environment and prevent the recovery of valuable materials. Due to the decreasing availability of resources and production materials, the relevance of WEEE recycling has increased. WEEE should be seen as an important source of raw materials for European economies. Moreover, e-waste recycling has a positive impact on the environment by limiting energy use and CO2 emissions during ore processing. The objective of this study was the analysis of the product use times, the reasons for purchasing new devices, and the consumers’ behavior, knowledge, and awareness concerning WEEE collection and treatment. This study discusses these issues based on a survey on electronic waste management in Wroclaw (Poland). The results from 495 questionnaire respondents indicated a shortening use time of many types of electronic and electric equipment (EEE). The “failure of the device” was the primary reason respondents replaced their products. It was indicated by 90% of the respondents. In many cases, the repair of devices was unprofitable. The most important factor determining the purchase of new devices was their price. The environmental factors, mainly those giving economic benefits, were also considered. Despite the implementation of the extended producer responsibility, the functioning model of WEEE collection has proven to be ineffective. A significant amount of small WEEE ended up in waste bins. For this reason, the willingness of residents to pay an additional fee for WEEE collection was also estimated. The results indicated that campaigns to increase residents’ awareness of WEEE management should continue

Energy Recovery from Waste—Closing the Municipal Loop

Municipal waste management in the EU has been challenged to a thorough transformation towards a Circular Economy. It is addressed by a number of quantitative policy targets, including a restriction on municipal waste landfilling to 10% in 2035. This paper presents the data on municipal waste composition in a large Polish city, based on thorough waste sorting analyses. On average, 374 kg of municipal waste is collected per capita in Wroclaw, of which 41% are separately collected fractions. The approach to implement the EU recycling targets until 2035 is presented, including an increase of sorting and recycling efficiency and a significant share of recyclables being retrieved from the residual waste fraction. Notwithstanding the recycling targets, an important stream of residual waste remains, amounting to 200 k ton in 2020 and approx. 130 k ton in 2035, which is available for energy recovery. The respective LHV values range from 8.5 to 7.6 MJ/kg. The results indicate that the residual waste stream, after satisfying the recycling targets, is still suitable for energy recovery through the whole period until 2035. Moreover, it is a necessary step towards closing the materials cycling in the municipal sector and the only option so far to reduce landfilling sufficiently

Non-reductive acidic leaching as a method for recovery of zinc and manganese from Zn-C and Zn-MnO2 battery waste

The dynamic growth of mobile technologies is a driving need for portable power sources. The most popular division of electrochemical cells relies on the type of chemical reaction within the cell. Current data coming from the Polish market show that despite the growth in the sale of secondary power sources, zinc-carbon and alkaline batteries are still the most popular. The results of non-reductive acidic leaching of zinc and manganese from the waste batteries stream have been presented. Manganese was leached with almost 100% yield in an experiment with a solid to liquid ratio equal to 4/1, pH of 1.04, and H2SO4 concentration of 72.5 wt. %. High yields were also obtained for zinc recovery from the waste stream (100% for two series with solid to liquid ratio 4/5, pH of 0.80; H2SO4concentration of 37.2 wt. %, and solid to liquid ratio 1/2; pH of 1.01; H2SO4 concentration of 27.3 wt. %). Besides, the quantitative and qualitative analysis of Zn-C and Zn-Mn batteries introduced to the Polish market and waste generated in the years 2010-2018 has been presented