Papers by Evangelos Gidarakos
Waste Management, Oct 1, 2014
Journal of Hazardous Materials, 2009
An examination regarding the determination of recyclables and hazardous substances in small waste... more An examination regarding the determination of recyclables and hazardous substances in small waste electrical and electronic equipment (WEEE) found in the residual household waste stream of the city of Dresden, Germany, is described. Firstly, attitudes towards the disposal of small WEEE in the latter are assessed, and product types and categories which mostly contribute to its composition are identified. Physical parameters which could be used as mechanical sorting criteria are measured, and the material composition of the small WEEE found is determined. The hazardous substances' "base" charge in the residual waste is established by means of atomic absorption spectrometry and ionic chromatography, as a first step in estimating the contribution of small WEEE to its pollutant load. Consequently, the content of small WEEE plastics in key heavy metals and halogens is determined. Key conclusions are drawn concerning the future strategic development and practical implementation of the 2002/96/EC Directive, in relation to small WEEE management and recycling.
Waste Management, Oct 1, 2009
The presence of hazardous substances and preparations in small waste electrical and electronic eq... more The presence of hazardous substances and preparations in small waste electrical and electronic equipment (sWEEE) found in the residual household waste stream of the city of Dresden, Germany has been investigated. The content of sWEEE plastics in heavy metals and halogens is determined using handheld X-ray fluorescence analysis (HXRF), elemental analysis by means of atomic absorption spectrometry (AAS) and ion exchange chromatography (IEC). Mean value of results for heavy metals in samples (n=51) by AAS are 17.4 mg/kg for Pb, 5.7 mg/kg for Cd, 8.4 mg/kg for Cr. The mass fraction of an additive as shown by HXRF (n=161) can vary over a wide range. Precise deductions as regards sWEEE plastics content in hazardous substances and preparations cannot be made. Additional research would be expedient regarding the influence of hazardous substances to recycling processes, in particular regarding the contamination of clean fractions in the exit streams of a WEEE treatment plant. Suitable standards for calibrating HXRF for use on EEE plastics or complex electr(on)ic components do not exist and should be developed.
Waste Management, 2007
Hospital waste management is an imperative environmental and public safety issue, due to the wast... more Hospital waste management is an imperative environmental and public safety issue, due to the waste's infectious and hazardous character. This paper examines the existing waste strategy of a typical hospital in Greece with a bed capacity of 400-600. The segregation, collection, packaging, storage, transportation and disposal of waste were monitored and the observed problematic areas documented. The concentrations of BOD, COD and heavy metals were measured in the wastewater the hospital generated. The wastewater's toxicity was also investigated. During the study, omissions and negligence were observed at every stage of the waste management system, particularly with regard to the treatment of infectious waste. Inappropriate collection and transportation procedures for infectious waste, which jeopardized the safety of staff and patients, were recorded. However, inappropriate segregation practices were the dominant problem, which led to increased quantities of generated infectious waste and hence higher costs for their disposal. Infectious waste production was estimated using two different methods: one by weighing the incinerated waste (880 kg day(-1)) and the other by estimating the number of waste bags produced each day (650 kg day(-1)). Furthermore, measurements of the EC(50) parameter in wastewater samples revealed an increased toxicity in all samples. In addition, hazardous organic compounds were detected in wastewater samples using a gas chromatograph/mass spectrograph. Proposals recommending the application of a comprehensive hospital waste management system are presented that will ensure that any potential risks hospital wastes pose to public health and to the environment are minimized.
The question of the composition variability frequently arises when evocating thetreatment or the ... more The question of the composition variability frequently arises when evocating thetreatment or the eventual use of municipal solid waste incineration (MSWI) residues. This studyaims to estimate this assumed variability by following the composition of electrostaticprecipitator (ESP) fly ashes from MSWI day by day during one month. The samples compositionis determined by X-ray fluorescence and their mineralogy is analysed by X-ray diffraction. Theresults show that the concentration values of MSWI ESP fly ash elements remain in the range of2 σ (standard deviation) around the average. An ANOVA test also indicates that there is nosignificant effect of the time-period on the ESP fly ash composition. The results suggest thus alow variability of the ESP fly ash composition over a one-month period. A one-year campaignbegan in March 2010 to investigate the MSWI ESP fly ash composition over a longer period. Alow variability of the MSWI ESP fly ash composition would constitute an incentive for th...
Proceedings of the Institution of Civil Engineers - Waste and Resource Management, 2012
Technological innovation has resulted in the generation of huge amounts of obsolete electronic eq... more Technological innovation has resulted in the generation of huge amounts of obsolete electronic equipment. As a result of financial constraints and lack of adequate knowledge, recycling and disposal of e-waste in India is „rudimentary, mostly carried out informally in backyard operations. Considerable amounts of wastes and residues are thus generated and contaminate the soil, air and groundwater of the surrounding environment. In this work, a survey in the Mandoli metal recycling area, in New Delhi, India, has been carried out in order to identify the extent of environmental degradation and associated health effects. Concentrations of copper, aluminium, lead, zinc, nickel, manganese and cadmium in soil samples indicate extensive contamination, compared with the reference site. Groundwater concentrations of manganese, copper, aluminium, chromium (VI) and selenium are beyond the desirable limits of Indian potable water. A survey conducted simultaneously revealed that health impairment ...
Applied Sciences
Mechanical composting is a popular treatment method for the mechanically separated organic fracti... more Mechanical composting is a popular treatment method for the mechanically separated organic fraction of municipal solid wastes to stabilize the waste material and reduce its environmental impacts. The model and life cycle inventory database are created based on the existing centralized mechanical composting facility located in Chania (Crete, Greece). This study aims to assess all stages of the composting process, wherein input-output flows are comprehensively analyzed based on specific waste fragments. The transfer coefficients are calculated for each waste fragment throughout the processes. The degradation rate is measured as kg of C and N released per Mg of the treated material. The results show that process degradation rates are independent of the initial fragmental composition. This is the first study that accurately models the fate of distinctive waste fragments in a composting plant, while the developed life cycle inventory (with regard to mass and energy balances) can be appli...
RSC Advances, 2020
The degree and source of recyclates contamination with polycyclic aromatic hydrocarbons was studi... more The degree and source of recyclates contamination with polycyclic aromatic hydrocarbons was studied in 8 polyolefin recyclate samples; 4 from post-consumer packaging waste and 4 from a mixed source (post-industrial, post-commercial, and post-consumer).
Journal of Environmental Management, 2021
Until the complete transition to a renewable energy sources based economy, the potential environm... more Until the complete transition to a renewable energy sources based economy, the potential environmental hazards associated with petroleum refinery industries affecting water, air and soil seek sustainable solutions. In the present study contaminated soil from a refinery is used as an alternative source for producing useful building materials by geopolymerization. To this end, soil remediation by thermal desorption was initially applied. Thermal treatment was performed between 60 and 250 • C for short time intervals (10-30 min) in order to remove organic pollutants (Total Petroleum Hydrocarbons, TPHs and Polycyclic Aromatic Hydrocarbons, PAHs). Physical, chemical analyses, mineral phase composition, as well as thermogravimetric analysis were employed to characterize the sample. Moreover, removal efficiency of TPHs and PAHs was evaluated. Subsequently, the treated soil presenting the maximum elimination of TPH and PAHs was used in geopolymer mortar formation aiming to stabilize the toxic metals (TMs) and produce a possible profitable material. For geopolymer synthesis the substitution of metakaolin (MT) by treated soil at 0, 50, 70 and 100% was tested. The produced specimens were evaluated based on the 28 day compressive strength and metals leaching. Results showed that the geopolymer constructed by 50% MT-50% remediated soil at 250 • C for 30 min, had negligible content of organic pollutants, TMs were immobilized and exhibited increased strength thus giving significant recycling benefits. Valorisation of industrial residues to produce building materials is a promising solution for sustainable waste management.
Construction and Building Materials, 2020
h i g h l i g h t s It was developed ceramics with 70 wt% of hazardous serpentinite extraction wa... more h i g h l i g h t s It was developed ceramics with 70 wt% of hazardous serpentinite extraction waste. Flexural strength of new ceramics (57 MPa) is 14 time higher than norms demands (4 MPa). Novel ceramics exhibit primarily glassy structures with some crystal inclusions. Obtained results permit bonding of all hazardous volatile ''fibrils" of serpentine.
Issue 4, 2013
The effects of different mixture ratios of sewage sludge (SS), organic fraction of municipal soli... more The effects of different mixture ratios of sewage sludge (SS), organic fraction of municipal solid waste (OFMSW) and yard trimmings (YT) on the performance of composting process were investigated in this study. The high water content and the proper carbon/nitrogen ratio make sludge ideal for this procedure, improving the characteristics of the initial composting mixture. OFMSW and YT enable the production of a quality product that may be used as a soil conditioner. Therefore, piles of about 1 m3 were prepared by mixing OFMSW, SS and YT in four different ratios (w/w) [only OFMSW, OFMSW:SS = 2:1, OFMSW:SS:YT = 3:1:2, and OFMSW:SS:YT = 4:1:2]. The piles were kept in controlled aerobic conditions for 10 weeks. The temperature of the piles was measured daily (for the first 4 weeks) and ranged between 60-70 oC, while air was provided to the piles by mechanical turning. Results showed that the pile OFMSW:SS:GW = 3:1:2 was most beneficial in composting, since its ability to accumulate and r...
Waste Management, 2017
The objective of the present study is to evaluate the use of animal by-products (ABP) as substrat... more The objective of the present study is to evaluate the use of animal by-products (ABP) as substrates for anaerobic digestion, aiming at methane production. Specifically, four ABP of Category 2 and 3, namely (i) stomach and rumen, (ii) stomach contents, (iii) breasts and reproductive organs and (iv) bladders and intestines with their contents, were selected. The methane potential of each ABP was initially determined, while the feasibility of anaerobic co-digestion of ABP with two agroindustrial waste, i.e. orange peels and olive leaves was also studied. To this purpose, Biochemical Methane Potential (BMP), as well as semi-continuous assays were respectively conducted. In the latter, the effect of the variation in the organic loading rate (OLR) on methane production was investigated. Results obtained from BMP assays showed that the samples containing breasts and reproductive organs, bladders and intestine, and stomach and rumen, had higher methane potentials of 815, 787 and 759 mLCH 4,STP /gVS, respectively. Moreover, according to the results of the semi-continuous assays, maximum methane yields between 253 and 727 mLCH 4 /gVS fed were obtained at an OLR of 0.8 gVS/L/d. The only case in which methanogenesis inhibition phenomena, due to increased ammonia concentrations, were observed, was the assay being fed with a mixture of breasts and reproductive organs and orange peels, at the highest OLR. This inhibition phenomenon was attributed to an inappropriate C/N ratio.
This study aims to determine the effect of low-temperature thermal pretreatment on two lignocellu... more This study aims to determine the effect of low-temperature thermal pretreatment on two lignocellulosic materials originating from agroindustrial activities, namely grape marc and cotton gin waste. More specifically, this paper focuses on the impact of thermal pretreatment on the solubilization and the methane potential of these two materials. Thermal pretreatment was carried out by soaking the materials in deionized water at three different temperatures, i.e. 75, 50 and 100°C. The effect of pretreatment duration was investigated in the range of 30-240 min. Solubilization of the materials was determined by measuring soluble chemical oxygen demand (sCOD) and total phenols concentrations in the liquid phase obtained after pretreatment. The methane potential of the solid and liquid fractions was determined through Biochemical Methane Potential (BMP) assays. The samples used in these assays were chosen on the basis of the solubilization data after pretreatment. According to the results, pretreatment temperature affects solubilization more, compared to pretreatment duration. Methane production data indicated that pretreatment favored both release of biodegradable material in the liquid phase, and digestibility of remaining solids. Thermal pretreatment at 75 °C provided the highest SMY for what concerns GM-solid substrates and CGW-liquid substrates, while the best results for GM-liquid substrates and CGW-solid substrates were obtained after pretreatment at 100 °C.
Waste Management, 2008
The present study evaluates the influence of alkaline (NaOH) pretreatment on anaerobic digestion ... more The present study evaluates the influence of alkaline (NaOH) pretreatment on anaerobic digestion of olive pomace. Batch hydrolysis experiments with different NaOH dosages, process durations and temperatures were conducted, in which the variation of olive pomace solubilization in the liquid phase was investigated. The effect of pretreatment on anaerobic digestion was studied through biochemical methane potential assays. The results demonstrated the effectiveness of the NaOH pretreatment in improving olive pomace solubilization as well as its biodegradability. Maximum specific methane yields were achieved at different NaOH dosages depending on the pretreatment temperature. Consequently, it was concluded that the two operating parameters of the pretreatment stage (NaOH dosage and temperature) may exert a joint effect on substrate biodegradability and methane yields. The highest methane yield (242 NmL CH 4 /gVS) was obtained for the material pretreated at 90°C, at a dosage of 1 mmol/gVS (4% of VS).
Waste Management, 2006
A one-year survey was conducted in the greater region of Crete (located at the lower region of th... more A one-year survey was conducted in the greater region of Crete (located at the lower region of the Aegean Sea) for the purpose of identifying waste composition (including chemical and physical characterization), as well as any seasonal variation. The investigation was carried out repeatedly at seven landfills and one transfer station in Crete, in four phases. Each sampling phase corresponded to a season (autumn, winter, spring, summer). ASTM D5231-92(2003) standard method and RCRA Waste Sampling Draft Technical Guidance were used. Hand sorting was used for classifying the collected wastes into the following categories: plastics, paper, metals, aluminium, leather-wood-textiles-rubbers, organic wastes, non-combustibles and miscellaneous. Further analysis included proximate and ultimate analysis of combustible materials. Metals such as lead, cadmium and mercury were also investigated. The results show that there has been a significant decrease of organic wastes during the last decade due to the increase of packaging materials, as a result of a change in consumption patterns. Three main waste categories were determined: organic wastes, paper and plastics, which combined represent 76% of the total waste in Crete. Furthermore, a high fraction of glass and a seasonal variation of aluminium indicate a strong correlation of waste composition with certain human activities, such as tourism. There is also a variation between the municipal solid waste (MSW) composition in the region of Crete (2003
Journal of Hazardous Materials, 2011
The electrochemical oxidation of stabilized landfill leachate with 2960 mg L(-1) chemical oxygen ... more The electrochemical oxidation of stabilized landfill leachate with 2960 mg L(-1) chemical oxygen demand (COD) over a Ti/IrO(2)-RuO(2) anode was investigated in the presence of HClO(4) as the supporting electrolyte. Emphasis was given on the effect of electrolysis time (up to 240 min) and temperature (30, 60 and 80°C), current density (8, 16 and 32 mA cm(-2)), initial effluent's pH (0.25, 3, 5 and 6), HClO(4) concentration (0.25 and 1M) and the addition of NaCl (20 and 100mM) or Na(2)SO(4) (20mM) as source of extra electrogenerated oxidants on performance; the latter was evaluated regarding COD, total carbon (TC), total phenols (TPh) and color removal. Moreover, the anode was studied by scanning electron microscopy and cyclic voltammetry. The main parameters affecting the process were the effluent's pH and the addition of salts. Treatment for 240 min at 32 mA cm(-2) current density, 80°C and the pH adjusted from its inherent value of 0.25 (i.e. after the addition of HClO(4)) to 3 yielded 90% COD, 65% TC and complete color and TPh removal at an electricity consumption of 35 kWh kg(-1) COD removed. Comparable performance (i.e. 75% COD reduction) could be achieved without pH adjustment but with the addition of 100mM NaCl consuming 20 kWh kg(-1) COD removed.
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Papers by Evangelos Gidarakos