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Mechelen, Belgium

Verbinnen B.,Catholic University of Leuven | Block C.,Catholic University of Leuven | Lievens P.,Catholic University of Leuven | Lievens P.,Leuven Engineering College Groep T | And 2 more authors.
Waste and Biomass Valorization | Year: 2013

Mo, Sb and Se form oxyanions in solution, and are therefore difficult to remove by traditional wastewater treatment methods (e.g. alkaline precipitation). In this paper, a method for the simultaneous removal of these three elements from wastewater by adsorption, zeolite-supported magnetite is developed. The adsorbent consists of finely divided magnetite particles on a zeolite substrate as carrier material. Basic adsorption parameters such as ideal pH, maximum adsorption capacity and equilibration time, are determined for the oxyanions separately. Much attention is paid to the study of interferences that can limit adsorption. Anions like sulphate and chloride, which often occur in large amounts in wastewaters, do not really compete for adsorption places on magnetite, but oxyanions largely interfere with each other. The reason for this competition is a similar adsorption mechanism (inner-sphere complex formation) for all studied oxyanions, except for selenate, that forms outersphere complexes, as was confirmed by geochemical modeling. The adsorption of Mo, Sb and Se oxyanions from an aqueous solution containing the most important detected interferences and from a real wastewater containing also cations is compared, showing that the most important interferences are identified. The order of adsorption is Mo(VI) > Sb(V) > Se(VI). As a case study, Mo, Sb and Se oxyanions are removed by adsorption from an industrial wastewater, the flue gas cleaning effluent of a waste incinerator. For an adsorbent concentration of 20 g/l, removal efficiencies of 99, 97 and 77% are obtained for Mo, Sb and Se. © Springer Science+Business Media 2013. Source

Van Caneghem J.,Catholic University of Leuven | Block C.,Catholic University of Leuven | Block C.,Leuven Engineering College Groep T | Van Brecht A.,INDAVER nv | And 2 more authors.
Chemosphere | Year: 2010

The amount of different persistent organic pollutants (POPs) in the input of waste incinerators was compared to that in the output. Three cases were considered: a rotary kiln incinerating hazardous waste, a grate furnace incinerating municipal solid waste (MSW) and the same grate furnace co-incinerating plastics of waste of electrical and electronic equipment (WEEE) and automotive shredder residue (ASR) with MSW. The mass balance for PCBs in the rotary kiln indicates that these POPs are destroyed effectively during incineration. The grate furnace can be a sink or source of PCDD/Fs and PCBs depending on the concentrations in the incinerated waste. In order to compare the total amount of POPs in input and output, a methodology was developed whereby the amount of POPs was weighed according to minimal risk doses (MRDs) or cancer potency factors. For both incinerators the PCDD/Fs, PCBs and polyaromatic hydrocarbons (PAHs) are the main contributors to total weighed POP output. In MSW, the PCDD/Fs, PBDD/Fs and polybrominated diphenylethers (PBDEs) are the main contributors to the weighed POP input. The ratios of the weighed POP-input over -output clearly indicate that the rotary kiln incinerating hazardous waste is a weighed POP sink. The grate furnace incinerating MSW is a weighed POP sink or source depending on the POP-concentrations in the waste, but the difference between output and input is rather limited. When e.g. ASR and plastics of WEEE, containing high concentrations of PBDEs and PCBs, are co-incinerated in the grate furnace, it is clearly a weighed POP sink. © 2009 Elsevier Ltd. All rights reserved. Source

Vermeulen I.,Catholic University of Leuven | Van Caneghem J.,Catholic University of Leuven | Block C.,Catholic University of Leuven | Van Brecht A.,INDAVER nv | And 2 more authors.
Clean Technologies and Environmental Policy | Year: 2012

Automotive shredder residue (ASR) is a heterogeneous waste stream with varying particle size and elemental composition. Owing to its complexity and hazardous characteristics, landfilling of ASR is still a common practice. Nevertheless, incineration with energy recovery of certain ASR fractions (Waste-to-Energy, WtE) emerges as an interesting alternative. In a full scale experiment, a waste mix of 25 % heavy ASR, 25 % refuse derived fuel (RDF), and 50 % waste water treatment (WWT) sludge was incinerated in the SLECO fluidized bed combustor (FBC) at the Indaver site in Antwerp, Belgium. Input and output streams were sampled and analyzed to make an inventory of the most important pollutants and toxics. The inventory was further used to determine the environmental impact. Results are compared to those of two other scenarios: incineration of the usual waste feed (70 % RDF and 30 % WWT sludge) and co-incineration of 39 % ASR with 61 % WWT sludge. It can be concluded that co-incineration of heavy ASR in an existing FBC is a valid and clean technology to increase current reuse and recovery rates. In the considered FBC, 27 % of the energetic value of ASR can be recovered, while all emissions remain well below regulatory limits and only 12.6 % of the heavy ASR needs to be landfilled. The proportion of ASR in the input waste mix is however limited by the heavy metal concentration in the ASR and the generated ashes. © US Government 2012. Source

Vermeulen I.,Catholic University of Leuven | van Caneghem J.,Catholic University of Leuven | Block C.,Catholic University of Leuven | Block C.,Leuven Engineering College Groep T | And 3 more authors.
WIT Transactions on Ecology and the Environment | Year: 2012

The Indaver integrated grate furnace, incinerating municipal solid waste (MSW) along with comparable industrial waste, is described. In the installation energy is recovered by producing steam which is delivered to other companies, or used to generate electricity. The bottom ashes are wet-washed; ferrous and non-ferrous metals and granulates are recovered. Next to the grate furnace, a fluidized bed combustor (FBC) operated by SLECO is situated. It can co-incinerate various types of industrial wastes (including ASR), RDF, waste water treatment (WWT) sludges, etc. and produces steam to generate electricity. The bottom ashes are recovered as secondary raw material. It is demonstrated that both installations have a good environmental performance and address many aspects of cleaner production. This way, both grate furnace and FBC may play an important role in sustainable waste management. Depending on the fractions of the energy carrier(s), the actual energy recovery varies from 41% for the grate furnace (steam + electricity) to 27% for the FBC (only electricity). The most important airborne emissions and solid residues are monitored in both installation and are discussed in detail. For all components of interest, emissions remain well below Flemish limit values. Moreover, it was shown that both installations act as a POP sink when flue gas emissions are taken into account as a POP output. From the bottom ashes of both incinerators ferrous and non-ferrous metals and granulates are recovered, representing 19.9 and 9.2 wt% of the original waste input of respectively the grate furnace and the FBC. When introducing higher amounts of heavy metals into the FBC, co-incinerating ASR, the bottom ashes still fulfil Flemish requirements for use as secondary raw material. © 201 WIT Press. Source

Van Caneghem J.,Catholic University of Leuven | Block C.,Catholic University of Leuven | Block C.,Leuven Engineering College Groep T | Vermeulen I.,Catholic University of Leuven | And 5 more authors.
Journal of Hazardous Materials | Year: 2010

The European directive 2000/53/EC implies a " reuse and recovery" rate for end-of-life vehicles (ELVs) of 95% to be reached by the year 2015. One of the options to increase the actual average European " reuse and recovery" rate of approximately 78% (EU 15, 2008) is incineration of automotive shredder residue (ASR) with energy-recovery. The mass balance and the congener fingerprints for PCDD/Fs, dioxin-like PCBs, PCBs and PAHs in a real scale fluidized bed combustor (FBC) incinerating 25% ASR with 25% refuse derived fuel (RDF) and 50% waste water treatment sludge (WWT sludge) were investigated. The PCDD/F, dioxin-like PCB, PCB and PAH concentrations in this input waste mix were more than hundred times higher than in the usual waste feed of the incinerator (30% RFD and 70% WWT sludge). In the outputs of the FBC, however, the concentrations of these POP groups were comparable or only slightly higher than in the outputs generated during the incineration of the usual waste feed. The considered POPs in the waste were destroyed efficiently and the formation of new POPs during cooling of the flue gas appeared to a large extent independent of the POP concentrations in the incinerated waste. © 2010 Elsevier B.V. Source

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