Study of adsorbents prepared by pyrolysis of sludge and sludge/disposal filter cake mix

摘要

Introduction Removal of metals like copper, zinc and molybdenum and an organic dye pollutant methylene blue (MB) from water is an important environmental issue. Many technologies have been developed to remove metals and MB from waters, e.g. adsorption. But the high cost of activated carbons stimulates researchers to develop low cost adsorbents. In this work, two different waste streams supplied by the chemical company BASF (Antwerp, Belgium) are used to prepare the adsorbents: i.e. sludge from the aerobic waste water plant (leftovers from basic chemistry, plastic and fertilizer production processes) and a filter cake (FC) produced during polyetherol production process. The adsorbents of sludge and sludge/FC mix are prepared by slow and fast pyrolysis. Slow pyrolysis is characterized by a slow heating rate and a long residence time of volatiles, while fast pyrolysis is characterized by a fast heating rate and a short residence time of volatiles. Different parameters of the pyrolysis process can influence the composition [1] and thus the adsorption characteristic of the pyrolysis solid adsorbent. The obtained adsorbents are post-treated with HC1, to partially dissolve the inorganic matter and to evaluate the influence of HC1 washing on metal and MB adsorption.