TY - JOUR
T1 - Understanding and improving the reusability of phosphate adsorbents for wastewater effluent polishing
AU - Suresh Kumar, Prashanth
AU - Ejerssa, Wondesen Workneh
AU - Wegener, Carita Clarissa
AU - Korving, Leon
AU - Dugulan, Achim Iulian
AU - Temmink, Hardy
AU - van Loosdrecht, Mark C.M.
AU - Witkamp, Geert Jan
N1 - Accepted Author Manuscript
PY - 2018
Y1 - 2018
N2 - Phosphate is a vital nutrient for life but its discharge from wastewater effluents can lead to eutrophication. Adsorption can be used as effluent polishing step to reduce phosphate to very low concentrations. Adsorbent reusability is an important parameter to make the adsorption process economically feasible. This implies that the adsorbent can be regenerated and used over several cycles without appreciable performance decline. In the current study, we have studied the phosphate adsorption and reusability of commercial iron oxide based adsorbents for wastewater effluent. Effects of adsorbent properties like particle size, surface area, type of iron oxide, and effects of some competing ions were determined. Moreover the effects of regeneration methods, which include an alkaline desorption step and an acid wash step, were studied. It was found that reducing the adsorbent particle size increased the phosphate adsorption of porous adsorbents significantly. Amongst all the other parameters, calcium had the greatest influence on phosphate adsorption and adsorbent reusability. Phosphate adsorption was enhanced by co-adsorption of calcium, but calcium formed surface precipitates such as calcium carbonate. These surface precipitates affected the adsorbent reusability and needed to be removed by implementing an acid wash step. The insights from this study are useful in designing optimal regeneration procedures and improving the lifetime of phosphate adsorbents used for wastewater effluent polishing.
AB - Phosphate is a vital nutrient for life but its discharge from wastewater effluents can lead to eutrophication. Adsorption can be used as effluent polishing step to reduce phosphate to very low concentrations. Adsorbent reusability is an important parameter to make the adsorption process economically feasible. This implies that the adsorbent can be regenerated and used over several cycles without appreciable performance decline. In the current study, we have studied the phosphate adsorption and reusability of commercial iron oxide based adsorbents for wastewater effluent. Effects of adsorbent properties like particle size, surface area, type of iron oxide, and effects of some competing ions were determined. Moreover the effects of regeneration methods, which include an alkaline desorption step and an acid wash step, were studied. It was found that reducing the adsorbent particle size increased the phosphate adsorption of porous adsorbents significantly. Amongst all the other parameters, calcium had the greatest influence on phosphate adsorption and adsorbent reusability. Phosphate adsorption was enhanced by co-adsorption of calcium, but calcium formed surface precipitates such as calcium carbonate. These surface precipitates affected the adsorbent reusability and needed to be removed by implementing an acid wash step. The insights from this study are useful in designing optimal regeneration procedures and improving the lifetime of phosphate adsorbents used for wastewater effluent polishing.
KW - Calcium adsorption
KW - Phosphate adsorption
KW - Regeneration
KW - Reusability
KW - Surface precipitation
KW - Wastewater effluent
UR - http://resolver.tudelft.nl/uuid:e05b6f0b-bddc-40d8-9313-98d5efe5f08f
UR - http://www.scopus.com/inward/record.url?scp=85053109883&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2018.08.040
DO - 10.1016/j.watres.2018.08.040
M3 - Article
AN - SCOPUS:85053109883
SN - 0043-1354
VL - 145
SP - 365
EP - 374
JO - Water Research
JF - Water Research
ER -