Hybrid Adsorbent for Selective Recovery of Phosphorus from Contaminated Water
Shantanu Agrawal1Deepak Jain2Sudipta Sarkar3
1. Civil Engineering at IITR2. the Department of Civil Engineering,IITR3. the Civil Engineering Department,IITR
摘要：Phosphorus is an essential part of the life’s building block,DNA.It acts as an essential nutrient for plant growth and agriculture.Humans have greatly impacted the biogeochemical cycle of phosphorus,mining it from rock and other underground deposits,converting it to fertilizer for its use around the world.Thus,the journey of phosphorus has been almost one way-it starts from phosphate-rich deposits and ends up being dispersed in food chain.The global availability of mineable phosphate is low and is concentrated within a few regions in the world.Therefore,unless phosphorus is recycled within the food chain,it is likely that phosphorus would become a supply-limited nutrient.It would play a major role in determining the future food price and also,on the global food security as well.Land run-offs,from agricultural fields and soil erosion,municipal wastewater carrying human and animal waste,poultry run-off are major sources through which phosphorus is lost from the food chain to the aqueous systems.The runoff containing high concentration of nutrients is known to cause a serious environmental problem known as eutrophication.On the other hand,removal and recovery of phosphorus from these sources have the potential to recycle much of phosphate that would otherwise be lost within the environment.In this study we attempted to develop and validate a hybrid adsorbent for selective removal and recovery of phosphate from contaminated water.The hybrid adsorbent has two phases,one phase has the polymeric backbone having weak base functionality and the other phase is dispersed nanoparticles of iron hydroxide.Batch adsorption studies at different p H values with a background of commonly available anions showed that adsorption closely follows Freundlich isotherm and most efficient at around neutral p H 7.The experimental results of kinetics study show that the adsorption is kinetically controlled by intraparticle diffusion process.The effect of competing ions such as sulfate,chloride or bicarbonate was not significant,thereby confirming the prevalence of inner-sphere complexation process in adsorption.We also carried out fixed-bed column runs,both with synthetic contaminated water as well as secondary treated wastewater.In both the cases,phosphate was successfully removed from the background of other anions for more than 2000 bed volumes.Regeneration performed by a solution of caustic soda was able to recover almost all the adsorbed phosphate,thus allowing for reuse of the adsorbent.The ability to remove and recover phosphate from wastewater demonstrated that it may be commercially feasible to recycle phosphate back into agricultural fields in the form of fertilizer.
2015 International Conference on Network Security & Computer Science （ICNSCS-15）;International Conference on Mechanical and Industrial Engineering （ICMAIE’2015）;2015 International Conference on Innovations in Chemical and Agricultural Engineering （ICICAE’2015）
Kuala Lumpur (Malaysia)