Phosphorus Removal from Wastewater Using Oven-Dried Alum Sludge

Abstract

The present study deals with the removal of phosphorus from wastewater by using oven-dried alum sludge (ODS) as adsorbent that was collected from Al-Qadisiya treatment plant (Iraq); it was heated in an oven at 105• C for 24 h and then cooled at room temperature. The sludge particles were then crushed to produce a particle size of 0.5-4.75 mm. Two modes of operation are used, batch mode and fixed bed mode, in batch experiment the effect of oven-dried alum sludge doses 10-50 g/L, pH of solution 5-8 with constant initial phosphorus concentration of 5 mg/L, and constant particle size of 0.5 mm were studied. The results showed that the percent removal of phosphorus increases with the increase of oven-dried alum sludge dose, but pH of solution has insignificant effect. Batch kinetics experiments showed that equilibrium time was about 6 days. Adsorption capacity was plotted against equilibrium concentration, and isotherm models (Freundlich, Langmuir, and Freundlich-Langmuir) were used to correlate these results. In the fixed bed isothermal adsorption column, the effect of initial phosphorus concentration (C o ) 5 and 10 mg/L, particle size 2.36 and 4.75 mm, influent flow rate (Q) 6 and 10 L/hr, and bed depth (H) 0.15-0.415 m were studied. The results showed that the oven-dried alum sludge was effective in adsorbing phosphorus, and percent removal of phosphorus reaches 85% with increasing of contact time and adsorbent surface area (i.e., mass of adsorbent 50 g/L with different pH).

Polycyclic aromatic hydrocarbons in road-deposited sediments, water sediments, and soils in Sydney, Australia: Comparisons of concentration distribution, sources and potential toxicity

“…3 that the higher the influent phosphorus concentration was, the faster the breakthrough and exhaustion took place. Higher retention rate and thus, earlier saturation might result from greater concentration gradient and smaller mass transfer resistance at higher phosphate concentration (Mohammed and Rashid, 2012;Paudyal et al, 2013). Similar tendency was reported by Zhang et al (2014) in case of removing phosphate using activated laterite.…”

Effect of pH and aging temperature on the phosphorus removal properties of layered hydroxide synthesized from zinc acetate

“…However, the treatment and disposal of excess sludge accounts for approximately 50-60% of the total cost of wastewater treatment. Conventional disposal methods, such as landfilling or ocean dumping, may cause secondary pollution problems and are strictly regulated in many countries [5][6][7]. For chemical precipitation process, the high sludge production and the associated disposal problems are also common concerns [8].…”

Study of the Potential of Water Treatment Sludges in the Removal of Emerging Pollutants

“…Besides the influence of the AC properties on its adsorption capacity, the presence of other elements could also have influenced the adsorption performance of the sludges tested. For example, the high aluminium content of the sludges ( Table 2 ) may have influenced the adsorption process, although there appears little consensus in the literature on this influence [ 36 , 38 , 51 , 62 ]. On the one hand, aluminium has been indicated to improve the adsorption capacity of WTS (e.g., Lee et al [ 58 ]).…”

“…Sludge-based adsorbents have been reported in the literature for the removal of several pollutants from water treatment plants (WTPs) and WWTPs [ 36 , 37 ]. Research efforts, however, have focused on their removal efficacy for compounds like heavy metals [ 38 , 39 , 40 , 41 , 42 , 43 ], dyes [ 44 , 45 , 46 ], phenols [ 47 , 48 ], phosphorus and phosphate [ 49 , 50 , 51 , 52 ] and antibiotics [ 53 ]. Consequently, the adsorbent potential of sludge for compounds like E2 and EE2 remains unknown.…”