Nitrogen and phosphorus removal from secondary effluent using drinking water treatment residuals fixed-bed column with intermittent operation

2014 ◽  
Vol 14 (5) ◽  
pp. 812-819
Author(s):  
Leilei Bai ◽  
Changhui Wang ◽  
Yuansheng Pei
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Fixed Bed ◽  
Drinking Water Treatment ◽  
Great Promise ◽  
Secondary Effluent ◽  
Water Treatment Residuals ◽  
Fixed Bed Column ◽  
Drinking Water Treatment Residuals ◽  
N Removal

This work aims to explore a novel intermittently operated fixed-bed column with drinking water treatment residuals (WTR) as main medium to remove nitrogen (N) and phosphorus (P) from secondary effluent under different hydraulic loading rates (HLRs). The results showed that the WTR was beneficial for N removal and the average removal efficiency reached 59%. The denitrification was the primary pathway for N removal and the denitrification rate (2.19 g N/m3 d) was higher than the theoretical value based on the organic matter removal rate (7.35 g CODcr/m3 d). The P removal was excellent and the efficiency still remained 98% after 260-day operation. The lifetime of the WTR fixed-bed column regarding P saturation was estimated to be 7.9 years under the highest HLR of 0.45 m3/m3 d. Moreover, the efficiency and stability of the nutrients removal further increased with the reduction of HLR. Based on regulations, the system holds great promise as a technology for water environment restoration and WTR recycling.

scholarly journals Nano-Scale Drinking Water Treatment Residuals Affect Arsenic Fractionation and Speciation in Biosolids-Amended Agricultural Soil

2020 ◽  
Vol 10 (16) ◽  
pp. 5633
Author(s):  
Ahmed M. Mahdy ◽  
Elsayed Elkhatib ◽  
Tiequan Zhang ◽  
Nieven O. Fathi ◽  
Zhi-Qing Lin
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Agricultural Soil ◽  
Drinking Water Treatment ◽  
Maximum Efficiency ◽  
Water Treatment Residuals ◽  
Edge Structure ◽  
Drinking Water Treatment Residuals ◽  
As Adsorption ◽  
Amended Soil

An incubation experiment was conducted to determine the effects of nanoscale drinking water treatment residuals (nWTRs) on arsenic (As) fractionation and speciation in agricultural soil amended with biosolids. The soils were treated with biosolids of 3% (w/w), along with nWTR application rates of 0, 0.25, 0.50, or 1.00% (w/w). The results revealed that the As adsorption rate increased with increasing the As treatment level from 50 to 800 mg/L. The maximum efficiency of As adsorption was 95%–98% in the soil treated with nWTRs of 1%, while the least As adsorption was 53%–91% in the soil treated with nWTRs of 0.25%. The overall As bioavailability in the biosolids-amended soil followed a descending order of nWTRs treatment: (0%) > 0.25% nWTRs, >0.50% nWTRs, and >1% nWTRs. The addition of nWTRs significantly changed As speciation in biosolids-amended soil. The X-ray absorption near-edge structure spectroscopy (XANES) and MINEQL+4.6 analyses showed that most of As was in a oxidized form of As5+ that likely incorporated in As pentoxide, and thus, with low mobility, bioavailability, and toxicity. This study demonstrated that nWTRs were effective in adsorbing and immobilizing As in biosolids-amended agricultural soils by forming stable As-nWTR surface complexes.

Sign in / Sign up

Export Citation Format

Share Document