Denitrifying phosphorus removal and impact of nitrite accumulation on phosphorus removal in a continuous anaerobic–anoxic–aerobic (A2O) process treating domestic wastewater

This paper studied denitrifying phosphorus removal of a novel two-line biological nutrient removal process treating low strength domestic wastewater under different sludge recycling ratios. Mass balance of intracellular compounds including polyhydroxyvalerate, polyhydroxybutyrate and glycogen was investigated together with total nitrogen (TN) and total phosphorus (TP). Results showed that sludge recycling ratios had a significant influence on the use of organics along bioreactors and 73.6% of the average removal efficiency was obtained when the influent chemical oxygen demand (COD) ranged from 175.9 mgL−1 to 189.9 mgL−1. The process performed better under a sludge recycling ratio of 100% compared to 25% and 50% in terms of ammonia and COD removal rates. Overall, TN removal efficiency for 50% and 100% sludge recycling ratios were 56.4% and 61.9%, respectively, unlike the big gap for carbon utilization and the TP removal rates, indicating that the effect of sludge recycling ratio on the anaerobic compartments had been counteracted by change in the efficiency of other compartments. The higher ratio of sludge recycling was conducive to the removal of TN, not in favor of TP, and less influence on COD. Thus, 25% was considered to be the optimal sludge recycling ratio.

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Optimizing aeration rate in an external nitrification–denitrifying phosphorus removal (ENDPR) system for domestic wastewater treatment

Chemical Engineering Journal ◽

10.1016/j.cej.2014.01.045 ◽

2014 ◽

Vol 245 ◽

pp. 342-347 ◽

Cited By ~ 17

Author(s):

Weitang Zhang ◽

Feng Hou ◽

Yongzhen Peng ◽

Qingsong Liu ◽

Shuying Wang

Keyword(s):

Wastewater Treatment ◽

Phosphorus Removal ◽

Domestic Wastewater ◽

Aeration Rate ◽

Denitrifying Phosphorus Removal ◽

Domestic Wastewater Treatment

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N2O Reduction During Denitrifying Phosphorus Removal With Propionate as Carbon Source

10.21203/rs.3.rs-375078/v1 ◽

2021 ◽

Author(s):

Li Cong ◽

Qian Wang ◽

Wenlin Jia

Keyword(s):

Carbon Source ◽

Phosphorus Removal ◽

Dominant Factor ◽

Nitrite Accumulation ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

N2o Reduction ◽

Denitrifying Phosphorus Removal ◽

Factors Affecting ◽

Mixed Carbon Source

Abstract Denitrifying phosphorus removal was realized in sequencing batch reactors using different carbons sources (acetate, propionate, and a mixture of acetate/propionate). Nutrient removal and N2O production were investigated, and the factors affecting N2O production were explored. Nitrogen removal was 40.6% lower when propionate was used as the carbon source instead of acetate, while phosphorus removal was not significantly different. N2O production was greatly reduced when propionate was used as the carbon source instead of acetate. The emission factor in the propionate system was only 0.43%, while those in the acetate and mixed-carbon source system were 16.3% and 1.9%, respectively. Compared to the propionate system, ordinary heterotrophic organisms (i.e., glycogen-accumulating organisms) were enriched in the acetate system, explaining the higher N2O production in the acetate system. The lower nitrite accumulation in the propionate system compared to the acetate system was the dominant factor leading to the lower N2O production.

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Basic Studies on Phosphorus Removal by the Contact Aeration Process Using Iron Contactors

Water Science & Technology ◽

10.2166/wst.1991.0514 ◽

1991 ◽

Vol 23 (4-6) ◽

pp. 641-650 ◽

Cited By ~ 4

Author(s):

S. Haruta ◽

T. Takahashi ◽

T. Nishiguchi

Keyword(s):

Corrosion Rate ◽

Phosphorus Removal ◽

Domestic Wastewater ◽

Small Scale ◽

Combined Method ◽

Sulfate Reducing ◽

Biological Sludge ◽

Aeration Process ◽

Basic Studies ◽

Volumetric Loading

The authors have developed what we call the submerged iron contactor process as a simple and inexpensive phosphorus removal method for small-scale plants disposing of domestic wastewater and household wastewater treatment tanks. In this method iron contactors are submerged in biological treatment tanks, where phosphate anions in wastewater are combined with iron cations produced through corrosion of the contactors, and the compound thus produced is precipitated and removed together with biological sludge. In these studies, laboratory experiments were made on the contact aeration process combined with the above-mentioned method, and the following findings were obtained. (1) It is desirable to treat wastewater by making use of corrosion by sulfate-reducing bacteria instead of corrosion by oxygen dissolved in wastewater, to conduct a stable phosphorus removal by this combined method. (2) The corrosion rate of iron contactors is affected by the volumetric loading of BOD in the tanks where they are submerged. (3) Assuming that an iron contactor continues to suffer corrosion evenly all over the surface when our combined method is applied, it is estimated that the corrosion rate is about 1mm or less in 30 years.

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