Microbiological mechanism of the improved nitrogen and phosphorus removal by embedding microbial fuel cell in Anaerobic–Anoxic–Oxic wastewater treatment process

Nitrogen and phosphorus are the nutrients induced eutrophication, therefore the removal of nitrogen and phosphorus is the main target of domestic wastewater treatment. In order to achieve better nutrient removal effect with lower construction and operation cost, a new nitrogen and phosphorus removal process was developed based on simulation. New process named MUST was developed by mixing UCT and step-feed BNR technology together, and possessed the advantages of two processes. The results of simulation show that MUST can achieve similar treating effect with 20% shorter hydraulic retention time (HRT) compared with UCT process. The influent splitting ratio of 4:3:3 was recommended for MUST operation. A pilot experiment of MUST was also carried out according to simulation results, and achieved very good pollutant remove effect, the average COD, NH4+-N, TN, TP removal efficiency were 85.4%, 94.0%, 65.1%, 62.3% respectively under the condition of low influent COD/TN ratio. Considering the excellent pollutant removal capacity of MUST, an upgrade project chose it as wastewater treatment process. This paper just starts the research of MUST, further study is necessary and valuable.

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Development of a new wastewater treatment process for resource recovery of carotenoids

Water Science & Technology ◽

10.2166/wst.2015.330 ◽

2015 ◽

Vol 72 (7) ◽

pp. 1191-1197 ◽

Cited By ~ 2

Author(s):

H. Sato ◽

H. Nagare ◽

T. N. C. Huynh ◽

H. Komatsu

Keyword(s):

Wastewater Treatment ◽

Phosphorus Removal ◽

Treatment Process ◽

Haematococcus Pluvialis ◽

Algal Species ◽

Microalgae Cultivation ◽

Nitrogen And Phosphorus ◽

Wastewater Treatment Process ◽

Astaxanthin Production ◽

Nitrogen Contents

A new wastewater treatment process that involves coagulation, ozonation, and microalgae cultivation has been developed. Here, two challenges are discussed. The first was minimizing phosphorus removal during coagulation in order to maximize algal production. The second was to optimize microalgae cultivation; algal species that grow rapidly and produce valuable products are ideal for selection. Haematococcus pluvialis, which produces the carotenoid astaxanthin, was used. Growth rate, nutrient removal ability, and astaxanthin production of H. pluvialis in coagulated wastewater were investigated. After coagulation with chitosan, the turbidity and suspended solids decreased by 89% ± 8.4 → 8% and 71 → 73% ± 16%, respectively. The nitrogen and phosphorus contents of the supernatant remained at 86% ± 6% and 69 → 67% ± 24%, respectively. These results indicate that coagulation with chitosan can remove turbidity and SS while preserving nutrients. H. pluvialis grew well in the supernatant of coagulated wastewater. The astaxanthin yield from coagulated wastewater in which microalgae were cultured was 3.26 mg/L, and total phosphorus and nitrogen contents decreased by 99.0% ± 1.4% → 99% + 1% and 90.3% ± 7.6% → 90% ± 8% (Days 31–35), respectively.

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