Biotransformative removal of cationic Red X-GRL by anaerobic activated sludge

RSC Advances ◽  
2015 ◽  
Vol 5 (33) ◽  
pp. 25699-25707 ◽  
Author(s):  
Bin Qiu ◽  
Xinzhu Xu ◽  
Yan Dang ◽  
Qiang Wang ◽  
Dezhi Sun ◽  
...  

Azo dye was completely decolorized and degraded to methane and ammonia by bacteria and archaea under anaerobic conditions.

2008 ◽  
Vol 57 (6) ◽  
pp. 915-919 ◽  
Author(s):  
L. Zhang ◽  
L. Mendoza ◽  
M. Marzorati ◽  
W. Verstraete

Hydrogen sulfide emission in sewers is associated with toxicity, corrosion, odor nuisance and a lot of costs. The possibility to inhibit sulfide generation by formaldehyde and its derivatives (paraformaldehyde and urea formaldehyde) has been evaluated under anaerobic conditions. The impact of formaldehyde on an activated sludge system and an appraisal of the economic aspects are also presented. The optimum dosage to inhibit sulfide generation in sewage was 12–19 mg L−1 formaldehyde. The dosages of 32 mg L−1 paraformaldehyde or 100 mg L−1 urea formaldehyde were not capable of inhibiting sulfide generation in sewage. The impact of 19 mg L−1 formaldehyde on activated sludge system was negligible in terms of COD removal, nitrification rate and oxygen uptake rate.


1982 ◽  
Vol 14 (1-2) ◽  
pp. 31-45 ◽  
Author(s):  
J L Barnard

This paper discusses the need for anaerobiases as a pre-requisite for phosphorus removal in activated sludge plants and the effect of nitrates on the anaerobic conditions. If the plant could be operated to avoid nitrification, biological phosphorus removal presents no problems. When nitrification is required, the nitrates must be reduced to a low level through internal denitrification. If sufficient carbon is available to ensure complete removal of the nitrates and anaerobic conditions in a specific zone in the plant, good phosphate removal can be ensured. Below COD : TKN ratios of 10 : 1 it is becoming more difficult to control the plant and special care should be taken to determine not only the quantity of organic carbon available as electron donors for removal of the nitrates but also the form in which it arrives at the plant.


2019 ◽  
Vol 79 (6) ◽  
pp. 1081-1091 ◽  
Author(s):  
V. F. Velho ◽  
G. Andreottola ◽  
P. Foladori ◽  
R. H. R. Costa

Abstract A full-scale anaerobic side-stream reactor (ASSR) for sludge reduction was monitored in terms of sludge production and compared with the previous conventional activated sludge configuration (CAS). A detailed solid mass balance was calculated on the whole full-scale plant to estimate the sludge reduction associated with the ASSR. The activity of the biomass, which undergoes alternation of aerobic and anaerobic conditions, was investigated by the respirometric test. The ASSR promoted a reduction of heterotrophic biomass activity and the substrate consumption rate in the activated sludge implemented with ASSR (AS + ASSR) was 36% smaller than in the CAS period. The solid mass balance indicated a sludge reduction of 28%. During the 270-day operation, the observed sludge yield passed from 0.438 kgTSS/kgCOD in the CAS to 0.315 in the AS + ASSR configuration. The solubilization of chemical oxygen demand (COD), NH4+-N and orthophosphate were verified under anaerobic conditions. The results suggest that the possible mechanisms of sludge reduction were the increase of the system sludge retention time (SRT) by ASSR addition, and the reduction in heterotrophic biomass activity added to the organic compounds' hydrolysis.


1983 ◽  
Vol 15 (3-4) ◽  
pp. 1-13 ◽  
Author(s):  
James L Barnard

This paper briefly summarizes the early work on phosphorus removal in activated sludge plants in the U.S.A. and observed that such removals only occurred in low SRT plants of the plug flow type and in the Phostrip plants, neither designed for full nitrification. The discovery of simultaneous nitrogen and phosphorus removal, as well as full-scale experiments are discussed. The Phoredox process was proposed utilizing internal recycling for the removal of nitrates and an anaerobic first stage in which the incoming feed is used to obtain the necessary anaerobic conditions, essential as a conditioning step for the uptake of phosphorus. Proposed mechanisms are discussed.


2008 ◽  
Vol 57 (6) ◽  
pp. 901-907 ◽  
Author(s):  
H. Yasui ◽  
K. Komatsu ◽  
R. Goel ◽  
Y. Y. Li ◽  
T. Noike

For plant wide modelling of wastewater treatment, it is necessary to develop a suitable state variables interface for integrating state of the art models of ASM and ADM1. ADM1 currently describes such an interface, however, its suitability needs to be experimentally evaluated. In this study, we characterised activated sludge under aerobic and anaerobic conditions to obtain representative state variables for both models. ASM state variables of XS, XH and XI (as obtained from aerobic tests) and ADM1 state variables of XC and XI (as obtained from anaerobic tests) were then correlated to assess the suitability of current interface. Based on the seven datasets of this study and seven datasets from literatures, it was found that in general ASM state variables were well correlated to the state variables of ADM1. The ADM1 state variable of XC could be correlated to the sum of state variables of XS and XH, while XI in both the models showed direct correspondence. It was also observed that the degradation kinetics of XC under anaerobic condition could be better described by individual degradation kinetics of XS and XH. Therefore, to establish a one to one correspondence between ASM and ADM1 state variables and better description of degradation kinetics in ADM1, replacing the composite variable of XC by the state variables of XS and XH is recommended.


2006 ◽  
Vol 54 (1) ◽  
pp. 47-53 ◽  
Author(s):  
E.M. Seviour ◽  
K. Eales ◽  
L. Izzard ◽  
M. Beer ◽  
E.L. Carr ◽  
...  

The in situ physiology of the actinobacterial bulking and foaming filamentous bacterium “Nostocoida limicola” II was studied by fluorescence in situ hybridization/microautoradiography. Substrate assimilation patterns of pure cultures of this bacterium were different to those seen in activated sludge biomass samples. There was no evidence to suggest that “N. limicola” II preferred hydrophobic substrates, but evidence was produced to support the view that it is metabolically active under anaerobic conditions in activated sludge.


PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0138448 ◽  
Author(s):  
Mohammad Danish Khan ◽  
Huda Abdulateif ◽  
Iqbal M. Ismail ◽  
Suhail Sabir ◽  
Mohammad Zain Khan

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