Removal of Selected Pharmaceuticals Spiked in the Secondary Effluent of a Wastewater Treatment Plant (WWTP) by Potassium Ferrate(VI)

2016 ◽  
pp. 275-285
Author(s):  
Zhengwei Zhou ◽  
Jia-Qian Jiang
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Potassium Ferrate

Textile Wastewater Reuse: Ozonation of Membrane Concentrated Secondary Effluent

1999 ◽  
Vol 40 (4-5) ◽  
pp. 99-105 ◽  
Author(s):  
A. Lopez ◽  
G. Ricco ◽  
R. Ciannarella ◽  
A. Rozzi ◽  
A. C. Di Pinto ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Acute Toxicity ◽  
Wastewater Treatment Plant ◽  
Textile Industry ◽  
Nonionic Surfactants ◽  
Wastewater Reuse ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Secondary Effluent ◽  
Complete Disappearance

Among the activities appointed by the EC research-project “Integrated water recycling and emission abatement in the textile industry” (Contract: ENV4-CT95-0064), the effectiveness of ozone for improving the biotreatability of recalcitrant effluents as well as for removing from them toxic and/or inhibitory pollutants has been evaluated at lab-scale. Real membrane concentrates (pH=7.9; TOC=190 ppm; CDO=595 ppm; BOD5=0 ppm; Conductivity=5,000 μS/cm; Microtox-EC20=34%) produced at Bulgarograsso (Italy) Wastewater Treatment Plant by nanofiltering biologically treated secondary textile effluents, have been treated with ozonated air (O3conc.=12 ppm) over 120 min. The results have indicated that during ozonation, BOD5 increases from 0 to 75 ppm, whereas COD and TOC both decrease by about 50% and 30 % respectively. As for potentially toxic and/or inhibitory pollutants such as dyes, nonionic surfactants and halogenated organics, all measured as sum parameters, removals higher than 90% were achieved as confirmed by the complete disappearance of acute toxicity in the treated streams. The only ozonation byproducts searched for and found were aldehydes whose total amount continuously increased in the first hour from 1.2 up to 11.8 ppm. Among them, formaldehyde, acetaldehyde, glyoxal, propionaldehyde, and butyraldehyde were identified by HPLC.

scholarly journals Tertiary Physico-chemical Treatment of Secondary Effluent from the Chania Municipal Wastewater Treatment Plant

2013 ◽  
Vol 9 (2) ◽  
pp. 166-173
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Chemical Treatment ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plant ◽  
Physico Chemical ◽  
High Doses

The present study investigated tertiary physico-chemical treatment of the secondary effluent from the Chania municipal Wastewater Treatment Plant (WTP). Laboratory experiments were carried out with the aim of studying coagulation efficiency regarding reduction of turbidity, soluble COD and phosphorus both in a conventional Coagulation-Settling treatment scheme, as well as by means of Contact Filtration. The results showed that high doses of coagulants (0,5 mmol Me+3 l-1 or higher) are required to achieve significant removals of turbidity after settling. At these high doses, soluble COD can be removed by about 50%, while soluble Phosphorus by 80-95%. Ferric Chloride demonstrated slightly better removal ability as compared to Alum. The Chania WTP effluent was also treated by Contact Filtration, using a very low dose of coagulants, 0,1 mmol Me+3 l-1. Turbidity was removed by around 50%, while at this low coagulant dose removals of COD and Phosphorus were insignificant. Filtration was effective in the first 35cm of the filter bed. No significant differences were observed between the coagulants Alum and FeCl3 in the elimination of turbidity. Nevertheless, with the use of Alum a smaller filter headloss was observed, during the first two hours of continuous filtration, in comparison with the use of FeCl3 (nearly double). No difference was observed between the headloss developed at a filter depth of 5cm as compared to that developed at a depth of 70cm. This indicates that the headloss increase was due to the accumulation of suspended and colloidal solids within the first layers of the sand filter.

Isolation of Biofilm-Forming Bacteria from the Secondary Effluent of the Wastewater Treatment Plant and its Ability to Produce N-Acylhomoserine Lactone as Quorum Sensing Signal

2017 ◽  
Vol 863 ◽  
pp. 135-140 ◽  
Author(s):  
Eri Nasuno ◽  
Yuto Abe ◽  
Ken-ichi Iimura ◽  
Masaki Ohno ◽  
Tetsuji Okuda ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Quorum Sensing ◽  
Wastewater Treatment Plant ◽  
Biofilm Formation ◽  
Communication Systems ◽  
Treatment Plant ◽  
Homoserine Lactone ◽  
Side Chain ◽  
Secondary Effluent ◽  
Acyl Side Chain

Bacterial quorum sensing (QS) is one of the cell-to-cell communication systems. N-Acyl-homoserine lactones (AHLs) are the most common QS signals and responsible for biofilm formation in gram-negative bacteria. Inactivation of QS, also referred to as quorum quenching, has been regarded as a popular strategy to control membrane bioreactor (MBR) operations because biofouling in MBR wastewater treatment systems is often caused by biofilm formation. In the present study, 24 bacterial strains were isolated from the secondary effluent of a wastewater treatment plant and AHL productivity and biofilm formation were evaluated on 8 out of 24 isolates. The isolated 8 strains can produce AHLs that only possess a long (C8-C14) acyl side chain. The representative 3 strains were selected from these isolates based on the higher activity of biofilm formation. The AHL separation analysis with a thin layer chromatography clearly showed that N-octanoyl-L-homoserine lactone (C8-HSL) and N-hexanoyl-L-homoserine lactone (C6-HSL) existed in the secondary effluent sample, while no C6-HSL producing strain was isolated. C8-HSL was identified as the product of isolate No. 6. These results suggest that the secondary effluent probably contains various cell-to-cell signaling molecules derived not only from the inhabitants but also from the other microorganisms involved in the activated sludge for the biological pre-treatment. In this secondary effluent, AHL trapping techniques can be proposed as one of the acceptable strategies for the control of the QS systems because the remaining AHLs have relatively long acyl side chain and low concentrations.

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