scholarly journals Sustainable Wastewater Treatment Using Electrocoagulation Process Coupled With Powdered Activated Carbon

Author(s):  
Farooq Sher ◽  
Sania Zafar Iqbal ◽  
Tahir Rasheed ◽  
Kashif Hanif ◽  
Jasmina Sulejmanović ◽  
...  

Abstract In this research an electrochemical technique in combination with powdered activated carbon (PAC) for the removal of micropollutants by adsorption as an advanced stage purification step from effluents of pilot plant wastewater treatment plants (WWTP). The effluents of sedimentation tank comprised of wastewater plus PAC (WWPAC). The pilot plant mainly consists of two parts; the first one consists of electrocoagulation (EC) reactor and the second consists of electrophoretic deposition (EPD) discs and electroflotation (EF) setup. The electrocoagulation (EC) reactor is a fiber box consisting of two chambers and thirty four plates of one material (either Fe or Al) on the whole in one EC reactor while one cell has seventeen plates. Both types of electrodes have been tested with the outflow of sedimentation tank. The outflow from the sedimentation tank has been entered into the EC reactor for the determination of EC reactor efficacy for the successful accomplishment of EC process at the designed pilot plant for WW treatment. The effect of different operational parameters; PAC dosage (20 mg), electrode nature (Fe and Al), current density (0.34–2.02 A/m2) has been studied to find out the optimum conditions. Sludge volume index (SVI) of the sludge, thermogravimetric (TG), differential thermal analyses (DTA) and particle size distribution (PSD) of the flocs generated after the EC process has also been studied. The turbidity, pH and conductivity of effluents before and after EC treatment has also been carried out. This pilot plant research gave promising results for future work in advance wastewater treatment direction.

2016 ◽  
Vol 7 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Am Jang ◽  
Jong-Tae Jung ◽  
Hayoung Kang ◽  
Hyung-Soo Kim ◽  
Jong-Oh Kim

We evaluate the applicability of a reverse osmosis (RO) system that combines powdered activated carbon (PAC) and ultrafiltration (UF) to treat the effluent discharged from tannery wastewater treatment plants. Conventional treatment processes such as neutralization, clariflocculation, and biological processes are used to clean the effluent before feeding to the PAC and UF combined RO system. The efficiency of the combined system was evaluated using the chemical oxygen demand Mn (CODMn), color, pH, turbidity, total nitrogen, total phosphate, and conductivity. The PAC was effective in greatly reducing the CODMn and color. The turbidity and silt density index of the UF permeate satisfied the water quality indices required for the RO feed. The RO system was constantly maintained at approximately 75% RO recovery, and the RO permeate satisfied the water quality requirements for reusing the processed water. Therefore, the PAC-UF combined RO system can be used to process effluent discharged from tannery wastewater treatment plants for reuse.


1999 ◽  
Vol 40 (1) ◽  
pp. 191-198 ◽  
Author(s):  
L. Nicolet ◽  
U. Rott

The use and recirculation of powdered activated carbon (PAC) as an advanced treatment for colour removal in municipal wastewater treatment plants is presented. Studied wastewaters consist of domestic effluents with a high portion of dyehouse residual waters. The particularity of the treatment is that PAC is not disposed of before being recirculated several times. Therefore, it enables the use of a great part of the total adsorption capacity of the PAC. A positive side effect is that halogenated and refractory organic compounds, which are not degraded by micro-organisms in a conventional municipal wastewater treatment plant, are removed too. This paper describes results which were obtained in batch experiments and in a pilot plant during two years of observation, and concludes with advantages and drawbacks of this technology.


2015 ◽  
Vol 73 (4) ◽  
pp. 790-797 ◽  
Author(s):  
Aleksandra Miłobędzka ◽  
Anna Witeska ◽  
Adam Muszyński

Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them – bulking and foaming of activated sludge.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.


1994 ◽  
Vol 29 (7) ◽  
pp. 229-237 ◽  
Author(s):  
J. Kruit ◽  
F. Boley ◽  
L. J. A. M. Jacobs ◽  
T. W. M. Wouda

Influent characterization and biosorption experiments were carried out with settled influent of seven wastewater treatment plants to study the influence of O2 in the selector in relation to the success of developing good settling properties of the sludge. In previous years working selectors were installed and/or pilot plant research was carried out at these wastewater treatment plants. Characterization of the influent was done with help of standard COD and BOD measurements with help of a coarse filter. The research has elucidated that the presence of O2 in the selector, at initial sludge loadings of 3.5-6.5 kg BOD/kg MLSS.d, is important for producing good settling properties of the sludge when the sum of readily biodegradable COD and rapidly hydrolysable COD is greater than 40%. When the sum of sludge COD and slow hydrolysable COD is greater than 50% an unaerated selector can be used.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Marion Woermann ◽  
Julios Armand Kontchou ◽  
Bernd Sures

Abstract Background In order to protect aquatic environments and to reduce the presence of micropollutants in the global water cycle, wastewater treatment plants (WWTPs) often implement an additional treatment step. One of the most effective measures is the use of powdered activated carbon (PAC) as an adsorbent for micropollutants. This method provides sufficient elimination rates for several micropollutants and has been successfully employed in many WWTPs. Despite this success, there might be a drawback as the retention of the PAC in the WWTP can be challenging and losses of micropollutant-loaded PAC into the aquatic environment may occur. Upon emission, micropollutant-loaded PAC is expected to settle to the benthic zone of receiving waters, where sediment-dwelling organisms may ingest these particles. Therefore, the present study investigated possible adverse effects of micropollutant-loaded PAC from a WWTP as compared to unloaded (native) and diclofenac-loaded PAC on the sediment-dwelling annelid Lumbriculus variegatus. Results Native PAC induced the strongest effects on growth (measured as biomass) and reproduction of the annelids. The corresponding medium effective concentrations (EC50) were 1.7 g/kg and 1.8 g/kg, respectively. Diclofenac-loaded PAC showed lower effects with an EC50 of 2.5 g/kg for growth and EC50 of 3.0 g/kg for reproduction. Although tested at the same concentrations, the micropollutant-loaded PAC from the WWTP did not lead to obvious negative effects on the endpoints investigated for L.variegatus and only a slight trend of a reduced growth was detected. Conclusion We did not detect harmful effects on L. variegatus caused by the presence of MP-loaded PAC from a WWTP which gives an auspicious perspective for PAC as an advanced treatment option.


2011 ◽  
Vol 1 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling

This article analyses the performance of 166 wastewater treatment plants operating in Brazil, comprising six different treatment processes: septic tank + anaerobic filter, facultative pond, anaerobic pond + facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The study evaluates and compares the observed effluent quality and the removal efficiencies in terms of BOD, COD, TSS, TN, TP and FC with typical values reported in the technical literature. In view of the large performance variability observed, the existence of a relationship between design/operational parameters and treatment performance was investigated. From the results obtained, no consistent relationship between loading rates and effluent quality was found. The influence of loading rates differed from plant to plant, and the effluent quality was dictated by several combined factors related to design and operation.


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