Decision Model for Optimization of Coagulation/Flocculation Process for Wastewater Treatment

Untreated wastewater of Batik industry can pollute the environment because it contains metal compound, COD, BOD, which are higher than the allowable values. Therefore, a treatment of this wastewater prior discharging to water stream (i.e. river) is very important. This research aims to investigate the use of Teak sawdust as activated carbon, and also the effect of adsorbent concentration, adsorption contact time, as well as coagulation-flocculation-adsorption sequencing process to the level of COD, BOD, and Zn in Batik wastewater. The Batik wastewater used for this research obtained from Batik industry in Rembang, which mostly used naphtol as the coloring agent. The wastewater was initially treated by coagulation-flocculation process, followed by adsorption process. The coagulant-flocculant used in this research was 1 g/L of alum and 3 g/L of lime. Whereas, the adsorbent used was activated carbon made from Teak sawdust with variation of concentrations: 10, 16, 23, and 26 g/L. Whereas, the adsorption contact times were 20, 40, 100, 160, and 220 minutes. The results showed that the coagulation-flocculation process was able to decrease the levels of COD, BOD, and Zn by 73.28%, 73.62%, and 79.21% respectively. Additionally, the adsorption process by activated carbon also further decreased the levels of COD, BOD, and Zn significantly. Based on the results, the optimum concentration of activated that gave the best result was 26 g/L with 220 minutes contact time. Overall, the combination of coagulation-flocculation and adsorption sequencing process was able to decrease the level of COD, BOD, and Zn up to 96.69%, 96.90%, and 91.90% respectively.

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A critical review on flocculants and flocculation

Non-Metallic Material Science ◽

10.30564/nmms.v1i1.645 ◽

2019 ◽

Vol 1 (1) ◽

Author(s):

Srijita Bharti

Keyword(s):

Wastewater Treatment ◽

Water Treatment ◽

Critical Review ◽

Wastewater Sample ◽

Test Protocol ◽

Chemical Alteration ◽

Jar Test ◽

Flocculation Process ◽

Suspended Loads

The article critically reviews the applications of biopolymers in the area of water treatment. A number of biopolymers were reported for their flocculation behavior for treating the wastewater and making it suitable for various industrial as well as agricultural purposes via chemical alteration onto its backbone. Wastewater treatment was followed by flocculation process using standard ‘Jar test protocol’. Minute quantities of dosage were found be ideal to diminish the organic, biological and suspended loads from wastewater sample. The process of flocculation using biopolymers was also found economically suitable compared to other various processes applied in water treatment.

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Ultrasonic Synthesis of Nanochitosan and Its Size Effects on Turbidity Removal and Dealkalization in Wastewater Treatment

Inventions ◽

10.3390/inventions6040098 ◽

2021 ◽

Vol 6 (4) ◽

pp. 98

Author(s):

Fitri Khoerunnisa ◽

Yustika Desti Yolanda ◽

Mita Nurhayati ◽

Firdha Zahra ◽

Muhamad Nasir ◽

...

Keyword(s):

Wastewater Treatment ◽

Wave Amplitude ◽

Simple Technique ◽

Irradiation Time ◽

Chitosan Nanoparticles ◽

Narrow Particle Size Distribution ◽

Key Factors ◽

Turbidity Removal ◽

Ultrasonic Synthesis ◽

Flocculation Process

A detailed study on the synthesis of chitosan nanoparticles under ultrasonication is reported in this paper. By using this simple technique, chitosan particles in nanometer range can be easily prepared without using any harmful and expensive chemicals. The results show that increasing the ultrasonic irradiation time and ultrasonic wave amplitude are the key factors for producing discrete chitosan nanoparticles with narrow particle size distribution. The resulting nanoparticles show superior turbidity removal efficiency (75.4%) and dealkalization (58.3%) in wastewater treatment than the bulk chitosan solid (35.4% and 11.1%, respectively), thus offering an eco-friendly and promising approach for treating wastewater via the coagulation/flocculation process.

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Traitement des eaux usées par coagulation-floculation avec recirculation des boues chimiques : Influence des réactifs

Canadian Journal of Civil Engineering ◽

10.1139/l00-046 ◽

2000 ◽

Vol 27 (4) ◽

pp. 719-734

Author(s):

Frédéric Monette ◽

François G Brière ◽

Michel Létourneau ◽

Marc Duchesne ◽

Robert Hausler

Keyword(s):

Wastewater Treatment ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Pollutant Removal ◽

Sludge Recycling ◽

Chemical Sludge ◽

Flocculation Process

Three series of tests were carried out at laboratory and pilot levels to examine the functions of reagents (coagulant, flocculant, sludge) involved in a coagulation-flocculation process with chemical sludge recycling. Results showed that the recycled sludge participates favourably in the process. The gains in efficiency are particularely significant for lower coagulant concentrations when flocculant concentration is not limitative. The pollutant removal increases with the sludge recycling load but seems reversible and dependent on coagulant concentration. Results also revealed the advantages of recycling sludge before injecting coagulant. To decrease the total chemical costs at a wastewater treatment plant, the strategy must focus on diminishing the coagulant concentration and increasing the flocculant concentration while maintaining a sufficient recycling sludge load to ensure gains in efficiency.Key words: recycling, sludge, preformed flocs, reagents, coagulation-flocculation, treatment, wastewater.

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