Influence of a new coagulant aid-Enteromorpha extract on coagulation performance and floc characteristics of aluminum sulfate coagulant in kaolin–humic acid solution treatment

2013 ◽  
Vol 417 ◽  
pp. 161-169 ◽  
Author(s):  
Shuang Zhao ◽  
Baoyu Gao ◽  
Yan Wang ◽  
Zhonglian Yang
Keyword(s):  
Humic Acid ◽  
Acid Solution ◽  
Aluminum Sulfate ◽  
Solution Treatment ◽  
Coagulation Performance ◽  
Floc Characteristics

New Seaweeds Coagulant Aids on Coagulation Performance and Floc Characteristics of Ferric Chloride Coagulant in Kaolin-Humic Acid Solution Treatment

2013 ◽  
Vol 743-744 ◽  
pp. 669-676
Author(s):  
Shuang Zhao ◽  
Bao Yu Gao ◽  
Yan Wang
Keyword(s):  
Humic Acid ◽  
Ferric Chloride ◽  
Sewage Treatment ◽  
Solution Treatment ◽  
Particle Sizing ◽  
Organics Removal ◽  
Coagulation Performance ◽  
Before And After ◽  
Floc Characteristics

Using coagulant aid to increase the organics removal is one of the main methods to improve the coagulation effect. The development of new coagulant aids has vital significance to water supply and sewage treatment. This paper develops two kinds of new seaweeds coagulant aids- Enteromorpha extract (EE) and sodium alginate (SA), and then the two coagulant aids were used together with ferric chloride (FC) in humic acid - kaolin water sample. The coagulation aid effect of EE and SA were studied through the comparation of coagulation effects before and after the application of them. Meanwhile, the growth, breakage and regrowth of flocs were investigated by use of a laser diffraction particle sizing device. The experimental results showed that Ee had significant coagulant aid effect while the aid role of SA was not obvious, but when used together with FC, flocs showed larger particle sizes and growth rates no matter which coagulant aid was selected. Meanwhile the strength and recovery ability of flocs showed a corresponding increase.

Toxicity of reactive red 141 and basic red 14 to algae and waterfleas

2008 ◽  
Vol 58 (6) ◽  
pp. 1193-1198 ◽  
Author(s):  
S. Vinitnantharat ◽  
W. Chartthe ◽  
A. Pinisakul
Keyword(s):  
Humic Acid ◽  
Acid Solution ◽  
Chlorophyll A ◽  
Small Molecule ◽  
Textile Wastewater ◽  
Dry Weight ◽  
Bulk Solution ◽  
Low Concentration ◽  
Chlorella Sp ◽  
Cell Counts

Textile wastewater normally has a visible color although it has low concentration. This may affect the aquatic ecosystem. Two dyestuffs, Reactive Red 141 (RR141) and Basic Red14 (BR14) were used as compound models. RR 141 is an anionic dye which has a big molecule whereas BR 14 is a cationic dye and has a small molecule. The target organisms for toxicity test were green algae (Chlorella sp.) and waterfleas (Moina macrocopa). The effect of humic acid on the toxicity of dyestuffs to test organisms was also investigated. From the observation of cell counts, Chlorophyll a and dry weight of algae in the dye solutions for 4 days, it was found that all parameters increased as times increased. This revealed that algae could utilize dyestuffs as a carbon source. However, BR14 gave higher absorbance than RR141 at the wavelength of 430 nm which competed to the Chlorophyll a for algal photosynthesis. This resulted in the 96-h EC50 of BR14 and RR141 to Chlorella sp. were 10.88 and 95.55 mg/L, respectively. As for dye toxicity to waterfleas, the 48-h LC50 of BR14 and RR141 to waterfleas were 4.91 and 18.26 mg/L, respectively. The high toxicity of BR14 to waterfleas related to the small molecule of dye could pass into the cell and was absorbed by organelles of waterfleas. Toxicity of BR14 in humic acid solution to Chlorella sp. showed less toxic than RR141 in humic acid solution. This dues to the negative charge of humic acid could bound with a positive charge of BR14, resulted in low amount of BR14 remaining in the bulk solution. The toxicity of BR14 and RR141 in humic acid solution to waterfleas was increased as humic acid increased. Hence, the proper treatment of textile wastewater to yield low concentration of dyes in the effluent before discharging to the natural water is needed.

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