Coagulation performance and floc properties of compound bioflocculant-aluminum sulfate dual-coagulant in treating kaolin-humic acid solution

2011 ◽  
Vol 173 (2) ◽  
pp. 400-406 ◽  
Author(s):  
Xiaowen Bo ◽  
Baoyu Gao ◽  
Nana Peng ◽  
Yan Wang ◽  
Qinyan Yue ◽  
...  
Keyword(s):  
Humic Acid ◽  
Acid Solution ◽  
Aluminum Sulfate ◽  
Coagulation Performance ◽  
Floc Properties

Coagulation performance and floc properties of Microcystis aeruginosa in the presence of humic acid

2014 ◽  
Vol 15 (2) ◽  
pp. 339-347
Author(s):  
Peixia Cheng ◽  
Fei Ge ◽  
Xingwang Liu ◽  
Xiaoshuang Zeng ◽  
Biao Chen
Keyword(s):  
Humic Acid ◽  
Microcystis Aeruginosa ◽  
Removal Efficiency ◽  
High Concentration ◽  
Polyaluminum Chloride ◽  
Charge Neutralization ◽  
Low Concentration ◽  
Chl A ◽  
Coagulation Performance ◽  
Floc Properties

Coagulation removal of algae in raw water could be significantly affected by humic acid (HA). A series of jar-tests were conducted to investigate the coagulation performance with polyaluminum chloride and floc properties of Microcystis aeruginosa, a unicellular cyanobacteria, in the presence of HA. Meanwhile the coagulation mechanism was explored through the measurement of zeta potential of the supernatant. The results showed that an optimal removal efficiency of chlorophyll-a (Chl-a) was obtained at pH 8.0 with a low concentration of HA (2 mg/L) and at pH 6.0 with a high concentration of HA (8 mg/L). The floc structure was more compact and bigger-sized and the calculated fractal dimension (Df) was larger at maximum coagulation efficiency. The variation of Df was consistent with that of Chl-a removal efficiency under the same coagulation conditions. Charge neutralization was inferred to be the dominant mechanism to remove algal cells with low concentration of HA, while charge neutralization, gathering and the bridging process worked together to remove algal cells with a high concentration of HA. These results provide insight on how to achieve an optimal removal efficiency of algae in the presence of different concentrations of HA in water treatment.

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.

Clay filter-aid in ultrafiltration (UF) of humic acid solution

Desalination ◽  
2012 ◽  
Vol 292 ◽  
pp. 73-86 ◽  
Author(s):  
M. Pontié ◽  
A. Thekkedath ◽  
K. Kecili ◽  
H. Dach ◽  
F. De Nardi ◽  
...  
Keyword(s):  
Humic Acid ◽  
Acid Solution ◽  
Filter Aid

The Coagulation Performance and Floc Properties of Polymeric Ferric Aluminum Chloride - Polydimethyl Diallylammonium Chloride Coagulant during Surface Water Treatment

2011 ◽  
Vol 90-93 ◽  
pp. 2921-2924
Author(s):  
Cui Zhen Sun ◽  
Jian Guang Liu ◽  
Li Zhu ◽  
Feng Qi
Keyword(s):  
Surface Water ◽  
Aluminum Chloride ◽  
Weight Ratio ◽  
Optimal Dosage ◽  
Surface Water Treatment ◽  
Coagulation Performance ◽  
Floc Properties ◽  
And Performance ◽  
Neutral Conditions ◽  
Different Molecular Weight

In this paper, new composite coagulants, polymeric ferric aluminum-polydimethyl diallylammonium chloride, were synthesized by combing Polymeric ferric aluminum chloride (PFAC) with polydimethyl diallylammonium chloride (PDMDAAC) under different molecular weight ratio (Aluminum to PDMDAAC, Wr=10, 4, 2 and 1). Furthermore, flocculating mechanisms and performance of these new composite coagulants were investigated in treating surface water. The growth of flocs during coagulation using composite coagulants were measured under optimal dosage and neutral conditions. The results indicated that the new composite coagulants exhibited better coagulation performance than PFAC for removing turbidity and dissolved organic matter. For the composite coagulants, the predominant coagulation mechanisms were bridge formation and charge neutralization.

Magnesium hydroxide coagulation performance and floc properties in treating high pH reactive orange wastewater

2015 ◽  
Vol 71 (9) ◽  
pp. 1310-1316 ◽  
Author(s):  
Meile Liu ◽  
Jingfang Lu ◽  
Lei Wei ◽  
Kang Wang ◽  
Jianhai Zhao
Keyword(s):  
Magnesium Hydroxide ◽  
Ph Value ◽  
Particle Dispersion ◽  
Magnesium Ion ◽  
Feeding Mode ◽  
High Ph ◽  
Coagulation Performance ◽  
Initial Ph ◽  
Floc Properties ◽  
Reactive Orange

Application of magnesium hydroxide as a coagulant for treating high pH reactive orange wastewater was studied. The coagulation performance and magnesium hydroxide-reactive orange floc properties were investigated under different dosages, feeding modes and pH values. Flocculation index (FI) was then discussed with controlled experiments using an intelligent particle dispersion analyzer and optimum coagulant dose of 150 mg/L (magnesium ion) was obtained for pH value 12. The results showed that the optimum magnesium ion dose tended to decrease with the increase of initial pH value. One time addition feeding mode led to relatively large FI value and higher removal efficiency compared with other addition modes. All of the flocs under investigation showed a limited capacity for re-growth when they had been previously broken. Based on the changes of zeta potential and floc properties, charge neutralization and precipitate enmeshment were proposed to be the main coagulation mechanisms.

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