The characteristics of sludge from enhanced coagulation processes using PAC/PDMDAAC composite coagulants in treatment of micro-polluted raw water

2015 ◽  
Vol 147 ◽  
pp. 125-131 ◽  
Author(s):  
Xiaoxiao Li ◽  
Yuejun Zhang ◽  
Xiaolei Zhao ◽  
Nana Gao ◽  
Tao Fu
Keyword(s):  
Raw Water ◽  
Enhanced Coagulation

Experimental Studies on Enhanced Coagulation of Tail Water

2013 ◽  
Vol 295-298 ◽  
pp. 1478-1481
Author(s):  
Feng Xun Tan ◽  
Jiu Mei Wang ◽  
Dao Ji Wu
Keyword(s):  
Ferric Chloride ◽  
Removal Rate ◽  
Reclaimed Water ◽  
Experimental Studies ◽  
Ammonia Nitrogen ◽  
Raw Water ◽  
Nitrogen And Phosphorus ◽  
Enhanced Coagulation ◽  
Tail Water ◽  
Water Eutrophication

Traditional wastewater treatment methods can no longer remove effectively nitrogen and phosphorus that are the direct murderers of water eutrophication hazard. Enhanced coagulation method was adopted to improve the treatment effect by dosing suitable coagulants and coagulant aids. The raw water was from the reclaimed water in a University. TP and ammonia nitrogen removal of the water had been researched through an enhanced coagulation process with dosing ferric chloride, aluminum sulfate, polymeric ferric chloride, and poly-aluminum chloride (PAC) in this study. The coagulants effects were estimated by determining the removal rate of ammonia nitrogen, TP, COD and turbidity. When dosing the raw water with 80 mg/L PAC, the removal rates of ammonia nitrogen, TP, COD and turbidity are respectively 6.12%, 67.79%, 26.21%, 85.41%. The experimental results can be used as a reference of water treatment in the reclaimed water station.

Performance of PAC/PDM composite coagulants for removal of algae from Lake Taihu waters in summer

2010 ◽  
Vol 62 (2) ◽  
pp. 330-339 ◽  
Author(s):  
Y. J. Zhang ◽  
X. L. Zhao ◽  
X. X. Li ◽  
Ch. Liu ◽  
L. L. Zhu
Keyword(s):  
Water Quality ◽  
Intrinsic Viscosity ◽  
Removal Rate ◽  
Lake Taihu ◽  
Raw Water ◽  
Removal Rates ◽  
Polyaluminum Chloride ◽  
Enhanced Coagulation ◽  
Algae Removal ◽  
Better Than

The enhanced coagulation of algae-rich raw water from Lake Taihu in summer was studied by use of composite coagulants. The composite coagulants were composed of polyaluminum chloride (PAC) and polydimethyldiallylammonium chloride (PDM) with various intrinsic viscosity values (0.55–3.99 dL/g) and different mass percentages (5–20%) in the formulation. For raw water with temperature of 28–29°C and algae content of 3.60 × 104–3.70 × 104 cells/ml, the algae-removal rates of 89.0% and 89.3–93.1% could be realized by using PAC and PAC/PDM (0.55/5%–3.99/20%) with dosages of 8.37 mg/L and 5.93–3.58 mg/L, respectively, when 2 NTU residual turbidity of treated water after sedimentation was required. Compared with using PAC only, the removal rate of CODMn using PAC/PDM increased at least 4.4% when the dosage was 8 mg/L, and increased at least 5.0% when the dosage was 10 mg/L. The composite coagulants could still function well when raw water quality deteriorated and algae content reached 8.00 × 104 cells/ml. The enhanced coagulation efficiency of PAC/PDM (0.55/5%) could be better than that of PAC combined with prechlorination process when the same dosages are used.

The response of typical South African raw waters to enhanced coagulation

2013 ◽  
Vol 13 (1) ◽  
pp. 20-28
Author(s):  
S. P. Dlamini ◽  
J. Haarhoff ◽  
B. B. Mamba ◽  
S. Van Staden
Keyword(s):  
South Africa ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Water Sources ◽  
Raw Water ◽  
Initial Water ◽  
Enhanced Coagulation ◽  
Target Values ◽  
Water Ph ◽  
Typical Treatment

Drinking water treatment plants in South Africa rely almost entirely on surface water sources, which are often compromised due to high return flows and indirect reuse. The typical treatment plants focus on the removal of physical and microbial contaminants which include turbidity, colour, chemical compounds and microorganisms. A relatively new concern to this list is natural organic matter (NOM) which has become a major concern in potable water treatment due to its recent regulation. In this study, eight different raw water samples from the various water types found in the country were seasonally collected and treated for the removal UV absorbance at a wavelength of 254 nm (UV254) using enhanced coagulation (EC). The efficacy of EC, which can be employed as a practical technology in the removal of both turbidity and NOM, was evaluated in remaining UV254 from these raw water sources. Jar tests were conducted, with ferric chloride used as the coagulant (due to its extensive use as a coagulant in the water treatment industry in South Africa) and specific pH values (initial water pH, 7.0, 6.0, 5.5, 5.0 and 4.5) were chosen as target values guiding the six different coagulant dosages for the jar tests. The pH of the low-alkalinity (<60 mg/L CaCO3) raw waters were adjusted and raised by the addition of sodium carbonate. The response parameters of the tests were turbidity (NTU), pH and UV254. Algorithms for finding the optimum coagulant dosage for UV254 removal were developed and consistently applied to all the results. Results showed large variations in the nature of NOM across the country from specific ultraviolet absorbance values. From the UV254 values, the concentrations of NOM also varied greatly geographically than temporally. The general trend observed in the EC results suggested that the pH should always be dropped to between 4.5 and 7.0 to lower the amounts of UV254 and turbidity to reasonable levels.

The performance of enhanced coagulation for treating slightly polluted raw water combining polyaluminum chloride with variable charge soil

2014 ◽  
Vol 70 (12) ◽  
pp. 1907-1912 ◽  
Author(s):  
Z. L. Zhang ◽  
C. D. Wu ◽  
Y. J. Wang ◽  
J. C. Tang ◽  
Y. P. Liu
Keyword(s):  
Heavy Metals ◽  
Main Mechanism ◽  
Raw Water ◽  
Polyaluminum Chloride ◽  
Enhanced Coagulation ◽  
Charge Neutralization ◽  
Variable Charge ◽  
Coagulation Performance ◽  
Removal Efficiencies ◽  
Variable Charge Soil

The feasibility and effectiveness of treating pollutants in slightly polluted raw water by variable charge soil and polyaluminum chloride (PAC) was investigated. Removal efficiencies of turbidity, phenol, aniline, algae and heavy metals (Cu2+, Zn2+ and Pb2+) were used to evaluate the coagulation performance. The results indicated that the addition of variable charge soil as a coagulant aid is advantageous due to the improvement of removal efficiencies. The tests also demonstrated that the presence of variable charge soil increased the removal of turbidity rather than adding residuary turbidity. The use of variable charge soil produced settleable flocs of greater density and bigger size. The main mechanism involved in the PAC coagulation was supposed to be sweep flocculation as well as charge-neutralization. Variable charge soil played a promoted aid role by adsorption in the enhanced coagulation process. It is concluded that the enhanced coagulation by PAC and variable charge soil, as coagulant and adsorbent, is more effective and efficient than traditional coagulation.

Enhanced Coagulation on Micro-Polluted Raw Water by Attapulgite Clay and PAC Combination Process

2010 ◽  
Vol 178 ◽  
pp. 137-142
Author(s):  
Hong Han ◽  
Xu Gu ◽  
Jin Long Jiang ◽  
Dong Li ◽  
Wen Wang
Keyword(s):  
Removal Rate ◽  
Low Cost ◽  
Good Prospect ◽  
Sludge Reduction ◽  
Raw Water ◽  
Combination Process ◽  
Enhanced Coagulation ◽  
Attapulgite Clay ◽  
High Removal Rate ◽  
Quality Indexes

Attapulgite clay and Poly aluminum chloride (PAC) combination process was adopted for enhanced coagulation on micro-polluted raw water, TOC and NH3-N served as water quality indexes. Results showed that, when the dosage of PAC was 15 mg/L and the dosage of attapulgite clay after 350 °C heat modification was 200 mg/L, the removal rates of TOC and NH3-N reached 82.5% and 75.3% respectively under optimal cogulation conditions, which increased by 72.2% and 230.3% respectively compared with traditional PAC process, and spared 1/4 of PAC dosage. Attapulgite clay and PAC enhenced process reflected advantages of low cost, easy handling, high removal rate, accelerated settlement, sludge reduction, less residual aluminium, chemical and biological safety, and so on. Its application in water supply treatment field was in good prospect.

Study on Chemical Pre-Oxidation Enhanced Coagulation for Micro-Polluted Raw Water Treatment

2013 ◽  
Vol 777 ◽  
pp. 472-475 ◽  
Author(s):  
He Zhao ◽  
Liang Wang ◽  
Zhao Hui Zhang ◽  
Bin Zhao ◽  
Hong Wei Zhang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Organic Carbon ◽  
Organic Molecules ◽  
Raw Water ◽  
Treatment Results ◽  
Small Organic Molecules ◽  
Enhanced Coagulation ◽  
Chemical Oxidants ◽  
By Products ◽  
Polyaluminium Chloride

The present paper studied the enhanced effects of O3 and KMnO4 as chemical oxidants on traditional coagulation for micro-polluted raw water treatment. Results showed that pre-oxidation using either ozone or KMnO4 could effectively improve the removal of turbidity and organic matters by coagulation. Compared with mere coagulation by polyaluminium chloride (PAC), pre-oxidation using 2 mg/l O3 for 20 minutes could increase the removal rates of both turbidity and total organic carbon by 5.33% and 5.06%. However, the effectiveness of pre-oxidation using KMnO4 was not as significant as that using O3. Besides the direct mineralization of small organic molecules into CO2 and H2O, O3 and KMnO4 could also destroy complex macromolecules in raw water. Therefore, the SUVA value of the effluent decreased markedly after the pre-oxidation and the subsequent coagulation. Based on these results, the process of chemical pre-oxidation enhance coagulation were expected to reduce the disinfection by-products formation potential.

Optimizing treatment for reduction of disinfection by-product (DBP) formation

2009 ◽  
Vol 9 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Edward Smith ◽  
Yasmine Kamal
Keyword(s):  
Natural Organic Matter ◽  
Cost Effective ◽  
Nile River ◽  
Source Water ◽  
Raw Water ◽  
Enhanced Coagulation ◽  
Regulatory Limits ◽  
Greater Cairo ◽  
Primary Fraction ◽  
High Alkalinity

Recent studies in communities in greater Cairo, Egypt have identified trihalomethanes (THMs) and haloacetic acids (HAAs) at levels that exceed regulatory limits depending upon the season. The objective of this study was to better understand the formation of DBPs in Nile River source water with a view toward optimizing conventional treatment, focusing on enhanced coagulation, to achieve reduction in DBP formation potential (FP) in a cost-effective scheme. To this end, characterisation of natural organic matter (NOM) in Nile raw water and after treatment by fractionating according to hydrophobic-hydrophilic properties was included in the analysis. Seasonal variations in raw water quality were found to be important for achieving optimum reduction of turbidity and DBP formation. In summer, alkalinity is lower; therefore, enhanced coagulation with 30 mg/L alum can be done at pH 6 without excessive additions of acid, and satisfactory reductions in turbidity and DBPs attained. During the remainder of the year, high alkalinity results in enhanced coagulation at about pH 6.5 and notably lower reduction of NOM, THMFP, and HAAs versus summer conditions. Supplementing enhanced coagulation with 10 mg/L PAC is highly recommended for these conditions as it improves removal of all DBP indicators. The transphilic fraction was the main contributor to DBP formation and the primary fraction removed by enhanced coagulation for achieving gains in THMFP reduction.

Removal of Arsenic from Micro-Polluted Water by Enhanced Coagulation Process

2012 ◽  
Vol 573-574 ◽  
pp. 594-598
Author(s):  
Ming Yu Li ◽  
Hai Bo Wu ◽  
Pei Pei Ma ◽  
Gang Cao ◽  
Lin Song ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Polluted Water ◽  
Raw Water ◽  
Residual Concentration ◽  
Initial Concentration ◽  
Enhanced Coagulation ◽  
Treated Water ◽  
Coagulation Process ◽  
Removal Of Arsenic

The removal of arsenic in micro-polluted water by enhanced coagulation with Poly Ferric Metasilicate (PFSS) was studied. The effects of dosage of PFSS , the dosage of oxidant and oxidize time on the removal efficiency of arsenic were discussed. Under the conditions of dosage of PFSS 0.065mmol/L, the residual concentration of arsenic in post-treated water was lower than 0.01 mg/L for raw water with initial concentration of arsenic 0.1 mg/L.

scholarly journals Study of PFS and PAC coagulation effect on Pi River water

2021 ◽  
Vol 272 ◽  
pp. 01012
Author(s):  
Wan-Fen Wang
Keyword(s):  
Water Sample ◽  
River Water ◽  
Removal Efficiency ◽  
Aluminum Chloride ◽  
Ph Value ◽  
Removal Rate ◽  
Raw Water ◽  
Mass Ratio ◽  
Enhanced Coagulation ◽  
Better Than

Using poly-aluminum chloride (PAC) and poly-ferric sulfate (PFS) as coagulants, the effects of the dosage of PAC and PFS on the removal of turbidity, chromaticity and UV254* in water were investigated by using the method of enhanced coagulation. The results show that when the raw water is neutral and the turbidity is less than 20NTU, and the pH value does not decrease much after coagulation and sedimentation, PAC and PFS are separately added to 7.5mg/l, 35mg/l. The removal rate of turbidity and chromaticity in the water sample can reach 83.75% and 48.47%, respectively, but the removal rate of UV254* is less than 30%, the mass ratio of PAC to PFS is 1:1 to 6:1, the removal efficiency of turbidity and Chroma increased by about 10%, but the removal efficiency of UV254* did not change or even decreased, both PFS and PAC can effectively remove the turbidity and Chroma in the micro polluted Pi River, but the removal effect of UV254* is not good, and the removal effect of PAC is better than PFS.

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