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Elimination of organic matter by optimising coagulation treatment: Case of water from the Sidi Yacoub dam, Algeria

Hadbi Taieb, Saaed Hamoudi Abdelamir

Journal of Water and Land Development

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2021

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no. 51

72--77

EN

The presence of natural organic matter (NOM) in water has a significant influence on water treatment processes. Water industries around the world consider coagulation/flocculation to be one of the main water treatment methods. The chief objective of conventional coagulation-based processes is to reduce the turbidity of the water and to remove natural organic matter (NOM) present in solutions. The aim of this paper is to present some developments in terms of improved coagulation for the drinking water of Sidi Yacoub treatment plant located in the Northwest of Algeria. The experiments involved studying the effects of the application of two coagulants (ferric chloride and aluminium sulphate) on the removal of turbidity and natural organic matter from water by measuring the chemical oxygen demand (COD) and the UV absorbance at 254 nm. The results showed that the rate of turbidity removal increased from 81.3% to 88% when ferric chloride was applied and from 89.91% to 94% when aluminium sulphate was applied. For NOM removal, the maximum removal rates of COD and UV254 were 48% and 52%, respectively, in the case of ferric chloride. These rates increased to 59% and 65% after optimised coagulation. When aluminium sulphate was used, the rate of removal in water increased from 43% to 55% for COD and from 47% to 59% for UV254 after optimised coagulation. The combination of the two coagulants at equal dosage shows a slight improvement in the values obtained after optimisation, both in terms of turbidity and the NOM.

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Influence of selected coagulants of indicator and dioxin-like pcb removal from drinking water

Rosińska A.

Ecological Chemistry and Engineering. S

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2017

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Vol. 24, nr 1

41--51

EN

The aim of the research was to compare selected coagulants efficiency in indicator and chosen dioxin-like PCB removal from surface water. As coagulants, there were used aluminium sulfate and 5 hydrolyzed polyaluminium chlorides, with trade names: PAX-XL1, PAX-XL10, PAX-XL19, PAX-XL60, PAX-XL69. For the research, surface water was used, collected from dam reservoir. The water composition was modified with standard mixtures PCB MIX24 and MIX13, in order to obtain concentration of each congener equal to 300 ng/dm3. The PCB MIX24 mixture was composed of indicator congeners solution: 28, 52, 101, 118, 138, 153, and 180, whereas the MIX13 mixture - solution of three dioxin-like PCB 77, PCB 126, and PCB 169. It was demonstrated that the application of aluminium sulfate allowed for reaching better effects for purifying water of PCB, than with the usage of pre-hydrolyzed salts, polyaluminium chlorides. Out of the studied coagulants, the best effects for indicator PCB removal were obtained with the application of aluminium sulfate, total PCB concentration was decreased by 65%. The highest efficiency for indicator congeners removal (90%) was obtained for PCB 138 and 153. After the application of hydrolyzed polyaluminium chlorides PAX-XL1, PAX-XL10 decrease in higher chlorinated PCB concentration was obtained, in the range of 23 to 74%. Selectivity of chosen PCB congener removal, depending on applied coagulant, was demonstrated; with the usage of aluminium sulfate, removal of heptachlorobiphenyl PCB 180 at the level of 34% was obtained, whereas with the application of PAX-XL1 and PAX-XL10 higher reduction efficiency for this congener was obtained, i.e. 83 and 74% respectively. For dioxin-like PCB, after application of aluminium sulfate, total concentration reduction by 74% was obtained, efficiency of this congeners removal amounted to from 54 (PCB 77) up to 72% (PCB 126), similar results were obtained after the usage of PAX-XL1. The lowest PCB removal from water rate was stated for coagulants PAX-XL60 and PAX-XL69.

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Influence of selected coagulants of indicator and dioxin-like PCB removal from drinking water

Rosińska A.

Proceedings of ECOpole

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2016

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Vol. 10, No. 1

75--82

EN

The aim of the research was to compare selected coagulants efficiency in indicator and chosen dioxin-like PCB removal from surface water. As coagulants, there were used aluminium sulfate and 5 hydrolyzed polyaluminium chlorides, with trade names: PAX-XL1, PAX-XL10, PAX-XL19, PAX-XL60, PAX-XL69. For the research, surface water was used, collected from dam reservoir. The water composition was modified with standard mixtures PCB MIX24 and MIX13, in order to obtain concentration of each congener equal to 300 ng/dm3. The PCB MIX24 mixture was composed of indicator congeners solution: 28, 52, 101, 118, 138, 153, and 180, whereas the MIX13 mixture - solution of three dioxin-like PCB 77, PCB 126, and PCB 169. It was demonstrated that the application of aluminium sulfate allowed for reaching better effects for purifying water of PCB, than with the usage of pre-hydrolyzed salts, polyaluminium chlorides. Out of the studied coagulants, the best effects for indicator PCB removal were obtained with the application of aluminium sulfate, total PCB concentration was decreased by 65%. The highest efficiency for indicator congeners removal (90%) was obtained for PCB 138 and 153. After the application of hydrolyzed polyaluminium chlorides PAX-XL1, PAX-XL10 decrease in higher chlorinated PCB concentration was obtained, in the range of 23 to 74%. Selectivity of chosen PCB congener removal, depending on applied coagulant, was demonstrated; with the usage of aluminium sulfate, removal of heptachlorobiphenyl PCB 180 at the level of 34% was obtained, whereas with the application of PAX-XL1 and PAX-XL10 higher reduction efficiency for this congener was obtained, ie 83 and 74% respectively. For dioxin-like PCB, after application of aluminium sulfate, total concentration reduction by 74% was obtained, efficiency of this congeners removal amounted to from 54 (PCB 77) up to 72% (PCB 126), similar results were obtained after the usage of PAX-XL1. The lowest PCB removal from water rate was stated for coagulants PAX-XL60 and PAX-XL69.

PL

Celem badań była porównanie efektywności wybranych koagulantów w usuwaniu z wody powierzchniowej wskaźnikowych i wybranych dioksynopodobnych PCB. Jako koagulanty wykorzystano siarczan glinu oraz 5 zhydrolizowanych chlorków poliglinu o nazwach handlowych: PAX-XL1, PAX-XL10, PAX-XL19, PAX-XL60, PAX-XL69. Do badań wykorzystano wodę powierzchniową. Skład wody zmodyfikowano mieszaniną wzorcową PCB MIX24 oraz MIX13 w celu uzyskania stężenia każdego kongeneru 300 ng/dm3. Mieszaninę PCB MIX24 stanowił roztwór wskaźnikowych kongenerów: 28, 52, 101, 118, 138, 153 i 180, a mieszaninę MIX13 roztwór trzech dioksynopodobnych PCB 77, PCB 126 oraz PCB 169. Wykazano, że zastosowanie siarczan glinu pozwoliło na uzyskanie lepszych efektów oczyszczania wody z PCB niż przy wykorzystaniu wstępnie zhydrolizowanych soli, chlorków poliglinu. Z przebadanych koagulantów najlepsze efekty usuwania wskaźnikowych PCB otrzymano po zastosowaniu siarczanu glinu, sumaryczne stężenie PCB zmniejszyło się o 65%. Najwyższą efektywność usuwania wskaźnikowych kongenerów (90%) uzyskano dla PCB 138 i 153. Po zastosowaniu zhydrolizowanych chlorków poliglinu PAX-XL1, PAX-XL10 uzyskano obniżenie stężenia wyżej chlorowanych PCB w zakresie od 23 do 74%. Wykazano selektywność usuwania wybranych kongenerów PCB w zależności od zastosowanego koagulantu; przy wykorzystaniu siarczanu glinu uzyskano usunięcie heptachlorobifenylu PCB 180 na poziomie 34%, natomiast przy wykorzystaniu PAX-XL1 i PAX-XL1o uzyskano większą efektywność redukcji tego kongeneru, tj. odpowiednio 83 i 74%. Dla dioksynopodobnych PCB po zastosowaniu siarczanu glinu uzyskano redukcję sumarycznego stężenia o 74%, efektywność usuwania tych kongenerów wynosiła od 54 (PCB 77) do 72% (PCB 126), podobne rezultaty otrzymano po zastosowaniu PAX-XL1. Najmniejszy stopień usuwania PCB z wody stwierdzono dla koagulantów PAX-XL60 i PAX-XL69.