تاثير فرآيند انعقاد و لخته سازي همراه با جذب سطحي در حذف بور از فاضلاب صنايع (مطالعه موردي:صنايع كاشي و سراميك)

Investigating the Effect of Coagulation and Flocculation - Adsorption Process on Boron Removal from Industrial Wastewater (Case Study: Ceramic Tile Industry

ﻋﻨﺼﺮ ﺑﻮر ﺑﻪ ﻃﻮر ﮔﺴﺘﺮده در ﻣﻮاد اوﻟﯿﻪ و ﻓﺎﺿﻼب ﺻﻨﺎﯾﻊ ﮐﺎﺷﯽ ﯾﺎﻓﺖ ﻣﯽﺷﻮد و ﺣﺬف آن از ﻣﺤﯿﻂﻫﺎي آﺑﯽ ﺑﺴﯿﺎر ﭘﯿﭽﯿﺪه اﺳﺖ. اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺎ ﻫﺪف ﺗﻌﯿﯿﻦ ﺣﺬف ﺑﻮر از ﻓﺎﺿﻼب ﺻﻨﻌﺖ ﮐﺎﺷﯽ و ﺳﺮاﻣﯿﮏ ﺑﺎ اﺳﺘﻔﺎده از ﻓﺮآﯾﻨﺪ اﻧﻌﻘﺎد و ﻟﺨﺘﻪﺳﺎزي ﺑﻪ ﻫﻤﺮاه ﺟﺬب ﺳﻄﺤﯽ اﻧﺠﺎم ﮔﺮﻓﺖ. ﻣﻮاد و روشﻫﺎ: اﯾﻦ ﻣﻄﺎﻟﻌﻪ از ﻧﻮع آزﻣﺎﯾﺸﮕﺎﻫﯽ ﺑﻮد. در اﺑﺘﺪا ﺑﺮاي ﻓﺮآﯾﻨﺪ اﻧﻌﻘﺎد ﭘﺎراﻣﺘﺮﻫﺎي pH ﺑﯿﻦ 5 ﺗﺎ 11، ﻏﻠﻈﺖﻫﺎي 150 ﺗﺎ 450 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ ﭘﻠﯽ آﻟﻮﻣﯿﻨﯿﻮم ﮐﻠﺮاﯾﺪ )Poly-aluminum chloride( و ﻏﻠﻈﺖﻫﺎي 0/5 ﺗﺎ 2/5 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ ﭘﻠﯿﻤﺮﻫﺎي آﻧﯿﻮﻧﯽ و ﮐﺎﺗﯿﻮﻧﯽ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺳﭙﺲ در ﻓﺮآﯾﻨﺪ ﺟﺬب، ﺗﺄﺛﯿﺮ ﻣﻘﺎدﯾﺮ ﻣﺨﺘﻠﻒ pH )2ﺗﺎ 7( در زﻣﺎنﻫﺎي ﺗﻤﺎس 5 ﺗﺎ 20 دﻗﯿﻘﻪ آزﻣﺎﯾﺶ ﺷﺪ. در ﻧﻬﺎﯾﺖ دادهﻫﺎ ﺑﺎ اﺳﺘﻔﺎده از آزﻣﻮن آﻣﺎري ﻫﻤﺒﺴﺘﮕﯽ ﭘﯿﺮﺳﻮن آﻧﺎﻟﯿﺰ ﮔﺮدﯾﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد، ﮐﻪ درﺻﺪ ﺣﺬف ﺑﻮر ﺗﻮﺳﻂ ﭘﻠﯽ آﻟﻮﻣﯿﻨﯿﻮم ﮐﻠﺮاﯾﺪ در pH ﺑﻬﯿﻨﻪ ﺑﺮاﺑﺮ 8 و ﻏﻠﻈﺖ 400 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ، 35/7 درﺻﺪ ﺑﺪﺳﺖ آﻣﺪ و در ﺗﺮﮐﯿﺐ ﺑﺎ 1/5 و 2/5 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ ﭘﻠﯿﻤﺮ آﻧﯿﻮﻧﯽ و ﮐﺎﺗﯿﻮﻧﯽ راﻧﺪﻣﺎن ﺣﺬف 54/2 درﺻﺪ ) از 35 ﺑﻪ 16 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( ﻣﺸﺎﻫﺪه ﺷﺪ. ﺳﭙﺲ در ﻓﺮاﯾﻨﺪ ﺟﺬب ﺑﺎ pH ﺑﻬﯿﻨﻪ ﺑﺮاﺑﺮ 5 و زﻣﺎن ﺗﻤﺎس 15 دﻗﯿﻘﻪ، راﻧﺪﻣﺎن ﺣﺬف 50 درﺻﺪ ) از 16 ﺑﻪ 8 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( ﺑﺪﺳﺖ آﻣﺪ. ﺑﺮرﺳﯽ اﯾﺰوﺗﺮمﻫﺎ در ﻓﺮاﯾﻨﺪ ﺟﺬب ﻧﺸﺎن داد، ﺟﺬب ﺑﻮر از اﯾﺰوﺗﺮم Freundlich و ﺳﻨﺘﯿﮏ درﺟﻪ اول ﭘﯿﺮوي ﻣﯽﮐﻨﺪ. ﻧﺘﯿﺠﻪﮔﯿﺮي: ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻠﻪ، ﻓﺮآﯾﻨﺪ ﺗﻠﻔﯿﻘﯽ اﻧﻌﻘﺎد و ﻟﺨﺘﻪﺳﺎزي ﺑﺎ ﺟﺬب، ﻣﯽﺗﻮاﻧﺪ ﺑﻪﻋﻨﻮان ﯾﮏ ﻓﺮآﯾﻨﺪ ﻣﺆﺛﺮ در ﺣﺬف ﺑﻮر ﻣﻌﺮﻓﯽ ﺷﻮد.

Boron is widely found in raw materials and wastewater of the tile industry and its removal from aquatic environments is very complex. The aim of this study was to remove boron from wastewater of ceramic tile industry using coagulation and flocculation-adsorption process. Materials and Methods This was an experimental study. Initially, for the coagulation process, pH parameters between 5 to 11, concentrations of 150 to 450 mg/L of poly-aluminum chloride (PAC) and concentrations of 0.5 to 2.5 mg/L of anionic and cationic polymers were examined. Then, in the adsorption process, the effect of pH between 2 to 7 at contact times of 5 to 20 min was investigated. Finally, the data were analyzed using Pearson’s correlation test. Results The results showed that the percentage of boron removal by poly-aluminum chloride at the optimum pH equal 8 and the concentration of 400 mg/L was 35.7% and in combination with 1.5 and 2.5 mg/L anionic and cationic polymer, removal efficiency of 54.2 % (from 35 to 16 mg/L) was observed. Then, in the adsorption process with an optimum pH equal 5 and contact time of 15 minutes, removal efficiency of 50% (from 16 to 8 mg/L) was obtained. Examination of isotherms in the adsorption process showed that boron adsorption follows the Freundlich isotherm and first-degree kinetics. Conclusion According to the results, the combined process of coagulation and flocculation with adsorption can be introduced as an effective process in boron removal.