The effects of the coagulation-flocculation process using polyaluminium chloride (PAC) and its aids on the removal of organics and nutrient in the combined sewage from Shanghai Zhuyuan First Municipal Wastewater Treat...The effects of the coagulation-flocculation process using polyaluminium chloride (PAC) and its aids on the removal of organics and nutrient in the combined sewage from Shanghai Zhuyuan First Municipal Wastewater Treatment Plant are studied. The coagulant aids include cationic polyacrylamide (PAM), polyvinyl alcohol (PVA), activated silica (AS) and a kind of polyelectrolyte called AN prepared by the authors. The coagulating solution was added to the glass jar holding 1 L wastewater and stirred to a uniform mixture which was stilled to let the supernatant turn out. The supernatant was analyzed to see the removal efficiencies of suspended solid (SS), chemical oxygen demand (COD), soluble chemical oxygen demand (S-COD), total phosphorus (TP) and orthophosphate (PO4 -P). It is found that PAC is efficient in reducing those five matters, PAM, PVA and 3? AN each faciliates the reduction of TP, SS, COD and S-COD and has little contribution to the removal of ammonia nitrigen and orthophosphate, and AS is noneffective at all. The coagulation-flocculation process with PAC has demonstrated applicable to the treatment of combined sewage in Shanghai, and it involves mainly the sweep coagulation mechanism and maybe some more complicated mechanism as well.展开更多
Control of clarifier in the activated sludge process is critical for ensuring effective wastewater treatment. This paper is to study appropriate control strategies for a clarifier in an industrial wastewater treatment...Control of clarifier in the activated sludge process is critical for ensuring effective wastewater treatment. This paper is to study appropriate control strategies for a clarifier in an industrial wastewater treatment plant. Five control strategies are proposed, implemented and evaluated in a simulation software （West ＋＋）. The sludge blanket height and the effluent suspended solids concentration were proposed as the measured variable. The manipulated variable was the quantity of polymer added to the system. The strategies were evaluated in terms of their ability to maintain the sludge blanket height below 1.5m, their polymer requirements, their sensitivity to poor tuning and the required control action.展开更多
In this work, new composite membranes were successfully prepared via phase inversion technique using polyvinyl chloride(PVC) and polyvinylpyrrolidone(PVP) as polymers and tetrahydrofuran(THF) and N-methyl-2-pyrrolidon...In this work, new composite membranes were successfully prepared via phase inversion technique using polyvinyl chloride(PVC) and polyvinylpyrrolidone(PVP) as polymers and tetrahydrofuran(THF) and N-methyl-2-pyrrolidone(NMP) as solvents. The prepared membranes have been characterized by scanning electron microscope(SEM), and fourier transforms infrared spectroscopy(FTIR). The scanning electron microscope results prove that the prepared membranes are smooth and their pores are distributed throughout the whole surface and bulk body of the membrane without any visible cracks. The stress–strain mechanical test showed an excellent mechanical behavior enhanced by the presence of PVP in the prepared membranes. The membranes performance results showed that the salt rejection reached 98% with a high flux. This, in turn, makes the prepared membranes can be applied for sea and brackish water treatment through membrane distillation technology.展开更多
Adsorption of catechol from aqueous solution with the hypercrosslinked polymeric adsorbent NDA-100 and its derivatives AH-1, AH-2 and AH-3 aminated by dimethylamine, the commercial resin Amberlite XAD-4 and weakly bas...Adsorption of catechol from aqueous solution with the hypercrosslinked polymeric adsorbent NDA-100 and its derivatives AH-1, AH-2 and AH-3 aminated by dimethylamine, the commercial resin Amberlite XAD-4 and weakly basic anion exchanger resin D301 was compared. It was found that the aminated hypercrosslinked resins had the highest adsorption capacities among the tested polymers. The empirical Freundlich equation was successfully employed to describe the adsorption process. Specific surface area and micropore structure of the adsorbent, in company with tertiary amino groups on matrix affected the adsorption performance towards catechol. In addition, thermodynamic study was carried out to interpret the adsorption mechanism. Kinetic study testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate and increase the adsorption apparent activation energy.展开更多
文摘The effects of the coagulation-flocculation process using polyaluminium chloride (PAC) and its aids on the removal of organics and nutrient in the combined sewage from Shanghai Zhuyuan First Municipal Wastewater Treatment Plant are studied. The coagulant aids include cationic polyacrylamide (PAM), polyvinyl alcohol (PVA), activated silica (AS) and a kind of polyelectrolyte called AN prepared by the authors. The coagulating solution was added to the glass jar holding 1 L wastewater and stirred to a uniform mixture which was stilled to let the supernatant turn out. The supernatant was analyzed to see the removal efficiencies of suspended solid (SS), chemical oxygen demand (COD), soluble chemical oxygen demand (S-COD), total phosphorus (TP) and orthophosphate (PO4 -P). It is found that PAC is efficient in reducing those five matters, PAM, PVA and 3? AN each faciliates the reduction of TP, SS, COD and S-COD and has little contribution to the removal of ammonia nitrigen and orthophosphate, and AS is noneffective at all. The coagulation-flocculation process with PAC has demonstrated applicable to the treatment of combined sewage in Shanghai, and it involves mainly the sweep coagulation mechanism and maybe some more complicated mechanism as well.
文摘Control of clarifier in the activated sludge process is critical for ensuring effective wastewater treatment. This paper is to study appropriate control strategies for a clarifier in an industrial wastewater treatment plant. Five control strategies are proposed, implemented and evaluated in a simulation software （West ＋＋）. The sludge blanket height and the effluent suspended solids concentration were proposed as the measured variable. The manipulated variable was the quantity of polymer added to the system. The strategies were evaluated in terms of their ability to maintain the sludge blanket height below 1.5m, their polymer requirements, their sensitivity to poor tuning and the required control action.
文摘In this work, new composite membranes were successfully prepared via phase inversion technique using polyvinyl chloride(PVC) and polyvinylpyrrolidone(PVP) as polymers and tetrahydrofuran(THF) and N-methyl-2-pyrrolidone(NMP) as solvents. The prepared membranes have been characterized by scanning electron microscope(SEM), and fourier transforms infrared spectroscopy(FTIR). The scanning electron microscope results prove that the prepared membranes are smooth and their pores are distributed throughout the whole surface and bulk body of the membrane without any visible cracks. The stress–strain mechanical test showed an excellent mechanical behavior enhanced by the presence of PVP in the prepared membranes. The membranes performance results showed that the salt rejection reached 98% with a high flux. This, in turn, makes the prepared membranes can be applied for sea and brackish water treatment through membrane distillation technology.
文摘Adsorption of catechol from aqueous solution with the hypercrosslinked polymeric adsorbent NDA-100 and its derivatives AH-1, AH-2 and AH-3 aminated by dimethylamine, the commercial resin Amberlite XAD-4 and weakly basic anion exchanger resin D301 was compared. It was found that the aminated hypercrosslinked resins had the highest adsorption capacities among the tested polymers. The empirical Freundlich equation was successfully employed to describe the adsorption process. Specific surface area and micropore structure of the adsorbent, in company with tertiary amino groups on matrix affected the adsorption performance towards catechol. In addition, thermodynamic study was carried out to interpret the adsorption mechanism. Kinetic study testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate and increase the adsorption apparent activation energy.
