| The heavy metal ions in industrial wastewater have great harm to the environment for human survival. People’s health suffered a huge threat, therefore, the control of heavy metal in wastewater system is imperative. Currently, not only organic macromolecule coagulant can be applyed to handle the heavy metal in sewage, but also inorganic polymer flocculant material is gradually being used to treat the heavy metal pollution system. This paper mainly studied the organic polymer materials anionic polymer modified starch flocculant and inorganic PAFS adsorbents, both of them can be used in heavy metal pollution system of industrial production. The principal factors while the polymers were prepared were also discussed, and the property of water govern was also discussed. Then we characterized the makings with some instruments. In this paper the principal details involve the following three sections, they were:(1) Synthetic modified starch graft flocculant by anionic solution polymerization, considered the influence of the reaction prerequisites on the coagulant and defined the most appropriate synthesis requirements:the most appropriate mass ratio of crosslinked starch and acrylamide can be defined as 1:3, the polymerization temperature was 55 ℃, initiator concentration of APS was 0.05 g/L. After the FTIR, SEM and TGA characterization of flocculant were conducted, it determined that the anionic starch graft acrylamide polymer was successfully synthesized. Investigated such anionic polymers for application performance on heavy metal ions, by the way of these experiments we had defined the most appropriate prerequisites for the adsorption of heavy metals ion:The first one, the optimal conditions to romove lead:temperature was 25 ℃, pH=6, each milliliter of 40 mg/L copper water was added per ml 40 mg/L flocculant, oscillated 10 h on constant temperature. The adsorption highest amount of Pb2+ was 423.8 mg/g. Secondly, the best factors to romove copper:temperature was 25 ℃, pH=6.5, each ml of 40 mg/L copper water was added per ml 50 mg/L flocculant, oscillated 10 h on constant temperature. The adsorption highest amount of Cu2+ was 526.9 mg/g. Thirdly, the optimal conditions to romove cadmium:temperature was 25 ℃, pH=6, each milliliter of 40 mg/L cadmium water was added per ml 50 mg/L flocculant, oscillated 10 h on constant temperature. The adsorption highest amount of cadmium was 358 mg/g. After the selective adsorption experiments were conducted, the result proved that the flocculant for Cu2+, Pb2+, Cd2+with good selectivity compared with K+,Na+,Ag+,Ba2+. The experimental adsorption isotherms pointed that the Langmuir isotherm may be a appropriate characterization of the above nexus. It showed that the removal process of anionic flocculant for Pb2+, Cu2+, Cd2+belonged to a single-layered adsorption.(2) Synthesis of PFAS by hydrothermal polymerization, mainly explored some impact of reaction conditions on product performance. Determined the optimal process conditions by optimizing experiment:the molar ratio of Fe/Al was 2:1, the reaction system temperature is 60 ℃, OH-/Fe molar ratio was 2:5. After the FTIR, SEM and TGA characterization of flocculant were conducted, it determined that the PAFS had been successfully admixed. Investigated the PAFS for the application property on the heavy metal ions in wastewater, by the mean of the adsorption experiments we have defined the most suitable prerequisites for the adsorption of heavy metals ion:The initial one, the optimal conditions to romove copper:temperature was 25 ℃, pH=8, each ml of 60 mg/L copper water was added per ml 350 mg/L flocculant, oscillated 8 h on constant temperature. The adsorption amount of Cu+ was 157.3 mg/g. Secondly, the optimal conditions to romove lead:temperature was 25 ℃, pH=8, each milliliter of 60 mg/L copper water was added per ml 300 mg/L flocculant, oscillated 8 h on constant temperature. The adsorption amount of Pb2+was 182.2 mg/g. Thirdly, the optimal conditions to romove cadmium: temperature was 25 ℃, pH=8, each milliliter of 50 mg/L cadmium water was added per ml 30 mg/L flocculant, oscillated 8 h on constant temperature. The adsorption amount of Cd2+was 100.8 mg/g. After selective adsorption experiments were conducted, it proved that the flocculant for Cu2+, Pb2+, Cd2+with good selectivity compared with K+,Na+,Ag+,Ba2+.(3) In the above-mentioned two seals, we mainly explored the adsorption behavior of the heavy metal ions of the organic macromolecule anionic coagulant and inorganic substance PAFS. Under the optimal conditions of this experimental, Organic polymer anionic flocculant absorbed the metal ions, the adsorption can over 350 mg/g, while the adsorption of the metal ions under the inorganic polymer PAFS absorbed can only over 100 mg/g. Comparatively speaking, organic macromolecule anionic flocculant modified starch graft acrylamide exceed inorganic coagulant PAFS in terms of adsorption of metal ions.The two kinds of synthetic polymer material in this paper, the preparation process easily to operate and control, it is conducive to large-scale industrial production. The process of deal with metal ions is easy, control the processing system in suitable conditions, the amount of heavy metals in the wastewater would greatly reduced, so that the two polymer materials with potential applications in the treatment of heavy metal. |
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