Research On The Use Of OH-Fe And OH-Fe-Al Pillar Bentonites In The Waste Water Treatment

Adsorption is a popular pHysics-chemical way in the waste water treatment. It is always a foucs on exploiting newer and cheaper sorbent which has high adsorption efficiency. Bentonites have its particular predominance as a kind of cheap and facile sorbent. This paper study the adsorption characteristic and application of bentonites on waste water treatment, which is bacesd on previously study on OH-Fe and OH-Fe-Al pillared bentonites.Firstly, OH-Fe and OH-Fe-Al pillared bentonites are prepared : OH/Fe (mol rate): 0.6,0.8,1,1.5,2 and Fe/Al (mol rate) : 0,0.05,0.1,0.2,0.5,1. EDTA-Cu is adsorbed in static experiments by OH-Fe and OH-Fe-Al pillared bentonites . The saturated capacity adsorption of pillared bentonites can be calculated by the result of static experiments. According to the saturated capacity adsorption, the conclusions can be reached as following:(1) The saturated capacity adsorption of OH-Fe bentonites increases as OH/Fe (mol rate) raising. It is close to adsorption balance at OH/Fe=1.5.(2) The saturated capacity adsorption of OH-Fe-Al pillared bentonites increases to maximum in Fe/Al=0.05.(3) According the saturated capacity adsorption experiment, 2OH-Fe and 0.05Fe-Al are chosen.Secondly, the adsorption characteristic of 2OH-Fe and 0.05Fe-Al is studied in various factors tha influence the results, such as different concentration of electrolyte, the size of molecule solute and temperature.At last, 2OH-Fe and 0.05Fe-Al are applied in active cobalt red X-3B and 081 organic stannum waste water treatment, by the experiment, the time of adsorption balance and the right weight of sorbent are comfirmed. The factors of concentration of electrolyte and pH is also be discussed. The model of dynamics and isotherm is also established based on the experiment datas.The results of the study shows that the saturated capacity adsorption of bentonite increased after OH-Fe and OH-Fe-Al pillared. Under the same conditions (the same adsorption time, weight of sorbent, pH) , there is a adsorption efficiency relationship among the three adsorbent, as following: 0.05Fe-Al>2OH-Fe> bentonite without pillared.