【摘要】 目前广泛应用的固体吸附法对高磷工业废水具有很好的除磷效果,对低ρ(磷)废水(<0.5mg.L-1)的除磷效果很差,然而富营养化水体的磷质量浓度一般都远远低于0.5mg.L-1,从而使固体吸附法在实际应用中遇到技术瓶颈。为解决上述瓶颈性问题,促进固体吸附法在富营养化水体除磷中的应用,试验以氯化镧、氯化铝、沸石为主要原料,通过配制金属离子溶液、配制沉淀剂溶液、沉淀反应、煅烧等工艺流程制成镧/铝改性沸石,并研究了镧/铝改性沸石对废水中磷的吸附特性及其对不同富营养化程度水体中磷的去除能力。结果表明,镧/铝改性沸石对高磷和低磷浓度废水都具有较好的除磷效果。30℃时,镧/铝改性沸石达到吸附平衡所需时间为36 h,饱和吸附量为2.44 mg.g-1。8 g.L-1的镧/铝改性沸石用量可使废水中的磷质量浓度从20mg.L-1降低到0.515 mg.L-1,去除率高达97.43%。镧/铝改性沸石的磷吸附量随作用时间的延长而增加,包括快速吸附期和慢速吸附期,其中快速吸附期主要发生在前3 h,此时废水中的磷去除率达57.1%,对磷的吸附量达1.43mg.g-1,占饱和吸附量的58.6%。对富营养化水体的除磷试验研究显示,通过2次过滤可使富营养化湖水中的磷质量浓度低于检出限(0.01mg.L-1),通过3次过滤可使富营养化池塘水中的磷质量浓度低于检出限(0.01mg.L-1),说明镧/铝改性沸石对低磷废水具有很好的除磷效果。镧/铝改性沸石对加磷湖水具有较高的磷去除能力,饱和吸附量达2.02 mg.g-1,但比对人工废水的饱和吸附量(2.44mg.g-1)低0.42mg.g-1,降低率达17.2%,表明自然水体中其他离子的共存会降低镧/铝改性沸石的除磷效率。更多还原

【Abstract】 Phosphorus is a very important element in water contamination.Excess discharge of phosphorus into water often causes eutrophication,and results in deterioration of water quality.The presence of trace concentration of dissolved phosphate in the treated wastewater from municipalities and industries is often responsible for causing eutrophication problems.Water pollution by phosphorus is increasing,and therefore there is an increasing demand for removal of phosphorus.Solid adsorption has been used widely in purifying waste water,and it has good effect on decreasing phosphorus when the phosphorus concentration of waste water is high,however,it has no effect on decreasing phosphorus when the phosphorus concentration of waste water is lower than 0.5 mg.L-1.Unfortunately,for the phosphorus concentration in eutrophic water is always lower than 0.5 mg.L-1,so there are some bottle-neck problem about the application of solid adsorption in purifying eutrophic water.In order to solve the bottle-neck problem and promote the application of solid adsorption in purifying eutrophic water,the phosphorus adsorption characteristics of Lanthanum/Aluminum-modified zeolite and its phosphorus adsorption capability on the eutrophic water were researched in the experiment.And the Lanthanum/Aluminum-modified zeolite used in the experiment was made of LaCl3,AlCl3and zeolite and by the technics flow of confecting metal ion solution,confecting precipitator solution,deposition reaction and calcination.The results showed that Lanthanum/Aluminum-modified zeolite had effective phosphorus removal capability both on higher and lower phosphorus concentration wastewater.The phosphorus adsorption reached equilibrium after 36 h at the temperature of 30 ℃,and the saturation adsorption amount was 2.44 mg.g-1.When the dosage of Lanthanum/Aluminum-modified zeolite was 8 g.L-1,the phosphorus in wastewater could decrease from 20 mg.L-1 to 0.515 mg.L-1 and the removal ratio was as high as 97.43%.The adsorption of phosphorus onto Lanthanum/Aluminum-modified zeolite increased with an increase of contact time.The adsorption process can be divided into two steps: a rapid initial adsorption(3 h) and a much slower subsequent adsorption process.During the rapid initial adsorption(3 h) period,the removal ratio and adsorption amount were 57.1% and 1.43 mg.g-1 respectively,and the adsorption amount accounted for 58.6% of the saturation adsorption amount.The results of Lanthanum/Aluminum-modified zeolite on phosphorus removal from eutrophic water showed that the concentrations of phosphorus in eutrophic lake water and eutrophic pond water were under the lowest detection limit(0.01 mg.L-1) after two times of filtration and three times of filtration respectively,which showed Lanthanum/Aluminum-modified zeolite has good effect on phosphorus removal from low phosphorus concentration waste water.Lanthanum/Aluminum-modified zeolite had effective phosphorus removal capability on lake water adding with phosphorus.However,the saturation adsorption amount(2.02 mg.g-1) of Lanthanum/Aluminum-modified zeolite on the lake water adding with phosphorus was lower than that on man-made wastewater,which meant that the coexisting ions in natural wastewater could decrease the phosphorus adsorption capability of Lanthanum/Aluminum-modified zeolite.更多还原