气浮-生化处理-砂滤工艺处理高浓度食品生产废水

食品生产废水属于高浓度有机废水,具有排水量大、污染物浓度、水质水量变化大的特点,如不处理就直接排放,将会对水环境造成严重的污染.本工程中废水原水水质参数为:CODCr＜5000mg/L,BOD5＜3000mg/L,SS＜500mg/L,pH5.0～7.5,水温20～30℃.针对该废水水质特点,采用气浮-生化-砂滤工艺处理食品生产废水.运行结果表明,该处理工艺具有处理效率高、操作管理简便、抗冲击负荷、污泥量小、出水水质稳定、运行成本低等优点,处理后出水CODCr85mg/L,BOD524.3mg/L,SS56.2mg/L,pH6～8,达到<污水综合排放标准>(GB8978-1996)中的一级标准.     

石英砂负载氧化铁的表征及其除锑吸附性能研究

通过SEM/EDAX以及Nova-1000表面分析仪对石英砂负载的氧化铁颗粒进行了表征,发现负载氧化铁的粒径为200 nm左右,其表面孔径及孔隙率分别为2×10-9～9×10-9m及0.11%,负载氧化铁的石英砂的比表面积为原砂的5倍.考察了石英砂负载氧化铁(IOCS)在不同的实验条件下(吸附时间,pH值,温度等)对水溶液中锑的去除效果,在pH为3～9范围内,其去除率均超过了98%.吸附动力学及吸附等温线实验数据分别符合二级反应动力学模型及Langmuir等温吸附模型.热动力学实验结果进一步表明:IOCS吸附锑的过程是自发的、吸热的化学吸附反应.     

铸型旧砂再生方法及系统设施选择

通过实例,针对某铸造分厂砂处理生产工艺落后,旧砂对车间、环境及产品质量的影响,提出了建立旧砂再生系统的技术改造方案,阐述了旧砂干法再生方法及系统设施选择,分析了砂处理后取得的环境效益和经济效益。可为中小型铸造厂提供借鉴。     

略阳电厂后部山体边坡的稳定性评价与初步治理设计

在对略阳电厂后部山体地质条件分析的基础上,采用定性分析与定量数值计算相结合的方法评价了电厂后部山体在开挖前后的稳定性问题,并对开挖后的坡体提出了相应的工程治理措施.     

采空区对地表稳定性的影响

为了考虑采矿空区对地表拟建建筑物的影响,采用先进的ANSYS大型有限元计算程序,计算了某采矿空区对地表稳定性的影响.所得结果不仅可以为拟建结构提供必要的地表变形参数,而且为认识采矿空区地表变形机理提供了技术思路.     

Variation in populations of the coastal dune building grassLeymus arenarius in Iceland revealed by endospermal prolamins

Variation in the endospermal protein patterns of seeds amongst and between inland and coastal populations of the dune building grassLeymus arenarius was examined in Iceland. Seeds were collected from six coastal populations and five inland populations in Iceland. Endospermal proteins (prolamins) of seeds were extracted with Tris-buffered 2-propanol (50%) and β-mercaptoethanol (0.5% v/v). We used 8% and 12% sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to separate the prolamin protein bands, which were stained with Coomassie Brilliant Blue R. Coastal populations were differentiated from inland populations on the basis of high frequency of high molar weight (HMW) (110–150 kg mol⁻¹) prolamins. Coastal populations had significantly higher proportions of their seed with more than two HMW prolamins, than those of inland populations. Subtle differences were found among the HMW prolamins of coastal and inland populations indicating limited intrapopulation variation. The dynamic environment of sand dunes probably influences the genetic composition of these populations. The results suggest that seeds of the inland and coastal populations should be treated separately in sand dune reclamation and restoration works     

金属氢氧化物包被砂过滤柱吸附与去除水体中的微生物

以氢氧化铁与氢氧化铝原位沉积包被砂作介质的过滤柱 ,用于去除脱氯自来水中人为污染的高浓度脊髓灰质炎病毒PV1、脆弱拟杆菌噬菌体B .fp和大肠杆菌E .coli.结果显示 ,包被修饰砂颗粒表面Zeta电动势由原来的 - 4 2 .8mV上升到 5 4 .7mV ,并因此提高了对微生物的吸附去除能力 .修饰砂过滤柱经 12 .5d连续过滤 30 0L水样后 ,仍可使进水微生物浓度分别高达n(cfu) /mL-1=5 .2× 10 6、2 .4× 10 5、2 .3× 10 5的E .coli、B .fp和PV1去除 92 %、97.2 %和 99.6 % .而未修饰砂柱 ,在相同条件下仅分别去除 5 3%、5 9%和 70 .6 % .修饰砂柱可在较大pH变化下稳定高效地去除微生物且在中性条件下效果最佳 ,这与未修饰砂柱明显不同 .扫描电镜显示 ,两种砂具有明显不同的表面结构 .修饰砂柱流出液中检测不到用于包被的铁、铝金属 ,说明氢氧化铁、氢氧化铝修饰物同砂结合牢固并因此提高了砂过滤柱的使用寿命 .修饰砂过滤介质可为饮用水处理提供更为安全可靠的去除病原微生物方法 .图 4表 4参 19     

城市污水回用三种处理工艺的选择

本文针对我国城市二级出水的特点,研究了污水深度处理的三种工艺:絮凝沉淀过滤、微絮凝过滤和直接过滤.装置采用网格反应池、翼片斜板沉淀池、气水同时冲洗粗砂滤池.药剂选用聚合硫酸铁,试验规模120m~3/d.     

Cesium migration in saturated silica sand and Hanford sediments as impacted by ionic strength

Large amounts of 137Cs have been accidentally released to the subsurface from the Hanford nuclear site in the state of Washington, USA. The cesium-containing liquids varied in ionic strengths, and often had high electrolyte contents, mainly in the form of NaNO3 and NaOH, reaching concentrations up to several moles per liter. In this study, we investigated the effect of ionic strengths on Cs migration through two types of porous media: silica sand and Hanford sediments. Cesium sorption and transport was studied in 1, 10, 100, and 1000 mM NaCl electrolyte solutions at pH 10. Sorption isotherms were constructed from batch equilibrium experiments and the batch-derived sorption parameters were compared with column breakthrough curves. Column transport experiments were analyzed with a two-site equilibrium-nonequilibrium model. Cesium sorption to the silica sand in batch experiments showed a linear sorption isotherm for all ionic strengths, which matched well with the results from the column experiments at 100 and 1000 mM ionic strength; however, the column experiments at 1 and 10 mM ionic strength indicated a nonlinear sorption behavior of Cs to the silica sand. Transport through silica sand occurred under one-site sorption and equilibrium conditions. Cesium sorption to Hanford sediments in both batch and column experiments was best described with a nonlinear Freundlich isotherm. The column experiments indicated that Cs transport in Hanford sediments occurred under two-site equilibrium and nonequilibrium sorption. The effect of ionic strength on Cs transport was much more pronounced in Hanford sediments than in silica sands. Effective retardation factors of Cs during transport through Hanford sediments were reduced by a factor of 10 when the ionic strength increased from 100 to 1000 mM; for silica sand, the effective retardation was reduced by a factor of 10 when ionic strength increased from 1 to 1000 mM. A two order of magnitude change in ionic strength was needed in the silica sand to observe the same change in Cs retardation as in Hanford sediments.