Adsorption removal of phosphate from aqueous solution by active red mud

Red mud is the waste of alumina industry and has high TiO_2 and Fe_2O_3 content which are active components for the adsorption of anion pollutants.In this study,the uptake of phosphate by red mud activated by heat treatment and acid-heat treatment was investigated. The factors influencing the adsorption were also investigated.The result showed that the red mud sample treated using acid-heat method at 80℃with 0.25 mol/L HC1 for 2 h achieved the highest phosphate removal.For the heat-activated red mud,the sample heated at 700℃for 2 h preformed better than the other heat treatment.Phosphate removal by the activated red mud was significantly pH dependent,and pH 7 was the optimal pH for phosphate removal.The adsorption fits Langmuir isotherm model well and the maximum adsorption capacities of the acid-heat activated red mud and the heat activated samples were 202.9 mgP/g and 155.2 mgP/g,respectively.     

铝工业废渣赤泥综合利用的技术成就

本文综合介绍了我国在赤泥再生资源开发利用的科研与生产实践中所取得的重要技术成就。分析了赤泥对自然环境的污染并指出了开展系统工程根治其危害的技术攻关方向。     

含油污泥无害化处理技术研究

在综合考虑经济因素和抗压强度要求的基础上,对长庆油田采油三厂的含油污泥进行了无害化固化处理。试验选取了固化剂最优配方:污泥、固化剂、促凝剂之比为4:1:0.01。强度性能检测表明,一般在1d内达到一定的强度,3 d后硬度提高,10 d后达到最大硬度。固化物污染指标测试还表明:其可溶出性盐量明显减少,矿化度下降了46%,含油量从未固化时的40000 mg/L下降为0.4 mg/L,硫化物含量仅为0.4 mg/L,均达到了外排的标准。     

铜冶炼厂污水治理技术及建议

阐述了用石灰中和法工艺治理铜冶炼厂所产生的含有重金属离子的酸性废水技术,并针对该工艺流程中清水池沉积2-3m深细泥、污泥压滤能力不够、污泥作为垃圾处理易造成二次污染问题，提出清除污泥，稳定化／固化污泥中的重金属离子，综合利用污泥，重新改造设备等措施。     

河水和底泥中有机污染物的分析

采用GC/MG分析方法,对河水和底泥中相同的有机污染物进行监测,初步分析两者的相关性。     

利用蚯蚓处理城市污水厂剩余污泥的初步试验研究

采用城市污水处理厂的剩余污泥（滤泥）和牛粪直接配置养殖蚯蚓的饲料,按照不同比例的配料分组进行了饲养蚯蚓的试验研究。在适宜的环境条件下,经过21 d培养,大平二号蚯蚓的最少增重为54％,最高增重达100％;平均产卵茧的数量为0．687个／条蚯蚓。研究结果表明,滤泥不需经过发酵即可用于养殖蚯蚓,牛粪与滤泥配置的比例为1∶1或0．3：0．7时,有利于蚯蚓的代谢和繁殖,并可确保蚯蚓养殖的安全。     

Acoustic Observations of Bottom Surge From Dredged Material Discharge in the Open Ocean

Abstract

Bottom surges generated from dredged material discharges in the open ocean have been observed using high frequency acoustic concentration profilers in several field studies during the past five years. the locations, water depths, bottom slopes, oceanographic conditions, and dredged material composition differed from study to study. Observed surges at three dredged material disposal sites may develop more than one surge peak for a single discharge. for water depths of the order of 10 m, surge height of the leading peak was estimated to be about one quarter of the water depth. for water of greater depth, of the order of 100 m, surge height reached 70 m, about 70% of the water depth. Surge height is established instantaneously when dredged material hits the bottom, and remains relatively constant as the surge advances horizontally. Total surge length reached 150 m for water depths of 10 m when measured from the impact point to the leading edge. for water depths of more than 100 m, the surge length reached more than 100 m. Length of the leading surge peak was as large as 45 m at this water depth.

Dimensional analysis was applied to relate the surge height of the leading surge peak to discharge parameters and oceanographic conditions. Results showed that the ratio of surge height to water depth was proportional to 1/10 power of the ratio of discharge volume to the third power of water depth.     

Effect of red mud addition on the fractionation and bio-accessibility of Pb,Zn and As in combined contaminated soil

Using soil incubation experiments, the effect of red mud addition on the fractionation and bioaccessibility of Pb, Zn and As in combined contaminated soil was studied. The results showed that red mud addition could significantly decrease the concentration of HOAc-extractable Pb and Zn in soil. Compared with the control, 5% red mud addition could significantly reduce the concentrations of HOAc-extractable Pb and Zn in soil after 1, 2 and 3 months of incubation [62.5, 65.3 and 73.5% decrease (Pb), 56.7, 65.8 and 67.4% decrease (Zn)]. Whereas adding red mud could remarkably increase the concentrations of specific absorbed As and residual As in soil. The result of a simple bioavailability extraction test (SBET) indicated that all treatments with red mud addition markedly reduced the concentration of bioaccessible Zn but increased the concentration of bioaccessible As in soil, while having little effect on the concentration of bioaccessible Pb in soil. After 3 months incubation, all treatments including 1, 2 and 5% red mud addition reduced the concentration of bioaccessible Zn by 53.1–56.7% compared with the control, but increased the concentration of bioaccessible As by 1.81–6.25 times. The results suggested that red mud is an additive with potential for the remediation soil contaminated soil by combinations of heavy metals, although it should be added based on the different heavy metals in the soil. Combined use of red mud and hyperaccumulators to remediate heavy metal contaminated soil needs further study.     

拜耳法赤泥制备三聚磷酸铝

拜耳法赤泥经石灰石烧结改性、盐酸浸取及碱液处理等工序得到氢氧化铝干胶,再以氢氧化铝干胶和工业磷酸为原料,通过中和反应、缩合反应和水化反应合成三聚磷酸铝.经单因素条件实验和正交实验得到最佳工艺条件为:磷酸体积(mL)与氢氧化铝干胶质量(g)的比3,中和反应温度常温,缩合反应温度290℃,缩合反应时间4h.在最佳工艺条件下合成的试样中,Al2O3和P2O5的含量与工业三聚磷酸铝ATP-200相近,经IR分析,该试样即为三聚磷酸铝.盐雾试验结果表明合成的三聚磷酸铝的防腐性能达到ATP-200的性能指标.     

硝酸铈改性赤泥制备除磷吸附剂

用六水硝酸铈改性赤泥并处理含磷废水.实验结果表明:当硝酸铈质量分数为0.45％、焙烧温度为500℃时,制备的吸附剂的吸附性能最好;用该吸附剂处理含磷废水,当初始废水pH为3、振荡时间为80 min时,废水TP去除率约为95％,废水中磷质量浓度为0.41 mg/L,达到GBI8918-2002《城镇污水处理厂污染物排放标准》中的一级标准.该吸附剂的吸附过程符合Langmuir吸附模型.