矿山循环水中SO42-的脱除研究

采用吸附法、七铝酸十二钙法、石灰-氯化铝絮凝沉淀法对矿山循环水中高浓度SO24-的脱除进行研究。结果表明:单纯采用吸附法来处理废水,处理后水中的SO24-远不能达到工业用水标准;实验室制备的七铝酸十二钙对SO24-的去除效果不理想,仅为35%,也无法达到工业用水标准;采用石灰-氯化铝絮凝沉淀法处理废水时,当Al3+投加量为420mg/L,pH值为11时,去除率高达90%以上,可使废水中的SO24-质量浓度从1 800 mg/L降至200mg/L以下,完全可循环回用于矿山的选矿和采矿生产。     

改性粉煤灰的制备及其对分散蓝的吸附

以聚二甲基二烯丙基氯化铵(PDMDAAC)为改性剂,制备PDMDAAC改性粉煤灰。采用正交实验考察了制备条件对PDMDAAC在粉煤灰上的负载量的影响。实验结果表明:在反应温度为70℃、反应时间为3 h、PDMDAAC质量浓度为50 g/L、溶液pH为10的最佳条件下,PDMDAAC在粉煤灰上的负载量为0.98 mg/g;在吸附温度为30℃、初始分散蓝质量浓度为50 mg/L、PDMDAAC改性粉煤灰加入量为4 g/L的条件下,PDMDAAC改性粉煤灰对分散蓝的去除率可达98%。PDMDAAC改性粉煤灰对分散蓝的吸附符合Langmuir吸附模型。     

GROUNDWATER QUALITY IN THE CORTARO AREA NORTHWEST OF TUCSON,ARIZONA1

ABSTRACT The Cortaro Area is currently the depository for much of the liquid waste from the City of Tucson. In the past, more than one-half of the sewage effluent was used for crop irrigation. However, since 1970 virtually all of the sewage effluent has been percolated in the normally dry Santa Cruz River channel. Nitrate and chloride contents were monitored monthly in water samples from about 20 large-capacity irrigation wells. Contents and seasonal trends for these constituents were closely related to the disposal of sewage effluent. Water quality problems other than nitrate include total dissolved solids, boron, coliform, and lead. High lead contents in the area appear to be a natural phenomenon and the coliform contents are likely related to poor well construction. The other quality problems are primarily due to sewage effluent.     

A CHLORIDE BUDGET FOR THE MISSISSIPPI RIVER,HEADWATERS TO MOUTH1

ABSTRACT Mass budgets for chloride were estimated from 1975-1978 for the Mississippi River from headwaters to near the mouth to determine the magnitudes of natural and anthropogenic sources. Annual chloride input from precipitation ranged from about 200 kg mi^-2yr^-1 at Royalton, Minnesota, to about 350 kg mi^-2yr^-1 at Vicksburg, Mississippi. Mass export ranged from about 900 kg mi^-2yr^-1 at Royalton to about 8000 kg mi^-2yr^-1 at Vicksburg. As much as 80 percent of the residual, the difference between input and export, probably is contributed by anthropogenic sources. In particular, semi-logarithmic scatterplots of monthly total discharge against chloride concentration show that, during early spring, chloride elevations in the Mississippi River and Ohio River are elevated, possibly because of flushing of road salt and leaching of chloride from the accumulated snowpack.     

GROUND WATER SEEPAGE IN LAKE WASHINGTON AND THE UPPER ST. JOHNS RIVER BASIN,FLORIDA1

Direct ground water seepage measurements were made in Lake Washington, Florida, to determine the importance of seepage as a water and chloride source to the lake and upper St. Johns River. Over 200 seepage measurements were made in the lake and adjoining canals from July through December 1978. Results indicated that seepage into the shore areas of Lake Washington was an insignificant water source to the lake, representing 0.6 percent of the inputs, and was nearly balanced by ground water recharge in the midlake region. Drainage canals entering Lake Washington, however, exhibited high average seepage rates (17.7 L/m²-day), over eight times the lake average (2.01 L/M²-day). Discharge from the St. Johns River was the dominant factor in the water budget of Lake Washington and represented approximately 88 percent of the inputs during the study year. Although inputs from the drainage canals represented only 6.6 percent of the St. Johns River annual discharge, these canals represented 20.4 percent of the annual St. Johns River chloride loading and 62.1 percent of the river chloride loading during the five driest months of 1978. Evidence from this study indicates that rising levels of chloride in the river in recent years are largely attributable to ground water seepage in channelized areas, particularly in the headwaters. These chloride inputs assume greater importance during low water/low flow periods.     

PAA改性纳米铁强化还原降解水中亚甲基蓝

利用纳米零价铁去除水中各类污染物是近年来的研究热点,但纳米零价铁颗粒在水中的团聚会导致反应活性降低,研究通过在纳米铁颗粒制备过程中添加分散剂聚丙烯酸(PAA),提高其分散性,强化其在水中反应活性,合成改性纳米零价铁颗粒(PAA-Fe),并首次用于降解水中的亚甲基蓝.对其SEM、TEM、XRD和比表面积表征结果表明,与未改性原始纳米零价铁颗粒相比,PAA-Fe颗粒表面较光滑,团聚减少、颗粒粒径减小,比表面积增大.改性剂PAA添加浓度为0.1 g·L-1时,经过60 min降解反应,PAA改性纳米铁颗粒对亚甲基蓝的脱色率为98.84%,较未改性颗粒脱色率提高了27.32%.改性纳米铁颗粒对亚甲基蓝的脱色效果受初始溶液的p H值、初始溶液的浓度、PAA-Fe投加量和反应温度影响.PAA-Fe与亚甲基蓝的脱色反应符合假一级反应动力学规律.     

污泥焚烧过程中氯化物对Cd迁移行为的影响

采用固定层燃炉及向污泥中添加Cd方式,分别研究了污泥焚烧过程中有机氯(PVC)与无机氯(NaCl)对Cd迁移转化行为的影响,同时考察了不同焚烧条件下Cd的迁移及分布规律.结果表明,污泥焚烧过程中不同氯化物的加入均增强了Cd向飞灰或者烟气中迁移,但随着氯化物加入量的增加,Cd挥发增加的趋势并不明显.随温度的升高,有机氯(PVC)与无机氯(NaCl)均使得Cd在底渣中的分布减少,而焚烧时间及初始浓度对Cd迁移分布没有显著影响.底渣和飞灰的SEM-EDS和XRD分析表明,污泥焚烧过程中NaCl的加入导致Cd易与氯化物形成CdCl2、Na2CdCl4、K2CdCl6、K2CdSiO4和NaCdO2,而PVC的加入,除了与Cd形成Na2CdCl4和CdCl2外,还生成了K4CdCl6和K6CdO4氯化物,可见有机氯(PVC)与无机氯(NaCl)对Cd迁移转化影响主要与Cd的生成物种类及形态有关.     

聚合氯化铝去除污泥水中磷的工艺优化

在对比聚合氯化铝(PAC)对浓缩脱水污泥水及其上清液除磷效果的基础上,通过响应曲面法(RSM)分析了污泥水上清液PAC除磷过程中Al/P摩尔比、pH和搅拌转速(MS)对除磷效果的单独效应和联合效应,并探讨了PAC除磷动力学.结果表明,PAC直接对污泥水混凝除磷会恶化其沉降性能,且除磷效率不高.RSM优化得到的上清液除磷最优工艺条件为:Al/P摩尔比为2.49,pH为8.3,MS为398 r·min-1,除磷效率为97.8%,实验验证结果表明该优化操作模式行之有效.动力学分析结果表明,PAC对污泥水的除磷过程分为化学沉淀与絮凝体快速吸附除磷和二级动力学沉淀除磷两阶段.     

水和废水中阴离子表面活性剂测定的影响因素

亚甲蓝分光光度法测定水和废水中阴离子表面活性剂时受到多种因素的影响。分别从pH、显色剂用量、破乳剂用量、萃取次数、干扰物质等方面进行了条件实验,得到了最佳实验条件,以保证阴离子表面活性剂测定结果的准确性。     

红球菌LSJ-6介导的金纳米颗粒的合成及其对亚甲基蓝的吸附去除

从湖南省冷水江市的土样中分离筛选到一株对重金属具有高抗性的菌株.16S rRNA基因序列分析可知,该菌株属于红球菌属(Rhodococcus),命名为Rhodococcus sp.LSJ-6.最适生长条件为30℃,pH为7,好氧.研究发现该菌株可以介导金纳米颗粒的合成,且纳米颗粒的大小随体系pH升高(pH 5~9)而减小(15~3 nm).当温度升高时(20~40℃),颗粒大小无显著性差异,但形貌的多样性减小.进一步研究了不同条件下合成的纳米颗粒对亚甲基蓝的吸附去除,发现在pH为9,30℃时合成的金纳米颗粒对亚甲基蓝的吸附去除率最高,可达96%.本研究为生物合成金纳米颗粒的环境应用奠定了基础.