地下式人工快速渗滤系统的室内砂柱试验研究

人工快速渗滤系统，其经济、高效、适于分散点源污水处理的特点，已在我国南方得到广泛的应用。为了解决应用于北方的“过冬问题”，没想采用地下构建来维持系统的正常运行。采用室内砂柱试验的方法对地下式构建人工快滤系统进行模拟，测定了系统的COD、NH4^＋-N、TN、TP等水质指标，验证了系统的出水水质情况。针对试验中出现的复氧、堵塞问题，分别提出了对系统增加预曝气和多级并联反冲洗的改进意见。同时，从出水水质的角度给出了水力负荷周期的推荐值由于该系统是一种新型的水处理技术，所以将之与曝气生物滤池进行了对比，指出了各自的优缺点，以增强对地下式CRI系统的认识。     

矿化垃圾生物反应床处理畜禽废水的试验研究

矿化垃圾具有较大的吸附比表面积 ,较强的阳离子交换容量 (6 7.9meq/ 10 0 g) ,无二次污染 ,是很好的污水处理生物介质。借助于矿化垃圾柱物理模型试验装置 ,在实验室进行了历时 6个月的矿化垃圾反应床处理畜禽污水试验。结果表明 ,系统出水有较大改善 ,出水溶解氧有较大提高 ,pH值呈中性。该处理系统对畜禽污水中色度、SS、CODCr、BOD5、NH3 N和总磷的平均去除率分别为 6 4.7%、5 4.2 9%、75 .33 %、88.71%、94.5 5 %和 99.83 % ;处理出水中CODCr、BOD5、NH4 N和总磷的平均浓度分别为 185 .6 1mg/L、14.94mg/L、2 6 .79mg/L和 0 .0 79mg/L ;总氮的平均去除率仅为 2 1.2 9%。反应器运行 6个月以来 ,运转良好 ,未发生阻塞现象     

饥饿对人工快速渗滤系统硝化性能的影响

为探究饥饿条件下人工快速渗滤(CRI)系统硝化性能的衰减及恢复情况,分别考察了不同饥饿时间(5、10、15、20 d)对稳定运行的CRI系统(C~1、C~2、C~3、C~4)内氮素污染物转化、硝化细菌活性及胞外多聚物(EPS)组分的影响.结果表明,C~1、C~2、C~3分别在恢复进水3、7、10 d后NH~+_4-N去除率可恢复至60%左右,而C~4在恢复进水24 d后NH~+_4-N去除率仅有40%左右;C~2、C~3、C~4在恢复进水后均表现出不同程度的NO~-_2-N积累现象,积累率最终分别稳定在25%、65%、80%左右.稳定运行期间亚硝酸氧化菌(NOB)的活性高于氨氧化菌(AOB),而饥饿期超过10 d时NOB的衰减速率开始高于AOB;经10、15 d饥饿后AOB活性可恢复至饥饿前水平而NOB活性无法完全恢复,导致NO~-_2-N积累;经20 d饥饿后AOB和NOB活性均难以恢复至饥饿前水平,导致NH~+_4-N去除率下降.饥饿期间EPS能为CRI系统内的微生物提供碳源和能源,维持细胞的新陈代谢;蛋白质(PN)/多糖(PS)比随着饥饿时间的延长而降低,表明饥饿期间对PN的利用更加显著.研究结论可为饥饿条件下CRI系统的运行优化提供理论支持,同时为进一步探寻饥饿时硝化性能的稳定调控策略奠定了基础.     

概率法计算不同下沉深度下凹绿地蓄水效率的研究

作为一种简单而实用的城市雨水渗蓄技术,下凹绿地具有削减洪峰流量、截留滞纳雨水的功能.结合天津市多年降雨统计资料,采用概率分析方法,探讨下凹绿地的蓄渗效率.结果表明:在绿地率为30％左右的条件下,即使是在土壤稳渗系数相对较低的地区开发下凹绿地,下挖深度只要满足60 mm,开发后的下凹绿地的渗蓄效率都可达到95％.但下凹深度超过100 mm后,随下凹深度继续增加而提高的渗蓄效率不足5％.考虑到建设成本和收益比等因素,建议天津市修建下凹绿地的深度范围为60 mm～100 mm.     

非饱和红壤土降雨入渗室内模拟试验

以江西省域范围内典型红壤土为研究对象,利用自行研制开发的降雨模拟试验设备与渗透试验装置,设计了大雨工况下土体初始含水率、干密度、降雨累积时间及降雨后土体静置时间等对其渗透性影响的室内试验。试验结果显示,土体渗透性随初始含水率的升高逐渐降低,给出的宏观渗透系数公式定量化描述了不同初始含水率的可渗透性强弱程度;在初始含水率相对固定的情况下,土体渗透性随干密度的增大逐渐减小,且干密度增大到一定程度后其渗透性锐减,各水平之间的差异性不再明显;累积降雨时间会显著影响深部土体的渗透性,降雨历时越长,深部土体的含水率越高;雨水的在降雨过程停止后继续沿土体纵深入渗,致使表层含水率降低,深部含水率提高,含水率特征曲线趋向竖直。     

INFLUENCE OF TWO WOODY RIPARIAN SPECIES ON CRITICAL CONDITIONS FOR STREAMBANK STABILITY: UPPER TRUCKEE RIVER,CALIFORNIA1

Over the past 35 years, a trend of decreasing water clarity has been documented in Lake Tahoe, attributable in part to the delivery of fine grained sediment emanating from upland and channel erosion. A recent study showed that the Upper Truckee River is the single largest contributor of sediment to Lake Tahoe, with a large proportion of the sediment load emanating from streambanks. This study combines field data with numerical modeling to identify the critical conditions for bank stability along an unstable reach of the Upper Truckee River, California. Bank failures occur during winter and spring months, brought on by repeated basal melting of snow packs and rain‐on‐snow events. Field studies of young lodgepole pines and Lemmon's willow were used to quantify the mechanical, hydrologic, and net effects of riparian vegetation on streambank stability. Lemmon's willow provided an order of magnitude more root reinforcement (5.5 kPa) than the lodgepole pines (0.5 kPa); the hydrologic effects of the species varied spatially and temporally and generally were of a smaller magnitude than the mechanical effects. Overall, Lemmon's willow provided a significant increase in bank strength, reducing the frequency of bank failures and delivery of fine grained sediment to the study reach of the Upper Truckee River.     

AQUIFER SALINIZATION IN THE YUN‐LIN COASTAL AREA,TAIWAN1

ABSTRACT: This study analyzes possible causes of shallow ground water salinization in the coastal area of Yun‐Lin. The local hydro‐geologic setting is determined from geological drilling data and sea floor topography. Three possible causes (sea water intrusion, salt water percolation through wells, and infiltration of salty water from fish ponds) are evaluated. Chloride concentration is used as an index to measure ground water salinization. Sea water intrusion is modeled by the advective/dispersive equation, and salt water infiltration from wells and fish ponds is calculated by estimating the amount of water percolated. The determined local hydrogeologic setting suggests that the shallow aquifer may be connected to the sea water, resulting in salt water intrusion as a large amount of shallow ground water is withdrawn. The percent contributions of sea water intrusion, percolation through wells, and infiltration of water from fish ponds, to the salinization of the shallow aquifer at Ko‐Hu in the Yun‐Lin coastal area are approximately 27 percent, less than 1 percent and 73 percent, respectively. The results suggest that the vertical infiltration of salt water from fish ponds is the major cause of shallow ground water salinization in the coastal area of Yun‐Lin.     

DEEP PERCOLATION IN A SAND HILL AREA1

Records for two rivers flowing in a Sand Hill area are used to derive a value for the infiltration reaching the water table. The infiltration is 0.23 feet per year which is 13 per cent of the precipitation.     

不同草坪覆盖地下渗滤系统处理生活污水研究

采用高羊茅和结缕草2种不同草坪草覆盖的地下渗滤系统对生活污水进行处理.结果表明,不同处理对COD均有较好的去除效果,COD浓度从97～357 mg·L-1降至48 mg·L-1以下,达到我国污水处理二级排放标准,不同处理间差异不显著;不同处理对氨氮的去除从76.3～125.8 mg·L-1降至0.5 mg·L-1以下,...     

土壤渗滤对污染河流重金属去除效果研究

本试验通过模拟野外河滩土壤渗滤,分析测定原水和渗滤出水水质重金属浓度,研究天然土壤和填充碎石、沸石、活性炭、陶粒的土壤组合介质对水中重金属浓度的去除效果。结果表明：天然土壤和填充碎石、沸石、陶粒的土壤组合介质对河水中Hg的平均去除率分别为73．3％、49．4％、25．0％、75．0％。填充沸石的土壤组合介质在运行15天左右对河水中Cd的去除率也能达到30％。