Studies on the effects of sewage effluent on gastropod populations in experimental streams

Population density, biomass, growth and reproduction rate of the gastropods Lymnaea peregra (Müller) and Potamopyrgus jenkinsi (Smith) were monitored over a 21 month period in three experimental earth channels, one carrying clean river water and the others 25 and 50% treated sewage effluent mixed with river water. Each channel was divided into riffle and pool stretches; the abundance and biomass of both species were higher in the riffles. The abundance and biomass of L. peregra were significantly greater (P < 0.01) in the riffle in the presence of effluent. Concentration of effluent did not have a significant effect on abundance or biomass. The abundance and biomass of P. jenkinsi were significantly greater (P < 0.001) in riffle and pool in the absence of effluent. In addition, the abundance and biomass of P. jenkinsi were significantly greater (P < 0.05) in the 25% effluent channel than in 50% effluent. No significant differences in the growth of L. peregra between channels were observed. The average number of eggs and of egg masses laid by L. peregra was significantly greater (P < 0.01) in riffle and pool in the presence of effluent. In the riffle, significantly more masses (P < 0.05) and more eggs per adult (P < 0.01) were laid in the 25% effluent channel than in 50% effluent. No differences were observed in the reproduction rate per adult of P. jenkinsi between the 0 and 25% effluent channels. It is concluded that population differences between channels are probably largely the result of differing mortality rates.     

Carrousel氧化沟技术处理制革废水工程实例

Carrosel氧化沟工艺处理制革废水,具有耐高有机负荷、耐高毒性负荷,耐高盐负荷冲击能力的特点,制革废水经处理后各项指标能达到GB8978－96《污水综合排放标准》二级标准。     

Control of Shattering Effect of Explosion in Mass Ore Caving

The results of experimental investigations into mutual location of bundle contiguous charges and vertical concentrated charges in the nonuniformly stressed rock masses are presented. The schemes are considered for ore blasting in blocks into the caved rock and compensation chambers. The parameters are given for drilling and blasting operations.     

内循环微生物接触氧化法处理含酚废水的研究

本文介绍了在没曝气情况下应用内循环微生物接触氧化原理法处理含酚废水和生物污水的方法并作了理论探讨。该方法节省了曝气风机，也节省了能源，降低了生产成本，适合于生产酚醛树脂的小厂。     

纳滤膜出水的生物稳定性研究

利用纳滤膜(NF)对微污染的H市自来水进行深度处理试验与研究,用经氯化的含TOC为0.23～0.34mg/L纳滤水对模拟小型试验配水系统内异养型微生物的生长与繁殖情况进行检测和电镜观察,来探讨纳滤出水是否具有生物稳定性.结果表明:在已形成生物膜的不同材质的铸铁管和ABS管中通入5个半月纳滤水后,在系统的终端细菌总数由1.43×104cfu/mL缓慢减到2.1×103cfu/mL,并且ABS管上在5个半月的时间内未形成生物膜,但纳滤膜出水的AOC值还有待于进一步测定.     

焦化厂污水处理现状分析

介绍了邯钢焦化厂污水采用A-A-O法处理的运行情况，讨论了处理过程中的影响因素、操作管理经验以及污水处理工艺的特点。     

PVC与PTFE圆板表面电荷分布研究

本文叙述了确定带电绝缘体表面电荷分布的新方法，给出了绝缘体圆板的电位分布，推导出表面电荷服从指数分布的公式。通过ＰＶＣ与ＰＴＦＥ两类材料的实验证明，这一理论与实验结果符合很好。     

Pressure-Induced Quantum Limit in a Q1D System in High Magnetic Fields

The quasi-one-dimensional (Q1D) materials, (Per)₂M(mnt)₂, have transition temperatures of 12 and 8 K for M = Au and Pt, respectively, as samples are cooled from a metallic state to an insulating, charge density wave (CDW) ground state. In these proceedings, we present results regarding the effect of quasi-hydrostatic pressure and high magnetic fields on the CDW and field-induced density wave (FIDW) states of these materials. With pressures greater than 4 kbar, Shubnikov de Haas oscillations appear in the M = Au compound, which reach the n=1 Landau level before the limit of the applied magnetic field. While lower field (B < 20 T) results are similar for M = Pt, the FIDW state persists in higher fields, even under 5.3 kbar of pressure.     

污水灌溉系统中氮磷转化运移的试验研究

本文详细介绍了污水处理和回用相结合系统的野外试验,讨论了试验系统的设计、安装和资料收集,分析了试验过程中的水分平衡、污水灌溉过程中各种污染物的变化、积累和运动,为进一步优化利用此类系统提供了基础数据。研究结果表明,文中所提出的污水回用与污水处理相结合的系统,结合高强度的作物种植,可以处理高负荷的污水,排水中氮磷的浓度明显减少。