模拟空间废水生物处理系统的设计及运行与微生物种群结构分析

废水循环利用是受控生态生保系统(environmental control and life support system,ECLSS)的关键技术之一.设计了空间废水组合生物处理系统,由两个序批间歇式反应器(sequencing batch reactor,SBR)、供氧部件、在线监测与控制部件等组成.利用该系统可同时处理卫生废水和尿液,降解卫生废水中的化学需氧量(chemical oxygen demand,COD),转化尿液中尿素生成硝态氮(NO-3),形成植物种植营养液.废水处理系统稳定运行后,模拟卫生废水COD去除率达到99.34%,出水NO-3浓度1 626.71mg/L,氮素转化率达到87.2%.对SBR中微生物的种群结构进行了分析,卫生废水反应器中γ-变形菌纲的Pseudomonas、Arenimonas属微生物占73.3%,尿液废水反应器中β-变形菌纲的Thauera、Nitrosomonas、Comamonas属微生物占48.8%,这些微生物对维持空间废水生物处理系统的正常运行具有重要作用.

微生物处理空间模拟废水工艺初探

目的开展模拟空间废水处理试验研究,探讨空间废水处理膜生物反应器处理模拟空间废水的较适环境条件,为今后设计空间膜生物反应器提供技术支持。方法利用前期研制的空间废水处理膜生物反应器和驯化后微生物,进行了模拟空间废水处理试验,检测了处理液进口和出口的化学耗氧量(COD)、生物耗氧量(BOD)、总有机碳和总氮的去除效率。结果空间废水处理膜生物反应器发挥最佳工作效能需要的环境条件分别为:pH6.5～7.5,温度24.0～26.0℃,水力滞留时间20 h,碳氮比0.81;在该条件下模拟空间废水的化学耗氧量和生物好氧量下降率均接近90%。结论研制的膜生物反应器可以有效地进行空间模拟废水的处理,适合的工艺条件能明显提高其废水处理效率。

MABR系统处理空间站模拟废水的研究

微生物法处理空间站废水是未来空间站水回收管理系统的发展方向之一,为了探究生化法对空间站废水的处理效果,设计并搭建了一套MABR反应器,以出水COD、NH_(4)^(+)-N和TN等作为主要考察指标,并结合NO_(2)^(-)-N、NO_(3)^(-)-N等指标对反应器的处理效果进行评估和分析。试验对比了不同曝气压力、不同断面流速下反应器的处理效能,从而找出各因素对反应器处理效果的影响规律,然后在一定条件对空间站模拟废水进行处理。结果表明:反应器启动后具有同步硝化反硝化功能;当处理市政污水时,设定曝气压力为0.015 MPa,断面流速为2.5 mm/s,HRT为24 h,COD、NH_(4)^(+)-N和TN去除率分别达到99.9%、97.8%和86.69%;当处理空间站模拟废水(稀释10%)时,补充碳源150 mg/L(葡萄糖),曝气压力为0.02 MPa,断面流速为2.5 mm/s,HRT为24 h,COD、NH_(4)^(+)-N和TN去除率分别达到93.11%、70.01%、49.05%。

Evaluation of development potential of pumped hydroelectric storage and geothermal utilization system in abandoned coal mine

Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.

The Changes of Water Quality in Space and Time in the Mekong River, Bassac River and Adjacent Waterways

Catfish （Pangasianodon hypophthalmus） farming along Mekong river and Bassac river depends heavily on water quality of the two rivers, whereas water quality of these rivers are affected by the waste of aquaculture activities, agricultural production, industrial and municipal waste. This report analyzes the monitoring data on Mekong river, Bassac river and adjacent waterways in the period of 2011-2012, focusing on parameters of organic pollution to assess the current quality of these two rivers. Based on the results, the water quality in the river-head was generally better than in the middle and at the end of the river, and the quality of water of the Mekong river was better than Bassac river. In terms of time, water quality in July was considered the best in all the basins. At adjacent natural rivers and canals, ammonia levels increased and exceeded the Vietnamese standard in April, and BOD values were also much higher compared to two major rivers. The results of the model also showed that the levels of pollution index of the Mekong and Bassac river were very low （1.33 and 1.47）, and the values （Y） in the canals were higher （1.63-1.67） but still in permitted level. Therefore, the water quality of the Mekong and Bassac river in the period 2011-2012 was generally still quite good.

Time difference based measurement of ultrasonic cavitations in wastewater treatment

Intensity of cavitation is significant in ultrasonic wastewater treatment,but is complicated to measure.A time difference based method of ultrasonic cavitation measurement is proposed.The time differences at different powers of 495 kHz ultrasonic are measured in experiment in comparison with conductimetric method.Simulation results show that time difference and electrical conductivity are both approximately positive proportional to the ultrasonic power.The degradation of PNP solution verifies the availability in wastewater treatment by using ultrasonic.

Seasonal and Spatial Variation in the Monitoring Parameters of Zomar Stream, Palestine during 2010

Levels of pollutants at Zomar stream, the only recreational area for the inhabitants of the northern part of the West Bank, Palestine, were recently determined, and have shown to be relatively high. Three bathing sites along the Zomar stream area were monitored for one year （fortnightly）. Wastewater samples were subjected to microbiological analysis （fecal coliforms, Escherichia coli, Pseudomonas, Enterococcus and Klebsiella）, physico-chemical analyses （water temperature, pH, electroconductivity and DO （dissolved oxygen））, biochemical oxygen demand, total Kjeldahl nitrogen and ammonia. The study results demonstrated seasonal and locational variations in all parameters studied. The highest levels of pollution were detected during summer, especially before a rainfall or after a discharge from onsite cesspits. Locations associated with sewage discharge were found to have the highest fecal indicator levels.