生物滴滤床净化二甲苯废气的性能研究

分别以大小两种拉西环作为生物滴滤床填料净化二甲苯废气,研究入口负荷、气体停留时间、营养液喷淋密度及营养液中氯化铵的质量浓度对生物滴滤床净化效果的影响.实验结果表明:随着入口负荷的增加,去除负荷也呈增加趋势,但二者并非线性关系.气体停留时间越长,去除效果越好.营养液中氯化铵的质量浓度对去除效果有显著影响,充足的氮源是高去除率的保证.在氮源充足的前提下,营养液喷淋密度对去除效果无显著影响.      

利用微型动物减少污泥产量的工艺探讨

在适宜的条件下,活性污泥系统中可以生长出大量的原生动物和后生动物等微型动物,这些微型动物在活性污泥中起着捕食者的作用,它们可以通过捕食,将污泥转化为能量、H2O和CO2,从而使污泥量减少。蚯蚓生物滤池工艺、两段式生物反应器工艺和淹没式生物膜工艺是目前国内外常见的3种利用微型动物减少污泥产量的工艺,本研究介绍了这3种工艺的污泥减量效果,并分析了各自的优缺点。     

水解酸化-好氧生物滤池处理炼油废水

以高炉水渣为填料,采用水解酸化-好氧生物滤池处理炼油废水。考察了好氧区气水比、水力停留时间对炼油废水处理效果的影响。实验结果表明：在水力停留时间为6h、温度为20～35℃、废水pH为6～9、好氧区气水比为10：1的条件下,该生物滤池对NH3-N,Ar-OH,COD的总去除率分别为100％,97％,85％,处理后出水水质达到国家《污水综合排放标准》一级标准。     

复合生物滤池处理NH3和H2S混合恶臭气体的实验研究

采用复合生物滤池处理NH₃和H₂S酸碱混合气体,其中复合生物滤池由生物滴滤池和生物过滤池组成.研究表明:在气体流量为0.9～1.4 m3/h,气体质量浓度为15 mg/m3,营养液喷淋量为4.56 L/h时,出气NH₃和H₂S的质量浓度分别达到<恶臭污染物排放标准>(GB14554-93)中的一级和二级排放标准,除臭效果好.研究还表明:复合生物滤池中微生物的生长条件差别较大,在生物滴滤池内生长的微生物为枯草芽孢杆菌、钟虫等细菌,而在生物过滤池内生长的微生物则为白曲霉菌、葡萄球菌等真菌.      

氨氮在饮用水生物滤池内的去除机制

为探讨饮用水生物滤池对NH4+-N的去除机制,测定生物滤池进出水中NH4+-N、NO2--N、NO3--N、高锰酸盐指数、总磷、单质氮(N2)、温度和溶解氧(dissolved oxygen,DO)等指标,并采集生物滤池不同层高(0、10、20、40、60 cm)活性炭生物填料,应用分子生物学技术,对样品中的细菌种群进行研究.结果表明,根据进水NH4+-N浓度分为3个阶段,第一、二和三阶段都发生了"氮亏损"现象(出水无机氮之和小于进水无机氮之和),氮亏损的量(出水无机氮之和与进水无机氮之和的差值)分别为0.94、0.32和0.15 mg.L-1.氮亏损的量与进水中NH4+-N浓度有很好的正相关性,但与进水中高锰酸盐指数浓度没有线性关系.第一阶段水中N2的平均浓度随着生物滤池填料层高呈上升趋势,进水中N2平均浓度是14.04 mg.L-1,出水N2平均浓度为14.67 mg.L-1.测序结果显示活性炭上生物膜中氨氧化细菌(ammonia-oxidizing bacteria,AOB)全部归为3个常见属:Nitrosococcus、Nitrosomonas和Nitrosospira.当生物滤池进水NH4+-N浓度较高时,生物滤池中发生的"氮亏损"现象是由AOB的作用.     

Betaine removal during thermo- and mesophilic aerobic batch biodegradation of beet molasses vinasse: influence of temperature and pH on the progress and efficiency of the process

The key issue in achieving a high extent of biodegradation of beet molasses vinasse is to establish the conditions for the assimilation of betaine, which is the main pollutant in this high-strength industrial effluent. In the present study, aerobic batch biodegradation was conducted over the temperature range of 27-63°C (step 9°C), at a pH of 6.5 and 8.0, using a mixed culture of bacteria of the genus Bacillus. Betaine was assimilated at 27-54°C and the pH of 8.0, as well as at 27-45°C and the pH of 6.5. The processes where betaine was assimilated produced a high BOD(5) removal, which exceeded 99.40% over the temperature range of 27-45°C at the pH of 8.0, as well as at 27°C and the pH of 6.5. Maximal COD removal (88.73%) was attained at 36°C and the pH of 6.5. The results indicate that the process can be applied on an industrial scale as the first step in the treatment of beet molasses vinasse.     

Effects of design parameters on performance and cost analysis of combined ultraviolet-biofilter systems treating gaseous chlorobenzene based on mathematical modeling

A conceptual mathematical model was used to evaluate the design parameters of a combined ultraviolet (UV)-biofilter system, and perform a cost analysis. Results showed that the UV light source strength and the gas residence times in the UV system (UVRT) and biofilter (EBRT) had positive effects on the overall chlorobenzene removal efficiency of the system. High ratio of UVRT to EBRT improved the removal efficiency, suggesting that the UV system has a greater effect on the overall performance of the system compared with the biofilter. Analysis of the capital and operating costs showed that the capital costs of the standalone biofilter system were much higher than those of the standalone UV system. However, the biofilter operating costs were lower than those of the UV system. The operating costs of the combined UV-biofilter system increased with increasing UVRT/EBRT ratio, whereas its capital costs decreased.     

恶臭气体生物处理技术研究进展

介绍了恶臭气体的种类、危害、特征、处理方法及原理；概述了恶臭气体的3种主要生物处理方法：生物滤池、生物滴滤池和生物洗涤器，介绍3种方法的工艺流程、技术特点及最新研究进展；提出了生物法处理恶臭气体亟需解决的问题及研究方向。     

生物滤塔处理含氨气体的长期运行研究

针对含氨恶臭气体的处理,选用堆肥和污泥颗粒作为填料,研究了生物滤塔长期运行(210d)处理氨的效果.结果表明,运行初期在低负荷(NH3浓度＜110 mg·m-3)条件下,生物滤塔对氨的去除能力均保持在较高水平,氨去除效率达到99%以上;随着负荷的不断增加,到实验后期,当进气浓度大于190 mg·m-3时,氨去除效率下降...     

Denitrification and biofilm growth in a pilot-scale biofilter packed with suspended carriers for biological nitrogen removal from secondary effluent

Tertiary denitrification is an effective method for nitrogen removal from wastewater. A pilot-scale biofilter packed with suspended carriers was operated for tertiary denitrification with ethanol as the organic carbon source. Long-term performance, biokinetics of denitrification and biofilm growth were evaluated under filtration velocities of 6, 10 and 14 m/hr. The pilot-scale biofilter removed nitrate from the secondary effluent effectively, and the nitrate nitrogen(NO_3-N) removal percentage was 82%, 78% and 55% at the filtration velocities of 6, 10 and 14 m/hr, respectively. At the filtration velocities of 6 and 10 m/hr, the nitrate removal loading rate increased with increasing influent nitrate loading rates, while at the filtration velocity of 14 m/hr, the removal loading rate and the influent loading rate were uncorrelated.During denitrification, the ratio of consumed chemical oxygen demand to removed NO_3-N was 3.99–4.52 mg/mg. Under the filtration velocities of 6, 10 and 14 m/hr, the maximum denitrification rate was 3.12, 4.86 and 4.42 g N/(m~2·day), the half-saturation constant was 2.61, 1.05 and 1.17 mg/L, and the half-order coefficient was 0.22, 0.32 and 0.24(mg/L)1/2/min,respectively. The biofilm biomass increased with increasing filtration velocity and was 2845,5124 and 7324 mg VSS/m~2 at filtration velocities of 6, 10 and 14 m/hr, respectively. The highest biofilm density was 44 mg/cm~3 at the filtration velocity of 14 m/hr. Due to the low influent loading rate, biofilm biomass and thickness were lowest at the filtration velocity of 6 m/hr.