Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants

Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditionalchlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaksin the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose.Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditionson the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration,liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9%was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically foundto be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammoniaremoval rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plantmembrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatmentplant, also paved the way towards a larger scale application.     

膜生物反应器中膜组件性能的对比研究

膜生物反应器中不同膜组件对废水的处理效果不同。论文主要对膜生物反应器中分别产自日本和德国的聚乙烯中空纤维膜膜组件处理生活污水的情况进行了考察,在给定的水力停留时间、污泥浓度、pH值等参数的条件下,对其膜组件性能进行了对比研究。通过对生活污水的降解试验发现,在相同的条件下,两种膜组件在浊度的去除方面均达到100%,并且系统处理出水COD均<50mg/L,去除率可分别达到86%和85%,但对氨氮去除两者均未达到60%,另外两种膜组件的膜通量的衰减相差较大,日本膜组件的衰减较缓慢而德国膜组件的衰减很快。     

棉印染废水处理回用技术研究

为将污水回用于生产,降低生产成本和减少环境污染,对棉印染废水进行清浊分流,将轻质废水作为处理对象采用生化-陶瓷膜过滤工艺对废水进行深度处理后回用,处理后水质满足印染回用水水质要求,其中COD、浊度和色度去除率分别达到85％,98％和95％。将处理后水全部回用于生产,对印染产品质量无影响。     

圆盘式固相萃取HPLC法测定饮用水中微囊藻毒素LR和RR

采用固相微萃取与高效液相色谱联用技术（SPE／HPLC）测定饮用水的微囊藻毒索,并对SPE的萃取条件和HPLC的色谱条件进行了优化,对SPE的多项参数,诸如萃取率、检出限及测定限以及准确度和精密度均作了测试。通过实际水样进行了分析,该方法测定MC—LR（LR型微囊藻毒索）的线性范围为0．5～50ug／L,相关系数为0．9992;测定MC—RR（RR微囊藻毒索）的线性范围为0．5—50ug/L,相关系数为0．9989。SPE法之优于LLE法主要在于分析过程快速,有机溶剂使用量大大减少,方法更适合于大量水样中有机污染物的现场取样处理。     

溶解性微生物产物对浸没式膜生物反应器运行的影响

对溶解性微生物产物(SMP)的累积行为及其对浸没式膜生物反应器(SMBR)操作运行的影响进行了研究.在90 d的实验过程中,对总有机碳(TOC)、相对分子质量分布(MWDs)、比耗氧速率(SOUR)进行定期监测,采用死端过滤实验来检测SMP对膜污染的影响.结果表明,在SMBR上清液中SMP出现明显累积;随着实验运行,SMP中相对分子质量大于10000的浓度增加显著;与相对分子质量小于1 000的SMP相比,此部分SMP对污泥活性和膜污染影响较大,对SMBR的出水水质影响较小.     

一体式膜生物反应器中环境条件对混合液粘度的影响研究

文章研究了一体式膜生物反应器中环境条件对混合液粘度的影响,以及混合液粘度对膜过滤阻力的影响。试验结果表明：混合液的粘度主要是由胞外聚合物引起的;混合液粘度随着胞外聚合物含量的变化而变化;混合液粘度与各操作条件之间存在一定的关系U=1．586（MESS）^0．614T^-0.106（DO）^0.4697;混合液粘度与膜过滤阻力有较好的相关性。     

Evaluation of factors influencing soluble microbial product in submerged MBR through hybrid ASM model

In this study, a mathematical model was established to predict the formation of the soluble microbial product (SMP) in a submerged membrane bioreactor. The developed model was calibrated under the reference condition. Simulation results were in good agreement with the measured results under the reference condition. The calibrated model was then used in the scenario studies to evaluate the effect of three chosen operating parameters: hydraulic retention time (HRT), dissolved oxygen concentration, and sludge retention time (SRT). Simulation results revealed that the SMP dominated the soluble organic substances in the supernatant. The scenario studies also revealed that the HRT can be decreased to 1 h without deteriorating the effluent quality; dissolved oxygen concentration in the reactor can be kept at 2–3 mg/L to maintain the effluent quality, reduce the content of SMP, and minimize operating costs; the optimal SRT can be controlled to 10–15 d to achieve complete nitrification process, less membrane fouling potential, and acceptable organic removal efficiency.     

Biodegradation of trace pharmaceutical substances in wastewater by a membrane bioreactor

The biodegradation of selected pharmaceutical micropollutants, including two pharmaceuticals with argued biodegradation, was studied by a lab-scale membrane bioreactor. The reaction kinetics and affecting factors were also investigated in this paper. Clofibric acid (CA) with contradictive biodegradation reported was degraded almost completely at different hydraulic retention times (HRTs) after adaptation to microorganisms. The biodegradation of CA was disturbed at low pH operation, while the activity of microorganisms recovered again after pH adjustment to neutral condition. Ibuprofen (IBP) degraded under neutral and acidic conditions. Removals of IBP and CA were zero-order and first-order reactions under high and low initial concentrations, respectively. Carbamazepine and diclofenac were not degraded regardless of HRTs and pH.     

膜生物反应器在屠宰废水中的应用

介绍了平板膜生物反应器在屠宰废水工程的应用实例。实践表明,膜生物反应器技术适合处理屠宰废水,具有工艺流程简单,处理效果好,处理后的废水可以回用,运行稳定和基建投资低等优点。     

硫酸铵-锌试剂-Tween-80萃取分离废镍镉电池金属

以废旧镍镉电池为原料,探索盐酸溶解废镍镉电池的溶解条件,并用ICP仪检测镍镉电池溶液中金属离子含量。研究了硫酸铵-锌试剂-Tween-80体系萃取分离金属离子Ni（Ⅱ）,Cd（Ⅱ）,Co（Ⅱ）的行为。实验表明：Ni（Ⅱ）,Co（Ⅱ）在pH6-9范围内,与锌试剂形成的螯合物可被Tween-80相完全萃取,而Cd（Ⅱ）基本不被萃取。进而实现了镍镉电池溶液中的Ni（Ⅱ）,Co（Ⅱ）离子与Cd（Ⅱ）离子的分离。