Membrane bioreactor with nonwoven fabrics as solid–liquid separation media for wastewater treatment

A nonwoven fabric module was utilized as a solid–liquid separation medium in a membrane bioreactor (MBR) for treating wastewater. The experimental results indicated that nonwoven fabrics had lower filtration resistance than microporous membranes in MBR applications. The optimal aeration intensity was approximately 0.01m³/m² s. The effect of mixed liquor suspended solid concentration on filtration resistance was not significant at an operating flux of under 0.8m³/m² d in the study range. The performance of nonwoven fabrics in a MBR application was further demonstrated in a pilot test. Chemical oxygen demand (COD) and suspended solids (SS) in the effluent were maintained under 60 and 10 mg/L, respectively, whereas influent COD varied from 800 to 1800mg/L. The transmembrane pressure was maintained below 5 kPa at a permeation flux of 0.18m³/m² d. The experimental results demonstrated that nonwoven fabrics maintained stable operation in MBR applications under appropriate operating conditions.     

异养菌与自养菌对好氧颗粒污泥稳定性的影响

研究了异养菌和自养菌颗粒污泥的特性：与异养菌相比,自养菌颗粒污泥粒径小、密度大、胞外多聚物（EPS）含量高但强度小。通过对粒径、EPS等特性与密度的变化规律分析,研究发现,自养菌颗粒污泥的粒径与密实度呈现出一致性,颗粒趋于稳定;而异养菌颗粒污泥粒径成长同时伴随着密度减小,粒径与密实度呈现不一致性,颗粒容易解体。颗粒强度的分析结果表明：在自养菌系统中EPS与孔隙率能够达到动态平衡是其长期维持稳定的主要原因,而异养菌中粒径与孔隙率无法达到平衡,操作条件无法控制高强度丝状菌的繁殖是其不稳定的主要因素。     

基于价值—价格模糊模型的东雷二期抽黄水资源定价研究

水资源作为维持人类生存和发展的重要资源,其定价保证了人们合理高效利用水资源.本文针对水资源定价问题展开研究,以东雷二期抽黄为例,采用模糊数学的方法,全面考虑水价制定过程中的影响因素,建立水价模糊综合评价模型,研究水资源价值评价和水价计算.科学制定东雷二期抽黄水资源水价,实现区域水资源高效利用和经济社会全面发展.     

内蒙古多伦地区参考作物蒸发蒸腾量演变研究

用Penman—Monteith和Priestley—Taylor两种方法分别计算了多伦地区的参考作物蒸发蒸腾量（ET0）,并对该地区的Ero演变情况进行了分析。经比较,Priestley—Taylor法计算所得Ero在量值上较大,但用两种方法计算得到的Ero整体趋势相同,以Penman-Monteith法计算结果为标准从整体上来分析该地区的ETo变化趋势、特点及其与不同要素之间的相关性,研究发现该地区年E％远大于年降雨量;E％整体上有微弱的减小趋势,呈现出平稳→增加→减少的过程;风速和日照对该地区E％的影响较大。可为当地生产及人类活动调控提供参考。     

冬季沁河(河南段)水化学特征

研究冬季沁河(河南段)的水化学特征为沁河水环境保护以及水资源利用提供依据。采集沿沁河及黄河9个断面样品并对样品的主要阴、阳离子和重金属进行检测,在此基础上运用水化学分析和因子分析法分析了沁河的主要水化学特征。结果表明:沿水流方向沁河取样断面由上到下水化学类型由Ca2+-SO42-+HCO3-型转变为Ca2+-HCO3-型;钙离子占阳离子总量51%,碳酸氢根离子占阴离子总量51%。黄河的水化学离子组成与沁河有较大区别,主要体现在钠离子和氯化物。沁河各点处的硝酸盐含量基本一致,平均为15.34mg/L(以NO3-计);氨氮浓度沿沁河径流路径呈上升趋势,平均浓度为1.42 mg/L(以NH3-N计)。冬季沁河(河南段)的水化学类型主要受控于自然因素,沁河水体中的硝酸盐主要来自地下水,氨氮主要来源于人类排放的污废水。     

好氧颗粒污泥脱氮除磷效率研究

以实验室模拟废水为进水,在SBR反应器中利用好氧颗粒污泥进行N、P的去除效率研究.研究表明:在运行周期约为4h,进水COD控制在500～1200 mg/L之间,室温条件下,好氧颗粒污泥对COD、氨氮、硝氮、TP的去除率稳定维持在97％、95％、92％、86％,说明好氧颗粒污泥特有的结构特性和生物特性有利于脱氮除磷.     

Effects of size and autoclavation of fruit and vegetable wastes on biohydrogen production by dark dry anaerobic fermentation under mesophilic condition

Fermentative hydrogen production from fruit and vegetable wastes (FVWs) through Dry Fermentation Technology (DFT) was studied through three independent experiments in order to find out the effect of particle size and autoclaving pretreatment on bio-hydrogen production from FVWs and as follows: (1) autoclaved FVWs with sizes < 5 cm (experiment I); (2) raw FVWs with sizes < 5 cm (experiment II) and (3) autoclaved FVWs with sizes > 5 cm (experiment III). The assay with autoclaved waste yielded a higher percentage of hydrogen in the headspace of the dry fermenter reaching a maximum value of 44% in experiment I. However, the maximum hydrogen production was obtained in experiment III with 14573 NmL at a yield of 23.53 NmL H₂/gVS. Profiling of the microbial communities by denaturing gradient gel electrophoresis (DGGE) indicated that the most prominent species were the genera Clostridium, Bifidobacterium, and Lactobacillus.     

Novel porous carbon felt cathode modified by cyclic voltammetric electrodeposited polypyrrole and anthraquinone 2-sulfonate for an efficient electro-Fenton process

A novelty two-step synthesized porous carbon felt (PCF) cathode modified by cyclic voltammetric (CV) electrodeposited polypyrrole (Ppy) and anthraquinone 2-sulfonate (AQS) (PCF/Ppy/AQS) for an efficient electro-Fenton process has been investigated. Brunauer Emmett Teller (BET) and scanning electron microscope (SEM) measurements verified the three-dimensional porous structure of the PCF, revealing that the specific surface area was approximately 2.5 times higher than that of the bare carbon felt (CF), which ensured more active sites available for oxygen reduction reaction (ORR). In addition, the electrodeposited Ppy decreases the charge transfer resistance (R_ct) of the PCF cathode. AQS, a type of anthraquinone that can serve as an oxygen reduction catalyzer, could accelerate the ORR process and subsequently improve the performance of the electro-Fenton system. Rotating disk electrode (RDE) analysis confirmed that the ORR catalyzed by AQS was a double-electron reduction process, which contributed to hydrogen peroxide (H₂O₂) generation. The removal efficiency of total organic carbon (TOC) from Rhodamine B (RhB) could reach 51% within 1 h in the electro-Fenton system equipped with the PCF/Ppy/AQS, resulting in an improvement of approximately 24% compared with the bare CF cathode without porous treatment. The cycle experiment showed a good stability of the PCF/Ppy/AQS cathode. Additionally, the possible mechanism of degradation process in the electro-Fenton equipped with the PCF/Ppy/AQS cathode was proposed based on the electron paramagnetic resonance (EPR) analysis and quenching experiment. The novel fabricated PCF/Ppy/AQS provides an alternative as a high-efficiency cathode, yielding energy savings in the electro-Fenton system.     

A critical review of soil moisture measurement

Soil moisture content has paramount importance in dictating engineering, agronomic, geological, ecological, biological and hydrological characteristics of the soil mass. Though earlier researchers have employed various techniques of moisture content determination of soils, both in laboratory and in situ conditions, ascertaining the applicability of these techniques to soils of entirely different characteristics and the ‘types of moisture content’, which they can measure, is still a point of debate. As such, a critical review of all the established and emerging soil moisture measurement techniques with respect to their merits and demerits becomes necessary. With this in view, efforts have been made in this paper to critically evaluate all the soil moisture measurement techniques, limitations associated with them and the influence of various soil-specific parameters (viz., mineralogy, salinity, porosity, ambient temperature, presence of the organic matter and matrix structure of the soil) on the measured soil moisture content. This paper also highlights the importance of various innovations based on Micro Electro Mechanical Systems (MEMS) and nano-sensors that are emerging in this context.     

造粒流化床对不同形态污染物的强化去除

分别采用溶解性葡萄糖和颗粒性淀粉作为配水中的有机物,考察了混凝(烧杯试验)及造拉流化床时有机物的去除特性.研究表明,对于溶解性有机物(COD)而言,混凝对其去除效果非常有限,去除率仅为13.3% ,而大部分的颗粒性有机物可通过混凝作用去除;造粒流化床时溶解性有机物(COD)的去除率高达97.8% ,远远高于混凝及强化一级处理(CEPT)的.由于颗粒的形成,使得造粒流化床所去除的污染物不仅包括混凝可沉淀和可混凝但不可沉淀两部分,甚至还去除了相当一部分不可混凝的污染物,这是造粒流化床去除效率较高的原因.另外,颗粒的形成对于去除溶解性有机物的强化作用要明显高于对颗粒性有机物的.