利用啤酒废水培养极大螺旋藻

利用啤酒废水培养极大螺旋藻（Spirulina maxima）。研究了初始COD、DO、氮磷元素等培养条件对藻生物量（每mL培养液中极大螺旋藻的质量,以干重计）及废水水质的影响。实验结果表明：将废水稀释至COD=700 mg/L,控制DO=2.5 mg/L,并添加氮磷元素使废水的碳氮磷质量比为225∶15∶1,培养3 d,极大螺旋藻的藻生物量可达175.55 mg/L,即每吨啤酒废水可生产极大螺旋藻175.55 g;废水中COD,TN,NH₃-N,NO₃^-,TP的去除率分别达到85.43%,94.54%,74.66%,94.53%,61.54%。利用啤酒废水培养螺旋藻在收获极大螺旋藻生物质的同时,还能对废水起到一定程度的净化作用。     

Influence of the organic loading rate on the performance and the granular sludge characteristics of an EGSB reactor used for treating traditional Chinese medicine wastewater

The effects of the organic loading rate (OLR) on the performance and the granular sludge characteristics of an expanded granular sludge bed (EGSB) reactor used for treating real traditional Chinese medicine (TCM) wastewater were investigated. Over 90 % of the COD removal by the EGSB reactor was observed at the OLRs of 4 to 13 kg COD/(m³ day). However, increasing the OLR to 20 kg COD/(m³ day) by reducing the hydraulic retention time (HRT 6 h) reduced the COD removal efficiency to 78 %. The volatile fatty acid (VFA) concentration was 512.22 mg/L, resulting in an accumulation of VFAs, and propionic acid was the main acidification product, accounting for 66.51 % of the total VFAs. When the OLR increased from 10 to 20 kg COD/(m³ day), the average size of the granule sludge decreased from 469 to 258 μm. There was an obvious reduction in the concentration of Ca²⁺ and Mg²⁺ in the granular sludge. The visible humic acid-like peak was identified in the three-dimensional excitation-emission matrix (EEM) fluorescence spectra of the soluble microbial products (SMPs). The fatty acid bond, amide II bond, amide III bond, and C–H bond bending were also observed in the Fourier transform infrared (FTIR) spectra of the SMPs. Methanobacterium formicicum, Methanococcus, and Bacteria populations exhibited significant shifts, and these changes were accompanied by an increase in VFA production. The results indicated that a short HRT and high OLR in the EGSB reactor caused the accumulation of polysaccharides, protein, and VFAs, thereby inhibiting the activity of methanogenic bacteria and causing granular sludge corruption.     

湍球塔和喷淋塔的海水脱硫冷态实验对比

通过湍球塔和喷淋塔的海水脱硫冷态实验对比,研究海水脱硫过程中烟气和海水参数对湍球塔和喷淋塔脱硫的不同影响。实验结果表明,SO2分压力增大,脱硫效率和尾水pH值减小;海水碱度、pH值和液气比增大,脱硫效率和尾水pH值也随之增大;湍球塔的脱硫效率和尾水pH值与液气比改变方式无关,实验用湍球塔的合适液气比值为2.3 L/m3;湍球塔脱硫实验中,塔内气速为1.58 m/s,SO2分压力为20 Pa,水温为10.2℃,液气比为1.1~2.8 L/m3时,尾水pH值在2.4~2.8之间;增大液气比时,喷淋塔改变海水流量的脱硫效果要比改变气体流量的脱硫效果明显;塔内气速1 m/s以上时,一级喷淋塔的脱硫效率要比湍球塔小很多,有时只有湍球塔的1/2左右。     

Boiler Briquette Coal versus Raw Coal: Part II—Energy,Greenhouse Gas,and Air Quality Implications

ABSTRACT

The objective of this paper is to conduct an integrated analysis of the energy, greenhouse gas, and air quality impacts of a new type of boiler briquette coal (BB-coal) in contrast to those of the raw coal from which the BB-coal was formulated (R-coal). The analysis is based on the source emissions data and other relevant data collected in the present study and employs approaches including the construction of carbon, energy, and sulfur balances. The results show that replacing R-coal with BB-coal as the fuel for boilers such as the one tested would have multiple benefits, including a 37% increase in boiler thermal efficiency, a 25% reduction in fuel demand, a 26% reduction in CO₂ emission, a 17% reduction in CO emission, a 63% reduction in SO₂ emission, a 97% reduction in fly ash and fly ash carbon emission, a 22% reduction in PM_2.5 mass emission, and a 30% reduction in total emission of five toxic hazardous air pollutant (HAP) metals contained in PM₁₀. These benefits can be achieved with no changes in boiler hardware and with a relatively small amount of tradeoffs: a 30% increase in PM₁₀ mass emission and a 9–16% increase in fuel cost.     

某饮用水处理厂中5种抗生素的去除

通过对美国某饮用水厂处理工艺和对象的介绍,研究各处理单元对克拉霉素(clarithromycin,CLA)、脱水红霉素(erythromycin-H2O,ERY)、左氧氟沙星(levofloxacin,LEV)、新诺明(sulfamethoxazole,SUL)和甲氧苄啶(trimethoprim,TRI)等5种目标抗生素的去除规律;从目标抗生素的残留和各处理单元的去除率角度分别分析时间和空间对去除规律的影响,并探讨抗生素和常规水质参数去除率间的相关关系。研究发现,原水中5种抗生素的平均浓度范围为0～26.8 ng/L,出水降至0～2.3 ng/L,该水厂工艺对5种抗生素的总去除率可达79.5%,其中CLA、ERY、LEV、SUL和TRI的去除率分别为92.8%、24%、100%、85.7%和53.2%;不同采样时间各采样点的抗生素浓度均呈现出秋季高的特点,但各处理单元的处理效率在不同的季节却表现出很大的差异;CLA可作为抗生素总量变化趋势预测的"指示抗生素";抗生素的总量浓度和总去除率与UV254的浓度及去除率之间有很好的正相关性,可以通过对UV254值的测定和去除率的计算来预测抗生素浓度的大小和去除率变化趋势。该研究从抗生素去除角度为我国新建和改扩建饮用水厂工艺提供较好的理论依据。     

温度和污泥浓度对碱性条件下剩余污泥水解酸化的影响

挥发性脂肪酸(VFAs)是脱氮除磷过程中易于利用的碳源。剩余污泥在碱性条件下发酵能产生大量的VFAs,而温度和污泥浓度是影响剩余污泥发酵的两个重要因素,为此考察了厌氧环境,温度15℃和35℃,pH为10的条件下,剩余污泥挥发性悬浮污泥浓度(VSS为1.708～11.049 g/L)对水解酸化的影响,为实现剩余污泥的资源化提供理论依据。研究得出如下结论:污泥浓度对剩余污泥溶解性化学需氧量(SCOD)溶出率影响不大。低污泥浓度和高污泥浓度均不利于剩余污泥产酸,最佳产酸的污泥浓度为8.540 g/L。各污泥浓度条件下产生的6种挥发性有机酸中乙酸的比例总是最大,且低污泥浓度条件下乙酸的百分含量要高于高污泥浓度条件下。温度对高污泥浓度条件下污泥的最大SCOD溶出量影响较大,而对低污泥浓度条件下污泥最大的产酸量影响较大。无论15℃还是35℃,中等污泥浓度对氨氮的释放量影响不大,35℃条件下污泥浓度对正磷酸盐的释放要比15℃条件下大。     

Stabilization of sewage sludge in the presence of nanoscale zero-valent iron (nZVI): abatement of odor and improvement of biogas production

The potential benefits of nanoscale zero-valent iron (nZVI) on sludge stabilization, either the abatement of odor or the improvement of biogas production, were investigated in this study. Two commercial-grade microscale iron powders were also utilized for comparison. Adding 0.10 wt% of nZVI in sludge during anaerobic incubation significantly reduced the concentration of H₂S in biogas by 98.0 % (96.2–98.9 %), probably attributed by reactions between sulfides and the neo-formed hydrous Fe(II)/Fe(III) oxides layer at the surface of ZVI nanoparticles. Meanwhile, the percentage of P in bioavailable fractions decreased from 76.8 to 52.5 %, possibly due to the formation of vivianite [Fe₃(PO₄)₂]. Furthermore, 0.10 wt% of nZVI in anaerobic digestion for 17 days enhanced the concentration of CH₄ in biogas by 5.1–13.2 % and improved the production of biogas and methane by 30.4 and 40.4 %, respectively. The amendment of iron nanoparticles during anaerobic digestion can not only effectively reduce H₂S in biogas, but also potentially boost methane production significantly.     

活性污泥法处理炼油碱渣废水

采用活性污泥法对某炼油厂预处理后的碱渣废水进行了处理。以目标废水为碳源对活性污泥进行了成功驯化,然后用驯化后的活性污泥对炼油碱渣废水进行净化处理,以降低其COD(化学需要氧量)值。实验结果表明,活性污泥生化处理对炼油碱渣废水的COD值具有较高的降低作用。在水力停留时间为24 h的条件下,COD的平均去除率可达76%,容积负荷为0.7 kg COD/(m3·d)左右,运行10 d后,COD总去除率可达74%左右,出水水质达到国家三级排放标准(GB 8978-1996)。     

填料表面亲水改性对MBBR处理船舶生活污水的影响

为研究填料表面亲水改性对移动床生物膜反应器(MBBR)处理废水的影响,考察了氧化处理、酸处理和碱处理3种亲水改性方法所得不同聚丙烯K1型填料(水的液面接触角分别为41°、62°和75°,未处理填料为87°)对模拟船舶生活污水的处理效果。结果表明,亲水性越强,挂膜量越多,膜结构越致密。在亲水性较低的情况下,挂膜量是限制污水处理的主要因素,亲水性越强污水处理效果越好;在亲水性较高的情况下,膜结构成为污水处理的限制因素,亲水性增强对水处理有不利影响。比较不同亲水性填料的污水处理结果可知,表面酸处理所得接触角为62°的填料污水处理效果相对最好,COD和氨氮的平均去除率分别为87%和61%;其次依次为液面接触角41°、75°和87°的填料。     

微波辅助光催化降解阿特拉津的表观动力学

以内分泌干扰物阿特拉津为目标物,建立循环流化床微波辅助光催化体系,研究其微波辅助光催化降解规律。表观动力学研究发现,当阿特拉津初始浓度较低时,其在微波辅助光催化体系中的降解符合表观一级反应动力学特征。降解反应速率常数与阿特拉津初始浓度呈负线性相关,与紫外光强呈正线性相关,与催化剂浓度呈抛物线性相关。表观反应速率常数kobs=3.95×10-4c-0.27030I1.2224W0.3283,该模型计算值与实验值吻合较好,平均相对偏差仅为0.5%,可用于预测微波辅助光催化降解低浓度有机污染物的反应规律。