Hydrogen Sulfide Gas Treatment by a Chemical‐Biological Process: Chemical Absorption and Biological Oxidation Steps

In order to remove high concentrations of hydrogen sulfide (H₂S) gas from anaerobic wastewater treatments in livestock farming, a novel process was evaluated for H₂S gas abatement involving the combination of chemical absorption and biological oxidation processes. In this study, the extensive experiments evaluating the removal efficiency, capacity, and removal characteristics of H₂S gas by the chemical absorption reactor were conducted in a continuous operation. In addition, the effects of initial Fe^2 + concentrations, pH, and glucose concentrations on Fe^2 + oxidation by Thiobacillus ferrooxidans CP9 were also examined. The results showed that the chemical process exhibited high removal efficiencies with H₂S concentrations up to 300 ppm, and nearly no acclimation time was required. The limitation of mass‐transfer was verified as the rate‐determining step in the chemical reaction through model validation. The Fe^2 + production rate was clearly affected by the inlet gas concentration as well as flow rate and a prediction equation of ferrous production was established. The optimal operating conditions for the biological oxidation process were below pH 2.3 and 35°C in which more than 90% Fe^3 + formation ratio was achieved. Interestingly, the optimal glucose concentration in the medium was 0.1%, which favored Fe^2 + oxidation and the growth of T. ferrooxidans CP9.     

固相萃取气相色谱法测定地表水中有机磷农药

建立了固相萃取(SPE)气相色谱火焰光度(GC-FPD)检测方法,并且检测了地表水中8种有机磷农药,检测限在0.09～0.26μg/L之间,相对标准偏差为3.1%～9.7%(n=8),加标回收率达到61.3%～103.2%,与传统的气相色谱法相比,该方法具有比较高的重现性和选择性,在地表水有机磷农药的测定中具有很好的应用前景.     

悬浮填料生物膜工艺的研究进展

悬浮填料生物膜工艺又称为移动床生物膜反应器工艺，是上世纪90年代初迅猛发展起来的一种新型水处理工艺．它既可以作为独立的生物处理系统，也能够与活性污泥法组合以增加后者的处理效能，还可以作为中高浓度工业废水的生物预处理手段．本文总结了悬浮填料生物膜工艺的流体力学、生化动力学规律、悬浮填料的开发现状，探讨了此工艺在市政生活污水、工业废水、低污染物浓度的水处理领域的研究和应用进展．进一步开发高效、廉价的功能型悬浮填料，提高填料的有效比表面积，优化与确定工艺和运行参数，将推动悬浮填料生物膜工艺在我国的全面应用．图3表1参64     

Sorption kinetic characteristics of polybrominated diphenyl ethers on natural soils

Sorption kinetic characteristics of BDE-28 and BDE-47 on five natural soils with different organic carbon fractions were investigated, and could be satisfactorily described by a two (fast and slow)-compartment first-order model with the ratio of rate constants ranged from 9 to 94 times. The fast compartment made a dominant contribution (71% ∼ 94%) to the total sorption amount in the whole process, and accounted for over 90% of the increase in the total sorption amount at initial 5 h. The influence of the slow compartment on the increase in the total sorption amount became principal (above 90%) in the subsequent stage approximately from 9 h or 25 h to the apparent equilibrium at 265 h. The results proposed the different sorption behaviors of the mathematically classified compartments for BDE-28 and BDE-47, which may correspond to the different soil components, such as soil organic fractions with amorphous and condensed structures, respectively.     

固定床中粒状脱硫剂除尘效率的研究

建立了非稳态过滤下的固定床颗粒层除尘效率模型.该模型尽可能地包含了影响固定床颗粒层除尘的参数,反映了沉积粉尘对除尘效率的影响;研究了以粒状脱硫剂为滤料的固定床在不同颗粒层厚度、空床气速、粒径下的除尘效率.结果表明,在颗粒层厚度为400～800 cm、空床气速≤0.4 m/s的条件下,颗粒层的除尘效率可达90％以上.     

以聚己内酯作为生物反硝化固体碳源的研究

为解决水体因低碳氮比而导致脱氮效率差的问题,将颗粒聚己内酯(PCL)重新塑形为阶梯环状,研究其作为反硝化过程的生物膜载体与固相碳源的反硝化性能。结果表明,在静态实验中,平均反硝化速率为8.57 mg NO3-N/(L·h);反硝化过程为零级反应。连续填充床实验中,超过90%的硝酸盐可被去除,出水NO2-N质量浓度低于0.20 mg/L;出水NH3-N质量浓度略有上升;出水溶解性有机碳(DOC)先上升后降低至1 mg/L左右。电子扫描显微镜扫描显示,PCL阶梯环反应表面空隙率较高,表面生物膜以杆菌为主,反应后被明显腐蚀;液相色谱检测显示PCL阶梯环分子量反应前后略有下降,其结构未受到破坏;表明该材料适合作为反硝化反应的碳源的同时,又可以作为载体供微生物附着生长。     

Limiting explosible concentration of hydrogen–oxygen–helium mixtures related to the practical operational case

This paper presents data on the limiting (minimum) concentrations of hydrogen in oxygen, in the presence of added helium, at elevated temperature and pressure related to the practical operational case. A 5 L explosion vessel, an ignition sub-system and a transient pressure measurement sub-system were used. Through a series of experiments carried out using this system, the limiting concentrations of hydrogen in oxygen and helium at different initial pressures and temperatures for the practical operational case were studied, and the influence of ignition energy and initial temperature on the limiting concentration of hydrogen in oxygen and helium was analyzed and discussed. The variation of ignition energy within the studied range is found to have a significant effect on the limiting concentration of hydrogen in oxygen and helium at lower initial temperature. However, when the ignition energy is higher than 32 mJ, the limiting hydrogen concentration remains almost changeless as the initial temperature increases from 21 °C to 90 °C. The limiting explosible concentration of hydrogen–oxygen–helium mixture decreases as the ignition energy increases when the initial temperature is lower. When the initial temperature is higher, the ignition energy has little effect on the limiting hydrogen concentration of hydrogen–oxygen–helium mixtures. When the initial temperature reaches 90 °C, the limiting hydrogen concentration remains almost changeless with an increase in ignition energy. The limiting explosible concentration of hydrogen in the mixtures, at the initial temperature of 21 °C and the ignition energy of 0.5 mJ, is 8.5% and that of oxygen is 11.25%.     

水稻和玉米的热氧化分解特性及几种动力学方法结果的比较

利用热重分析仪在空气气氛、不同的升温速率下对带壳稻谷粉和玉米粒粉进行了热重测试,依据热重实验数据,采用多种热解动力学分析方法计算了水稻和玉米的活化能数值并进行比较,结果表明水稻和玉米的热氧化反应活化能随着转化率出现先增加后降低的趋势,并在转化率为70%左右达到了极大值。     

火电厂石灰石-石膏脱硫设施环保验收监测若干问题的探讨

以"十一五"期间较为常见的火电厂石灰石-石膏脱硫设施竣工环保验收监测为例,着重就验收过程监测布点、设施处理效率计算、污染物总量核算、减排项目标准执行以及环境管理检查中存在的问题进行探讨,提出解决问题的方法与思路,为今后火电厂竣工环保验收监测工作提供借鉴。     

丝瓜瓤固定无花果曲霉吸附活性艳蓝KN-R的脱色研究

利用植物载体丝瓜瓤对无花果曲霉(Aspergillus ficuum)进行固定,并对活性艳蓝KN-R进行脱色研究探讨了固定化菌体的菌龄、pH、温度、菌量对染料脱色的影响.比较了固定化菌体与菌丝球对活性艳蓝KN-R的脱色效果,研究了该固定化菌体的重复利用和动力学实验,并进行了实际废水的脱色研究.结果表明,最佳脱色条件为菌龄3d,温度33℃,pH为6.0,菌量对染料脱色的影响依次为2%＞1%＞0.5%;固定化菌体对活性艳蓝KN-R的脱色效果优于菌丝球,且它对实际染料废水的脱色率均达80%以上;丝瓜瓤固定无花果曲霉对不同初始浓度(25～186mg·L-1)活性艳蓝KN-R的脱色过程遵循二级动力学方程;经6次重复利用后的该固定化菌体,其脱色率仍达80.79%.