Simultaneous removal of CO2, NOx and SOx using single stage absorption column

Capturing flue gases often require multiple stages of scrubbing, increasing the capital and operating costs. So far, no attempt has been made to study the absorption characteristics of all the three gases (NO, SO₂ and CO₂) in a single stage absorption unit at alkaline pH conditions. We have attempted to capture all the three gases with a single wet scrubbing column. The absorption of all three gases with sodium carbonate solution promoted with oxidizers was investigated in a tall absorption column. The absorbance was found to be 100% for CO₂, 30% for NO and 95% for SO₂ respectively. The capture efficiency of sodium carbonate solution was increased by 40% for CO₂ loading, with the addition of oxidizer. Absorption kinetics and reaction pathways of all the three gases were discussed individually in detail.     

超声波预处理对厌氧生物制氢的可行性探讨

由于能实现废弃物资源化,减少环境污染,制取清洁能源氢气,生物厌氧发酵制氢技术日益受到人们关注。在众多废水生化预处理技术中,超声波技术拥有高效氧化、焚烧、超临界氧化的特点,而且超声波操作简单,对设备的要求不高。本文阐述了厌氧发酵生物制氢的菌种来源、产氢机理及超声波技术在废水处理方面的应用。同时探讨了超声波预处理猪场废水对提高厌氧发酵生物产氢量的可行性,提出了优化性建议。     

Sulfur-oxidizing autotrophic and mixotrophic denitrification processes for drinking water treatment: elimination of excess sulfate production and alkalinity requirement

The activity of copper oxide, titanium carbide and silicon nitride nanoparticles for the oxidative degradation of environmentally relevant concentrations (μg L⁻¹ range) of enrofloxacin - an important veterinary antibiotic drug - in aqueous solutions was investigated. With hydrogen peroxide as an oxidative agent, both copper oxide and titanium carbide decrease the concentration of enrofloxacin by more than 90% over 12 h. Addition of sodium halide salts strongly increases the reaction rate of copper oxide nanoparticles. The mechanism for the formation of Reactive Oxygen Species (ROS) was investigated by Electron Spin Resonance (ESR).     

双氧水催化氧化中Cu/γ-Al_2O_3催化剂的稳定性研究

针对废水湿式双氧水催化氧化,采用浸渍法制备Cu催化剂,研究非均相Cu催化剂在常温常压湿式双氧水催化氧化中的稳定性与失活问题。研究表明,催化剂制备条件及催化氧化反应条件对催化剂中Cu2＋溶出均有影响。研究同时表明,催化剂失活与活性组分流失和活性组分被有机中间产物覆盖有关,高温焙烧可对催化剂再生。     

磷酸氢二钠-柠檬酸缓冲溶液调控下白菜对钼矿区重金属污染土壤的修复

采用ICP-AES分析土壤及植物体中各种重金属元素的含量,研究了在磷酸氢二钠-柠檬酸缓冲溶液在其不同浓度梯度下投加,白菜地上部分对钼矿区重金属污染土壤的修复潜力。结果表明:投加磷酸氢二钠-柠檬酸缓冲溶液的条件下均能显著提高白菜的地上部分富集土壤中重金属元素的能力(Cd除外),但缓冲溶液对白菜积累重金属能力的促进作用也存在重金属元素种类及浓度梯度之间的差异;投加磷酸氢二钠-柠檬酸缓冲溶液可以提高白菜对土壤中重金属的富集系数(Hg、Mo、Zn最为显著)。     

Estimating source strengths of HCl and SO2 emissions in the flue gas from waste incineration

HCl and SO_2 emission is one of the major concerns related to municipal solid waste incinerator(MSWI). In this study, a material flow analysis model was developed to estimate the HCl and SO_2 concentrations in the MSWI flue gases(FGs), and their concentrations in the full-scale MSWI were monitored. The calculated concentrations of HCl and SO_2 in the FG were 770–1300 mg/Nm~3 and 150–640 mg/Nm~3, respectively, in close agreement with the monitored values. More than 99% of Cl and 92% of S from the FG were captured into solid residues by the air pollution control(APC) systems. Moreover, since only 48.4%–67.5% of Cl and 21.3%–53.4% of S were transferred to the FG from the municipal solid waste(MSW), it was more reliable to estimate the source strengths and release amounts of HCl and SO_2 in the FG based on the amounts of Cl and S in the APC residues(AR) and exhaust gas rather than in the MSW. This simple method is easily applicable and the estimated results could provide scientific basis for the appropriate design and operation of the APC systems as well as corrosion control of heat recovery systems.