木材燃烧过程气相中长寿命自由基的研究

利用研制的防火液对木材进行阻燃处理,通过ＥＳＲ自旋捕捉技术和热分析仪考察其燃烧特性,对木材燃烧后长寿命自由基进行研究。实验结果表明,阻燃处理后木材的燃烧过程中长寿命自由基浓度下降,同时阻燃剂加速木材的热分解,对木材有较好的阻燃效果     

Visual determination of nitrite and nitrate in waters by color band formation method

A spot test for aqueous nitrate and nitrite for controlling nitrogen removal performance in small-scale wastewater treatment facilities is proposed. In this method, NO(2)(-) ion in water samples was allowed to react with sulfanilic acid and 1-naphthol to form an anionic azo dye. The resulting colored solution was introduced onto a mini column (similar to a gas detecting tube) packed with PVC particles coated with benzyl cetyl dimethyl ammonium chloride (BCDMA) and biphenyl. The NO(2)(-)-N concentration was determined visually by measuring the color band length (CBL) in the column. The CBL correlates linearly with nitrite concentration in the 4-20 mg-N l(-1) range. The concentration of nitrite+nitrate was determined after reduction to nitrite with zinc. The concentration of NO(3)(-)-N species was calculated by difference. This method was used to visually determine the concentrations of NO(2)(-)-N and (NO(2)(-)+NO(3)(-))-N in domestic wastewater samples with maximum suspended solid (SS) and chemical oxygen demand (COD) concentrations of 114 mg l(-1) and 73.9 mg l(-1), respectively.