NDA-100大孔树脂对水溶液中水杨酸的吸附行为研究

通过静态吸附试验，研究了NDA－100大孔树脂对水溶液中水杨酸的吸附动力学及热力学特性，结果表明吸附符合一级动力吸附方程，颗粒内扩散过程是影响吸附速率的主要控制步骤，吸附符合Langmuir和Freundlich等温吸附方程，吸附为放热的物理吸附过程。     

降解酚的根瘤菌的研究

对两铢以铺代谢方式降解酚和离体固氮的根瘤菌(代号为:101-3,97-1)的特性进行了研究,其耐酚能力在1200ppm内,五天内能在完全培养基中把300ppm苯酚降解完;在含酚培养基中多次传代后,生长周期加快、产气,而结瘤特性丧失,但离体固氮酶活性比原菌株略有增加。经60ppm的吖啶橙处理后,获得的无质粒菌株,其降解酚的能力和结瘤特性完全消失,TTC(3-苯基-4-氮唑化氯)还原性增加,而革兰氏染色反应、运功性不变。     

Pb(II) removal from water using Fe-coated bamboo charcoal with the assistance of microwaves

Bamboo charcoal(BC) was used as starting material to prepare iron-modified bamboo charcoal(Fe-MBC) by its impregnation in FeCl 3 and HNO 3 solutions simultaneously,followed by microwave heating.The material can be used as an adsorbent for Pb(Ⅱ) contaminants removal in water.The composites were prepared with Fe molar concentration of 0.5,1.0 and 2.0 mol/L and characterized by means of N 2 adsorption-desorption isotherms,X-ray diffraction spectroscopy(XRD),scanning electron microscopy coupled with energy dispersive X-ray spectrometry(SEM-EDS),Fourier transform infrared(FT-IR) and point of zero charge(pH pzc) measurements.Nitrogen adsorption analyses showed that the BET specific surface area and total pore volume increased with iron impregnation.The adsorbent with Fe molar concentration of 2 mol/L(2Fe-MBC) exhibited the highest surface area and produced the best pore structure.The Pb(Ⅱ) adsorption process of 2Fe-MBC and BC were evaluated in batch experiments and 2Fe-MBC showed an excellent adsorption capability for removal Pb(Ⅱ).The adsorption of Pb(Ⅱ) strongly depended on solution pH,with maximum values at pH 5.0.The ionic strength had a significant effect on the adsorption at pH < 6.0.The adsorption isotherms followed the Langmuir isotherm model well,and the maximum adsorption capacity for Pb(Ⅱ) was 200.38 mg/g for 2Fe-MBC.The adsorption processes were well fitted by a pseudo second-order kinetic model.Thermodynamic parameters showed that the adsorption of Pb(Ⅱ) onto Fe-MBC was feasible,spontaneous,and exothermic under the studied conditions,and the ion exchange mechanism played an significant role.These results have important implications for the design of low-cost and effective adsorbents in the removal of Pb(Ⅱ) from wastewater.     

Reduction of hexavalent chromium with scrap iron in a fixed bed reactor

The reduction of hexavalent chromium by scrap iron was investigated in continuous long-term fixed bed system. The effects of pH, empty bed contact time (EBCT), and initial Cr(VI) concentration on Cr(VI) reduction were studied. The results showed that the pH, EBCT, and initial Cr(VI) concentration significantly affected the reduction capacity of scrap iron. The reduction capacity of scrap iron were 4.56, 1.51, and 0.57 mg Cr(VI)·g^-1 Fe⁰ at pH 3, 5, and 7 (initial Cr(VI) concentration 4 mg·L^-1, EBCT 2 min, and temperature 25°C), 0.51, 1.51, and 2.85 mg Cr(VI)·g^-1 Fe⁰ at EBCTs of 0.5, 2.0, and 6.0 min (initial Cr(VI) concentration 4 mg·L^-1, pH 5, and temperature 25°C), and 2.99, 1.51, and 1.01 mg Cr(VI)·g^-1 Fe⁰ at influent concentrations of 1, 4, and 8 mg·L^-1 (EBCT 2 min, pH 5, and temperature 25°C), respectively. Fe(total) concentration in the column effluent continuously decreased in time, due to a decrease in time of the iron corrosion rate. The fixed bed reactor can be readily used for the treatment of drinking water containing low amounts of Cr(VI) ions, although the hardness and humic acid in water may shorten the lifetime of the reactor, the reduction capacity of scrap iron still achieved 1.98 mg Cr⁶⁺·g^-1 Fe. Scanning electron microscope equipped with energy dispersion spectrometer and X-ray diffraction were conducted to examine the surface species of the scrap iron before and after its use. In addition to iron oxides and hydroxide species, iron-chromium complex was also observed on the reacted scrap iron.     

High zinc removal from water and soil using struvite-supported diatomite obtained by nitrogen and phosphate recovery from wastewater

Zinc is known as an essential element of human life. However, excessive zinc discharge into water and soil causes water pollution, leading to serious health issues such as septicemia, meningitis and iron-deficiency anemia. Here, a novel material made of struvite-supported diatomite was obtained from eutrophic water treated by mesoporous MgO-modified diatomite. This material was applied for zinc remediation in aqueous solutions and contaminated soils to test the reuse of P-containing products. Struvite-supported diatomite was characterized by field emission scanning electron microscopy and X-ray diffraction. Results show that the maximum removal efficiency of Zn(II) from wastewater streams reached 90.54% at an initial pH of 5 and struvite-supported diatomite dosage of 0.3 g/L. Moreover, the X-ray diffraction patterns of precipitates after Zn(II) sorption show that the combination between zinc and the phosphate group played a key role for zinc removal in solution. For Zn-contaminated soils amended with 10% struvite-supported diatomite, available Zn decreased by 65.38% and acid soluble Zn decreased by 56.9% after 56 days.     

悬浮填料移动床处理苏州河支流河水试验研究

采用悬浮填料移动床工艺处理苏州河支流河水 ,试验结果表明 ,填料填充率为 5 0 % ,水力停留时间为 1h ,进水CODCr44— 2 32mg/L ,BOD519— 10 1mg/L时 ,出水CODCr34.1mg/L ,BOD59.1mg/L。在适宜的水温条件下 ,进水氨氮≤30mg/L ,水力停留时间为 1.5h ,亦能取得较好的氨氮去除效果     

Biosorption of Direct Black 38 by dried anaerobic granular sludge

The biosorption of Direct Black 38 by dried anaerobic granular sludge in a batch system under specific temperatures and initial pH was investigated. The adsorption reaction is pH dependent with higher removal at low pH. The adsorption equilibrium data fit very well with both Langmuir and Freundlich models in the concentration range of Direct Black 38 at all chosen temperatures. The adsorption parameters show that the adsorption of Direct Black 38 is an endothermic and more effective process at high temperatures. The kinetics of adsorption was found to be second order and adsorption rate constants increased with increasing temperature. Activation energy was determined as 26.8 kJ/mol for the process. This suggests that the adsorption of Direct Black 38 by dried anaerobic granular sludge is chemically controlled.     

微波辅助氢氧化钠改性竹炭对水溶液中铜离子的吸附

以竹炭为原料,NaOH为改性药剂,采用微波辅助加热的方法对竹炭进行改性,并利用SEM、EDAX、BET、FTIR、pHzpc和Boehm滴定等方法对改性前后的竹炭进行表征.考察了溶液pH、吸附时间、温度和离子强度等对改性竹炭吸附Cu2+的影响.结果表明微波辅助NaOH改性提高了竹炭的比表面积,增加了其表面含氧官能团和总碱基的数量;改性竹炭吸附Cu2+的最佳pH值约为5,吸附过程符合拟二级动力学模型,Langmuir吸附等温方程比Freundlich方程更适合描述Cu2+在改性竹炭上的吸附行为,吸附为放热的物理吸附过程.     

嗜冷杆菌(Psychrobacter sp.)微生物传感器毒性分析性能研究

采用嗜冷杆菌(Psychrobacter sp.)微生物传感器毒性分析系统,对Hg2+、Cu2+、Zn2+、Cr6+、Cd2+、Pb2+、Co2+等重金属和邻氯苯酚(2-CP)、2,4-二氯酚(2,4-DCP)、邻硝基酚(2-NP)、对硝基酚(4-NP)、四环素、十二烷基苯磺酸钠(LAS)等有机物的生物急性毒性进行分析.试验结果表明,基于对数生长后期和稳定期的Psychrobacter sp.微生物传感器具有良好的毒性分析性能,呼吸基质盐度低于10%和pH=5～10时,对Psychrobacter sp.微生物传感器的分析性能影响不明显.测试得到Cd2+、Zn2+、Cr6+、Cu2+、Hg2+和Pb2+对Psychrobacter sp.的半数有效浓度(EC50)分别为47.3、10.9、14.0、2.6、0.8和100.1mg·L-1,Co2+的30%有效浓度(EC30)为56.6mg·L-1;4-NP、2,4-DCP、四环素和LAS的EC50分别为424.4、163.8、103.5和754.6mg·L-1,2-NP和2-CP的EC30值分别为249.23和195.6mg·L-1.     

Low-temperature preparation of a N-TiO2/macroporous resin photocatalyst to degrade organic pollutants

Environmental Chemistry Letters - Highly active TiO2 photocatalysts prepared at a low temperature are promising reagents to degrade organic pollutants. &nbsp;Moreover, the addition of...