Hexavalent Chromium Adsorption from Aqueous Solution by Agricultural Waste Materials

Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out to study the adsorption kinetics mechanism of Cr(Ⅵ) effect of adsorbent dosage, pH, contact time, and temperature. The best results are obtained at 15g/L adsorbent concentration, 60min contact time, 298K temperature, and 50mg/L adsorbate initial concentration at pH 2. The adsorption isotherms, using initial concentrations of Cr(Ⅵ) between 10 and 500mg/L for the Cr(Ⅵ) removal, show the maximum metal uptake capacities of adsorbent were 10.48, 6.71, and 8.54mg/g for WS, RH, and PH, respectively. And the adsorption data fitted well to the Langmuir adsorption isotherm for WS, RH, and PH with correlation coefficients of 0.9862, 0.9723, and 0.9714, respectively. Moreover, the FTIR analysis of WS, RH, and PH before and after adsorption of Cr(Ⅵ) suggested that Cr ions were combined to some functional groups of compounds contained in these materials.     

城镇生活污水人工绿地处理技术及其应用

由于工农业的快速发展，我国水资源紧缺和水污染问题十分严重。一方面大量的淡水资源被浪费．另一方面水体污染日益加剧。尽管城市工业废水的产生得到了一定的控制，但以生活污水、养殖废水和农村化学品流失为主要污染物的非点源污染又呈现迅速上升的趋势，而且更加难以控制。     

水处理新技术和水资源管理

厦门是一座缺水城市。人均水资源占有量约为全国的40％。主城区是海岛，原水80％靠外来水源调配。推进水资源的节约和综合利用对于厦门保持良好的生态环境、提升城市竞争力、建设和谐厦门，最终实现厦门经济、社会、环境的协调和可持续发展具有极其重要的意义。     

厦门龙舟三池水体氮磷的污染状况及来源分析

对厦门龙舟三池水体、底泥和周围排污口进行了监测,监测指标主要为pH、溶解氧、氨态氮、亚硝态氮、硝态氮、总氮、总磷和叶绿素8个理化指标,并对龙舟三池氮磷污染状况和来源进行了分析.结果表明:龙舟三池水体呈弱碱性;水体和底泥中氮磷营养元素浓度较高,其主要污染物来源为外海来水;外海来水和内池水体处于富营养状态,龙舟池和中池具有...     

红壤对三氮吸附-解吸性能实验研究

以厦门市农田土壤为研究对象,通过室内吸附实验,分析了土壤对三氮的吸附性能,并探讨了氯离子对吸附行为的影响.实验结果表明:红壤对氨态氮具有明显的吸附作用,吸附等温线符合Henry线性等温吸附模型;对亚硝态氮以解吸为主;对硝态氮明显表现为解吸作用;在氯离子作用下,水土体系中有亚硝化作用发生,而硝化作用则明显受到了抑制.在氮素数学模型中,在不考虑亚硝态氮的前提下,对氨态氮需考虑吸附常数,而对硝态氮则需考虑解吸常数.对盐渍化或滨海土壤中三氮迁移转化进行研究时,还要考虑氯离子对三氮迁移转化的影响.     

复配调理剂对茶园土壤质量和茶叶品质的改良效果

以复配调理剂（50%生物炭+25%牡蛎壳粉+25%鸟粪石）为试验材料，在土壤酸化茶园进行田间试验，探究复配调理剂对土壤和茶叶品质的改良效果。设置CK组和T1～T3处理组，分别施加土壤调理剂0，1 500，3 000，4 500 kg/hm2进行试验。结果表明:与对照组相比，施用调理剂可提高土壤pH值和有机质、有效磷、速效钾的含量，分别提高了0.68~1.55，26.80~37.00 g/kg，22.82~39.18 mg/kg，86.23~108.04 mg/kg。同时，施加调理剂后，茶叶水浸出物和游离氨基酸含量增加，茶多酚含量降低，酚氨比下降，Cd、Cr、As和Pb含量在残留限量规定范围内。可见，施加复配调理剂可增加土壤肥力，提高茶叶的品质。