多组分电镀污泥酸浸出液中铁的分离

研究了采用Ｐ５０７－煤油－Ｈ２ＳＯ４萃取体系分离电镀污泥酸浸出液中Ｆｅ＾３＋的工艺，确定了从含有多种上金属组分的硫酸溶液中萃取铁的最佳工艺条件以及负载有机相反萃取较优工艺条件，研究结果表明，以Ｐ５０７为萃取剂，硫酸为洗涤剂，经３级萃取、２级洗涤的分馏萃取后，可以从含有多种金属组分的硫酸溶液中分离出９９．９％的铁，其他金属的流失量小于１％，不影响后者的回收，铁在工艺过程中以ＦｅＣｌ３·６Ｈ２Ｏ的形式     

FTIR研究非完全脱乙酰甲壳质对金属离子的吸附机理

以傅立叶交换红外光谱(FTIR)法研究了非完全脱乙酰甲壳质(NCTS)与Cu~ (2+),Ni~(2+),Co~(1+),Zn~(2+),Cd(2+),Hg~(2+),Ag~+,Pb~(2+)等八种金属离子形成的配合物的结构特征,并对各配合物在4000—400cm~(-1)范围内的主要吸收带作了经验归属.研究结果表明,在NCTS的金属离子配合物中,除—NH_2,—OH参予了配位外,羰基((?)C=O)和酰胺基(—CONH—)亦在不同程度上参予了配位;NCTS对Hg~(2+),Ag~+的吸附过程中存在着明显的氧化还原现象,Hg~(2+),Ag~+,分别被还原为Hg_2~(2+)和Ag~0,而NCTS分子中的—CH_2OH有可能被氧化成—COOH.     

Catalytic fast pyrolysis of Kraft lignin with HZSM-5 zeolite for producing aromatic hydrocarbons

Catalytic fast pyrolysis (CFP) of Kraft lignins with HZSM-5 zeolite for producing aromatics was investigated using analytical pyrolysis methods. Two Kraft lignins were fast pyrolyzed in the absence and presence of HZSM-5 in a Curie-point pyrolyzer. Without the catalyst, fast pyrolysis of lignin predominantly produced phenols and guaiacols that were derived from the subunits of lignin. However, the presence of HZSM-5 changed the product distribution dramatically. As the SiO₂/Al₂O₃ ratio of HZSM-5 decreased from 200 to 25 and the catalyst-to-lignin ratio increased from 1 to 20, the lignin-derived oxygenates progressively decreased to trace and the aromatics increased substantially. The aromatic yield increased considerably as the pyrolysis temperature increased from 500°C to 650°C, but then decreased with yet further increase of pyrolysis temperature. Under optimal reaction conditions, the aromatic yields were 2.0 wt.% and 5.2 wt.% for the two lignins that had effective hydrogen indexes of 0.08 and 0.35.     

H2O2预氧化对负载铁制备污泥炭基催化剂效能的影响

以城市污水厂二沉池污泥为原料,考察了不同H_2O_2投加量下污泥预氧化对铁负载污泥形成前驱体及其热解后制得炭基催化剂性能的影响,研究了污泥预氧化对强化铁负载制备均一分散型污泥炭基催化剂的机理.结果表明,污泥预氧化促进了污泥细胞破解,降低了絮体颗粒粒径和表面Zeta电位,使铁负载量增加、铁活性位点在污泥载体上的分散性明显增强,形成炭基催化剂保持着高催化活性,其稳定性显著增加.对模拟含铬黑T染料废水的多相芬顿降解试验说明,当污泥预氧化H_2O_2投加量为2.25%时制备的炭基催化剂,其反应120 min后铬黑T的降解率为91%,略低于未预氧化时污泥炭基催化剂的降解效率(96%);但未预氧化炭基催化剂其反应后溶液中铁离子的溶出量(18.9%)远高于预氧化后形成的催化剂(2.5%),且后者循环3次对铬黑T的降解率仍可达到86%,表现出较强的稳定性.     

Effect of liming and seasonal variation on lead concentration of tea plant (Camellia sinensis (L.) O. Kuntze)

Tea is a widely consumed beverage. However, recent studies revealed that there were an increasing number of cases of tea products exceeding the former maximum permissible concentration (MPC) in China for Pb (2 mg kg(-1)). Tea Pb contamination is an issue affecting trade and consumer confidence. Root uptake of Pb could contribute significantly to Pb accumulation in tea leaves due to the strong acidity of many tea garden soils. We conducted pot and field experiments to evaluate the effect of liming on Pb uptake by tea plants on two highly acidic soils (pH3.6). Additions of CaCO(3) significantly increased soil pH by up to 1 unit and decreased soil extractable Pb by up to 32%. Liming resulted in a decrease in the proportion of Pb in the exchangeable and carbonate-bound fractions, with a concurrent increase in the fractions bound to Fe/Mn oxides and residues. Liming significantly decreased Pb concentrations of fine roots, stems and new shoots of tea plants in the pot experiment. In the field experiments, the effect of liming was not significant during the first year following CaCO(3) application, but became significant during the second and third years and Pb concentration in the new shoots was decreased by approximately 20-50%, indicating that liming of acidic tea garden soils is an effective way to reduce Pb contamination of tea. The study also reveals a distinct seasonal variation, with Pb concentration in the new shoots following the order of spring>autumn>summer.     

蓝藻与污泥混合厌氧发酵产沼气的初步研究

为了实现太湖蓝藻打捞后的快速处置,对厌氧颗粒污泥、消化污泥、剩余污泥与蓝藻混合厌氧发酵产沼气进行了研究。结果表明,蓝藻与污泥混合可以有效促进沼气发酵。在蓝藻与厌氧颗粒污泥物料比为6∶1时,产气效果最佳,沼气产率为73 mL/g VS,平均甲烷含量为69%,最大产气速率为138 mL/d,累计产甲烷量为50 mL CH₄/g干物质,分别是蓝藻与消化污泥、剩余污泥混合发酵时的1.5倍和2.3倍。厌氧颗粒污泥、消化污泥、剩余污泥与蓝藻混合,其VS降解率为11.40%～13.73 %,COD减少了27.97%～46.38%。厌氧发酵对蓝藻藻毒素的含量有较大影响,分别从356、366和244 μg/L降低到检测限5 μg/L 以下。     

南京外秦淮河河岸带原生植被初步调查

对南京外秦淮河河岸带原生植被进行了初步调查.外秦淮河河岸带原生植被共有28科、50属、53种,其中漂浮植物4种,占7.55%,沉水植物1种,占1.89%,挺水和湿生植物13种,占24.53%,陆生草本和藤本植物24种,占45.28%,乔木和灌木11种,占20.75%.在概括外秦淮河自然环境和分析原生植被主要特征的基础上,提出在进行河岸带植被群落重建时应注重闸下段河岸带植被群落的重建,增加沉水植物、浮叶植物和观赏性植物的种植.另外,植被群落可按河道垂向的常水位以下区域、变化水位区域和洪水位以上区域来构建.     

呼和浩特学生尿中1—羟基芘的抽样分析

用反相高压液相色谱对呼市小学生及对照点草原牧民尿中的１－羟基芘进行测定,同时测定两地区大气颗粒物及空气中多环芳烃的含量。结果表明,市区小学生尿中１－羟基芘的浓度采暖季节高于非采暧季节;且显著高于对照点的浓度;尿中１－羟基芘的浓度与空气中全态多环芳烃（ＰＡＨｓ）的代表化合物芘或ＢａＰ有很好的正相关。     

Degradation of Polypropylene by the Pseudomonas aeruginosa Strains LICME WZH-4 and WGH-6

Journal of Polymers and the Environment - In the present study, two strains of Pseudomonas aeruginosa, WZH-4 and WGH-6, were isolated based on their ability to survive with polypropylene (PP) as...