Distribution of aromatic amines,phenols, chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China

• The total organic pollutant concentrations in sediment were 27.4-1620 ng/g. • The phenol concentrations were relatively high in the sediment of the Dianchi Lake. • Average total concentrations decreased as follows: Caohai>Waihai>Haigeng Dam. • 1,4-dichlorobenzene, 3- or 4-methylphenol, 1,2,4-trichlorobenzene might be risks. Organic pollutants are widespread environmental pollutants with high toxicity, persistence, and bioaccumulation. Our aim was to investigate the distribution of aromatic amines, phenols, chlorobenzenes, and naphthalenes in the surface sediment of the Dianchi Lake, China. Nineteen surface sediment samples were collected from the Dianchi Lake, and 40 types of organic pollutants were analyzed via gas chromatography–mass spectrometry. The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62 × 10³ ng/g. The concentrations of phenols were much higher than those in other water bodies but still within a controllable range, whereas the concentrations of the other organic pollutant classes were similar or even lower. The detection ratio of 3- or 4-methylphenol was the highest (100.00%) among the pollutants. The average total organic pollutant concentrations decreased in the following order: Caohai (540 ng/g)>the middle of Waihai (488 ng/g)>the edge of Waihai (351 ng/g)>Haigeng Dam (90.4 ng/g). Pearson analysis showed a strong correlation among 1-methylnaphthalene, 2-methylnaphthalene, 1,3-dinitronaphthalene, and 1,4-dinitronaphthalene (p<0.01). Caohai, the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration; meanwhile, 1,4-dichlorobenzene, 3- or 4-methylphenol and 1,2,4-trichlorobenzene were more likely to cause risks.     

Occurrence and removal of polycyclic aromatic hydrocarbons and their derivatives in an ecological wastewater treatment plant in South China and effluent impact to the receiving river

Ecological wastewater treatment plant (EWWTP), a kind of emerging wastewater treatment plant (WWTP) in recent years, combined microbiology with botany which is efficient for the removal of nitrogen and organic matter, as well as deodorization. The occurrence and removal of micro-organic pollutants in EWWTPs were still not well known. Polycyclic aromatic hydrocarbons (PAHs) and their typical derivatives (SPAHs) including the oxygenated PAHs (OPAHs), chlorinated PAHs (ClPAHs), and methyl PAHs (MPAHs) were investigated in an EWWTP in Guangdong Province, China. The concentrations of the Σ6 OPAHs (114–384 ng/L) were higher than the Σ16 PAHs (92–250 ng/L), and much higher than the Σ4 MPAHs (13–64 ng/L) and Σ9 ClPAHs (2–3 ng/L) in the EWWTP and the effluent receiving river. The total removal efficiencies of the PAHs, OPAHs, MPAHs, and ClPAHs in the EWWTP (43?±?14%, 41?±?7%, 55?±?16%, and 18?±?4%) were lower than the traditional WWTPs, probably due to the lower concentration of the sludge in the ecological treatment. The advanced treatment process (microfiltration and UV disinfection treatment) contributed much less (0–20%) to the whole removal efficiency than the ecological treatment (80–100%). The effluent from the EWWTP slightly reduced the PAHs and SPAHs concentrations in the receiving river. The high concentrations of the PAHs and SPAHs in the receiving river were similar to the influent of the EWWTP, indicating that some untreated wastewater was directly discharged to the river, especially in the upstream.

     

毒性微生物传感器的研制及应用

以从土壤中分离、筛选出的X4菌株作为分子识别元件,采用夹层法制备微生物膜并与极谱型氧电极组成了呼吸抑制型毒性微生物传感器。实验确定了传感器的最佳工作条件:温度为30℃,pH范围为7.0~7.5;以HgCl2作为参比毒物时,微生物传感器标准曲线为y=1.05 x+0.21,线性相关系数为0.9933,线性范围为0.1~1.97 mg/L,相对标准偏差为1.8%。用该微生物传感器对某印染废水的毒性进行测试,该废水的毒性相对于HgCl2的浓度为1.69 mg/L,属于剧毒,与发光细菌法进行比对,测定结果具有一致性。     

机械活化对CRT锥玻璃浸出动力学的影响

通过研究CRT锥玻璃经机械活化后在硝酸溶液体系中浸出反应动力学规律,考察了机械球磨转速、浸出温度以及硝酸初始浓度对锥玻璃中铅的浸出效果影响。研究结果表明,锥玻璃经机械活化预处理后,反应活性显著增强,锥玻璃中铅浸出率大幅度提高。浸出反应的表观活化能和反应级数由109.4 kJ/mol和0.79降至54.3 kJ/mol和0.51。     

曝气对水平潜流人工湿地水力特性的影响

通过构建曝气及未曝气潜流人工湿地小试实验系统,以NaCl为示踪剂开展示踪实验,研究曝气对人工湿地水力特性的影响。实验结果表明,两对比系统均存在不同程度的短流及死区现象,短流主要发生在床体表层,而死区则存在于床体底层。其中未曝气人工湿地系统的流场分布不均匀现象较为严重,示踪剂滞留在床体底层难以回收,系统水力效率较低(0.56)。比较而言,由于气流对水体的扰动作用,曝气对人工湿地系统水力效率有明显改善作用,减缓了床体表层水流速度,提高了示踪剂回收率,缩小了死区的范围,曝气人工湿地系统的水力效率为0.75。     

转轮式洗轮机对车轮带泥的冲洗效果简

施工车辆车轮带泥是我国道路扬尘污染控制面临的共性和突出问题。为在国内推广使用洗轮机提供技术依据,通过检测工地出口外道路积尘负荷来估算转轮式洗轮机对车轮带泥的冲洗效率,并以该洗轮机作为车轮带泥检测设备,检测和统计北京市车轮带泥量。结果表明,（1）转轮式洗轮机可以将工地出口外100 m道路积尘负荷增量由64.4 g/m²降至5.9 g/m²,转轮式洗轮机对车轮带泥的冲洗效率大于90%;（2）渣土车和混凝土车车轮带泥量的平均值分别为5.1和2.2 kg/车;（3）北京市未来车轮带泥量将超过8.8万t/a,施工车辆全部经过转轮式洗轮机冲洗后,车轮带泥量可削减7.9万t/a。建议在相关法律法规中以强制性条款落实施工车辆车轮带泥机械化冲洗要求。     

曝气对潜流人工湿地污染物沿程降解规律的影响

通过构建曝气及未曝气潜流人工湿地小试实验系统,研究曝气对人工湿地床体中污染物沿程变化规律的影响。实验结果表明,曝气对污染物沿程降解规律的影响与污染物种类有关,在净化COD和氨氮时,曝气人工湿地污染物主要以水平推流式降解为主,未曝气系统床体中则出现分层现象,深度为40 cm以上的床体区域中污染物以水平推流式降解为主,40 cm以下区域则以垂直梯度降解方式为主。对于磷来说,两对比系统均以水平推流降解方式为主,但不同深度上的降解速率有所差异,曝气系统30~50 cm的床体中间层降解速率较快,而未曝气系统50 cm以下的床体底层降解速率较快。将对比系统总体净化效果进一步比较发现,对于COD的去除来说,温度的影响大些,而对于氨氮和TP的去除来说,曝气的影响则更为显著。     

The effect of municipal sludge compost on the mobility and bioavailability of Cd in a sierozem-wheat system in an arid region northwest of China

The effect of sewage sludge on the mobility and the bioavailability of trace metals in plant-soil systems have aroused wide interested and been widely explored. Based on a wheat-cultivating experiment, the effect of municipal sludge compost (MSC) on the mobility and bioavailability of Cd in a soil-wheat system was studied. With the application of MSC, soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) in the soil increased significantly, while concentrations of trace metals (Cu, Zn, Ni, Pb, Cd) were below the China’s minimum thresholds. The application of MSC could improve wheat growth. The application of MSC at the rate of 0.5 % had no significant effect on the chemical fraction distribution of Cd in soil. In two soil treatments, Cd mainly existed in the labile chemical fractions (exchangeable chemical fraction (EXCF) and carbonate chemical fraction (CABF)). However, the application of MSC could reduce accumulation of Cd by wheat. Cd contents in each part of the MSC-applied wheat were significantly less than that of non-MSC-applied wheat. In the tested soils, the extractable concentrations decreased in the order: EDTA > MgCl₂ ≈ NH₄OAc > DTPA. There were no significant differences between soil treatments in the amounts of extractable Cd when the extraction was done under neutral conditions, although significant differences were observed when the extraction was done under alkaline conditions. In this study, the DTPA extraction procedure provided a good indication of Cd bioavailability. Our results suggest that, in the short term at least, amending soils with MSC may benefit crop dry matter production while not increasing the risk of human exposure to Cd through consumption of wheat grown on MSC-amended soils.     

Novel bacterial consortia isolated from plastic garbage processing areas demonstrated enhanced degradation for low density polyethylene

Environmental Science and Pollution Research - This study aimed to formulate novel microbial consortia isolated from plastic garbage processing areas and thereby devise an eco-friendly approach for...     

以吡啶、喹啉和吲哚为单一碳源时反硝化过程中亚硝酸盐积累及动力学研究

以吡啶、喹啉和吲哚为单一碳源,通过摇床实验进行反硝化过程动力学研究。实验结果表明,以吡啶和喹啉为单一碳源的反硝化过程中,NO-2-N的积累率分别达到了53.4%和16.4%;以吲哚为单一碳源的反硝化过程中,NO-2-N的积累现象不明显,最高不超过4%。以NO-3-N+0.6 NO-2-N作为反硝化电子受体,采用基于Monod方程的动态模型进行拟合,拟合曲线与实验测定值相关性良好。其次,采用基于Monod方程的微分方程组模型,也能够很好地拟合3种碳源条件下反硝化过程硝酸盐、亚硝酸盐质量浓度的变化,得到相应的动力学参数。