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161.
新型活性炭固定化产品的制备及其处理焦化废水的特性 总被引:1,自引:0,他引:1
为解决优势菌种工程应用,研究不同固定化方法、载体和结构的固定化产品对焦化废水的降解特性。用活性炭粉末吸附菌种后,与聚乙烯醇和海藻酸钠混合制备了新型固定化球;用聚乙烯醇和海藻酸钠包埋吸附菌种的活性炭纤维毡,与立体弹性塑料填料连用,制备出3种不同形状的活性炭纤维膜片固定化产品复合填料。将游离菌和制备的4种活性炭固定化产品投入A/A/O工艺系统平行实验,考察处理焦化废水的效果。结果表明,活性炭纤维膜片固定化产品复合填料对焦化废水的降解能力优于其他固定化产品:缺氧池出水硝酸盐氮和亚硝酸盐氮浓度分别稳定在1.96 mg/L和0.49 mg/L,未产生氮的累积现象,COD去除率可达到60.92%。好氧池COD和氨氮降解效率分别为78.83%和85.52%,苯酚、氰化物降解效率均为97%以上。 相似文献
162.
Ming-Hong Wu Liang Tang Gang Xu Jing Ma Ning Liu Liang Wang Jian-Qiu Lei 《Environmental science and pollution research international》2013,20(4):2651-2660
Fourteen and 17 sediment samples were collected from three main rivers of Shanghai in July and November, respectively. Eight polybrominated diphenyl ether (PBDE) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, and BDE-209) were detected in these samples to clarify the pollution status in the metropolis. Instrumental analyses showed that the concentrations of ∑8PBDEs ranged from 10.97 to 64.05 ng/g dry weight (dw), with an average value of 29.71 ng/g dw. BDE-209 was the predominant congener accounting for more than 97 % of total PBDEs, followed by BDE-47 and BDE-99. Remarkable spatial and seasonal distributions of PBDE concentrations were observed, suggesting that local sources, seasonal climates, and hydrologic conditions might be the influencing factors. Moderate correlations (r 2?=?0.28–0.51, p?<?0.05) were found between total organic carbon and PBDEs, which indicated that organic carbon content influenced the distributions of PBDEs in sediment of Shanghai at some extent. Hazard quotients revealed PBDEs posed no potential risk to benthic organisms in the study area at present. 相似文献
163.
Xian-De Xie Xiao-Bo Min Li-Yuan Chai Chong-Jian Tang Yan-Jie Liang Mi Li Yong Ke Jie Chen Yan Wang 《Environmental science and pollution research international》2013,20(9):6050-6058
Floatation tailings (FT) are the main by-products of the hydrothermal sulfidation–flotation process. FT (FT1 and FT2) were obtained by treating two different neutralization sludges (NS) (NS1 and NS2). This paper quantitatively evaluated the environmental risks of heavy metals (Zn, Cd, Cu, Pb, and As) in FT versus NS. The total concentration and leaching rates (R 2) of heavy metals in FT were much lower than those in NS, demonstrating that the hydrothermal sulfidation–flotation process was able to effectively suppress the mobility and leachability of heavy metals. The BCR-three sequence leaching procedure of FT confirmed that all metals were transformed into more stable forms (residue and oxidizable forms) than were found that in NS. The potential ecological risk index indicated that the overall risks caused by heavy metals decreased significantly from 6627.59 and 7229.67 (very serious risk) in NS1 and NS2, respectively, to 80.26 and 76.27 (low risk) in FT1 and FT2, respectively. According to the risk assessment code, none of the heavy metals in FT posed significant risk to the natural environment except Zn (with low risk). In general, the risk of heavy metals in FT had been well controlled. 相似文献
164.
Zhiqiang Nie Zhenwu Tang Xiaohua Zhu Yufei Yang Haihui Fu Qingqi Die Qi Wang Qifei Huang 《Environmental science and pollution research international》2013,20(12):8751-8762
The concentrations, compositional profiles, and possible sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) in water column and surface sediment samples from the lower reaches of the Yangtze River were investigated, and the potential risks posed by these chemicals were evaluated. Concentrations of the 17 2,3,7,8-substituted PCDD/PCDF in the water and sediment samples ranged from 0.45 to 10.0 pg TEQ/L (mean 2.34 pg TEQ/L) and from 0.31 to 51 pg TEQ/g dw (mean 5.25 pg TEQ/g dw), respectively. Water and sediments from the Nanjing–Nantong sections of the Yangtze River were found to have elevated PCDD/PCDF levels, and the PCDD/PCDF TEQ concentrations in 13 sediment samples exceeded the probable effect levels (PEL), above which adverse biological effects are likely. Multivariate statistical analysis indicated that the principal PCDD/PCDF contamination source for the water and sediment was the production and use of pentachlorophenol (PCP) or sodium pentachlorophenate (PCP-Na). PCDD/PCDF concentrations were stable over time near the Yangtze River Estuary but had increased sharply in recent decades in the Nanjing–Nantong section, which will have been related to the growth in industrial activities and other anthropogenic PCDD/PCDF sources. Total organic carbon (TOC) and PCDD/PCDF concentrations correlated significantly (R?=?0.474, P?<?0.01), suggesting that TOC plays an important role in the transport and re-distribution of PCDD/PCDF in the Yangtze River basin. 相似文献
165.
Xiaojiao Chen Minjian Chen Bo Xu Rong Tang Xiumei Han Yufeng Qin Bin Xu Bo Hang Zhilei Mao Weiwei Huo Yankai Xia Zhengfeng Xu Xinru Wang 《Chemosphere》2013
Widespread use of phenols has led to ubiquitous exposure to phenols. In experimental animals, phenols increased resorptions, reduced live litter size and fetal body weights. However, there are limited epidemiological evidences of the relationships between exposure to phenols and pregnancy outcomes. We evaluated the associations between parental urinary levels of various phenols and spontaneous abortion in a Chinese population residing in the middle and lower reaches of the Yangtze River. A case-control study was conducted that included 70 case couples with medically unexplained spontaneous abortion and 180 control couples who did not have a history of spontaneous abortion and had at least one living child. Both parental urinary phenols were measured by ultra-high performance liquid chromatography-tandem mass spectrometry including bisphenol A (BPA), benzophenone-3 (BP-3), 2,3,4-trichlorophenol (2,3,4-TCP), pentachlorophenol (PCP), 4-n-octylphenol (4-n-OP) and 4-n-nonylphenol (4-n-NP). Compared with the low exposure group, there was an increased risk of spontaneous abortion with high paternal urinary PCP concentration [odds ratio (OR) = 2.09, 95% Confidence Interval (CI), 1.05–4.14], and maternal exposure to 4-n-OP and alkylphenol(s) also significantly increased the risk of spontaneous abortion (OR = 2.21, 95% CI, 1.02–4.80; OR = 2.81, 95% CI, 1.39–5.65, respectively). Our study firstly provides the evidence that paternal PCP exposure, maternal 4-n-OP and alkylphenol(s) exposure are associated with spontaneous abortion in humans. 相似文献
166.
灵芝漆酶对直接蓝86的催化脱色性能 总被引:1,自引:0,他引:1
利用灵芝菌Ganoderma lucidum U-281漆酶对直接蓝86进行酶促氧化脱色,并对其降解机理进行了探讨。结果表明,染料-漆酶共反应体系在20~50℃及pH小于5.0范围内,直接蓝86均可脱色50%以上;漆酶对直接蓝86具有宽泛的浓度适应性,对300 mg/L的该染料仍具有耐受性。最优脱色工艺参数为温度40℃、pH 5.0、染料初始浓度200 mg/L、漆酶用量1 U/mL。在优化条件下,直接蓝863 h的脱色率达到54.54%,48 h脱色率达到91.54%。紫外-可见吸收光谱分析表明,漆酶的酶促氧化导致染料的分子结构产生了变化,是造成直接蓝86脱色的主要发生机制。 相似文献
167.
采用生物过滤法,以鸡粪堆肥和PE混合物为填料,在高气速条件下间歇式处理高负荷H2S废气。空床停留时间为20、15、10、6.7和5 s时,入口浓度3 000 mg/m3下的平均去除率分别为100%、100%、96.5%、89.2%和90.5%。高气速EBRT为5 s时,高入口负荷2 147 g/(m3.h)时的去除负荷为2 023 g/(m3.h),去除率达94%。采用Michaelis-Ment-en模型进行生物降解宏观动力学研究,其中Ks为550 mg/m3,Vm为6.8×104g/(m3.d)。结果表明,在实验温度17~24℃,湿度30%~50%下,生物过滤法间歇式处理高气速高负荷H2S的去除性能好。 相似文献
168.
用人工驯养的厌氧污泥进行除铀实验,探讨了微生物投加量(VSS)、pH值、U(Ⅵ)初始浓度、外加电子供体和污泥重复利用等对污泥处理U(Ⅵ)的影响,并进行了相关机理分析。实验结果表明,在适当的pH范围内(5.2~6.6),厌氧污泥对铀保持较长时间的高效去除率;当以还原铁粉和无水乙醇作电子供体时,U(Ⅵ)去除率保持在95%以上的时间为未加电子供体时的2倍。U(Ⅵ)去除速度与VSS投加量成正比关系,U(Ⅵ)初始浓度对去除效果的影响不大,厌氧污泥可以长期使用。pH值的影响最关键,其次是外加电子供体。厌氧污泥除U(Ⅵ)机理为氧化还原和吸附的共同作用。 相似文献
169.
以累托石、丙烯酸及腐殖酸为原料制备出能同时吸附重金属和多环芳烃的吸附剂聚丙烯酸/腐殖酸/累托石,采用响应面试验设计法优化吸附剂的制备条件。利用Design Expert软件,建立了预测吸附剂对Cd2+、菲吸附量的二次回归模型,对回归模型进行了方差分析,并确定了吸附剂的最佳制备条件。结果表明,二次回归模型能较好地模拟Cd2+、菲的吸附量与影响因子丙烯酸中和度、引发剂量和交联剂量之间的关系。各因子对Cd2+吸附量的影响次序为:交联剂量>引发剂量>丙烯酸中和度;对菲吸附量的影响次序为引发剂量>交联剂量>丙烯酸中和度。吸附剂的最佳制备条件为:累托石、丙烯酸和腐殖酸三者的质量比为65∶30∶5,丙烯酸中和度、引发剂量和交联剂量分别为75.16%、2.57%和0.44%。在此优化条件下制备的吸附剂对Cd2+和菲的吸附量分别为170.19 mg/g和7.36 mg/g。 相似文献
170.
黄菖蒲和狭叶香蒲根系对氮磷的吸收动力学 总被引:3,自引:0,他引:3
采用改进的常规耗竭法,研究了黄菖蒲(Iris pseudacorus L.)和狭叶香蒲(Typha angustifolia L.)根系对NH4+、NO3-和H2PO4-的吸收特征及差异。结果表明,这2种植物根系对NH4+、NO3-和H2PO4-的吸收动力学特征均可采用Michaelis-Menten方程描述。2种植物根系对NH4+、NO3-和H2PO4-的亲和力(Km)和最大吸收速率(Vmax)有显著差异。吸收H2PO4-时,黄菖蒲根系具有较高的Vmax值和较低的Km值,说明黄菖蒲具有嗜磷特性,并能够适应广范围浓度的H2PO4-环境,适宜用于污染水体磷的去除;吸收NO3-时,狭叶香蒲根系具有较高的Vmax值和较低的Km值,表明狭叶香蒲可用于广范围浓度NO3-污染的水体修复;吸收NH4+时,黄菖蒲根系具有较低的Vmax值和Km值,而狭叶香蒲根系具有较高的Vmax值和Km值,说明黄菖蒲适宜用于NH4+污染较轻水体的修复,而在NH4+污染较重水体中宜选用狭叶香蒲作为先锋植物。 相似文献