蜡状芽孢杆菌WXZ-8的异养硝化/好氧反硝化性能研究

通过聚合酶链式反应(PCR)扩增、16S rDNA测序并结合同源性分析,鉴别出菌株WXZ-8为蜡状芽孢杆菌(Bacillus ce-reus).对菌株WXZ-8进行异养硝化/好氧反硝化性能测定,并通过正交实验进行培养条件的优选,选取的因素为COD/N、温度、转速和pH.结果表明,对菌株WXZ-8影响最大的因素是转速,其次为COD/N;在最优条件(即温度=30℃、COD/N=25、pH=9.0、转速=180 r/min)下,菌株WXZ-8的氨氮去除率最高达到96.06%.在最优条件下,提高初始氨氮质量浓度为211.52、429.16、897.29mg/L时.菌株WXZ-8在前48 h的氨氮去除速度均达到最大,分别为119.04、94.76,142.21 mg/(L·d),其氨氮去除率最高分别为94.41%、73.43%、51.08%.菌株WXZ-8具有良好的异养硝化/好氧反硝化性能.     

Using diatom indices for water quality assessment in a subtropical river, China

Diatoms have been regularly used as bioindicators to assess water quality of surface waters. However, diatom-based indices developed for a specific geographic region may not be appropriate elsewhere. We sampled benthic diatom assemblages in the upper Han River, a subtropical river in China, to evaluate applicability of 14 diatom-based indices used worldwide for water quality assessment. A total of 194 taxa from 31 genera were identified in the dry season and 139 taxa from 23 genera in the wet season. During the dry season, significant relationships were found for all but one of the diatom-based indices (Index Diatom Artois–Picardie) with one or more physical and chemical variables including nutrients and ion concentrations in river waters. The Biological Diatom Index (IBD) and diatom-based eutrophication/pollution index (EPI-D) were strongly related to trophic status and ionic content, while Watanabe’s Index was related to organic pollution and conductivity. Yet, the diatom indices showed weak relationships with physical and chemical variables during the wet season. It suggests that diatom-based indices developed in Europe can be applied with confidence as bioindicators of water quality in subtropical rivers of China, at least during base-flow conditions.     

稻秆对铜绿微囊藻抑制作用的研究

研究了稻秆浸出液对铜绿微囊藻生长的抑制作用.研究表明,稻秆浸出液中含有的化学物质抑制了铜绿微囊藻的生长繁殖.稻秆浸泡时间的延长,有利于提高浸出液的抑藻效果,但浸泡时间过长则无益于抑藻效果提高,浸泡时间为15 d时,抑制率能高达75.99%.稻秆浸出液投加量达7.5%以上具有显著的抑藻效果.不同部位的水稻秸秆浸出液对铜绿...     

The catalytic performance of Cu46Zr47-xAl7Yx amorphous ribbons in the degradation of AO II dye wastewater

Environmental Science and Pollution Research - Metallic glasses (MGs) with unique disordered atomic stacking structures exhibit excellent catalytic performance in wastewater treatment. The...     

Research progress on the association between environmental pollutants and the resistance mechanism of PARP inhibitors in ovarian cancer

Environmental Science and Pollution Research - The occurrence and progression of ovarian cancer are closely related to genetics and environmental pollutants. Poly(ADP-ribose) polymerase (PARP)...     

Characteristics and chemical speciation of waste copper slag

Environmental Science and Pollution Research - Waste copper slag contains abundant valuable metal element Fe, and residual elements such as Cu, As, Pb, Zn, and Mo. Simply stockpiling or landfilling...     

磷酸盐对亚硝化系统的抑制及恢复

通过接种城镇污水处理厂的污泥,采用连续流反应器启动亚硝化系统并改变进水磷酸盐的浓度,研究了不同磷酸盐浓度对亚硝化系统的影响.结果表明经过14 d的运行,亚硝化系统启动成功,氨氮转化率达到92.2%,亚硝酸盐累积率为73.66%,亚硝酸盐产生速率达到14.42 g·(m~3·d)~(-1).磷酸盐浓度在10~30 mg·L~(-1)时对亚硝化系统的影响并不大;随着磷酸盐浓度持续提高,氨氮转化率在不断降低.当磷酸盐的浓度为80 mg·L~(-1)时,系统的氨氮转化率为13.6%,亚硝酸盐累积率仅18.19%,亚硝酸盐产生速率仅0.54 g·(m~3·d)~(-1),亚硝化反应受到严重抑制.将进水磷酸盐浓度降低到0,经过14 d运行,亚硝化系统获得恢复,且氨氮转化率可以达到80%以上,亚硝酸盐累积率达到86.96%,亚硝酸盐产生速率为15.63g·(m~3·d)~(-1).     

铁炭内电解垂直流人工湿地对污水厂尾水深度脱氮效果

针对污水厂尾水总氮(TN)含量偏高、微生物可利用碳源低的问题,构建铁炭内电解垂直流人工湿地(ICIE-VFCW)装置,研究了ICIE-VFCW对尾水的处理效果,并采用紫外-可见光光谱(UV-VIS)、凝胶过滤色谱(GFC),进一步探讨了ICIEVFCW强化脱氮机制.结果表明,ICIE-VFCW可提高系统对尾水中COD的去除,出水COD可稳定在30 mg·L~(-1)以下,全年、暖季、寒季COD平均去除率较普通垂直流人工湿地分别可提高10.16%、9.81%、11.22%.系统出水TN可维持在10 mg·L~(-1)以下,全年、暖季、寒季TN平均去除率较普通垂直流人工湿地分别提高13.72%、12.90%、16.17%.经过人工湿地处理后,污水中有机物的腐殖度、芳香度及相对分子质量(Mr)均有所下降,且ICIE-VFCW中Mr下降更为明显.湿地基质掺杂铁炭可促进尾水中大分子有机物转化为小分子,为微生物提供更多可利用碳源,从而提高脱氮效率.     

石油烃类污染物对中肋骨条藻和微型原甲藻的毒性效应研究

选择中肋骨条藻（Skeletonema costatum）,微型原甲藻（Prorocentrum minimum）作为受试生物,测定了原油、燃料油分散液（WAF）以及添加溢油分散剂后的乳化液（DWAF）对两种微藻的毒性效应参数。结果表明:低浓度的原油WAF和DWAF以及燃料油DWAF均对中肋骨条藻的生长起促进作用,其中,当原油WAF浓度为0.3 mg/L时,促进作用最强;而原油DWAF浓度低于0.5 mg/L时,开始促进生长,当浓度低至0.1 mg/L时,种群增长速率最大。两种微藻在4种不同石油烃类污染物体系中的96 h-EC₅₀差异较大,96 h-EC₅₀值介于0.07~30.77 mg/L之间;其中燃料油DWAF毒性最强,对中肋骨条藻和微型原甲藻的96 h-EC₅₀分别为0.45 mg/L和0.07 mg/L;而微型原甲藻对原油WAF毒性效应敏感性最低,其96 h-EC₅₀高达30.77 mg/L。     

某站场对焊法兰环焊缝缺陷原因分析

目的研究法兰环焊缝缺陷产生的原因,采取相应针对性措施,预防泄露事故发生。方法通过宏观分析、超声检测、化学成分分析、金相分析、能谱分析对环焊缝裂纹形成原因进行分析。结果裂纹起源于根焊焊材与母材间,两端较为平滑,沿环焊缝周向方向扩展。焊缝中夹渣的残留药皮和层间未熔合缺陷,是形成裂纹的内在原因。结论焊缝产生裂纹由焊接参数控制不当引起的。