The treatment of black-odorous water using tower bipolar electro-flocculation including the removal of phosphorus,turbidity, sulfion,and oxygen enrichment

• An innovative bubble column tower BPE was designed to treat the black-odorous water. • PO₄³⁻, S²⁻ and turbidity were removed, and dissolved oxygen was enriched in the BPE. • An aluminum bipolar electrode gave the best oxygen enrichment and pollutant removal. • Changes of microorganisms confirmed the improvement in water quality achieved. The large amount of municipal wastewater discharged into urban rivers sometimes exceeds the rivers’ self-purification capacity leading to black-odorous polluted water. Electro-flocculation has emerged as a powerful remediation technology. Electro-flocculation in a bubble column tower with a bipolar electrode (BPE) was tested in an attempt to overcome the high resistance and weak gas-floatation observed with a monopolar electrode (MPE) in treating such water. The BPE reactor tested had a Ti/Ta₂O₅-IrO₂ anode and a graphite cathode with an iron or aluminum bipolar electrode suspended between them. It was tested for its ability to reduce turbidity, phosphate and sulphion and to increase the concentration of dissolved oxygen. The inclusion of the bipolar electrode was found to distinctly improved the system’s conductivity. The system’s electro-flocculation and electrical floatation removed turbidity, phosphate and sulphion completely, and the dissolved oxygen level improved from 0.29 to 6.28 mg/L. An aluminum bipolar electrode performed better than an iron one. Changes in the structure of the microbial community confirmed a significant improvement in water quality.     

富锌金针菇菌株的诱变选育及酶谱分析

以金针菇F19为出发株,通过制备菌丝断片悬液和紫外线照射(3—14min)来筛选突变株。结果发现,12min处理使菌丝体生物量减少了5.14%(p>0.05),但富锌量提高了18.78%(p<0.01);在连续3代的遗传稳定性实验中,菌丝体生物量为1.342—1.419g/100ml,富锌量为49.78—50.45mg/g,与原代差异均不显著(p>0.05)。PAGE技术测定发现,EST是金针菇遗传分析最适标记之一;高锌通过提高EST、POD的合成和活性来促进有机锌的转化和菌丝体的生长。     

2017~2018年冬季菏泽大气PM2.5中金属元素特征及健康风险评估

于山东省菏泽市采集了2017年10月15日至2018年1月31日期间菏泽学院、华润制药和污水处理厂共3个采样点的大气PM_2.5样品,利用电感耦合等离子体质谱仪（ICP-MS）测定PM_2.5中21种金属元素的浓度,并讨论元素富集程度、评估重金属的健康风险和潜在生态风险.结果表明,采样期间3个采样点中ρ（PM_2.5）范围为26.7~284.1 μg·m^-3且浓度值差别不大,均处于较高污染水平;3个采样点金属元素中K浓度最高,分别占总量的31.03%、39.47%和38.43%,主要由于菏泽作为较大农业城市,其秋冬季生物质燃烧贡献率较高;3个采样点微量元素中ρ（Zn）最高,分别为89.70、84.21和67.68 ng·m^-3.富集因子结果表明,Zn、Pb、Sn、Sb、Cd和Se的富集因子值均高于100,其中Cd和Se的富集因子分别高于2 000和4 000,受人为活动影响显著,可能与工业生产、金属冶炼、道路源和燃煤排放等有关.健康风险结果表明,As存在一定的潜在非致癌风险（儿童和成人HQ>0.1）,3个采样点对儿童和成人均存在综合潜在非致癌风险（HI>0.1）和一定的潜在致癌风险（CRT>1×10^-6）,其中污水处理厂对成人的致癌风险较为显著（CRT>1×10^-4）,成人的致癌风险略高于儿童可能与成人室外活动时间较长和PM_2.5暴露量更高有关.潜在生态风险值最高的元素为Cd、As和Pb,其中Cd表现为极高的潜在生态风险,应引起重视;3个采样点均呈现出极高的综合潜在生态风险,强度在空间上表现为：菏泽学院>华润制药>污水处理厂.     

Distribution, Enrichment and Accumulation of Heavy Metals in Coastal Sediments of Salina Cruz Bay, México

Surface sediment samples collected from the Salina Cruz Bay in the last twenty years, were analyzed for the total available trace elements (Cr, Cu, Fe, Pb, Ni, V, and Zn) to evaluate metal contamination due to possible anthropogenic inputs. Normalization of metals to iron and fine-grained fraction (< 63 μm) indicated relatively high enrichment factors for lead during the last two decades. Sediment Quality Guidelines suggest that lead must be considered as a chemical of potential concern in the marine and estuarine ecosystem. Concentration levels of lead ranged from 5–124 μg/g, while Ni and V below 70 and 30 μg/g, respectively. Geoaccumulation and enrichment factors for the rest of elements show comparable values to those reported for sites with similar activities in the world. Spatial distribution suggests that in addition to harbor activities, a transboundary source for Pb must account for the observed trends.     

Spatial Variability and Monitoring of Pb Contamination of Farming Soils Affected by Industry

In this study, the relationship between some physico-chemical properties of soils and lead contamination in soil due to emission from industrial operations in Samsun province of Turkey was investigated. The extent of timely contamination was studied by comparing the obtained results with the results of the study conducted in the same region in 1998. An area of 225 km² (15 km × 15 km), which was divided into 1000 × 1000 m grid squares (16 lines in the east and south directions), was selected within the industrial area. The total of 256 grid points was obtained and soil samples were collected from three depths (0–5, 5–15, and 15–30 cm) of each grid center in 2004. The total Pb concentrations of soil samples were determined as 65.84–527.04 μg g⁻¹ at 0–5 cm in depth, 58.50 – 399.54 μg g⁻¹ at 5–15 cm in depth, and 44.65–330.07 μg g⁻¹ at 15–30 cm in depth. DTPA-extractable Pb concentrations of soils were found to be in the range of 1.52–9.03 μg g⁻¹, 0.54–7.09 μg g⁻¹, 0.19–6.13 μg g⁻¹ at 0–5, 5–15, and 15–30 cm depths, respectively. There were significant relationships between both total or DTPA-extractable Pb concentrations and selected physico-chemical properties of soil. According to enrichment factor (EF) values calculated from the total Pb concentrations, 11.3% of the study area (225 km²) was enriched with Pb in high level, but 77% of the area was in significant enrichment level with Pb. The average total and DTPA-extractable Pb concentrations increased as 11 and 13%, respectively in comparison with the results of 1998.     

南京市不同功能区大气降尘的沉降通量及污染特征

选择南京市的钢铁工业区、工业与居民混合区、交通干道、居民生活区、风景区、城市郊区6种典型城市功能区,按月定期收集降尘,计算沉降通量.应用ICP-AES分析降尘中元素的含量,比较其化学组成和污染物特征.结果表明,研究期间南京市降尘沉降通量为3.39～65.95g/(m²·月),工业区降尘通量显著高于其他区域,说明其局部来源的贡献超过了区域背景;不同功能区降尘中地壳元素绝对含量均较高,为主要的成分,而一些污染元素(Cu、Zn、Pb、Ni、As)的含量在工业混合区和钢铁工业区则相对较高.降尘中Ca、Cu、Zn、Pb的富集系数均>10.北方远程来源的降尘对南京地区的影响很大,特别是对该地区的土壤“复钙”作用有很大的影响.     

长江中游若干湖泊中水生植物体内重金属分布

用ICP-AES测定了长江中游若干湖泊的水生植物中重金属的含量,发现水生植物对重金属(Zn,Cr,Pb,Cd,Co,Ni和Cu)有很强的吸收积累能力,而一些重金属元素,比如Cd含量增加的同时也会减少必需元素(如Zn)的含量.此外,水生植物会控制重金属在植物体内的分布,使得更多的重金属积累在根部.根据重金属污染指数(MPI)判断,位于城市附近的湖泊重金属的水平较高,位于农村附近的湖泊的金重属含量水平较低.      

Cadmium in aquatic microcosms: Implications for screening the ecological effects of toxic substances

A two-phase set of experiments was conducted to address some of the problems inherent in ecological screening of toxic substances in aquatic microcosms. Phase I was a 4×4 factorial experiment dealing with the interactive effects of cadmium and nutrients in static microcosms. Phase II was a 2×4 factorial experiment using flowthrough microcosms to study temporal aspects of system behavior in response to nutrient loading and chronic versus acute cadmium perturbations. Nutrient enrichment resulted in increased biomass and metabolic activity in both static and flowthrough microcosms. Cadmium treatments generally resulted in a decrease in abundance of grazing crustaceans and a subsequent increase in community respiration, suggesting a change in community structure from a grazing to a detritus food chain. Of the variables measured, community metabolism, community composition, and output/input ratios of nitrate-nitrogen were the most useful indicators of system response to cadmium. Nutrient enrichment significantly influenced cadmium effects with respect to most of the variables measured; high levels of enrichment reduced the effects of cadmium. For screening the ecological effects of toxic chemicals, a series of experiments is proposed, including 1) relatively simple static microcosms, 2) flow through microcosms, and 3) more detailed but selective studies in microcosms derived from specific ecosystems. Each step yields increasingly more information and serves as a guide for subsequent experiments; in addition, each step more closely approximates natural ecosystems.     

N-DAMO菌群的富集及其生长代谢影响因子

亚硝酸盐型甲烷厌氧氧化（N-DAMO）是某些微生物在厌氧条件下以甲烷为电子供体和唯一碳源还原亚硝酸盐（NO₂^-）为氮气（N₂）的过程,为解决废水生物脱氮碳源不足问题提供了新思路.然而,N-DAMO菌群生长缓慢,对环境要求严苛,富集培养难度大,工程应用困难.本文以湿地土壤为菌源,通过强化富集获得一个N-DAMO菌群,并研究了主要环境因子和生长因子对其生长代谢的影响.结果表明,该N-DAMO菌群的NO₂^-还原速率可达0.27 mmol·g^-1·d^-1,其最佳培养条件为35℃、pH 7.5、NO₂^-浓度为2.0 mmol·L^-1和甲烷分压为（P（CH₄））98 kPa等.少量添加维生素液、血红素和甜菜碱等生长因子,均能刺激菌群的代谢活性,使其NO₂^-还原速率分别提高1.32、1.22和1.96倍.本研究有助于进一步了解N-DAMO菌群的生理生态特性,为其工程应用提供参考.     

两种油菜不同铅富集能力差异机理

通过水培试验和大田试验研究了秦油1号（QY-1）和三月黄（SYH）2种油菜对Pb的吸收富集能力,并从叶片的亚细胞结构和抗氧化酶活性等角度探究二者对Pb的耐性和解毒机制.结果表明,在水培条件下,2种油菜的生长均未受到明显的抑制,随着Pb胁迫的增加,油菜吸收的Pb更倾向于分配在根部,减弱向地上部的转运.同时,在高Pb处理浓度（20mg/L）下,SYH的地上部和根部的Pb含量分别比QY-1提高了17.03%和77.07%.油菜叶片中Pb亚细胞区隔化研究结果表明,将Pb区隔在生物解毒组分（金属富集颗粒组分和热稳定蛋白组分）中是油菜富集Pb的重要耐性机制,其中SYH在该组分中Pb的分布显著高于QY-1.此外,抗氧化系统是这2种油菜应对Pb胁迫的重要解毒机制,Pb胁迫下SYH体内过氧化物酶和过氧化氢酶活性显著高于QY-1,可更有效地应对Pb胁迫对其的毒害效应.大田试验表明,田间条件下2种油菜吸收的Pb更倾向于转运到地上,且SYH的富集系数、地上部和根部Pb含量均显著高于QY-1.综上,SYH具有更高的Pb富集能力,具有修复中轻度Pb污染土壤的应用潜力.