一株产絮酵母菌废菌体对Cd~（2＋）的吸附特性

将一株产絮酵母菌（编号B-02号）发酵后的废菌体制成生物吸附剂,研究该生物吸附剂对废水中Cd2＋的生物吸附特性。结果表明：（1）pH值对Cd2＋会产生较大的影响,偏酸性（pH=4～6）条件利于吸附;该吸附剂对Cd2＋吸附速率较快,8～10 min就可达到吸附平衡;（2）吸附剂的吸附动力学符合二级动力学模型,吸附Cd2＋的实验数据对Langmuir等温式的拟合情况良好,吸附剂吸附Cd2＋的最大吸附量为70.752 mg/g。用0.5 mol/L HNO3对吸附Cd2＋的酵母菌进行解吸,解吸率可达89.7%。     

磁性LDH负铜催化剂的制备及其对直接青莲D-BL的脱色

实验以滴定共沉淀法制备Mg-Al LDH晶体包覆的Fe3O4颗粒,利用LDH的层间阴离子交换性使其吸附[Cu(C2O4)2]-络合离子,通过焙烧获得磁性焙烧态LDH载体的负铜催化剂。并通过SEM、X-Ray、FT-IR等方法以及静态实验,表征及考察了材料的物化特性及其直接性偶氮染料直接青莲的脱色性能。结果表明,材料对该染料废水有较强去处能力,且磁性良好易于分离回收;其最佳制备条件为用浓度为20 g/L的K2[Cu(C2O4)2]溶液改性一次,反应结束后于450℃下焙烧5 h;上述条件下制备的材料投加量为1 g/L、H2O2浓度为6.53 g/L、处理时间2 h,对200、300和500 mg/L浓度的模拟直接青莲D-BL染料废水去除率分别为99.62%、90.43%和81.92%。     

污水处理厂污泥干化焚烧处理可行性分析

以绍兴污水处理厂脱水污泥为研究对象,通过实验分析了污泥进行干化焚烧处理的可行性。对污泥泥质进行分析,采用桨叶式污泥干化机对污泥的热干化特性、干化过程污染排放特性进行研究,使用流化床污泥焚烧试验装置对污泥焚烧工况及焚烧过程中污染物的排放特征进行研究,结果表明,绍兴污水处理厂脱水污泥的泥质特征与大多数污水污泥类似,灰分较高、发热量较低,需干化后才可实现稳定燃烧;污泥在小型桨叶式污泥干化机内的干化速率最高达到0.6kg/(m2·min),并随污泥干化的进行而逐渐降低;干化过程产生的常规污染气体中氨气浓度最高,可达170 mg/Nm3;污泥干化冷凝水的COD高达820 mg/L,氨氮等指标也很高。污泥干化系统的设计需充分考虑污泥热干化过程中气体和液体污染物的排放,设置相应的处理设施。污泥干化至含水率30%时,可在不投加辅助燃料的情况下实现流化床焚烧炉内的焚烧处理,干化污泥焚烧时需关注烟气中常规污染气体和重金属的控制,焚烧灰渣浸出毒性未超过国标限值。     

温度对改性矿物吸附剂脱除气态汞影响

以蛭石、丝光沸石、膨润土及经改性后各物质为吸附剂,N2气氛下,在固定床实验台上进行了对烟气中单质汞脱除的实验研究,主要考察了温度的改变对改性矿物吸附剂脱除气态汞的影响。研究结果显示,膨润土、蛭石对汞的吸附基本不受温度的影响;未改性的吸附剂对汞的吸附能力均比较差;温度的提高有利于改性吸附剂对单质汞的脱除,说明改性后的吸附剂的脱汞过程以化学吸附为主;真正起作用的活性组分CeO2占据了丝光沸石的大部分表面积和空隙;丝光沸石经CuO改性前后吸附能力几乎未发生变化。     

Influence of rhizosphere microbial ecophysiological parameters from different plant species on butachlor degradation in a riparian soil

Biogeochemical processes in riparian zones regulate contaminant movement to receiving waters and often mitigate the impact of upland sources of contaminants on water quality. However, little research has been reported on the microbial process and degradation potential of herbicide in a riparian soil. Field sampling and incubation experiments were conducted to investigate differences in microbial parameters and butachlor degradation in the riparian soil from four plant communities in Chongming Island, China. The results suggested that the rhizosphere soil had significantly higher total organic C and water-soluble organic C relative to the nonrhizosphere soil. Differences in rhizosphere microbial community size and physiological parameters among vegetation types were significant. The rhizosphere soil from the mixed community of Phragmites australis and Acorus calamus had the highest microbial biomass and biochemical activity, followed by A. calamus, P. australis and Zizania aquatica. Microbial ATP, dehydrogenase activity (DHA), and basal soil respiration (BSR) in the rhizosphere of the mixed community of P. australis and A. calamus were 58, 72, and 62% higher, respectively, than in the pure P. australis community. Compared with the rhizosphere soil of the pure plant communities, the mixed community of P. australis and A. calamus displayed a significantly greater degradation rate of butachlor in the rhizosphere soil. Residual butachlor concentrations in rhizosphere soil of the mixed community of P. australis and A. calamus and were 48, 63, and 68% lower than three pure plant communities, respectively. Butachlor degradation rates were positively correlated to microbial ATP, DHA, and BSR, indicating that these microbial parameters may be useful in assessing butachlor degradation potential in the riparian soil.     

两性高分子污泥脱水剂P(AM-DAC-AMPS)的表征与应用

采用三元自由基水溶液聚合法,以丙烯酰胺(AM)、丙烯酰氧乙基三甲基氯化铵(DAC)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,经过复合引发制备了两性高分子脱水剂P(AM-DAC-AMPS),简称为PADA).采用傅里叶变换红外光谱(FT-IR)、透射电镜(TEM)对结构进行了表征,结果证明聚合物为三元共聚物,并具有良好的直链结构.经过PA-DA、CPAM调理后的污泥最佳比阻(r)分别为1.58×109s2/g和1.8×109s2/g,离心后含水率分别为77.4％和78.1％;污泥沉降速度分别为0.3 mL/min和0.25 mL/min;污泥滤液中,多糖去除率分别为70.3％和40.7％,蛋白质去除率分别为31.5％和17.5％;表明PADA比CPAM具有更好的脱水性能.并且通过SEM观察,发现PADA的调理增强了污泥絮体的密实性.     

Characteristics of lead geochemistry and the mobility of Pb isotopes in the system of pedogenic rock–pedosphere–irrigated riverwater–cereal–atmosphere from the Yangtze River delta region,China

Knowledge of the characteristics of Pb and its isotopic transfer in different compartments is scant, especially for the mobility of Pb isotopes in the geochemical cycle. The present study characterizes differential Pb transport mechanism and the mobility of Pb isotopes in the pedogenic parent rock–pedosphere–irrigated riverwater–cereal–atmosphere system in the Yangtze River delta region, by determining Pb concentration and Pb isotopic ratios of pedogenic parent rocks, fluvial suspended particle matter, tillage soils, soil profiles, irrigated riverwater, fertilizer, Pb ore, cereal roots and grains. The results show that Pb isotopes in the geochemical cycle generally follow the equation of ²⁰⁸Pb/²⁰⁶Pb = −1.157 × ²⁰⁶Pb/²⁰⁷Pb + 3.46 (r² = 0.941). However, Pb isotopes have different mobility in different environmental matrixes. Whereas in the pedosphere, the heavier Pb (²⁰⁸Pb) usually shows stronger mobility relative to the lighter Pb, and is more likely to transfer into soil exchangeable Pb fraction and carbonates phase. The lighter Pb shows stronger transfer ability from soil to cereal grain via root compared to the heavier Pb. However, the cereal grains have lower ²⁰⁶Pb/²⁰⁷Pb and higher ²⁰⁸Pb/²⁰⁶Pb ratios than root and tillage soil, similar to the airborne Pb and anthropogenic Pb, implying that a considerable amount of Pb in cereal grains comes from the atmosphere. The estimate model shows that 16.7–52.6% (average: 33.5%) of Pb in rice grain is the airborne Pb.     

Haze is a risk factor contributing to the rapid spread of respiratory syncytial virus in children

This study investigated whether respiratory syncytial virus (RSV) infection in children was associated with ambient temperature and air pollutants in Hangzhou, China. A distributed lag non-linear model (DLNM) was used to estimate the effects of daily meteorological data and air pollutants on the incidence of RSV infection among children. A total of 3650 childhood RSV infection cases were included in the study. The highest air pollutant concentrations were in January to May and October to December during the year. The yearly RSV-positive rate was 10.0 % among children with an average age of 4.3 months. The highest RSV-positive rate occurred among patients 0 to 3 months old. Children under 6.5 months old accounted for 80 % of the total patients infected by RSV. A negative correlation was found between ambient temperature and RSV infection, and it was strongest with minimum ambient temperature (r = ?0.804, P < 0.001). There was a positive correlation between the infection rate and the particulate matter (PM) 2.5 (r = 0.446, P < 0.001), PM10 (r = 0.397, P < 0.001), SO₂ (r = 0.389, P < 0.001), NO₂ (r = 0.365, P < 0.001) and CO (r = 0.532, P < 0.001). The current study suggested that temperature was an important factor associated with RSV infection among children in Hangzhou. Air pollutants significantly increased the risk of RSV infection with dosage, lag and cumulative effects.     

呼吸计量法对甲醇和葡萄糖为基质的ASM1参数测定

污水水质和污泥特性不同,活性污泥1号模型(ASM 1)参数的测定结果也不相同。研究以甲醇和葡萄糖为基质,对分别经过甲醇和葡萄糖驯化的活性污泥,通过呼吸计量法测定高食微比、中食微比和零食微比下的氧利用速率(OUR)随时间变化的曲线。确定了异养菌产率系数(YH)、异养菌最大比增长速率(μ^H)和衰减系数(bH),并根据YH、μ^H和bH的测定结果和对中食微比下OUR曲线的数值拟合确定了异养菌半饱和常数(ks)、最大比水解速率(kh)和慢速可生物降解底物水解的半饱和常数(KX)。研究结果表明,在20℃下,采用甲醇和葡萄糖为基质测得的YH、bH、μ^H、ks、KX和kh分别为0.53、0.48、5.75、0.9、0.03、3.0和0.87、1.03、2.27、4.45、0.01、7.0。YH、bH、μ^H和ks的值与ASM1中城市污水的推荐值0.67、0.62、6.0、20.0不同,反映了不同基质对参数测定结果的影响。对于慢速可生物降解有机物(Xs)含量低的水质来说,KX和kh对生化反应过程影响不大,可采用ASM1模型的推荐值。