Leaching of seven pesticides currently used in cotton crop in Mato Grosso State—Brazil

This study aimed to evaluate the leaching of pesticides and the applicability of the Attenuation Factor (AF) Model to predict their leaching. The leaching of carbofuran, carbendazim, diuron, metolachlor, α and β endosulfan and chlorpyrifos was studied in an Oxisol using a field experiment lysimeter located in Dom Aquino – Mato Grosso. The samples of percolated water were collected by rain event and analyzed. Chemical and physical soil attributes were determined before pesticide application to the plots. The results showed that carbofuran was the pesticide that presented a higher leaching rate in the studied soil, so was the one representing the highest contamination potential. From the total carbofuran applied in the soil surface, around 6 % leached below 50 cm. The other pesticides showed lower mobility in the studied soil. The calculated values to AF were 7.06E-12 (carbendazim), 5.08E-03 (carbofuran), 3.12E-17 (diuron), 6.66E-345 (α-endosulfan), 1.47E-162 (β-endosulfan), 1.50E-06 (metolachlor), 3.51E-155 (chlorpyrifos). AF Model was useful to classify the pesticides' potential for contamination; however, that model underestimated pesticide leaching.     

Accumulation and relationship of metals in different soil aggregate fractions along soil profiles

Different aggregates vary in their ability to retain or adsorb metals in soil. Five soil profiles were sampled from different soil horizons and grouped, and the concentrations of Al, Mg,Ca, Fe, Mn, Cd, Cu and Pb were determined in six sizes of aggregates(> 2, 2-1, 1-0.6, 0.6-0.25,0.25-0.053, < 0.053 mm). Significantly high(p < 0.05) structural stability indexes(SSI) and aggregate stability indexes(ASI) were recorded in the topsoil horizon, which may be attributed to the high soil organi...     

生物强化MBR-AF工艺短程硝化反硝化研究

本试验将短程硝化功能菌和反硝化功能菌分别接种至膜生物反应器(MBR)和上流式厌氧生物滤池(AF)中,构建了生物强化的MBR-AF短程硝化反硝化工艺,并以活性污泥作空白对照,考察该工艺对高氨氮废水的短程脱氮性能.结果表明,强化体系MBR的启动期短,仅需30d,而活性污泥体系MBR的启动期长达100d;强化体系MBR亚硝酸氮积累率始终维持在95%以上;在30℃下,随着运行时间的延长,强化体系MBR-AF工艺总氮去除率不断升高,最高达90%以上,比活性污泥体系高20%;强化体系MBR膜污染程度轻,膜的使用寿命长.说明功能菌强化在高效亚硝酸氮积累和氨氮转化方面起关键作用,可作为实现短程硝化反硝化的有效手段.     

豆奶粉废水生物处理技术

维维集团第二生产基地污水处理设施为全国第一套豆奶粉废水处理设施。该设施采用了“ＵＡＳＢ（ＡＦ）—活性污泥法”工艺。其中ＵＡＳＢ（ＡＦ）反应器是国内最大规模的生产性ＵＡＳＢ装置之一。     

双酚AF暴露对胚胎期和幼鱼期斑马鱼的毒性效应

为明确不同发育阶段的斑马鱼对BPAF(双酚AF)暴露的易感性,采用暴露试验法初步研究了BPAF对胚胎期和幼鱼期斑马鱼的发育毒性. 结果表明:①BPAF暴露可延缓胚胎期斑马鱼的发育和孵化,使其出现心包水肿、卵黄囊异常、心率下降、心脏搏动停止等症状. ②暴露96 h后,ρ(BPAF)为2.0、2.5、3.0 mg/L暴露组胚胎期斑马鱼的畸形率高达100%,暴露24 h致畸的EC₅₀(半数效应浓度)为2.00 mg/L,暴露96 h的LC₅₀(半数致死浓度)为1.84 mg/L. ③暴露72 h后,对照组幼鱼期斑马鱼鱼鳔发育缺陷率为0;除ρ(BPAF)为1.0 mg/L暴露组外,其余BPAF暴露组幼鱼期斑马鱼鱼鳔发育缺陷率为100%. ④随着暴露时间的延长以及中毒程度的加深,幼鱼期斑马鱼出现的中毒症状依次表现为心包水肿、卵黄囊水肿、背脊弯曲、心跳停止,暴露48和72 h时其心包水肿的EC₅₀分别为1.76、1.56 mg/L,暴露96 h的LC₅₀为1.77 mg/L. 胚胎期和幼鱼期斑马鱼对BPAF暴露响应的差异分析显示,幼鱼期斑马鱼对BPAF暴露的反应更为敏感,幼鱼期斑马鱼的心包水肿症状可作为BPAF毒性响应的最佳指标之一.      

AF+BAF用于处理树脂化工集中区废水厂尾水的研究

采用厌氧滤池(AF)+曝气生物滤池(BAF)工艺处理树脂化工废水,曝气生物滤池以陶粒为生物载体,进水COD为200~300 mg·L-1,实验规模均为2~4 L·d-1.实验表明,采用AF+BAF工艺对化工园区尾水有较好的处理效果,在AF停留24h,BAF停留12 h的条件下,COD的去除率最高可达73.4%,NH+4-N的去除率达到93.8%.通过气相色谱-有机质谱联用仪(GC-MS)和三维荧光光谱分析发现,系统对小分子有机物和微生物代谢产物的去除显著,但对饱和烷烃和含氮杂环类物质去除效果不佳.变性梯度凝胶电泳(DGGE)谱图显示,AF中的微生物种类比原废水厂上流式厌氧池(UASB)中更为丰富,表明化工园区废水采用二次厌氧效果明显.