BPAC-UF对二级出水中抗生素抗性基因的去除及膜污染缓解机制

采用生物粉末活性炭(BPAC)-超滤(UF)组合工艺去除控制二级出水中抗生素抗性基因(ARGs),并对ARGs的去除和BPAC缓解膜污染机制进行了探讨。结果表明：与直接超滤工艺相比,组合工艺对水中四环素类抗性基因(tetA、tetW)、磺胺类抗性基因(sul Ⅰ、sul Ⅱ)以及溶解性有机碳(DOC)的去除效果均有较大的改善,这主要是由于BPAC对ARGs的吸附降解作用所致;水中16S rDNA、int Ⅰ 1和DOC含量与不同种类ARGs浓度具有显著相关性,强化上述指标的去除可有效促进ARGs的削减;在BPAC投加量较低时,组合工艺的膜比通量较直接UF有所提高,膜污染状况明显改善;直接UF时,膜污染状况与滤饼层过滤模型的拟合度最好,而组合工艺的膜污染状况与标准膜孔堵塞模型和滤饼层过滤模型拟合度均较好。BPAC-UF组合工艺是一种较好的去除ARGs的工艺。     

负载Cr和Mo锰矿粉基催化剂的脱硝脱氨性能

氨选择性催化还原 (NH₃-SCR) 技术在焚烧烟气NO_x减排控制中广泛应用。然而,目前广泛商业化使用的SCR催化剂价格昂贵且低温活性差。以价格低廉的天然锰矿粉 (MOP) 为载体,采用浸渍法制备了Cr和Mo负载改性MOP,在温度范围150~400 ℃,对比研究了MOP和负载改性MOP的脱硝和脱氨催化效率,并基于NH₃-TPD-MS、FE-SEM-EDS、XRD和XPS对所制备的催化剂进行表征。结果表明：MOP具有较高的催化脱硝脱氨活性;Cr负载可大幅提升MOP的氨转化率,且对脱硝效率没有明显影响;Cr主要以无定形Cr₂O₃形式物理附着于MOP表面,Cr与Mn之间没有明显的相互作用。同时,Mo负载对MOP的氨催化转化也有明显促进作用,2%Mo负载仅轻微减少了MOP在150~250 ℃时的脱硝效率。在5%Mo改性MOP表面,酸性位点数量和NH₃吸附能力显著提高,但Mo与K反应生成钾钼盐结晶,导致Mn⁴⁺和O_α的相对含量降低。该研究结果可为低温低尘尾部布设SCR的同时脱硝脱氨提供参考。     

镧、锆改性油菜杆和菱角壳去除养猪废水中的磷

磷是引起地表水富营养化的重要因素之一,选择高效低成本的吸附材料是去除废水中磷的关键所在。基于此,采用共沉淀法制得镧、锆改性的油菜秆(La-BC、Zr-BC)和菱角壳(La-TN、Zr-TN),探究了其对模拟废水中磷的吸附去除;分别考察了在改性材料不同投加量、溶液pH、磷的初始浓度、反应时间等条件下对磷吸附特征的影响。FT-IR和SEM-EDS表征结果表明,镧和锆均已成功负载于油菜秆和菱角壳的表面上。La-TN、La-BC、Zr-TN和Zr-BC对磷的吸附量随改性材料投加量的增加呈指数下降,最大吸附量分别为12.49、11.41、6.85、6.83 mg$ \cdot {{\rm{g}}}^{-1}$。随pH的上升,镧改性材料对磷的吸附量呈先上升后下降的趋势,而锆改性材料呈幂函数式下降。4种改性材料的吸附动力学使用叶诺维奇模型描述更为合适,且吸附等温线使用Freundlich模型拟合更佳。La-BC、Zr-BC、La-TN、Zr-TN在养猪废水中吸附量分别为14.82、10.36、15.41和8.91 ${\rm{m}}{\rm{g}} \cdot {{\rm{g}}}^{-1}$,较改性前分别提升了34、20、53、37倍,这表明4种改性材料可作为养猪废水中除磷的潜在材料。以上研究结果可为废水中磷的去除及农业废弃物的资源化利用提供一定的参考。     

红壤立体栽培模式中玉米氮、磷、钾配方施肥数学模型的研究

采用氟、磷、钾化肥三因素通用旋转组合设计，通过计算机模拟寻优，建立了湘南砂岩红壤玉米－大豆立体栽培模式中玉米施肥量－产量、玉米施肥量－利润数学模型；优选出玉米产量和利润最高的各10套施肥方案；计算出玉米最高产量的施肥量为：尿素750kg／hm2，过磷酸钙1125kg／hm2，氯化钾332kg／hm2，N∶P2O5∶K2O＝1∶0.39∶0.58；计算出玉米最佳经济效益施肥量为：尿素712.8kg／hm2，过磷酸钙1125kg／hm2，氯化钾285.2kg／hm2，N∶P2O5∶K2O＝1∶0.41∶0.52．玉米与大豆的产量间以及两者的利润间均呈极显著正相关．     

Assessment of Genotoxicity of Lignin Substances as Risk Factors for Aquatic Ecosystems

The genotoxicity of lignin substances (LSs) isolated from biologically purified wastewaters of the pulp and paper industry was studied in experiments on Baikal endemic mollusks and corn. Both toxicity and mutagenic activity of LSs were revealed, with their levels depending on the physicochemical characteristics of LSs, the test organism, and experimental conditions. These results provide evidence that LSs discharged into water bodies create a genetic hazard to their ecosystems.     

Biodegradability and compostability of polymers—test methods and criteria for evaluation

The treatment of solid waste in controlled composting facilities is an important possibility for reducing garbage. Natural and synthetic polymeric materials can be used for many purposes, for example, as packaging materials, where compostability is required. A prerequisite for official regulations and the decision as to which materials may be composted is investigations on their biodegradability and the quality of the compost produced. Several standardization groups at the ISO, CEN, and DIN are developing definitions, test methods, and classification systems for differentiating compostable from noncompostable materials. The concept which will be standardized and used in Germany is described in detail. It includes characterization of the test material, determination of the biodegradability using laboratory tests such as simple aquatic batch tests and a controlled aerobic composting test, investigation of the disintegration of the test material in industrial or bench-scale composting facilities, and finally, chemical and ecotoxicological analysis of the compost produced.     

黄淮平原不同多熟模式生产力特征与资源利用效率研究

对黄淮平原一麦三玉米、一麦二玉米和一麦一玉米三种多熟模式的产量、资源利用及经济效益状况进行了比较分析。结果表明，三种模式年亩产均超过吨粮，说明在集约栽培条件下黄淮平原亩产吨粮的现实性。三种模式产量梯度差异表明，在水肥供应基本充足的情况下，通过集约多熟种植并配合以合理调控技术是在高产基础上进一步提高产量的有效途径。一麦三玉米最高产量达２２０１ｔ／ｈｍ２（亩产１４６７ｋｇ），是在现有技术条件下接近与突破亩产吨半粮的有效种植模式之一。全年玉米总穗数增加是增产的关键。一麦三玉米模式通过接茬移栽等综合措施的有效配合，能维持较高的同化功能，光热资源利用效率提高。经济效益上表现为高投入高产出，但部分产投经济指标有下降的趋势。从综合考虑公顷产量与公顷纯收入及物质费用、用工等因素上综合评判，一麦三玉米模式总体上表现优势。     

Prenatal diagnosis and management of anterior abdominal wall defects in the West of Scotland

An attempt was made to identify all the cases of abdominal wall defects occurring in the West of Scotland over a 7-year period to determine the current incidence, prenatal diagnosis, management, and prognosis for fetuses and neonates with abdominal wall defects. Cases were identified because they presented either for prenatal diagnosis, or to the Department of Pathology following termination or spontaneous pregnancy loss, or as neonates to the Neonatal Surgical Department. The incidence of abdominal wall defects was found to be 1 in 2500 births. Exomphalos was diagnosed before birth in 66 per cent of cases, and in 30 per cent of cases it was associated with another major abnormality. There was a 20 per cent intact survival in the cases diagnosed prenatally who had no fetal anomaly and who opted to continue with the pregnancy. Gastroschisis was diagnosed before delivery in 70 per cent of cases, and in the group who continued with the pregnancy there was an intact survival of 77 per cent. Body stalk anomalies were all diagnosed prenatally and terminated. Maternal serum alpha-fetoprotein was elevated in 89 per cent of the cases with exomphalos and in 100 per cent of the cases with gastroschisis and body stalk anomalies in which it was tested.     

Early sonographic diagnosis of body stalk anomaly

Ultrasonographic features of a fetus at 18 weeks of gestation suggesting a body stalk anomaly are presented. These included a large abdominal anterior wall defect in apparent continuity with the placenta, severe kyphoscoliosis of the lower spine, the absence of one kidney, and a very short umbilical cord with only one umbilical artery. The amniotic fluid was reduced and the fetus was almost immobile at short-interval ultrasound examinations. The pregnancy was terminated and autopsy of the fetus showed abnormalities compatible with maldevelopment of both cephalic and caudal embryonic folds.     

粉状活性炭在气浮工艺处理滇池水中的应用研究

粉状活性炭应用于气浮工艺中能发挥吸附和提供絮聚中心的协同作用 ,提高工艺效率。该工艺对滇池水的色度、COD、BOD及藻类的去除率分别达到 72 %、 57 2 %、 2 4 %和 97 6%。