聚硅酸锌铝的制备及其性能研究

以硅酸钠、硫酸锌、硫酸铝为原料,通过共聚法制备了无机高分子絮凝剂聚硅酸锌铝（PSZAS）,研究了Na₂SiO₃的摩尔浓度、活化时间、Al/Si、Zn/Si 配比及絮凝剂的投加量对絮凝效果的影响,用X-射线衍射（XRD）和电子扫描电镜（SEM）对该絮凝剂的结构及形貌进行了表征。结果表明：当硅酸钠的浓度为0.4 mol/L,硅酸活化时间为2 h,Si∶Al∶Zn=1∶1∶1.5,絮凝剂投加量为20 mL/L废水时,絮凝剂的电中和能力和吸附架桥能力最强,絮凝剂对含H-酸染料模拟废水的絮凝效果最好。     

How good is GLASOD?

The Global Assessment of Soil Degradation (GLASOD) has been the most influential global appraisal of land quality in terms of environmental policy. However, its expert judgments were never tested for their consistency and could not be reproduced at unvisited sites, while the relationship between the GLASOD assessments of land degradation and the social and economic impact of that degradation remains unclear. Yet, other methodologies that could respond to urgent calls for an updated assessment of the global environmental quality are not operational or, at best, in progress. Therefore, we evaluate the reliability and social relevance of the GLASOD approach and assess its candidacy for new global environmental assessments. The study concentrates on the African continent, capitalizing on new GIS data to delineate and define the characteristics of GLASOD map units. Consistency is tested by comparing expert judgments on soil degradation hazard for similar combinations of biophysical conditions and land use. Reproducibility is evaluated by estimating an ordered logit model that relates the qualitative land degradation classes to easily available information on explanatory variables, the results of which can be used to assess the land degradation at unvisited sites. Finally, a cross-sectional analysis investigates the relation between GLASOD assessments and crop production data at sub-national scale and its association with the prevalence of malnutrition. The GLASOD assessments prove to be only moderately consistent and hardly reproducible, while the counter-intuitive trend with crop production reveals the complexity of the production-degradation relationship. It appears that increasing prevalence of malnutrition coincides with poor agro-productive conditions and highly degraded land. The GLASOD approach can be improved by resolving the differences in conceptualization among experts and by defining the boundaries of the ordered classes in the same units as independent, quantitative land degradation data.     

On-line production of ferrate with an electrochemical method and its potential application for wastewater treatment – A review

A number of studies on the oxidation of various organic/inorganic contaminants by ferrate(VI) were reported in the 1980s and 1990s. The exploration of the use of ferrate(VI) for water and wastewater treatment has been well addressed recently. However, challenges have existed for the implementation of ferrate(VI) technology in practice due to the instability of a ferrate solution or high production cost of solid ferrate products. The research has been carried out aiming at the generation and application of ferrate(VI) in situ. This paper thus reviews ferrate chemistry and its overall performance as a water treatment chemical, discusses the factors affecting the ferrate yield efficiency using the electrochemical method, and finally, summarises the work on the production and use of ferrate in situ which is currently under study.     

Assessment of Reclaimed Municipal Wastewater Application on Rice Cultivation

Field research was carried out to assess the effects of the application of reclaimed municipal wastewater on rice cultivation in Thessaloniki, Greece during a 2-year period (1999–2000). Effects on production cost, soil composition, and health risk were examined. A randomized complete block design was used for the paddy field with three treatments and four replicates. The treatments were (1) river irrigation water with N–P fertilization, (2) reclaimed wastewater irrigation with surface N fertilization, and (3) reclaimed wastewater irrigation without fertilization. The results showed that the total production cost decreased 8.8% and 11.9% by applying the second and third treatments, respectively, compared to the first treatment, without significant differences in the agronomic and rice quality traits. Soil composition showed discrepancies between the 2 years and the three treatments, whereas the pathogens of the reclaimed wastewater and rice tissues posed a low human risk when taking the needed precautions.     

纳米级聚合氯化铝处理石化废水絮凝效果研究

采用自制的纳米级聚合氯化铝絮凝荆处理石大科技股份公司胜华炼油厂隔油池出水,以处理后水样的透光率作为混凝沉降效果的评价指标,并对絮凝剂投加量、搅拌速度、搅拌时间等影响混凝效果的因素进行了研究。试验表明,聚合氯化铝对石化废水的处理达到较为理想的效果,聚合氯化铝混凝处理石化废水的最佳条件为：纳米级聚合氯化铝投加量为15mg／L左右,慢速搅拌的搅拌速度为50～60rpm,快速搅拌的搅拌速度为190—225rpm,快速搅拌时间90s。慢速搅时间10min时效果最佳。使用Al-Ferron逐时络合比色法及XRD对絮凝荆进行了表征,结果证实样品中Alb含量可达到85％左右。     

负载型TiO2薄膜光催化剂降解亚甲基蓝

采用溶胶-凝胶法制备了玻璃负载的TiO2薄膜光催化剂,研究了该催化剂对亚甲基蓝溶液的光催化降解,考察了反应时间、水样的初始浓度、溶液的pH等对光催化降解效果的影响。     

固定化真菌漆酶对分散兰-2BLN的脱色和降解

采用改良壳聚糖固定化的真菌漆酶对染料分散兰-2BLN进行脱色和降解条件的研究,探索了固定化漆酶活力、处理时间、染料浓度、温度和pH对其降解效果的影响。结果表明,固定化漆酶脱色降解分散兰-2BLN的适宜条件为：固定化漆酶活力18.2U／mL,染料浓度100mg／L,温度40℃,pH4.6,在上述条件下降解1.5h,分散兰-2BLN脱色率能达到87.68％。重复分批使用固定化漆酶处理2BLN兰,在使用6批次后,脱色率仍能保持在55％以上,其催化效率得到了较大提高。     

废水中环氧丙烷降解菌株的培育及降解效果研究

本文通过对污泥的驯化筛选得到4株降解环氧丙烷废水的优势茵A、B、C、D,并对降解效果最好的一个菌株A进行研究,得到其最佳降解条件是温度为30℃、pH为5、废水浓度为20％、反应时间为9h,其COD去除率可达到63．24％左右。     

改性纤维球在油田污水处理中的应用

纤维球过滤可充分发挥出滤料深层的截污能力。介绍了改性纤维球滤料的技术要求,在使用过程中主要存在的几个问题,改性纤维球过滤器的结构及特点,在油田污水处理中的现场应用情况。试验证明,经50%互溶剂+2%表面活性剂+2%烧碱清洗后,改性纤维球滤料颜色变为灰白,纤维之间松散,不存在粘结现象,清洗较为彻底。     

粉煤灰处理染料废水的研究

利用粉煤灰吸附性能较好、来源广泛及价格低廉等特点,对染料废水进行吸附试验研究。结果表明,粉煤灰的活化方式、粒度及用量对染料废水吸附性能有影响。160—200目30%硫酸活化粉煤灰吸附能力最强,且对染料废水的吸附过程符合Langmuir吸附等温曲线,最大吸附量为667mg/g。