Sorption of ammonium and phosphate from aqueous solution by biochar derived from phytoremediation plants

The study on biochar derived from plant biomass for environmental applications is attracting more and more attention. Twelve sets of biochar were obtained by treating four phytoremediation plants, Salix rosthornii Seemen, Thalia dealbata, Vetiveria zizanioides, and Phragmites sp., sequentially through pyrolysis at 500 °C in a N2 environment, and under different temperatures(500, 600, and 700 °C) in a CO2 environment. The cation exchange capacity and specific surface area of biochar varied with both plant species and pyrolysis temperature. The magnesium(Mg) content of biochar derived from T. dealbata(TC) was obviously higher than that of the other plant biochars. This biochar also had the highest sorption capacity for phosphate and ammonium. In terms of biomass yields, adsorption capacity, and energy cost, T. dealbata biochar produced at 600 °C(TC600) is the most promising sorbent for removing contaminants(N and P) from aqueous solution. Therefore, T. dealbata appears to be the best candidate for phytoremediation application as its biomass can make a good biochar for environmental cleaning.     

染料芬顿氧化脱色参数计算的新方法研究

以活性紫为模型染料,讨论了芬顿氧化脱色过程中散射和染料中间体对反应速率常数和脱色率的影响,提出了一种新的参数计算方法．结果表明,脱色体系的残留色度是由游离染料、两种中间体及散射四部分组成．若采用传统的测定反应速率常数和脱色率的方法,散射及中间产物的存在将导致较大的系统误差．采用多元线性回归分析法,从总残留色度中区分出散射及中间产物所占比例后,所得脱色率和反应速率常数更为合理．     

化学絮凝过程中活性染料混合物的残余色度分布

以聚环氧氯丙烷二甲胺（PEPIDA）为絮凝剂,测量了化学絮凝过程中由活性黑（KN—B）和活性艳红（K-2BP）构成的二元混合染料模拟有色废水脱色过程中的残留色度分布．溶液残留色度与游离染料、结合态染料、粒子散射5个组分的浓度有关．在PEPIDA投加量不足的区间,KN-3R优先去除．在投加量过量的区间,样品中的残余色度主要来自重新稳定的染料＋PEPIDA配合物,粒子光散射也是降低脱色率的另一个原因,它引起1—4％的脱色率下降．根据残留色度分布曲线,得到KN—B和K-2BP与PEPIDA的结合常数分别为1．86×10^6．72×10^5L／mol．     

基于Haar小波多分辨分析非线性图像消噪的研究

本文基于Haar小波多分辨分析研究非线性图像消噪 ,通过小波收缩得到消噪的阈值范围 ,提出了小波包的重构 .实验结果表明 :Harr小波图像处理 ,实现再次低通滤波图像的噪声消除 ,其高频滤波特性优良 ,图像有较好的消噪结果     

A disposal strategy of industrial hazardous wastes in the Three Gorges Region

1. Introduction The Three Gorges Region in the Yangtze River Watershed is one of the most famous tourism spots in the world due to its unique and magnificent scenery. It is along the procession of hills dominating the Yangtze River for more than 200 km. The Three Gorges Region comprises many valleys in the western Chongqing and adjoining Hubei and Hunan provinces. The total area of the region is 1 010 936 km2 with mountains occupying 78 % of the land area, hills 18.2 %, and flatlands 3.8…     

征地、拆迁案的法律经济学分析

在城市化的推进过程中，全国各地进行了大规模的征地、拆迁，引发了许多的法律纠纷案件。这些问题的出现，主要是权力与资本的失法和立法与司法的伦理判断发生了失误。应尽快在立法、行政和司法实践中解决好征地、拆迁过程中公民财产权利的保护问题。     

Effects of loading rate and hydraulic residence time on anoxic sulfide biooxidation

The optimal operation conditions in an anoxic sulfide oxidizing (ASO) bioreactor were investigated. The maximal removal rates for sulfide and nitrate were found to be 4.18 kg/(m3·d) and 1.73 kg/(m3·d), respectively. The volumetrical volumetric loading rates (LRs) observed through decreasing hydraulic retention time (HRT) at fixed substrate concentration are higher than those by increasing substrate concentration at fixed HRT. The sulfide oxidation in ASO reactor was partially producing both sulfate and sulfur; but the amount of sulfate produced was approximately one third that of sulfur. The process was able to tolerate high sulfide concentration, as the sulfide removal percentage always remained near 99% when influent concentration was up to 580 mg/L. It tolerated relatively lower nitrate concentration because the removal percentage dropped to 85% when influent con- centration was increased above 110 mg/L. The process can tolerate shorter HRT but careful operation is needed. Nitrate conversion was more sensitive to HRT than sulfide conversion since the process performance deteriorated abruptly when HRT was decreased from 3.12 h to 2.88 h. In order to avoid nitrite accumulation in the reactor, the influent sulfide and nitrate concentrations should be kept at 280 mg/L and 67.5 mg/L respectively. Present biotechnology is useful for removing sulfides from sewers and crude oil.     

村田No.778卷绕头丝饼移位故障分析及处理

根据村田No．778卷绕头纸管涨紧原理，分析了丝饼移位故障的原因，并提出了处理方法，实践证明是行之有效的。     

Testing the limits: The theoretical development and practical reality of a large-scale agarose gel treatment for a discolored Morris Louis

The raw canvas paintings of Morris Louis and similar color field works, with their extreme vulnerability to staining and structural damage, present a challenge for safe and successful treatment design, often testing the bounds of our abilities as conservators and stimulating expansion of treatment methodologies. The ability to draw from specialized textile and painting conservation techniques, and to understand their long-term implications and impact on aesthetic perception, is essential for the conservator of these modern paintings. A large Morris Louis, Untitled (Floral), held as a non-accessioned work at the Museum of Fine Arts, Houston, provided an ideal example to explore the intersection of minimally interventive treatments with the need for aesthetic perfection.     

燃烧热测定实验失败原因的剖析

该文根据氧弹热量计的构造剖析了“燃烧热测定”实验失败的因素.主要从氧弹电极短路、点火丝与电极间存在较大的接触电阻、点火丝与样品接触不良等不易察觉的隐患着手,探讨了这些因素存在的原因以及对实验成功率的影响,找到了消除导致实验失败的不利因素的方法.