江西境内萍水河水质状况评价及变化趋势分析

通过对萍水河监测断面水质监测数据的分析,利用内梅罗污染指数法及秩相关系数法进行水质评价,分析了"十二五"期间萍水河水质情况及其变化趋势,阐述了萍水河的水质空间分布规律。结果表明:萍水河断面水质以Ⅱ类、Ⅲ类为主,水质总体较好,但呈下降趋势;其上游水质较好,中游较差,下游略有好转,麻山河等萍水河支流水质较好。     

Ecological characteristics of Alhagi sparsifolia Shap. seedling roots under different irrigation treatments

An trench profile method was used to study seasonal variation of root ecological characteristics of Alhagi sparsifolia Shap. seedlings under different irrigation treatments. The results indicated the following: (1) Root morphology: under excellent soil moisture conditions, A. sparsifolia seedlings developed many horizontal roots and root sprouts to compete for light; but under poor soil moisture, the vertical root system expanded its resource space into deeper soil. Plasticity of root morphology is an important strategy to capture water and adapt to the hyperarid environment. (2) Root/shoot ratio: root/shoot ratio increased with declining soil moisture, and this trend was more obvious later in the growing season. Increase of root/shoot ratio is a strategy for adapting to drought. (3) Growth of root system: The seedlings prefer to develop roots in shallower surface layers with less water availability. The growth depth and vertical growth rate of roots increased with decreased soil moisture. (4) Accumulation of root biomass: biomass and surface area of the root system decreased with increased soil depth, with the roots distributed in an ??inverted pyramid?? in vertical section view. The formation of root biomass conformed to a logistic ??slow-quick-slow?? growth curve, and total biomass decreased with intensity of soil drought. The findings will provide data useful for effective restoration of A. sparsifolia and better utilization of water resources in hyperarid regions.     

不同应力状态下混凝土碳化耐久性试验研究

旨在研究混凝土在应力和碳化共同作用下的损伤机理。试验采用无应力、拉应力、压应力3种试件进行了快速碳化试验。测量了受力在0,0.15,0.3,0.45,0.6,0.75倍拉/压设计强度下的混凝土的碳化深度。实验结果表明,拉、压应力分别加快和减缓了混凝土碳化速率,且应力越大,对混凝土碳化的影响也越大。说明应力对混凝土碳化耐久性的影响是显著的。与此同时,在考虑应力影响系数的情况下,结合使用条件建立了大气环境中应力状态下混凝土碳化深度的预测模型。通过计算值和实验值的计算对比,证明了该模型的有效性。     

Levels and distribution patterns of short chain chlorinated paraffins in sewage sludge of wastewater treatment plants in China

Short chain chlorinated paraffins (SCCPs) are listed as persistent organic pollutant candidates in the Stockholm Convention and are receiving more and more attentions worldwide. In general, concentrations of contaminants in sewage sludge can give an important indication on their pollution levels at a local/regional basis. In this study, SCCPs were investigated in sewage sludge samples collected from 52 wastewater treatment plants in China. Concentrations of total SCCPs (ΣSCCPs) in sludge were in the range of 0.80-52.7 μg/g dry weight (dw), with a mean value of 10.7 μg/g dw. Most of SCCPs in the sludge samples showed a similar congener distribution patterns, and C(11) and Cl(7,8) were identified as the dominant carbon and chlorine congener groups. Significant linear relationships were found among different SCCP congener groups (r(2) ≥ 0.9). High concentrations of SCCPs in sewage sludge imply that SCCPs are widely present in China.     

China’s wastewater discharge standards in urbanization

Background and purpose

China's environmental problems and pollution control have global implications. China??s water pollution has been increasing with its urbanization and industrialization. Although great efforts have been taken to keep its wastewater discharge standards in pace with the water pollution development and technological advances, many challenges remain. A summary of the past achievements and lessons as well as the current problems in water pollution may provide a basis for future improvements in China and a reference for other countries.

Methods

Statistical data are summarized to reveal the evolution of China??s population, wastewater discharge and corresponding discharge standards over the past four decades. In particular, the specific control indexes and number of controlled items are discussed in details. The present water pollution situation is clearly illustrated by the water pollution map and the water quality distribution diagram. A comparison between China??s present wastewater discharge standards and those in the USA and the EU are also presented to find the possibilities for future improvement.

Results

The historical origins, major challenges and future perspectives of China??s wastewater discharge standards are overviewed. The barriers and ongoing efforts for standards formulation and implementation are highlighted. Some suggestions for future endeavors are given.

Conclusions

China??s wastewater discharge standard system has seen significant improvement over the past decades, but it still has many defects and limitations. Nonetheless, unprecedented great efforts are underway to address all these challenges. More stringent standards and subsequently a cleaner water environment in China can be expected in the near future.     

气相色谱/质谱测定苯酚丙酮生产废水中半挥发性有机物

建立了用二氯甲烷液液萃取对苯酚丙酮生产废水进行预处理,气相色谱/质谱法同时测定废水中半挥发性有毒有机物异丁酸、异丙苯、α-甲基苯乙烯、2-苯基丙醛、苯乙酮、2-苯基-2-丙醇、α-甲基苯甲醇、苯酚和苯甲酸等的定性定量分析方法。色谱条件为:DB-17MS型色谱柱,程序升温,进样量为1μL,质量选择检测器(MSD)。实验结果表明,该色谱条件对苯酚丙酮生产废水中各半挥发性组分具有较好的分离效果。而对9种组分的最低检出限均低于0.04mg/L,精密度实验相对标准偏差2.14%～5.15%,实际水样的加标回收率稳定。苯酚丙酮生产废水中的主要污染物为2-苯基-2-丙醇,其次为苯酚、异丁酸和异丙苯。     

外负载Ce-TiO_2/活性炭复合体对亚甲基蓝光催化

用超临界流体沉积法处理过的活性炭（AC）为载体,钛酸丁酯为前驱物,硝酸铈为掺杂剂,乙醇为溶剂,制备了外负载TiO2-Ce/Csurf复合材料。在紫外灯照射下,以亚甲基蓝溶液为标准模拟降解物,研究了复合体不同热处理温度、不同浓度、不同亚甲基蓝浓度、不同铈掺杂量以及不同反应温度对光催化性能的影响。结果表明：外负载催化剂的催化性能要高于纯TiO2和体负载催化剂。铈离子掺杂能抑制TiO2晶粒生长,阻碍了TiO2由锐钛矿型向金红石型的转变。当铈离子掺杂量为1.5%,热处理温度为600℃,亚甲基蓝溶液初始浓度为5.5 mg/L,样品浓度为1.5 g/L时,光催化性能最好。     

脉冲电絮凝法处理黄连素废水

以Fe为电极,采用脉冲电絮凝法对实际黄连素制药废水进行处理。为了确定脉冲电絮凝法处理黄连素废水最优工艺条件,选择占空比、电流密度、脉冲频率、电极间距和pH等5个因素,开展了正交实验研究。对正交实验结果进行极差与方差分析,确定了各因素的显著性及优选条件。结果表明,各因素对废水COD去除率影响程度依次为:占空比>pH>电极间距>脉冲频率>电流密度;对黄连素去除率影响程度依次为:占空比>pH>电流密度>脉冲频率>电极间距。最优工艺条件为电极间距为1.5 cm,电流密度为16.7 mA/cm2(电流3.5 A,电压11.2 V),占空比为0.4,脉冲频率为0.1 kHz,pH为10,此时废水的COD与黄连素的去除率分别为61%与74%。     

黄姜纤维素渣固态发酵生产蛋白饲料

利用酵母菌和黑曲霉对黄姜纤维素渣进行固态发酵生产蛋白饲料。研究了接种量、温度、固液比、发酵时间和通风量对发酵的影响。同时在单菌种发酵的基础上,对酵母菌和黑曲霉的混合发酵进行了初步探索,研究结果表明,混菌发酵的实验效果比单菌发酵的效果好。当条件为:黄姜纤维素渣25 g,加入脲0.53 g,KH2PO40.05 g,K2HPO40.05 g,Mg-SO40.05 g,NaCl 0.05 g,CaCl20.01 g,接种量为14%,温度30℃,固液比2∶1,发酵产物的蛋白质量分数可达到13.98%。     

猪场废水厌氧发酵液循环脱氮工艺

研究了水解酸化与生物接触氧化组合循环工艺处理猪养殖场废水厌氧发酵液的脱氮特性,重点考察了组合工艺的最佳运行工况和参数,同时讨论了组合工艺低温运行的性能。结果表明,水力停留时间24 h和污水循环比1∶3为最佳运行工况,此时出水氨氮浓度为2.16～8.20 mg/L。溶解氧(DO)浓度2～3 mg/L和有机负荷3 g/L以下为最佳运行参数,出水氨氮浓度稳定在10 mg/L以下。在春季低温条件下(8～12℃),组合工艺也能较好运行,水解酸化池内小分子有机酸产生总量为114.50～244.22 mg/L。组合工艺连续运行3个月以上,污染物去除效果稳定。