不同复合人工湿地对高污染河流有机污染物的去除

为了研究复合人工湿地对高污染河流污水中有机污染物的去除效果及规律,实验构建了不同水力负荷下的潜流+潜流、潜流+表面流、潜流+潜流+表面流、表面流+表面流等人工湿地单元组合成的5个复合人工湿地.连续运行一年以来,各复合人工湿地对BOD5、COD和SS的去除效果分别为91.9％ ～94.7％、69.3％ ～75.8％和92.3％ ～ 93.9％,相对于多级表流湿地,多级潜流湿地更利于有机污染物和悬浮物的去除;BOD5、COD和SS主要在各复合湿地的第一级湿地单元内得到去除;复合人工湿地对COD去除效果秋夏季两季好,春冬两季差;复合人工湿地能有效去除悬浮态BOD5和COD,出水中部分溶解态有机物难以有效降解.     

电炉炼锡废渣制备白炭黑

以电炉炼锡废渣为原料,经过酸浸处理去除Fe元素后,再用沉淀法制备白炭黑。探索了制备白炭黑的最佳工艺条件。分别采用XRD、FTIR、SEM及粒度分析等技术表征了白炭黑产品的物相、形貌、粒径及其分布。实验结果表明,制备白炭黑的最佳工艺条件为:Na OH溶液浓度8 mol/L、固液比1∶10(干燥废渣质量与Na OH溶液体积比,g/m L)、搅拌速率300 r/min、反应温度90℃、反应时间6 h。在最佳工艺条件下制备的白炭黑产品中Si O2质量分数达92.8%。表征结果显示,所制备的白炭黑产品是由近似球形的颗粒聚集而成的无定形非晶体水合二氧化硅,粒径为95~200 nm的颗粒约占87.5%。     

银钛共负载型光催化材料降解甲基橙废水简

以膨胀珍珠岩为载体,采用溶胶凝胶法对其进行负载,制备出不同类型的光催化材料（TiO₂-EP、Ag⁺-TiO₂-EP）,并在模拟日光条件下,研究其对甲基橙溶液的降解效果。结果表明,浸渍3次且担载0.04% Ag⁺的负载型TiO₂光催化活性最高,在光催化剂用量为0.3 g,20 mL初始浓度为10 mg/L甲基橙溶液光照4 h后降解率可达81.6%,且甲基橙的光催化降解服从一级动力学方程。回收3次后仍有较强的活性,其2 h降解率为24.8%。     

调理剂对堆肥产品重金属生物有效性的影响

城市污泥中重金属含量及其生物有效性是限制污泥农用的主要因素,因此,研究污泥堆肥化处理过程中重金属生物有效性,对污泥的农用具有重要意义。实验以城市污泥为原料,以菌菇渣和秸秆为调理剂,设置4个处理:A(污泥∶菌菇渣∶秸秆=1∶0.4∶0.025)、B(污泥∶菌菇渣∶秸秆=1∶0.3∶0.025)、C(污泥∶秸秆=1∶0.12)和D(污泥∶秸秆=1∶0.09),进行好氧堆肥实验,采用BCR顺序提取法测定各种形态的重金属,研究堆肥前后重金属形态的变化规律。结果表明,城市污泥中Cu、Ni、Pb和Cr主要以可氧化态及残渣态存在,生物有效性较低,而Zn和Cd主要以酸溶态和可还原态存在,生物有效性较高;堆肥过程显著降低了Cu、Zn、Ni和Pb的生物有效性,并改变了Cu、Zn、Ni、Pb、Cr和Cd的形态分布,使污泥中的Cu、Zn、Ni、Pb和Cd向着更稳定的可氧化态或残渣态转变;污泥经过堆肥处理后,Cu、Zn和Ni 3种重金属生物有效性关系为:ABCD,与其他处理相比,处理A残渣态的Pb和Cr增加比例较多,综合来看,处理A对重金属生物有效性的降低最为明显,重金属钝化效果最佳。     

Slightly acidic electrolyzed water for reducing airborne microorganisms in a layer breeding house

Reducing airborne microorganisms may potentially improve the environment in layer breeding houses. The effectiveness of slightly acidic electrolyzed water (SAEW; pH 5.29–6.30) in reducing airborne microorganisms was investigated in a commercial layer house in northern China. The building had a tunnel-ventilation system, with an evaporative cooling. The experimental area was divided into five zones along the length of the house, with zone 1 nearest to an evaporative cooling pad and zone 5 nearest to the fans. The air temperature, relative humidity, dust concentration, and microbial population were measured at the sampling points in the five zones during the study period. The SAEW was sprayed by workers in the whole house. A six-stage air microbial sampler was used to measure airborne microbial population. Results showed that the population of airborne bacteria and fungi were sharply reduced by 0.71 × 10⁵ and 2.82 × 10³ colony-forming units (CFU) m^?3 after 30 min exposure to SAEW, respectively. Compared with the benzalkonium chloride (BC) solution and povidone-iodine (PVP-I) solution treatments, the population reductions of airborne fungi treated by SAEW were significantly (P < 0.05) more, even though the three disinfectants can decrease both the airborne bacteria and fungi significantly (P < 0.05) 30 min after spraying.

Implications: There are no effective methods for reducing airborne microbial levels in tunnel-ventilated layer breeding houses; additionally, there is limited information available on airborne microorganism distribution. This research investigated the spatial distribution of microbial population, and the effectiveness of spraying slightly acidic electrolyzed water in reducing microbial levels. The research revealed that slightly acidic electrolyzed water spray was a potential method for reducing microbial presence in layer houses. The knowledge gained in this research about the microbial population variations in the building may assist producers in managing the bird housing environment and engineers in designing poultry houses.     

洚解菌Pigmentiphagasp．strainD-2对啶虫脒污染土壤的生物修复作用

啶虫脒属于一种新型的氯化烟碱类杀虫剂,被认为是替代有机磷农药的重要品种之一,在世界范围内已经得到了广泛的应用,其在环境中的残留备受关注,利用微生物修复异源污染物是一种有效的措施。在实验室条件下,研究了高效降解菌D-2（噬染料菌属,Pigmentiphagasp．）对被啶虫脒污染土壤的修复作用及其影响因素。结果表明,降解菌株在未灭菌土壤中的降解效果要略好于灭菌土壤,在土壤外源添加降解菌2×10^8cfu／g,温度20～40℃,弱碱性（pH7．5）的条件下,该菌株能有效降解土壤中1～200mg／kg的啶虫脒。啶虫脒施用对土壤种群结构有一定的影响,可以刺激细菌和真菌的生长,从而使土壤微生物群落结构发生改变,而降解菌的施用可缓解啶虫脒对土壤微生物的影响,修复受污染土壤。因此,人工接种降解菌D-2可提高土壤中啶虫脒的降解率,有效降低其在土壤中的残留。     

太湖流域上游外源氮、磷入湖通量模拟初步研究

湖泊-流域构成的复杂系统是湖泊富营养化研究的热点。应用SWAT模型对长江下游太湖流域上游外源氮、磷入湖通量进行模拟,以反映陆源入湖氮、磷营养盐的通量、空间分布和时间变化情况。以水文模拟为基础,引入相关系数（R）和Nash Sutcliffe效益系数（Ens）评价模拟结果。水文模拟率定期月均值R多在85%以上,Ens在024~090,模拟年平均径流量相对误差为32%。验证期各站月均值R均在80%以上,模拟年总量误差为81%。模拟结果显示,流域多年平均径流量为10415×108m3,营养盐输出浓度浙西区TN、TP分别为238 mg/L、018 mg/L;湖西区分别为568 mg/L、043 mg/L;武虞锡澄区分别为614 mg/L、040 mg/L。流域营养盐多年平均入湖通量TN为42 730 t/a,TP为3 075 t/a,2000年开始,流域TN、TP的入湖通量均有下降趋势。流域营养盐具显著空间差异,陈东港-大浦口、小梅口-长兜港、武进港-直湖港是最主要的入湖通道,贡献率分别达到27%、24%和20%,应作为流域外源营养物质管理和控制的重要区域     

Investigation on pretreatment of centrifugal mother liquid produced in the production of polyvinyl chloride by air-Fenton technique

Centrifugal mother liquid (CML) is one of the main sources of wastewater produced during the production of polyvinyl chloride in chlor-alkali industry. CML is a typical poorly biodegradable organic wastewater, containing many kinds of refractory pollutants. Specifically, it contains dissolved refractory polymers, especially polyvinyl alcohol (PVA), which can pass though the biotreatment processes and clog the membranes used for further treatment. In this study, to ensure the CML applicable to biotreatment and membrane treatment, a novel efficient and mild technique, air-Fenton treatment, was employed as a pretreatment technique to improve biodegradability of the CML and to break down the polymers in the CML. Firstly, the technique was optimized for the CML treatment by optimizing the main parameters, including the dosage of ferrous sulfate, initial pH of the wastewater, [H₂O₂]/[Fe²⁺], aeration rate, reaction time, and temperature, based on removal efficiency of COD and PVA from the CML. Then, the optimized technique was tested and evaluated. The results indicated that under the optimized conditions, the air-Fenton treatment could remove 66, 98, and 55 % of the COD, PVA, and TOC, respectively, from the CML. After the treatment, biodegradability of the wastewater increased significantly (BOD/COD increased from 0.31 to 0.68), and almost all of the PVA polymers were removed or broken down. Meanwhile, concentration of the remaining iron ions, which were added during the treatment, was also quite low (only 2.9 mg/L). Furthermore, most of the suspended materials and ammonia nitrogen, and some of the phosphorus in the wastewater were removed simultaneously.     

破碎站粉尘逸散规律及降尘技术的数值模拟及其应用

针对露天矿破碎站粉尘污染严重、治理技术中存在的缺陷,提出了超声波雾化喷雾降尘技术。以平朔安家岭煤矿为例,根据破碎站区域粉尘污染情况,应用数学模型对破碎站粉尘逸散规律进行解算,将模拟结果与现场实测数据对比,确定对卸载坑采用150~300μm雾滴粒径和对破碎机各产尘点采用1~10μm雾滴粒径的机体梁上外喷雾方式,通过对采取治理方案后破碎站粉尘浓度逸散的数值模拟和现场实际应用后的测试数据,显示全尘和呼吸性粉尘降尘效率分别达到94%和82%。结果表明,超声波喷雾降尘技术能有效降低破碎站粉尘浓度,保障了作业人员工作环境和安全。     

声场中PM2.5颗粒碰撞运动模型

建立了声场中PM2.5颗粒碰撞运动模型。模拟结果表明,颗粒碰撞前速度与水平面的夹角θ是影响颗粒运动轨迹的一个重要因素,它的改变将决定颗粒在声场中是否碰撞、碰撞的位置以及碰撞后颗粒如何运动;颗粒碰撞前的速度大小将决定颗粒碰撞后是沿声波方向运动还是逆声波方向运动或是停留在原地振动;声场频率的不同改变了颗粒在发生碰撞时的运动趋势及颗粒的在碰撞时的运动趋势,同时,声场频率的改变将影响碰撞后颗粒的振幅;声场声强的改变不但影响了颗粒运动的振幅,而且影响了颗粒碰撞后运动趋势。