A Box-Behnken design for determining the optimum experimental condition of the fungicide (Vapam) sorption onto soil modified with perlite

In the present study, response surface methodology (RSM) based on the Box-Behnken design (BBD) was employed to investigate the effects of the different operating conditions on the removal of the fungicide (Vapam) onto soil modified with perlite using sorption process. The process parameters such as pH of the fungicide solution (2, 5 and 8), temperature (15, 25 and 35°C), shaking time (2, 13 and 24 h) and the percentage of perlite in the modified soil (0, 2 and 4 %) were investigated using a four-factor-three-level Box-Behnken design at an initial fungicide concentration of C₀ = 1.6 mg/L as a fixed input parameter. A second-order quadratic model suggested the optimum conditions to be as follows: fungicide solution pH of 3.57, temperature of 15°C, shaking time of 3.5 h and 4% of perlite in the modified soil which resulted in the improvement of Vapam sorption. Under optimum conditions, the fungicide (Vapam) removal was predicted 12.88 μg/g by BBD. The confirmatory experiments were conducted and the results revealed that the fungicide removal was 13.14 μg/g which indicated that the predicted and the observed values of response (Vapam removal) were in close agreement. Therefore, the soil modified with perlite holds good potential for Vapam sorption. This is the first report on fungicide Vapam sorption onto soil modified with perlite using statistical experimental design employing response surface methodology.     

天氧膨胀床处理低浓度污水的污泥颗粒和生物活性变化

污泥的聚集形态和活性，是影响厌氧反应器处理效率的关键因素。通过对厌氧膨胀床反应器（anaerobicex—pandedblanketreactor，AEBR）处理低浓度城镇污水在启动和稳定运行期的污泥活性研究，AEBR在启动运行期内，接种颗粒污泥为适应低浓度基质条件，污泥粒径经历从大变小，再重新颗粒化粒径变大的过程。在运行期第103天，粒径小于1000μm污泥的体积比达到44．7％，平均粒径为952μm，到运行期第173天，粒径小于1000μm污泥的体积比降为28％，平均粒径达1179μm，污泥重新颗粒化完成。颗粒污泥适应新的环境后，单位重量污泥的最大比产甲烷活性（specificmetha．nogensisactivity，SMA）值和胞外聚合物含量增加，分别达到112mLCH4／（gVSS·d）和215mg／gVSS。在处理实际城镇污水的AEBR反应器内，辅酶F420含量可以有效指示污泥样品的产甲烷活性，AEBR反应器不同高度位置的污泥活性不一样，反应器底部污泥活性低于中上部区域污泥的活性。     

厌氧附着膜膨胀床处理白酒废水启动实验的研究

对用颗粒活性炭作为载体的AAFEB反应器处理白酒废水的启动实验进行了研究。结果表明：在采用恒定进水COD浓度和pH的条件下,通过不断提高温度到35℃,缩短水力停留时间至8 h,维持床层膨胀率在18%～20%,经36 d反应器成功启动,此时反应器有机容积负荷6 kg COD/（m3.d）,COD去除率达到82.9%,容积...     

纳米TiO2/EP光催化降解罗丹明B废水的研究

通过溶胶-凝胶法制备出可漂浮于水面的膨胀珍珠岩(EP)负载型TiO2,研究其在水中对罗丹明B(RB)的去除效果、吸附降解动力学以及最佳工艺条件,并研究其多次回收再生后的降解效果。结果表明,浸渍3次的负载型TiO2光催化活性最高,回收5次后活性变化很小,降解率下降不到8%;光催化剂用量为0.2 g,20 mL初始浓度为10 mg/L和15mg/L RB溶液光照6 h后降解率分别达98%和74%。在实验浓度范围内,该光催化反应可用一级反应动力学方程描述。     

含13种有机氯农药土壤标准样品的研制

采用分级稀释混合法将来自不同采样点的含不同种类和浓度的有机氯农药(OCPs)的样品进行混合制得含13种OCPs的土壤标准样品。根据GB/T 15000《标准样品工作导则》系列标准对土壤标准样品进行均匀性检验、稳定性检验,并和16家实验室协作定值。实验结果表明:土壤标准样品中13种OCPs指标均匀性良好,保证土壤标准样品足够均匀的最小取样量为0.50 g;在室温(不超过30℃)避光贮存条件下,在为期12个月的稳定性检验期间,该土壤标准样品中13种OCPs稳定性良好。该土壤标准样品中13种OCPs指标的含量范围为0.08~5.23μg/g,扩展不确定度为0.014~0.82μg/g,基本满足我国土壤、沉积物等环境样品中OCPs的质量控制检测需求。     

低能耗组合工艺处理小城镇污水的中试研究

开发中小城镇适用的简易高效污水处理成套技术,解决城镇污水处理厂的三高问题,这对于污染严重、资源短缺、经济尚不够发达的我国,在一段时期内具有重要意义。在城市污水处理厂建立了改进型膨胀颗粒污泥床(EGSB)+接触氧化组合中试工艺处理城市污水,在组合工艺停留时间为8h时,出水COD、氨氮、SS都能够达到城市污水二级排放标准。水力停留时间对组合工艺出水中的氨氮、SS去除效果影响明显,随着水力停留时间的提高,出水中的氨氮、SS下降。当处理量为1000t/d时,对该组合工艺的能耗进行了计算,吨水能耗为0.13元,为传统城镇污水处理吨水能耗的55%左右。     

膨胀蛭石同步脱铵除磷的影响因素研究

为探讨膨胀蛭石同步脱铵除磷能力,采用静态吸附实验考察了氨氮和磷酸盐共存时接触时间、粒径、pH值以及温度对膨胀蛭石去除氮磷效果的影响。结果表明,膨胀蛭石具有较好的同步脱铵除磷性能,在pH值为7,温度为25℃条件下,用1.00g粒径为80~100目膨胀蛭石对100mL氨氮和磷酸盐浓度分别为50mg/L和10mg/L的模拟污水处理4h后,氨氮和磷酸盐去除率分别达79.4%和93.0%,两者吸附过程均明显表现为"快速吸附,减速平衡"二阶段特征。中性条件下氨氮去除效果最好,酸性或碱性条件有利于磷酸盐去除,温度升高,氨氮去除率下降,磷酸盐去除率上升。等温吸附实验研究表明,膨胀蛭石对氨氮与磷酸盐的等温吸附线均较好的符合Langmuir方程。     

Production and the application of anaerobic granular sludge produced by landfill

Sludge granulation is considered to be the most critical parameter governing successful operation of an upflow anaerobic sludge blanket and expanded granular sludge bed (EGSB) reactors. Pre-granulated seeding sludge could greatly reduce the required start-up time. Two lab-scale and a pilot-scale EGSB reactors were operated to treat Shaoxing Wastewater Treatment Plant containing wastewater from real engineering printing and dyeing with high pH and sulfate concentration. The microbiological structure and the particle size distribution in aerobic excess sludge, sanitary landfill sludge digested for one year, and the granular sludge of EGSB reactor after 400 d of operation were analyzed through scanning electron microscopy (SEM) and sieves. The lab-scale EGSB reactor seeded with anaerobic sludge after digestion for one year in landfill showed obviously better total chemical oxygen demand (TCOD) removal efficiency than one seeded with aerobic excess sludge after cation polyacrylamide flocculation-concentration and dehydration. The TCOD removed was 470.8 mg/L in pilot scale EGSB reactor at short hydraulic retention time of 15 h. SEM of sludge granules showed that the microbiological structure of the sludge from different sources showed some differences. SEM demonstrated that Methanobacterium sp. was present in the granules of pilot-scale EGSB and the granular sludge produced by landfill contained a mixture of anaerobic/anoxic organisms in abundance. The particle size distribution in EGSB demonstrated that using anaerobic granular sludge produced by sanitary landfill as the seeding granular sludge was feasible.     

膨胀石墨-ZnO复合材料的制备及其光催化降解原油的性能

采用化学氧化-浸渍法制备出膨胀石墨-ZnO（EG—ZnO）复合材料，采用扫描电镜、X射线衍射仪、紫外-可见分光光度法及傅里叶变换红外光谱仪等表征手段对该复合材料的形貌、结构及其光催化降解水面原油的性能进行了研究。研究结果表明，EG—ZnO复合材料保持了膨胀石墨疏松多孔的蠕虫形貌，六方晶系结构的ZnO晶体均匀地分布于膨胀石墨的层间和表面。经紫外光照射72h后，吸附于EG—ZnO复合材料中的原油发生了显著的光催化降解反应。当该复合材料中ZnO的质量分数为80％时，原油的降解率可达35％，降解产物中有酮、醛及醇类等物质。     

CTMAB/TiO_2表面修饰膨胀珍珠岩制备及降解苯酚研究

用溴化十六烷基三甲铵(CTMAB)和/或TiO2对膨胀珍珠岩(EP)进行表面修饰,获得不同表面修饰膨胀珍珠岩(EP、TiO2-EP、CTMAB-EP和TiO2/CTMAB-EP)。并研究了其对水中苯酚的吸附降解动力学方程以及去除效果和影响因素。结果表明,膨胀珍珠岩对苯酚的吸附去除能力很小,CTMAB对其进行表面修饰后可小幅提高对苯酚的去除率,同时负载CTMAB和TiO2的膨胀珍珠岩对水中苯酚的去除率有很大提高;修复材料投加量、振荡时间、苯酚初始浓度和pH值等对苯酚的去除效果有较大影响;在溶液初始pH小于8时,TiO2对苯酚的光催化降解能力随pH增加而提高,强酸或强碱环境均不适合苯酚的光催化降解。在膨胀珍珠岩上同时负载CTMAB和TiO2可望成为一种高效去除环境中有机污染物的新型环境修复材料。