通化钢铁公司动力厂给水絮凝剂选择实验

通化钢铁公司的生产用水是由自备水厂提供的,该水厂在冬季运行时,易产生反应池污泥上浮,出水达不到用水标准。通过改变混凝剂的种类,采用新型混凝剂聚合氯化铝铁(PAFC)与聚丙烯酰胺(PAM)配合使用,可以满足用水水质要求,且药剂费用也较低,在最佳实验条件下,PAFC投加量为30mgL,PAM投加量为0.1mgL时,出水浊度可以达到4.1NTU。针对水厂运行中出现的反应池污泥上浮问题,进行了详细的研究,发生该现象的原因主要是由于水泵夹气现象产生的,可以通过调节水泵,增加进水水面高度等方法加以解决。     

厌氧UASB-混凝沉淀法处理高浓度屠宰废水

应用UASB混凝沉淀法对高浓度屠宰废水的处理进行了试验研究。用UASB反应器处理屠宰废水,CODCr容积负荷可达6.8g(L·d),CODCr去除率达93%左右,并对UASB出水投加一定量的混凝剂PFS和助凝剂MZ,实验表明:系统出水达到《肉类加工工业水污染物排放标准》(GB1345792)二级标准。     

污水处理厂化学除磷精确控制系统研究——以山东某污水处理厂为例

我国总磷排放标准日趋严格,污水处理厂为保证出水总磷达标,过量投加化学除磷剂,造成资源浪费.为在出水水质达标的基础上节省化学除磷剂添加量,以山东某污水处理厂为例设计了化学除磷精确控制系统.在充分考虑仪器故障潜在风险的前提下,根据进水磷酸盐负荷实时调整药剂投加量,采用"前馈+反馈"控制的模式,实现加药过程的自动化及智能化....     

Traction performance across the life of slip-resistant footwear: Preliminary results from a longitudinal study

Introduction: Slips, trips, and falls are a major cause of injury in the workplace. Footwear is an important factor in preventing slips. Furthermore, traction performance (friction and under-shoe fluid drainage) are believed to change throughout the life of footwear. However, a paucity of data is available for how traction performance changes for naturally worn, slip-resistant footwear. Method: The presented research is a preliminary analysis from an ongoing, larger study. Participants wore slip-resistant footwear while their distance walked was monitored. Friction and under-shoe fluid pressures were measured using a robotic slip tester under a diluted glycerol contaminant condition after each month of wear for the left and right shoes. The size of the worn region was also measured. Results: Friction initially increased and then steadily decreased as the distance walked and the size of the worn region increased. Fluid pressures increased as the shoes were worn and were associated with increased walking distance and size of the worn region. Discussion: Consistent with previous research, increases in the size of the worn region are associated with increased under-shoe fluid pressures and decreased traction. These trends are presumably due to reduced fluid drainage between the shoe-floor interface when the shoe becomes worn. Conclusions: Traction performance changes with natural wear. The distance walked in the shoe and the size of the worn region may be valuable indicators for assessing loss of traction performance. Practical Applications: Current shoe replacement recommendations for slip-resistant shoes are based upon age and tread depth. This study suggests that tools measuring the size of the worn region and/or distance traveled in the shoes are appropriate alternatives for tracking traction performance loss due to shoe wear.     

汽车空气滤芯厂聚氨酯废水处理的试验研究

采用“混凝—破乳—活性白土吸附”的物化组合水处理工艺降解某汽车空气滤芯厂的聚氨酯PU工艺废水。该组合工艺将COD从9500 mg/L降至200 mg/L,其去除率大于95%,出水可以直接排放到厂区内的污水生化处理池。该组合工艺处理成本低。     

玉米酒精生产过程COD产污系数计算模型的建立

基于玉米酒精生产工艺流程,采用实测和物料衡算结合的方法,分析玉米酒精生产关联物料,并建立关联物质量平衡方程。实验测得绝干全玉米的COD负荷值为1611 mg/g,在此基础上推导出玉米酒精生产工艺的COD产污系数与淀粉出酒率、玉米淀粉含量、胚芽收率、玉米油收率、杂醇油收率和干玉米酒糟收率的量化模型。采用国内行业相关参数值代入模型进行核算,并与《第一次全国污染源普查工业污染源产排污系数手册》和《清洁生产标准酒精制造业》(HJ 581—2010)中的相关系数进行对比。结果表明:手册值在模型计算范围内;模型计算值略大于标准指标,与标准中一级COD产污指标基本一致。     

预氧化+混凝沉淀+MAP预处理畜禽养殖废水研究

畜禽养殖废水由于具有高COD、高SS、高氨氮等特点,属于高浓度难降解废水,不宜直接采用生化处理,需对其进行预处理。试验采用预氧化+混凝沉淀+MAP对畜禽养殖废水进行预处理。结果表明:预氧化+混凝沉淀+MAP沉淀预处理畜禽养殖废水具有极强的可行性,同时当次氯酸钠投加量为1260 mg/L,PAC为700 mg/L,PAM投加量为10 mg/L时,处理效果最佳,并且药剂投加不宜采用同步进行,适宜先进行预氧化,然后进行强化混凝,最后采用MAP沉淀法处理畜禽养殖废水,可以达到更好的预处理效果,提高可生化性。     

聚硅硫酸铁混凝去除石化废水二级出水中有机污染物的研究

采用聚硅硫酸铁(PFSiS)混凝剂对石化废水二级出水进行了强化混凝实验,考察其对有机污染物的去除效果,并对不同时期的絮体微观结构进行了研究。结果表明,PFSiS可有效去除水中COD,当PFSiS投加量为40 mg/L(以Fe计),静置时间为120 min,COD去除率可达50%左右;絮体的微观结构为空间网状结构,随静置时间的延长,絮体密实程度提高,颜色加深。     

弹性系数在“绿色GDP”核算研究中的应用

本文总结了四川省在"中国环境经济核算体系总体框架"下"绿色GDP"核算结果的局限性,进而提出了"绿色弹性系数"的概念,并比较分析了2005~2007年四川省各地区的"绿色弹性系数",有效地反映了环境污染负荷的变化与社会经济的发展相互制约的关系以及发展趋势和规律。     

基于Voronoi图的居民点空间分布特征研究——以甘肃省为例

采用GIS查询统计与Voronoi图CV值相结合的分析方法,通过计算点状目标的Voronoi多边形面积的变异系数(CV值)方法来分析点状目标的空间分布特征。分析结果表明,甘肃省有9个市、县为随机分布,其余市、县为集群分布,但总体上为集群分布。最近邻指数和CV值通过级差变换后,发现其存在相关性,相关系数为负值,表明两者之间存在负相关关系。