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排序方式: 共有875条查询结果,搜索用时 15 毫秒
801.
确定了絮凝-氧化工艺对焦化二沉池水进行强化处理,选择了聚硅硫酸铁(PFSS)作为絮凝剂,次氯酸盐作为氧化剂,并考察了pH值、n(Fe)/n(Si)、药剂投加量等因素对处理效果的影响,得出最佳处理条件为:絮凝时废水pH=6.0~7.5,絮凝剂PFSS投加量为400mg/L(以Fe3 计),其中n(Fe)/n(Si)=2;氧化时废水pH=6.5~7.5,氧化剂M-180B投加量为0.4 g/L.处理后焦化废水的COD由1 837.6 mg/L降至125.3 mg/L,出水pH值在7.3左右,能够达标排放. 相似文献
802.
Global sea-level rise is recognised, but flooding from anthropogenic land subsidence is ignored around northern Manila Bay, Philippines 总被引:2,自引:0,他引:2
Land subsidence resulting from excessive extraction of groundwater is particularly acute in East Asian countries. Some Philippine government sectors have begun to recognise that the sea-level rise of one to three millimetres per year due to global warming is a cause of worsening floods around Manila Bay, but are oblivious to, or ignore, the principal reason: excessive groundwater extraction is lowering the land surface by several centimetres to more than a decimetre per year. Such ignorance allows the government to treat flooding as a lesser problem that can be mitigated through large infrastructural projects that are both ineffective and vulnerable to corruption. Money would be better spent on preventing the subsidence by reducing groundwater pumping and moderating population growth and land use, but these approaches are politically and psychologically unacceptable. Even if groundwater use is greatly reduced and enlightened land-use practices are initiated, natural deltaic subsidence and global sea-level rise will continue to aggravate flooding, although at substantially lower rates. 相似文献
803.
804.
典型南方水强化混凝有机物分级处理研究 总被引:10,自引:1,他引:9
采用强化常规工艺,对有效去除水体有机物,降低DBP前驱物进行了系统研究.通过烧杯试验和现场试验(中试和生产性试验)对强化混凝和使用PAM作助凝剂进行了对比;着重利用吸附树脂DAX-8的选择性吸附作用,测定了原水、沉后水的有机物分离分级组成状况.发现强化混凝和助凝强化对亲水性致UV254物质有较好地处理效果,去除率可达90%以上;现场条件下强化混凝对疏水碱性物和疏水酸性物有较好的处理能力,相应去除率分别为66%和35%;助凝强化对亲水性有机物效果较好,相应去除率为45%左右;但二者总体去除TOC效果相当. 相似文献
805.
806.
807.
808.
絮凝DAF中试工艺处理密云水库低温低浊水的影响因素 总被引:8,自引:2,他引:6
系统研究以硫酸铝和聚铝为絮凝剂时絮凝-DAF工艺中的水力学参数对除浊率的影响 .结果表明聚铝表现出了更优越的参数值 .在凝聚段 ,聚铝需要的高速混合时间为 15s,而硫酸铝则为 30s以上 ,2者对混合强度的要求为G=300~1000s-1.聚铝的絮凝反应时间为 5.0min以上 ,硫酸铝为 7.5min以上 ,而且搅拌强度范围平均G值 =40~140s-1;确定合适的总平均GT值≥2×104.当应用聚铝为絮凝剂时 ,可以采用两级或三级等速搅拌 .对于仿MJ型的释放器 ,在实验的范围内释气压力为 2.5~3.3kg/cm2 时 ,5.0 %~8.3%的回流比较合适 .气浮接触区的水力条件和停留时间对絮凝气浮的除浊效果有较大的影响 . 相似文献
809.
Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes 总被引:1,自引:0,他引:1
The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculation and advanced oxidation processes (AOP) had been studied. The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H202, UV/O3 and UV/H2O2/O3 processes was determined under acidic conditions. For each of these processes, different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater. Coffee wastewater is characterized by a high chemical oxygen demand (COD) and low total suspended solids. The outcomes of coffee wastewater treatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD, color, and turbidity. It was found that a reduction in COD of 67% could be realized when the coffee wastewater was treated by chemical coagulation-flocculation with lime and coagulant T-1. When coffee wastewater was treated by coagulation-flocculation in combination with UV/H2O2, a COD reduction of 86% was achieved, although only after prolonged UV irradiation. Of the three advanced oxidation processes considered, UV/H2O2, UV/O3 and UV/H2O2/O3, we found that the treatment with UV/H2O2/O3 was the most effective, with an efficiency of color, turbidity and further COD removal of 87%, when applied to the flocculated coffee wastewater. 相似文献
810.