种衣剂废水处理方法研究

发布时间：2018-03-21 19:52

  本文选题：种衣剂废水　切入点：混凝沉淀　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：种衣剂作为赋予农用种子抗病虫害功能的高效、安全、环保型农药制剂受到越来越多的关注。在种衣剂生产和提纯过程中,会产生高COD、高色度和含生物抑制性农药(杀虫剂、杀菌剂)的清洗废水。针对此种废水的性质,在种衣剂废水处理工程中,为确保其出水达到《污水综合排放标准》[GB8978-1996]一级排放标准,选用采用混凝沉淀-厌氧-生物接触氧化-深度氧化组合工艺对其进行处理,以出水COD和色度为主要指标,考察各主要处理单元以其及组合工艺的处理效果。在混凝沉淀处理单元,考察了混凝剂的种类、助凝剂及其投加量和投加量等参数工艺和操作条件对COD和色度去除效果。其实验结果表明该研究发现,混凝沉淀处理该类种衣剂废水效果明显,可明显地提高废水的可生化性,其COD和色度去除率分别达到81.7%和56.3%,BOD5/COD(B/C)从起初的0.28升至0.43,颜色由深红色乳液变为透明的浅红色。在生化混凝沉淀处理单元经混凝沉淀预处理后的种衣剂废水,采用"厌氧-接触氧化"生化处理。在厌氧处理单元,稳定运行期的进水COD约900.0 mg/L,容积负荷则维持在0.8 kg COD/m3.d和停留时间为24 h时,废水COD和色度去除率分别稳定在33%和80%左右,其出水COD和色度分别保持在605.3 mg/L和150倍;在生物接触氧化处理单元,其溶解氧浓度保持在4.0～6.0 mg/L之间,经24 h 运行,其出水 COD 由 605.3 mg/L 降至 203.7 mg/L。在深度氧化单元,选择Fe(Ⅱ)/次氯酸钠(NaClO)氧化法,考察了 NaClO和FeSO4投加量和反应时间条件等参数对出水COD的影响。其结果显示表明,当NaOCl投加量为5.0ml/L,FeSO4投加量为0.4g/L,以快速(200r/min)搅拌1 h,出水种衣剂废水的COD去除率达到约为55.2%,最终出水的COD为94.5 mg/L。经过本研究选用的组合工艺处理后的种衣剂废水,COD从最初的4400 mg/L降至94.5 mg/L,去除率高达97.8%,色度从最初的1600倍降至无色。
[Abstract]:Seed coating agents, as an effective, safe and environmentally friendly pesticide preparation to endow agricultural seeds with resistance to diseases and insect pests, have attracted more and more attention. In the production and purification of seed coating agents, high COD, high color, and biosuppressive pesticides (insecticides, insecticides, insecticides) are produced. Cleaning wastewater of fungicides. In order to ensure that the effluent meets the first class discharge standard [GB8978-1996] in the seed coating wastewater treatment project, The coagulation-sedimentation, anaerobic, biological contact oxidation-depth oxidation process was used to treat the effluent. The COD and chromaticity of the effluent were taken as the main indexes. The treatment effect of each main treatment unit and its combination process was investigated. In the coagulation sedimentation treatment unit, the kinds of coagulant were investigated. The effects of coagulation aid, dosage and dosage of coagulant on the removal of COD and chromaticity were studied. The experimental results showed that the coagulant sedimentation treatment of this kind of seed coating wastewater was effective, and the biodegradability of the wastewater could be improved obviously. The removal rates of COD and chromaticity reached 81.7% and 56.3% respectively from 0.28 to 0.43, and the color changed from dark red emulsion to transparent light red. In the anaerobic treatment unit, the influent COD of stable operation period is about 900.0 mg / L, the volumetric load is maintained at 0.8 kg COD/m3.d and the residence time is 24 h, the removal rate of COD and chroma of wastewater is about 33% and 80%, respectively, in the anaerobic treatment unit, and when the volume load is maintained at 0.8 kg COD/m3.d and the residence time is 24 h, the removal rate of COD and chromaticity of wastewater is about 33% and 80% respectively. The COD and chroma of the effluent were kept at 605.3 mg/L and 150 times respectively, and the dissolved oxygen concentration in the biological contact oxidation unit was kept between 4.0 mg/L and 6.0 mg/L. After 24 h operation, the COD of the effluent decreased from 605.3 mg/L to 203.7 mg / L in the deep oxidation unit. The effects of NaClO and FeSO4 dosage and reaction time on the COD of effluent were investigated by the method of Fe (鈪，

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