Department of Environmental Sciences and Engineering, Kheradgarayan Motahar Institute of Higher Education, Mashhad, Iran.
Sustainable Developments in Civil Engineering Research Group, Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
Environ Sci Pollut Res Int. 2018 Dec;25(34):33978-33991. doi: 10.1007/s11356-018-3340-0. Epub 2018 Oct 2.
Paper mill wastewater leads to a serious damage on the environment owing to the high content of organic matters, suspended solids, toxic substances, and lignin. Hence, exploring new treatment technologies is the passion of environmental engineers to minimize the effluent impact on the environment and cleaner production aspects. This research focused on the performance of full-scale coagulation-fluctuation/DAF system for pre-treatment of high strength wastepaper-recycling wastewater and its effect on biodegradability improvement. To optimize unit performance, optimum coagulant and flocculant doses were firstly determined by jar test without prior change and adjustment of pH in lab-scale experiments. The optimum dosages were obtained by 1500 mg L polyaluminum chloride (PACl) as coagulant coupled with 40 mg L cationic polyacrylamide (C-PAM) as flocculant. Percentage removals of 39 ± 10, 6.8 ± 3.6, 31.0 ± 6.7, 24.0 ± 3.8, and 33.0 ± 20.0 were achieved for COD, sCOD, BOD, sBOD, and color, respectively. The average BOD to COD ratio after pre-treatment increased from 0.44 to 0.5, whereas the ratio of sBOD/sCOD dropped from 0.65 to 0.53. A superior effectiveness in reduction of TSS (98.1%) and VSS (98.4%) was also achieved. The results show that the application process is able to prevent malfunction operation in the following bioreactors which is obtainable through bio-treatability enhancement of pre-treated wastewater and reducing the risks of clogging and sludge washout. Attached growth processes are suggested to be applied in the further anaerobic/aerobic processes because of high proportion of soluble fraction of COD in the effluent to avoid poor floc formation and dispersed growth problems.
造纸厂废水由于有机物含量高、悬浮物、有毒物质和木质素含量高，对环境造成严重破坏。因此，探索新的处理技术是环境工程师的热情所在，旨在将废水对环境的影响和清洁生产方面降到最低。本研究专注于全尺寸混凝-波动/DAF 系统预处理高强度废纸回收废水的性能及其对提高可生物降解性的影响。为了优化单元性能，首先在实验室规模实验中通过烧杯试验确定了最佳的混凝剂和絮凝剂剂量，而无需预先改变和调整 pH 值。通过使用 1500mg/L 的聚合氯化铝（PACl）作为混凝剂，结合 40mg/L 的阳离子聚丙烯酰胺（C-PAM）作为絮凝剂，获得了最佳剂量。COD、sCOD、BOD、sBOD 和颜色的去除率分别为 39±10%、6.8±3.6%、31.0±6.7%、24.0±3.8%和 33.0±20.0%。预处理后平均 BOD/COD 比从 0.44 增加到 0.5，而 sBOD/sCOD 比从 0.65 降低到 0.53。TSS（98.1%）和 VSS（98.4%）的去除效率也很高。结果表明，该应用过程能够防止后续生物反应器发生故障，这是通过提高预处理废水的可生物处理性和降低堵塞和污泥冲刷的风险来实现的。建议在进一步的厌氧/好氧工艺中应用附着生长工艺，因为废水中 COD 的可溶部分比例高，以避免形成较差的絮体和分散生长问题。
