Study on the dewatering process for water treatment residuals: Applicability of freezing–thawing, compression, and electro-osmotic treatment
Study on the dewatering process for water treatment residuals: Applicability of freezing–thawing, compression, and electro-osmotic treatment
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DOI：
10.1080/07373937.2016.1253021
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发表时间：
2017-06
影响因子：
3.3
通讯作者：
Yuqi Hu;Yili Wang
中科院分区：
文献类型：
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作者：
Yuqi Hu;Yili Wang
摘要通过冻融处理后的加压电渗透脱水(PEOD)工艺，研究了冻融、压缩和电渗透组合工艺对脱水水处理残渣的适用性。结果表明，在最佳冻结温度为10℃、冷冻时间为22h的条件下，−冻融处理可释放86.12%的结合水，在最佳机械压力811kPa、电压30V的条件下，后续的PEOD处理可使污水处理系统的含水率达到58.70%，预计能耗为0.107 kWh/kg(去除水分)，压缩处理可明显去除游离水，但结合水含量保持稳定。此外，冻融处理显著缩短了PEOD持续时间，从200分钟缩短到20分钟。电渗透处理可以加快脱水速度，提高脱水效率，特别是对生料污水处理厂。因此，对于温暖地区的污水处理厂，可以采用直接压缩的方式，而在寒冷地区，可以选择自然冻融结合压缩/电压缩的处理方法。
ABSTRACT The applicability of freezing–thawing, compression, and electro-osmotic unit on dewatering water treatment residuals (WTRs) was studied through freezing–thawing conditioning followed by a pressurized electro-osmotic dewatering (PEOD) process. Results showed that 86.12% of bound water was released after freezing–thawing treatment at the optimum freezing temperature of −10°C and duration of 22 h. At optimized mechanical pressure of 811 kPa and voltage of 30 V, the subsequent PEOD could lead to a water content of 58.70% in WTRs with estimated energy consumption of 0.107 kWh/kg (water removed), and free water was obviously removed by compression, while bound water content (BWC) remained stable. Moreover, freezing–thawing treatment remarkably reduced the PEOD duration from 200 to 20 min. Electro-osmotic treatment could accelerate dewatering rate and improve dewatering efficiency especially for raw WTRs. Therefore, direct compression on raw WTRs could be suited to warm regions, while natural freezing–thawing treatment combined with compression/electrical compression will be selected in cold regions.