Purpose

In this study, the coagulation performance of a biomass-based fly ash leachate (FLC) and alum on a thermomechanical pulping (TMP) pressate was compared systematically.

Methodology

Fly ash leachate (FLC) was first produced via mixing fly ash with water and extracting the soluble part of fly ash. Then, the coagulation performance of FLC in TMP pressate was studied and compared with that of alum, as a benchmark. The effects of the dosage of the coagulant and treatment time on the chord length of particles in the TMP pressate as well as the chemical oxygen demand (COD) and lignin content of the TMP pressate were systematically monitored.

Results

It was observed that FLC and alum coagulated the dissolved materials of the TMP pressate. The COD and lignin removals were 18.4% and 26.9%, respectively, when FLC was added to a TMP pressate under the conditions of 5060 mg/kg FLC/TMP pressate, 200 rpm, pH 12.5 298 K and 30 min. Calcium ions of FLC were the main contributor to the coagulation performance of FLC for TMP pressate. The chord length analysis of solution revealed that the particles in the 1–10 and 10–50 µm ranges were rapidly coagulated, forming larger aggregates in the 50–150 and 150–300 µm size ranges and reaching the maximum mean chord length within approximately 4 min when the coagulant was an alum. FLC led to the slower conversion of particles in 1–10 µm range and a faster conversion in the 10–50 and 50–150 µm ranges than alum did. As FLC can be readily produced inexpensively onsite, it could be a suitable coagulant for eliminating the dissolved components of the pulp and paper effluents.

Graphic Abstract

中文翻译：

---

生物质粉煤灰渗滤液在热机械制浆（TMP）压榨物中的凝结效率

目的

在这项研究中，系统地比较了基于生物质的粉煤灰浸出液（FLC）和明矾在热机械制浆（TMP）压榨物中的混凝性能。

方法

粉煤灰渗滤液（FLC）首先通过将粉煤灰与水混合并提取粉煤灰的可溶部分来生产。然后，研究了FLC在TMP加压液中的凝结性能，并与明矾作了比较。系统地监测了凝结剂的剂量和处理时间对TMP压入物中颗粒弦长以及TMP压入物中化学需氧量（COD）和木质素含量的影响。

结果

观察到FLC和明矾使TMP压合物的溶解物质凝结。当在5060 mg / kg FLC / TMP压榨液，200 rpm，pH 12.5 298 K和30分钟的条件下将FLC添加到TMP压榨液中时，COD和木质素的去除率分别为18.4％和26.9％。FLC的钙离子是FLC对TMP加压液的凝结性能的主要贡献者。溶液的弦长分析显示，在1–10和10–50 µm范围内的粒子快速凝结，在50–150和150–300 µm尺寸范围内形成较大的聚集体，并在大约4的范围内达到最大平均弦长分钟，当凝结剂是明矾时。与明矾相比，FLC导致1–10 µm范围内的颗粒转化较慢，而10–50和50–150 µm范围内的颗粒转化更快。

图形摘要