Simonič Marjana
Faculty of Chemistry and Chemical Engineering, University of Maribor, 2000 Maribor, Slovenia.
Membranes (Basel). 2021 Dec 10;11(12):976. doi: 10.3390/membranes11120976.
The aim of this work was to purify mixed wastewater from three different production processes in such a manner that they could be reused as process water. The maximum allowed concentrations (MAC) from the Environmental Standards for emissions of substances released into surface water were set as target concentrations. Wastewaters contained solid particles, sodium, aluminium, chloride, and nitrogen in high amounts. Quantitatively, most wastewaters were generated in the production line of alumina washing. The second type of wastewater was generated from the production line of boehmite. The third type of wastewater was from regeneration of ion exchangers, which are applied for feed boiler water treatment. The initial treatment step of wastewater mixture was neutralisation, using 35% HCl. The precoat filtration followed, and the level of suspended solids was reduced from 320 mg/L to only 9 mg/L. The concentrations of ions, such as aluminium, sodium and chlorides remained above the MAC. Therefore, laboratory reverse osmosis was applied to remove the listed pollutants from the water. We succeeded in removal of all the pollutants. The concentration of aluminium decreased below 3 mg/L, the sodium to 145 mg/L and chlorides to 193 mg/L. The concentration of nitrate nitrogen decreased below 20 mg/L.
这项工作的目的是以可作为工艺用水重复使用的方式净化来自三种不同生产工艺的混合废水。将排入地表水的物质排放环境标准中的最大允许浓度（MAC）设定为目标浓度。废水中含有大量固体颗粒、钠、铝、氯和氮。从数量上看，大多数废水产生于氧化铝洗涤生产线。第二类废水产生于勃姆石生产线。第三类废水来自用于锅炉给水预处理的离子交换器的再生。废水混合物的初始处理步骤是使用35%的盐酸进行中和。随后进行预涂层过滤，悬浮固体含量从320毫克/升降至仅9毫克/升。铝、钠和氯等离子的浓度仍高于MAC。因此，采用实验室反渗透法从水中去除所列污染物。我们成功去除了所有污染物。铝的浓度降至3毫克/升以下，钠降至145毫克/升，氯降至193毫克/升。硝酸盐氮的浓度降至20毫克/升以下。
