Department of Applied Sciences, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia.
Department of Applied Sciences, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia.
J Environ Manage. 2024 Sep;368:122207. doi: 10.1016/j.jenvman.2024.122207. Epub 2024 Aug 23.
Mountain salts produced from the highland region in NE Sarawak have a market value and also provide basic income to the communities. During the salt-making process, microplastics (MPs) may enter into commercial table salts from various sources, which has not been explored yet. Hence, the current research investigates the presence of MPs in the rock salts produced from the highland saline water in two different locations (L1 and L2) in NE Sarawak. Among the brine water and rock salt samples analysed, the highest concentrations of MPs were detected from the salt samples. It has been revealed that both the water and salt samples have the highest concentration of MPs occurring within the size range of 1-1000 μm. Transparent MPs are the most common colour observed in both salt and water samples, followed by white, blue, red, and black. The most prevalent shapes of MPs are fibers, which account for almost 47% in water samples and 87% in salt samples. Based on the ATR-FTIR study, polyethylene (PE) is the most prevalent polymer observed in salt samples, followed by polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET). In water samples, PP is the most dominating polymer, followed by PE and PS. Through SEM microphotographs, fiber-type MPs have smooth surfaces, fragment-type MPs have rough edges, and sheet-type MPs have layered surfaces. EDX analysis revealed that carbon (C) and oxygen (O) are the most abundant elements, followed by aluminium (Al) and sodium (Na) in MPs. Based on the results, it is inferred that the MPs in the rock salts are mainly sourced from the different stages of salt-making production. This preliminary study shed light on the presence and characteristics of MPs in rock salts in this region. The research outcomes could support sustainable management plans to improve the salt quality and enhance the market value.
产自砂拉越东北部高原地区的山盐具有市场价值，也为当地社区提供了基本收入。在制盐过程中，微塑料（MPs）可能会从各种来源进入商业精盐，而这一点尚未得到探索。因此，目前的研究调查了砂拉越东北部两个不同地点（L1 和 L2）的高盐水生产的岩盐中是否存在 MPs。在所分析的卤水和岩盐样本中，盐样本中检测到的 MPs 浓度最高。结果表明，水和盐样本中的 MPs 浓度最高的尺寸范围为 1-1000μm。在所研究的盐和水中样本中，最常见的 MPs 颜色是透明色，其次是白色、蓝色、红色和黑色。最常见的 MPs 形状是纤维，占水样中近 47%，盐样中 87%。根据 ATR-FTIR 研究，PE 是盐样中最常见的聚合物，其次是 PP、PS 和 PET。在水样中，PP 是最主要的聚合物，其次是 PE 和 PS。通过 SEM 显微照片，纤维型 MPs 具有光滑的表面，碎片型 MPs 具有粗糙的边缘，片状 MPs 具有分层的表面。EDX 分析表明，MPs 中 C 和 O 是最丰富的元素，其次是 Al 和 Na。根据结果推断，岩盐中的 MPs 主要来源于制盐生产的不同阶段。这项初步研究揭示了该地区岩盐中 MPs 的存在和特征。研究结果可以为提高盐质和增加市场价值的可持续管理计划提供支持。
