Instituto de Ciências Ambientais, Químicas e Farmacêuticas da Universidade Federal de São Paulo (UNIFESP - Campus Diadema), Rua São Nicolau, 210, Diadema, SP, CEP: 09913-030, Brazil.
Environ Sci Pollut Res Int. 2020 Apr;27(12):13599-13616. doi: 10.1007/s11356-020-07873-7. Epub 2020 Feb 6.
In tropical environments, nutrient-poor soils are commonly found, leading to high fertilizers application rates to support agricultural activities. In contrast, anthropogenic activities generate large amounts of effluents containing nitrogen. In this study, two minerals (natural zeolite and vermiculite) were tested to remove NH from an industrial effluent with high pH and contents in Na and K. Afterwards, they were tested as an alternative slow-release fertilizer in the soil. To verify the best conditions to adsorb NH, batch tests were conducted using synthetic solutions and an industrial effluent. In general, the efficiency of both minerals in removing NH was high (85% for zeolite and almost 70% for vermiculite) as well as the ability to decrease the industrial effluent pH. In this process, more NH and K ions were removed in comparison with Na, which remained in solution. These minerals were tested as slow-release fertilizers by leaching with distilled water (both minerals releasing 2 mg L NH) and with an acid solution (releasing 10 mg L NH from zeolite and 50 mg L NH from vermiculite-corresponding only to 12% of total NH retained by zeolite and 29% by vermiculite). During the test of soil incubation with zeolite-NH, the NH ions of the exchangeable sites were retained for a longer period, minimizing their loss by leaching and biological nitrification. Consequently, soil acidification was prevented. Therefore, both minerals showed high efficiency in removing NH from solution which can then be slowly released as a nutrient in the soil.
在热带环境中，通常会发现养分贫瘠的土壤，这导致需要大量施用肥料来支持农业活动。相比之下，人为活动会产生大量含有氮的废水。在这项研究中，两种矿物质（天然沸石和蛭石）被测试用于去除高 pH 值、高含量的 Na 和 K 的工业废水中的 NH。然后，它们被测试作为土壤中替代的缓释肥料。为了验证吸附 NH 的最佳条件，使用合成溶液和工业废水进行了批量测试。总的来说，两种矿物质去除 NH 的效率都很高（沸石为 85%，蛭石接近 70%），并且能够降低工业废水的 pH 值。在这个过程中，与 Na 相比，更多的 NH 和 K 离子被去除，而 Na 仍留在溶液中。这些矿物质通过用蒸馏水（两种矿物质都释放 2mg/L NH）和酸溶液（沸石释放 10mg/L NH，蛭石释放 50mg/L NH——仅相当于沸石中保留的总 NH 的 12%和蛭石中的 29%）浸出来测试作为缓释肥料的性能。在沸石-NH 的土壤培养试验中，交换位上的 NH 离子被保留了更长的时间，从而最大程度地减少了它们通过淋洗和生物硝化的损失。因此，防止了土壤酸化。因此，两种矿物质都表现出从溶液中去除 NH 的高效率，然后可以作为土壤中的养分缓慢释放。
