Species and potential sources of phosphorus in groundwater in and around Mataram City, Lombok Island, Indonesia

Abstract

Geochemical evaluation of the species and potential sources of P in groundwater in and around Mataram City, Lombok Island, Indonesia can aid in the initial research on evaluating the fate of P when detailed geological information is unavailable. The results of ion chromatography and inductively coupled plasma-optical emission spectroscopy show that the concentrations of PO43– and total dissolved P (TDP) in groundwater range from approximately 0.1 to 8.5 mg l–1 and from 0.04 to 2.95 mg l–1, respectively. Dissolved inorganic P accounted for 86%, on average, of the TDP concentration, and PO43– represented the predominant P species in this groundwater. The potential sources for most of this dissolved PO43–, according to indices developed based on the PHREEQC software and groundwater quality data, could be the dissolution of hydroxyapatite and/or vivianite minerals. However, the potential sources of dissolved PO43– in groundwater with a TDP concentration of ≥ 1 mg l–1 is likely to be the reduction of Fe(III)–(hydro)oxides, the initial decomposition of organic matter, or the dissolution of carbonate-rich fluorapatite considering the Fe2+, dissolved organic carbon, Ca2+ and F− concentrations measured. In addition, as several groundwater samples had a TDP concentration of ≤ 1 mg l–1 and comparatively high concentration of NO3–, other potential sources of dissolved PO43– in this groundwater could be anthropogenic.

Terrestrial Nutrients and Dissolved Organic Matter Input to the Coral Reef Ecosystem via Submarine Springs

“…In addition, natural sources also affect soluble PO study conducted in western Lombok found that, in the absence of NH 4 + concentration in some parts of the island, the elevated groundwater PO 4 3− concentration was derived from the dissolution of hydroxyapatite and/or vivianite minerals, originated from volcanic lava deposits of Mount Rinjani. 62 DSi concentrations in the coastal groundwater were in a range of 170−780 μM; however, two inland spring samples from the mountain slope had DSi concentrations up to 1140 μM (Table 1, Figure 2). These inland springs receive their water from recharge at the slopes of Mt.…”

“…In addition, natural sources also affect soluble PO 4 3– concentration in groundwater. A recent study conducted in western Lombok found that, in the absence of NH 4 + concentration in some parts of the island, the elevated groundwater PO 4 3– concentration was derived from the dissolution of hydroxyapatite and/or vivianite minerals, originated from volcanic lava deposits of Mount Rinjani …”

Evaluation of Phosphorus Enrichment in Groundwater by Legacy Phosphorus in Orchard Soils with High Phosphorus Adsorption Capacity Using Phosphate Oxygen Isotope Analysis

“…Legacy P is likely to increase this P discharge; however, an increase in P accumulation in the soil does not become an immediate P leaching risk because aluminum (Al), iron (Fe), and calcium (Ca) in the soil easily sorb P, thus preventing P movement from surface soils to groundwater. , Therefore, to evaluate the P leaching from soils to groundwater, the sorption characteristics from the surface to deeper layers are important. , However, it is challenging to collect the samples from a depth of several meters, making it difficult to assess whether legacy P in the surface soil has reached the groundwater table. In addition to P leaching from soils, P enrichment in groundwater can occur through significant P enrichment mechanisms, such as sewage contamination, , P leaching from the lithological materials associated with the reductive dissolution of Fe, − and groundwater acidification. , Therefore, there are still difficulties in clarifying the mechanisms of P enrichment in groundwater.…”

Groundwater Dynamics near the Saltwater–Freshwater Interface in an Island of Seto Inland Sea

“…Islands lack freshwater resources, and groundwater wells and reservoirs have long been exhausted on islands in the Seto Inland Sea [1,2]. These local water resources are especially important on islands with high water demands, such as tourism-focused coral reef islands [3] and national parks in the Seto Inland Sea [2][3][4][5][6]. The adoption of local water resources should be encouraged to achieve the sixth Sustainable Development Goal (SDG) by 2030 (clean water and sanitation for all) [7].…”