Nutrient Removal Efficiency of Rhizophora mangle (L.) Seedlings Exposed to Experimental Dumping of Municipal Waters

Abstract

Mangrove forests are conspicuous components of tropical wetlands that sustain continuous exposure to wastewater discharges commonly of municipal origins. Mangroves can remove nutrients from these waters to fulfill their nutrients demand, although the effects of continuous exposure are unknown. An experimental greenhouse imitating tidal regimes was built to measure the efficiency of mangrove seedlings to incorporate nutrients, growth and above biomass production when exposed to three periodic wastewater discharges. The experiment totaled 112 d. Nutrient removal by the exposed group, such as phosphates, ammonia, nitrites, nitrates and dissolved inorganic nitrogen (97%, 98.35%, 71.05%, 56.57% and 64.36%, respectively) was evident up to the second dumping. By the third dumping, all nutrient concentrations increased in the interstitial water, although significant evidence of removal by the plants was not obtained (p > 0.05). Nutrient concentrations in the control group did not change significantly throughout the experiment (p > 0.05). Treated plants increased twofold in stem girth when compared to the control (p < 0.05), although control plants averaged higher heights (p < 0.05). Biomass of treated group increased up to 45% against 37% of the control during the duration of the experiment (p < 0.05). We suggest that nutrient removal efficiency of mangroves is linked to the maintenance of oxic conditions in the pore-water because of oxygen transference from their aerial to their subterranean radicular system that facilitates the oxidation of reduced nitrogen compounds and plants uptake. Nevertheless, continuous inflows of wastewater would lead to eutrophication, establishment of anoxic conditions in water and soil, and lessening of nutrient absorption of mangroves.

Porewater Sulfide: The Most Critical Regulator in the Degradation of Mangroves Dominated by Tides

“…Stagnation and evaporation increase the concentration of soil nutrients. The waterlogging and the decrease in topography from the basin towards the impaired site favor soil anaerobic conditions, increasing the concentration of reduced compounds such as sulfides, ammonium, and methane [49,[51][52][53][54][55][56][57]. The increase in organic matter and low soil density result from the loss of connectivity between the impaired site and the main tidal channel of Estero Pargo.…”

The Structure and Composition of Puerto Rico’s Urban Mangroves

“…This may be because the most urban mangroves are permanently or periodically flooded (0.001-2.5 times per day) by urban waters, which likely carry elevated nitrogen and phosphorus concentrations that have been tied to roads and sewage [76][77][78]. Such nutrient enrichment has been shown to increase girth but decrease height of mangrove seedlings [79], while the height of dwarf mangroves was found to increase with both nitrogen and phosphorus fertilization [80]. Thus, these nutrients likely influence urban mangrove growth depending upon antecedent conditions and their interaction with other water quality and flooding conditions.…”

Evaluation of a naturally derived tannin extracts biopolymer additive in drilling muds for high-temperature well applications

“…Reports from the Forest Research Institute Malaysia (FRIM) revealed that Bakau minyak barks contain significant amounts of tannins, which is, however, subject to the method of extraction and type of solvents used (Sukardjo 1987). Rhizophora mucronata and Rhizophora mangle are common representatives of the Rhizophora family (Basyuni et al 2018;Ghazali et al 2018a, b, Vigneswaran et al 2018Maricusa et al 2018). Locally derived tannin-based Rhizophora mucronata is abundant in soft tissues form, such as leaves, needles and barks wastes (Vigneswaran et al 2018).…”