The Potential Use of Nephelium lappaceum Seed as Coagulant–Coagulant Aid in the Treatment of Semi-Aerobic Landfill Leachate

Chemical-based coagulants and flocculants are commonly used in the coagulation–flocculation process. However, the drawbacks of using these chemical materials have triggered researchers to find natural materials to substitute or reduce the number of chemical-based coagulants and flocculants. This study examines the potential application of Nephelium lappaceum seeds as a natural coagulant–coagulant aid with Tin (IV) chloride (SnCl4) in eliminating suspended solids (SS), colour, and chemical oxygen demand (COD) from landfill leachate. Results showed that the efficiency of Nephelium lappaceum was low when used as the main coagulant in the standard jar test. When SnCl4 was applied as a single coagulant, as much as 98.4% of SS, 96.8% of colour and 82.0% of COD was eliminated at an optimal dose of 10.5 g/L and pH 7. The higher removal efficiency of colour (88.8%) was obtained when 8.40 g/L of SnCl4 was applied with a support of 3 g/L of Nephelium lappaceum. When SnCl4 was utilised as a coagulant, and Nephelium lappaceum seed was used as a flocculant, the removal of pollutants generally improved. Overall, this research showed that Nephelium lappaceum seed is a viable natural alternative for treating landfill leachate as a coagulant aid.

PEMANFAATAN EKSTRAK DAUN RAMBUTAN (Nephelium lappaceum) SEBAGAI INHIBITOR KOROSI PADA PLAT BESI (STEEL) DALAM MEDIA AIR LAUT

Korosi adalah proses perusakan pada permukaan logam yang disebabkan oleh terjadinya reaksi kimia (reaksi elektrokimia) pada permukaan logam. Untuk mengurangi laju korosi bisa dengan menambahkan inhibitor alami salah satunya daun rambutan yang mengandung tanin sehingga dapat membentuk senyawa komplek dengan Fe(III) di permukaan logam, sehingga laju reaksi korosi akan mengalami penurunan. Studi penggunaan ekstrak daun rambutan sebagai inhibitor korosi pada plat besi akan dilakukan secara eksperimen murni di laboratorium dengan menggunakan metode perendaman. Media korosif untuk perendaman digunakan air laut yang telah ditambahkan inhibitor. Inhibitor yang digunakan yaitu inhibitor organik yang diambil dari ekstrak daun rambutan. Perendaman dilakukan dalam interval waktu (3, 6, 9, 12, dan 15) hari dengan konsentrasi inhibitor (0, 50, 100, dan 150) ppm. Hasil pengujian menunjukkan bahwa serangan korosi terjadi secara merata dipermukaan logam, Besarnya laju korosi dinyatakan sebagai besarnya kehilangan berat benda uji per satuan luas permukaan per satuan waktu perendaman. Dari hasil penelitian diperoleh bahwa laju korosi plat besi dalam lingkungan air laut menurun secara segnifikan dengan meningkatnya konsentrasi ekstrak daun rambutan dan waktu perendaman. Penurunan ini akibat pembentukan lapisan tipis dipermukaan plat besi, sehingga menghambat kontak langsung antara plat besi dan lingkungan. Efesiensi inhibisi tertinggi diperoleh pada perendaman 15 hari dengan konsentrasi 150 ppm yaitu 96%

Flooding tolerance of four tropical peatland tree species in a nursery trial

In order to facilitate hydrological restoration efforts, initiatives have been conducted to promote tree growth in degraded and rewetted peatlands in Indonesia. For this initiatives to be successful, tree seedlings need to be able to survive flooding episodes, with or without shade. We investigated the survival of different shading and water levels under controlled conditions in a nursery, with artificial rainwater and with peat soils as the medium. The research focused on the fllowing questions (i) whether trees can grow on flooded peat soils; and (ii) which plant traits allow plants to cope with inundation, with or without shade. The four tree species compared ( Shorea balangeran, Cratoxylum arborescens, Nephelium lappaceum, and Durio zibethinus ) include two natural poineer and two farmer-preferred fruit trees. The experiment used as a split-split plot design with 48 treatment combinations and at least 13 tree-level replicates. The study found that S. balangeran and C. arborescens developed adventitious roots to adapt to the inundated conditions. D. zibethinus, S. balangeran and N. lappaceum grew best under moderate (30%) shading levels, while C. arborescens grew best in full sunlight.

Application of Essential Oils for Maintaining Postharvest Quality of ‘Rongrien’ Rambutan Fruit

The postharvest quality of rambutan fruits (Nephelium lappaceum Linn.) is mainly influenced by dehydration, which causes browning of the peel and spinterns. This research investigated the effects of some essential oils—from citronella, clove, kaffir lime, and lemongrass—on ‘Rongrien’ rambutan fruit quality during storage at 13 °C. Screening of effective concentrations from 0.01 to 0.16% was conducted for each essential oil. The results showed that, of the essential oil treatments tested, a kaffir lime oil coating of 0.01% could best maintain the quality of fruits, reducing both weight loss and browning of the peel and spinterns. However, essential oil concentrations exceeding 0.04% severely damaged the fruit pericarp, in which scores of spintern browning were higher than those of peel browning. These results suggest that kaffir lime oil can maintain the postharvest quality of ‘Rongrien’ rambutan fruit as a supplement in some edible coatings.

Review of Nephelium Lappaceum and Nephelium Ramboutan-Ake: A High Potential Supplement

Nephelium lappaceum (N. lappaceum) and Nephelium ramboutan-ake (N. ramboutan-ake) are tropical fruits that gain popularity worldwide due to their tastiness. Currently, their potential to be used as pharmaceutical agents is underestimated. Chronic diseases such as cancer, diabetes and aging have high incidence rates in the modern world. Furthermore, pharmaceutical agents targeting pathogenic microorganisms have been hampered by the growing of antimicrobial resistance threats. The idea of food therapy leads to extensive nutraceuticals research on the potential of exotic fruits such as N. lappaceum and N. ramboutan-ake to act as supplements. Phytochemicals such as phenolic compounds that present in the fruit act as potent antioxidants that contribute to the protective effects against diseases induced by oxidative stress. Fruit residuals such as the peel and seeds hold greater nutraceutical potential than the edible part. This review highlights the antioxidant and biological activities (anti-neoplastic, anti-microbial, hypoglycemic actions and anti-aging), and chemical contents of different parts of N. lappaceum and N. ramboutan-ake. These fruits contain a diverse and important chemical profile that can alleviate or cure diseases.

Nephelium lappaceum Extract as an Organic Inhibitor to Control the Corrosion of Carbon Steel Weldment in the Acidic Environment

Organic inhibitors have been considered as an effective way to control the corrosion of carbon steel weldment in an acidic environment. This work proposes a new green organic inhibitor made of extract of rambutan fruit (Nephelium lappaceum) peel and aims at analyzing its corrosion inhibitor properties and protection mechanism. Specimens of carbon steel weldment were tested for their corrosion by using electrochemical and immersion methods in 1M HCl solution containing 0 to 6 g/L of Nephelium peel (NP) extract. Results showed that, in the same solution, the corrosion rate was measured to be higher on the weld metal zone than that of base metal zone, which could be related to the coarser grain of the weld metal zone and the stability of the formed oxide layer. The addition of NP extract was found to increase the stability of the oxide layer, thus increasing the corrosion resistance of the specimens. The maximum inhibition efficiency of the NP extract was reached at 97% for weld metal with 5 g/L of extract, at 80% for the heat affected zone with 5 g/L, and at 70% for base metal with 4 g/L. This work reveals the particularity of different weldment zones to the different needs of inhibitor concentration for obtaining the optimum corrosion protection.

The performance of paludiculture commodities at different peat depths in Central Kalimantan

Paludiculture is one of the alternative efforts to restore degraded peatland. It involves rewetting, revegetation and revitalization of local livelihood. This research evaluated three paludiculture demonstration plots at Central Kalimantan, one in the shallow peat of Pilang village and two plots in the deep peat of Tumbang Nusa village. The plots were evaluated in terms of the plant’s growth, productivity, commodities introduced and environmental monitoring, including water table, soil physical and chemical properties, carbon stocks and CO2 emission. The results showed that the three plots were categorized as “compromised” paludiculture plots because some of the commodities were not local peatland species. Belangeran (Shorea balangeran) and horticultural plant species such as rambutan (Nephelium lappaceum) and pineapple (Ananas comosus) showed good growth performance. Liberica coffee (Coffea liberica) was not suitable for deep peat due to its low survival rate and poor growth. The result also showed that soil peat characteristics of the sites were still in good condition; however, the impact of peatland utilization should have been monitored to support land-use sustainability. Moreover, stingless bee cultivation and vegetables could become potential commodities to be developed in shallow and deep peatland.

Agroecological coverings for the sustainable production of Rambutan (Nephelium lappaceum L.)

Objective: To evaluate the influence of living and dead covers on the yield and quality of rambutan fruits (Nephelium lappaceum L.) in Soconusco, Chiapas, Mexico. Design / methodology / approach: Five treatments were evaluated, two live covers, two dead covers and an always clean control without covers. The following were evaluated: plant height, crown volume, fruit quality, fruit yield (t ha-1). The data were analyzed under a randomized block experimental design. Results: All the agroecological modalities of hedging evaluated produced fruits with the quality required for national and international commercialization. Study limitations / implications: The morphological and physiological response of the crop can change with the age of the tree. Findings / conclusions: An agroecological management strategy is presented to develop rambutan cultivation in Soconusco region.