Introduction

Access to safe water is a fundamental human need. A UN report has highlighted the significant challenges faced by 2 billion people globally in accessing this basic necessity. Southeast Asia is one of the regions most affected by water insecurity, with 110 million individuals facing problems with clean water supply despite the region’s progress in the water sector (Geall 2019). Even though 75% of the earth is covered by water, access to clean water is still limited, especially in developing countries like Indonesia. Indonesia, with approximately 18,000 islands, has recently experienced rapid economic growth, with an annual increase of 6% and a GDP of approximately $3000 (World Bank Group 2024). Nevertheless, issues such as sanitation and access to clean water still require attention.

Indonesia, with a population of approximately 275 million people, is the fourth-largest country in the world and has the largest economy in Southeast Asia. However, it faces significant challenges related to water access and sanitation. In contrast, Malaysia, which is one of Indonesia’s closest neighbors, enjoys 94% access to safe drinking water. Indonesia, on the other hand, has only 30% access to safe drinking water and similarly falls behind in sanitation as well (UN-Water 2024a, b). This stark contrast highlights Indonesia’s urgent need to improve its clean water infrastructure and sanitation systems to keep pace with other Southeast Asian nations with similar geographical conditions. Moreover, monitoring at 563 points across 34 provinces in Indonesia from 2015 to 2020 revealed that 65.30% of river water was classified as heavily polluted (Ministry of Environment and Forestry-Indonesia et al., 2021). This pollution not only possibly threatens public health, leading to various health issues across regions, but also contributes to economic losses in tourism, fisheries, housing, irrigation, and drinking water supply.

The issue of water scarcity is urgent due to the increasing demand for this vital resource. Consequently, the necessity for water purification and waste disposal has become a significant research topic in recent years to develop sustainable, eco-friendly, and cost-effective water purification and recycling methods. Various pollutants are found in water, including heavy metal ions, high-concentration salts, microbes, oil, petroleum byproducts, plastic waste, organic dyes, and pharmaceuticals. The accumulation of these pollutants in water significantly threatens human health and other organisms. Over the years, various methods have been proposed for removing pollutants from water, encompassing physical, chemical, and biological processes. Technologies such as filtration (Nawi et al. 2022; Abdiyev et al. 2023), adsorption (Elgarahy et al. 2021; Varghese et al. 2022), coagulation/flocculation (Mao et al. 2024; Usman et al. 2023), and phytoremediation (Wu et al. 2023; Retta et al. 2023) have been implemented.

The use of plant-based materials in the treatment of water and wastewater is receiving growing attention in the field of applied polymer science. Over the past decade, numerous studies on wastewater treatment have been published in polymer science journals, emphasizing the focus on these materials (Islam et al. 2024). Research is ongoing to replace synthetic compounds with natural ingredients or modify natural materials to minimize synthetic content. Some studies even combine two natural raw materials to enhance performance (Usman et al. 2023). This shift highlights the significant potential of plant biodiversity in overcoming water treatment challenges. The connection between biodiversity and sustainable wastewater treatment technologies is exemplified by the use of biomass as a raw material for producing sustainable bio-based materials (SBMs). Utilizing biomass aligns with the principles of sustainability by reducing costs and environmental impacts while also making use of existing natural resources (Wu et al. 2022). A literature review by Mishra et al. (2024) specifically discussed how biodiversity, in this case, is the abundance of cellulose, which becomes a valuable product for wastewater treatment. There is increasing interest in developing sustainable and efficient materials for wastewater treatment to address wastewater treatment issues. The use of these natural materials supports the principle of sustainability by reducing dependence on hazardous chemicals and increasing the efficiency of wastewater treatment (Ahsan et al. 2001).

Indonesia, known for its rich biodiversity and major agricultural production, has a significant opportunity to enhance sustainable water and wastewater treatment solutions. Approximately 29% of Indonesia’s 190 million hectares of land is used for agriculture (Quincieu 2015), making it one of the largest tropical fruit producers in the ASEAN region (Food and Agriculture Organization of the United Nations 2023). The variety of local Indonesian plants includes thousands of species, each comprising tens to hundreds of subspecies or varieties (Thomson et al. 2007). This paper reviews the potential of Indonesia’s local plants in the process and efforts of water and wastewater treatment. Of course, in this case, Indonesia’s rich biodiversity is utilized to reveal the potential for developing innovative and sustainable solutions to global challenges related to clean water.

Method

Data collection

Search strategy

A comprehensive and methodical examination of the literature was conducted, and data pertinent to water treatment was gathered from many indexing databases. It is recommended that researchers employ a multitude of search engines to achieve optimal results, rather than relying on a single search engine (Samadzadeh et al. 2013). In light of the popularity of two indexers of scientific publications on topics encompassing science, engineering, and social sciences, the Web of Science and Scopus were employed (Mongeon and Paul-Hus 2016). In consideration of its extensive reach, researchers also utilize Google Scholar as a search engine, despite the limitations of this search engine in comparison to traditional bibliographic data. These limitations include the absence of essential functions such as chunking (word formation), proximity operators, the use of brackets, and search history (Bramer et al. 2017). However, using these three databases is considered sufficient for a systematic review that will reveal the potential of Indonesia’s local plant-based water treatment. The strategy was prepared in early May 2024 and executed on May 14, 2024.

Keywords

This review considers perspectives on research on Indonesia’s local plants in water and wastewater treatment. The keyword “natur*” was used to identify findings on using natural materials in water treatment, including wastewater, with the understanding that it would be sorted explicitly for plant-based processing. The potential for implementing integrative processing using several types of natural materials was also considered. Indonesian specifications were also provided, given that the expected target is natural materials abundant in the Indonesian area.

It should be noted that the data search sequence varies between databases. Specifically, the option to export metadata documents in bulk is unavailable when searching in Google Scholar. To obtain Google Scholar results, the Publish or Perish software (Harzing 2023) was used. However, this software restricts downloads to a maximum of 1000 results. Consequently, we elected to limit the search to articles published between 2014 and 2023 on the Google Scholar indexer. The detailed search queries are presented in Table 1.

Table 1 Databases searched, including the search strings used and the number of hits
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Study selection

To minimize bias, we reviewed all relevant titles and abstracts, manually excluding some using the cloud-based software Rayyan if they did not match the search terms. Table 2 outlines the criteria for including or excluding articles.

Table 2 Inclusion and exclusion criteria for retrieving the dataset
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Data management and analysis

The reference details, including abstracts, were imported into Zotero 6 for Windows (Corporation for Digital Scholarship 2023) and then exported to Rayyan (Valizadeh et al. 2022) for title, abstract, and full-text screening. Documents meeting the inclusion criteria were categorized by their characteristics. For water treatment-related documents, plant material use was identified by the plant part, type of water or wastewater processed, key research findings on water conditions, and treatment mechanisms. Following this, coding was performed based on the established categories related to the type of plants, the type of treated water, and the mechanisms that may occur in the treatment process. Coding was conducted using Atlas.ti 25 and visualized with the aid of https://sankeymatic.com/.

Finding

A total of 39 academic documents that met the inclusion criteria were subjected to further analysis. These included 39 documents on water treatment (32 journal articles and 7 conference proceedings). The document acquisition process is illustrated in Fig. 1.

Fig. 1
figure 1

Flow diagram of the search strategy

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Numerous documents highlight the potential of Indonesia’s local plants, which are utilized through various plant parts. These plants involve different water treatment mechanisms, including adsorption, coagulation-flocculation, filtration, and phytoremediation. The variations in water treatment are demonstrated by the types of water or wastewater being improved using various water quality parameters. In this review, we classify treated water into two categories: challenging raw water and wastewater. Challenging raw water includes natural water sources with complex characteristics that make treatment difficult, such as peat water, wetland saltwater, and turbid river water. These sources are usually high in organic matter, salinity, or suspended particles, which require advanced treatment processes. Wastewater, on the other hand, originates from domestic, industrial, or agricultural activities and contains pollutants that must be removed before discharge or reuse. This distinction is important because while both require treatment, challenging raw water primarily undergoes purification for direct use, while wastewater treatment focuses on contaminant removal and environmental protection. Tables 3 and 4 provide a detailed analysis and grouping of the potential of Indonesia’s local plants in the water treatment process. These 39 documents are all marked with an asterisk (*) in the reference list.

Table 3 Studies on plant-based water treatment for addressing challenging raw water
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Table 4 Studies on plant-based water treatment for addressing wastewater
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The 39 existing research studies focused on raw water treatment (N = 15) and wastewater treatment (N = 25), with one study having a dual focus on raw water and wastewater in one article (Hendrawati et al. 2016). Additionally, there were four studies that used more than one type of plant in their research (Radityaningrum & Kusuma 2017; Koosdaryani et al. 2019; Henny et al. 2019; Rahmadyanti et al. 2021). In these discussions, two studies considered more than one type of plant for treatment (Radityaningrum and Kusuma 2017; Henny et al. 2019), and one study examined treatment involving several mechanisms (Koosdaryani et al. 2019). The coding and visualization of findings in the literature indicate that the predominant types of plants are aquatic and wetland species. The mechanisms frequently discussed relate to phytoremediation and coagulation-flocculation, while the processing primarily focuses on wastewater, as illustrated in Fig. 2.

Fig. 2
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The relationship among the type of plant, the type of treated water, and the mechanisms in the PbWT

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Discussion

The findings presented in Tables 3 and 4 indicate that Indonesia is rich in local plant species that could effectively support plant-based water treatment methods to address challenging raw water and wastewater. Various processes are involved in the treatment of water from different sources. Sustainable water treatment highlights the need to understand the properties of water and wastewater from different activities or industries to choose suitable treatment methods (Kato and Kansha 2024). This discussion section will further explore potential types of plants, the possible mechanisms involved in the treatment process, the types of challenging raw water or wastewater that require treatment, and the challenges and future directions for implementing local plant-based water treatment in Indonesia. It will also address how these methods can support environmental sustainability.

Types of Indonesia’s local plants with potential in water and wastewater treatment processes

Aquatic and wetland plants

They are the dominant groups that are often used in water treatment in Indonesia. The reviewed document includes eleven types of plants: duckweed, watermilfoil, vetiver, heliconia, mangrove, water hyacinth, cattail, azolla, lemna, papyrus, and bulrush (Harbowo and Choesin 2014; Titah et al. 2016; Radityaningrum and Kusuma 2017; Ahmad et al. 2017; Effendi et al. 2017; Koosdaryani et al. 2019; Henny et al. 2019; Prihatinningtyas 2019, 2020; Noor et al. 2020; Cundari et al. 2023; Nooryaneti et al. 2023). These plants can play an important role in adsorbing pollutants and nutrients from the aquatic environment.

Fruit plants

Fruit plants such as orange peel, banana, papaya, areca nut, coconut, and oil palm are widely suggested in wastewater treatment. Parts of these plants, such as peel or fiber, have effective adsorptive properties to attract and reduce contaminant content and were used in eight applications (Yudanto et al. 2016; Allwar et al. 2019; Novallyan et al. 2021; Zainol et al. 2022; Pramono et al. 2022; Elma et al. 2022; Widiyanti et al. 2023; Wilanda et al. 2023).

Fiber plants

Fiber plants, particularly kapok, sugar cane, and bamboo, are commonly used in various applications (Koosdaryani et al. 2019; Rusdi et al. 2023). They play a significant role in coagulation and filtration processes, serving as absorbents or filters for large particles and organic materials. Specifically, sugar cane and bamboo have been utilized in an integrated system.

Grain plants

Grain plants such as moringa, winged bean, soybean, rice, and mung bean are also widely used, as seen in eight applications, two of which are used in integrated systems (Hendrawati et al. 2016; Sisnayati et al. 2019; Koosdaryani et al. 2019; Maulidya and Putra 2020; Putra et al. 2021b; Rahmadyanti et al. 2021; Istiqomah et al. 2023). These grains are often relied upon as natural coagulants that are effective in reducing water turbidity, especially in domestic or industrial waste.

Medicinal and ornamental plants

Medicinal and ornamental plants, such as aloe vera, tiger lilies, parrot’s beak heliconia, and Indiana shot provide additional contributions in reducing certain contaminants and maintaining water quality, with a total of four suggested applications utilizing the natural properties of these plants in treating water, one of which is used in integrated systems (Rahmadyanti et al. 2020, 2021; Putra et al. 2021a; Sutanto and Bawole 2021).

Timber and latex-producing trees

Timber and latex-producing trees, such as agarwood, rubber trees, kusambi, leucaena, and laban, in five applications (Fenditasari et al. 2019; Kristianto et al. 2019; Neolaka et al. 2020; Sri Hartati et al. 2021; Zulfikar et al. 2020). These plants are often chosen because of the ability of their wood and seeds to adsorb organic and inorganic substances in water.

Vegetables and food crops

These plants were applied in four studies. Vegetables and food crops, including Chinese cabbage and sweet potatoes, provide additional benefits with high adsorption capacity, although they are used in more limited quantities (Alni et al. 2019; Kusuma et al. 2021; Rohana and Asmoro 2020). Another type of plant we include in this category is organic starch-producing plants, specifically sago (Fauzia et al. 2019), which serves as a primary food source providing carbohydrates, like sweet potatoes.

Mechanisms involved in the treatment process

Water treatment aims to meet high hygiene standards for human consumption, while wastewater treatment focuses on eliminating hazardous substances so they can be safely discharged or reused. Wastewater typically contains organic matter, heavy metals, dyes, and pathogens, necessitating coagulation, adsorption, and phytoremediation to bind and decompose these pollutants. In contrast, uncontaminated water that needs filtration usually contains only minor impurities, minerals, or microorganisms, which can be removed through filtration and sterilization. Thus, the production of clean water is held to stricter quality standards for safe consumption, whereas wastewater treatment emphasizes safe disposal. Environmental safety considerations in water and wastewater treatment reflect the goal of developing processes that are more sustainable and beneficial for both the environment and human health (Mohamed Noor and Ngadi 2024).

Water treatment aims to remove contaminants from polluted water, including colloidal particles, pathogens, suspended molecules, and other toxic materials that can harm human health. The treatment comprises two stages: the primary stage employs sedimentation and filtration to mechanically remove solid particles, while the secondary stage employs biological agents (anaerobic or aerobic microorganisms) to break down and remove remaining waste and minute particles. Water treatment methods include chemical, physical, and biological techniques (Koul et al. 2022). Chemical methods encompass coagulation, ion exchange, disinfection, catalytic reduction, oxidation, and softening processes (Guo et al. 2020; Alibeigi-Beni et al. 2021). Physical methods include adsorption, UV processes, settling, and media and membrane filtration (Ali and Gupta 2006; O’Malley et al. 2020). Biological methods involve phytoremediation, bioreactor processes, microbial biodegradation, and wetlands (Ang and Mohammad 2020). A combination of these methods is often used to enhance efficiency (Hamzah et al. 2017; Koosdaryani et al. 2019; Rahmadyanti et al. 2020, 2021; Nimesha et al. 2022). The categorization presented in Tables 3 and 4 indicates that the mechanisms underlying water treatment using Indonesia’s local plants are related to adsorption, coagulation-flocculation, membrane filtration, and phytoremediation.

Adsorption

Removing metals, non-metals and small particulates from a solution by adsorption mechanism through any biological component is known as biosorption. Researchers have demonstrated the biosorption potential of various Indonesian plants, including agarwood (Hartati et al. 2021), areca fiber waste (Novallyan et al. 2021), banana fruit bunches (Allwar et al. 2019), Chinese cabbage (Alni et al. 2019), sago bark (Fauzia et al. 2019), rubber seeds (Zulfikar et al. 2020), Kusambi wood (Neolaka et al. 2020), orange peels (Zainol et al. 2022), and water hyacinth (Cundari et al. 2023). Tables 3 and 4 highlight how these plant parts are converted into high-carbon adsorbents, indicative of their adsorption capacity. Cellulose, hemicellulose, and lignin are primary components in grain-based products, with proportions varying by product. For instance, rice-based biomass contains 32.24% cellulose, 21.34% hemicellulose, and 21.44% lignin, while wheat-based biomass has 39% cellulose, 35% hemicellulose, and 14% lignin (Demirbas 2008; Farooq et al. 2010). Cellulose is known to adsorb phenol (Alni et al. 2019) and humic acid (Pramono et al. 2022). Cellulose and hemicellulose in agricultural and plant biomass enhance their biosorption potential. Other agricultural byproducts like tea, coffee, shells, nuts, and various fruit seeds also contain cellulose, hemicellulose, and lignin (Mathew et al. 2016).

Interactions between water pollutants and biosorbents occur via surface sorption and interstitial sorption. In surface sorption, sorbate molecules move from the solution to the biosorbent’s surface, attaching to active sites through dipole interactions, hydrogen bonds, or Van der Waals forces (Sulyman et al. 2017). In interstitial sorption, pollutants diffuse into the biosorbent’s pores and attach to the inner surface (Joseph et al. 2019). Electrostatic interactions also play a significant role in adsorbing water contaminants. The abundance of functional groups on the surfaces of biosorbents renders them highly effective in capturing pollutants from water systems (Elgarahy et al. 2021).

Coagulation-flocculation

Plant-based coagulants are more readily available than coagulants derived from animals or microorganisms. Several plant-based products, including aloe vera (Putra et al. 2021a), papaya (Widiyanti et al. 2023; Wilanda et al. 2023), sweet potato (Rohana and Asmoro 2020; Kusuma et al. 2021), duckweed (Prihatinningtyas 2019, 2020), laban wood (Fenditasari et al. 2019), mung bean (Putra et al. 2021b), soybean (Maulidya and Putra 2020), winged bean (Istiqomah et al. 2023), moringa (Hendrawati et al. 2016), and leucaena (Kristianto et al. 2019) have been employed in the treatment of polluted water. Macromolecules originating from these plants, such as proteins, polysaccharides, and certain functional groups, facilitate adsorption, polymer linking, and charge neutralisation, rendering them effective in water treatment with moderate turbidity levels of 50–500 NTU. The efficacy of natural coagulants can be enhanced through the optimization of the extraction and purification process, thereby improving waste disposal efficiency (Koul et al. 2022).

Coagulation gathers unstable particles into larger groups for separation through sedimentation or filtration. The coagulation-flocculation mechanism involves charge neutralization, polymer bridging, sweep-flocculation, and double-layer compression. Charge neutralization occurs when oppositely charged coagulants adsorb onto colloidal particles, while polymer bridging connects particles with long-chain polymers. Sweep-flocculation takes place when metal coagulants exceed solubility limits, forming amorphous hydroxides, and double-layer compression occurs in high-electrolyte solutions, diminishing repulsive forces. Among these, polymer bridging and charge neutralization are predominant in plant-based coagulants (Yin 2010; Koul et al. 2022).

Membrane filtration

Banana peel, containing about 24.8% pectin, enhances the hydrostability and mechanical strength of mesoporous silica membranes in wetland water treatment through ultrafiltration. Adding carbon from pectin to the silica matrix improves hydro stability and water desalination performance (Elma et al. 2022). Rice husk is also used in fabricating ceramic membranes (Sisnayati et al. 2019). Supplementary membrane materials must combust completely, avoiding tar or ash, and create smaller pores than the primary material (clay). Other research has demonstrated the phase inversion method effectively fabricates PVDF (polyvinylidene fluoride) and PVDF/cellulose membranes for treating humic acid water, with cellulose from oil palm fruit bunches available as microcrystalline (MCC) and nanocrystalline cellulose (NCC) (Pramono et al. 2022). Kapok, composed of 64% cellulose, 13% lignin, and 23% pentosan, also shows promise for oil-contaminated water treatment but requires delignification to remove lignin that interferes with metal ion binding (Rusdi et al. 2023). Additionally, coconut fiber, a material from cellulose plant parts, is used in microfiltration with active zeolite filters for treating river water (Yudanto et al. 2016).

This membrane technology employs permeable or semi-permeable barriers to separate contaminants based on size and charge. This process relies on driving forces like pressure and concentration gradients (Waqas et al. 2021; Mustalifah et al. 2021; Isnasyauqiah et al. 2022; Nawi et al. 2022). The separation of contaminants depends on their size and charge. To facilitate movement across the membrane, driving forces such as pressure differences, concentration gradients, and potential fields are necessary. Pressure-driven membrane systems are classified according to their operating pressure. Low-pressure membranes (microfiltration and ultrafiltration) operate at 10–30 psi, while high-pressure membranes (nanofiltration and reverse osmosis) require 75–250 psi (Othman et al. 2021).

Phytoremediation

Plants for rhizofiltration should have dense root systems, high biomass, and heavy metal tolerance. Both terrestrial and aquatic plants are useful. Aquatic species like water hyacinth (Noor et al. 2020; Nooryaneti et al. 2023), azolla, duckweed, and cattail (Radityaningrum and Kusuma 2017) are favoured for their heavy metal accumulation, tolerance, fast growth, and biomass. Ornamental plants such as papyrus (Harbowo and Choesin 2014), heliconia (Sutanto and Bawole 2021), and parrot’s beak heliconia (Rahmadyanti et al. 2020) can also treat wastewater and improve water quality. Grasses in swamps, like bulrush (Titah et al. 2016) and vetiver (Effendi et al. 2017), reduce total suspended solids, chemical oxygen demand, and biological oxygen demand in grey water and oil spills. The mangrove ecosystem includes vegetation like R. mucronate (Ahmad et al. 2017), effective in treating brackish water and preventing eutrophication and pollution-related disease outbreaks.

Phytoremediation is a plant-based approach that employs plants to extract and remove pollutants or reduce their bioavailability (Raskin et al. 1997; Oladoye et al. 2022). The physical and chemical properties of wetlands create conditions that favour phytoremediation of water pollution and strengthen redox reactions between plants and microorganisms in the rhizosphere (Macek et al. 2000). In order to reduce eutrophication in aquatic ecosystems, plants are used to remove nitrogen and phosphorus from water (Liu et al. 2016; Wei et al. 2021). Figure 3 illustrates the removal of pollutants in wastewater through synergistic interactions between vegetation, microorganisms, aquatic animals, and substrates in constructed wetlands (CWs) (Lee et al. 2009; Wu et al. 2023). The organic matter in CWs is primarily decomposed by bacteria attached to plant roots and filter media. The transformation and removal of nitrogen in CWs encompasses microbial cycling, ammonia evaporation, absorption, desorption, burial, and leaching (Vymazal 2007, 2011). Phosphorus transformation and removal involves adsorption, desorption, precipitation, dissolution, absorption by plants and microbes, leaching, mineralization, sedimentation, and burial (Vymazal 2007). Furthermore, water purification in CWs can result in the production of significant quantities of greenhouse gases through diffusion or the formation of gas bubbles in the water, or active transport by plants (Malyan et al. 2016; Maucieri et al. 2017).

Fig. 3
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The mechanisms of the phytoremediation process in a constructed wetland (modified from Wu et al. 2023)

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Types of treated water

Challenging raw water

In water treatment, local plants can be utilized to process challenging raw water, making it suitable for consumption or community use. For instance, peat water is treated with soybean and mung bean, which act as natural coagulants to precipitate dyes and organic impurities, resulting in clearer and safer water for domestic or agricultural needs (Maulidya and Putra 2020). Peat water and wetland saline water, which contains natural organic matter and salt, can be treated using banana peels as an adsorbent. The banana peels bind organic compounds and salts, effectively reducing the levels of these contaminants in both peat water and saline wetland water (Elma et al. 2022). For river and well water, areca palm fiber and kapok fiber can serve as adsorbents to remove heavy metals, such as lead (Pb), and E. coli bacteria, ensuring that the water is safe for consumption and household use (Novallyan et al. 2021).

Wastewater

In the case of domestic wastewater from infiltration wells and households, parrot’s beak heliconia, and water hyacinth can be employed as phytoremediators. These plants absorb nutrients and organic matter, significantly reducing turbidity, BOD, phosphate levels, and coliform bacteria. In one study, parrot’s beak heliconia reduced BOD by 71.64%, phosphate by 50.92%, and coliform bacteria by 99.67% from domestic wastewater (Sutanto and Bawole 2021). In aquaculture effluent from shrimp pond water, which is prone to eutrophication, mangrove (R. mucronata) can be utilized to absorb excess nutrients and organic compounds, helping control pollution and inhibit the growth of harmful bacteria (Ahmad et al. 2017). For tofu-tempeh and tapioca factory wastewater, which is rich in organic matter and requires turbidity reduction, winged bean seeds can be used to precipitate particles through natural coagulation. This process produces clearer water and increases dissolved oxygen (DO) levels, making it safer for the environment (Istiqomah et al. 2023).

Wastewater from the textile industry, known for high levels of BOD, COD, and total suspended solids (TSS), is processed using moringa seeds through a coagulation-flocculation mechanism, along with agarwood as an adsorbent. The coagulation process of moringa seeds helps to precipitate suspended particles, while agarwood absorbs organic matter and reduces colour in textile wastewater, making it safer for discharge (Hartati et al. 2021). For dye waste from the batik industry, which contains oils and dyes, tiger lily can act as a phytoremediator to reduce COD, TSS, oil, and fat, while bamboo charcoal columns effectively adsorb dyes and stabilize the wastewater. This combination reduced COD by 72–86% and TSS by 95–98% (Rahmadyanti et al. 2020). For wastewater containing heavy metals, kusambi wood, and sago bark are effective in adsorbing heavy metals like chromium (Cr(VI)). These plants have a high absorption capacity, ensuring that the water is safer for disposal (Neolaka et al. 2020). Wastewater from oil and gas factories is treated with vetiver grass, which functions as a phytoremediator in decomposing crude oil and organic compounds through active absorption. Additionally, kapok fiber can be utilized as a membrane filtration medium to filter TDS, phenols, and heavy metals. The treatment results showed a reduction in oil, COD, and BOD by 84–90% (Effendi et al. 2017).

Challenges and future directions for plant-based water treatment

Tables 3 and 4 outline various plants with the potential to be used in treating water and wastewater, particularly in laboratory studies. Plants like Chinese cabbage, rubber seeds, oranges, and bananas, along with various plant parts, effectively removed simple pollutants such as phenols and heavy metals from artificial wastewater. However, these results may not fully represent the actual complexity of wastewater treatment. Pilot projects can assess their effectiveness in small-scale facilities using real wastewater. Successful trials could lead to large-scale implementation, requiring methods for regenerating materials and managing pollutant variations. Plants such as agarwood and winged bean seeds have proven effective in reducing organic pollutants and dyes in specific contexts like textiles and tofu-tempeh production. Further small-scale pilot projects are necessary to explore their potential, and larger systems will be needed for comprehensive management in industrial settings.

Plants such as papaya, sweet potato, duckweed, and water hyacinth are effective in treating domestic wastewater and river water that contain low to moderate concentrations of organic pollutants. These plants have demonstrated positive results in improving water quality by reducing TSS, pH, and COD. However, domestic wastewater treatment in Indonesia faces challenges due to high volumes of untreated greywater and insufficient treatment infrastructure at the household level (Widyarani et al. 2022). In pilot projects, constructed wetlands or simple biofiltration systems can be tested in residential areas or near rivers to evaluate the potential adaptation of these plants to real-world conditions. Implementing plant-based water and wastewater treatment on a large scale, particularly through constructed wetland systems like vertical sub-surface flow constructed wetlands, involves several considerations. These include the requirement for large areas, routine maintenance of biomass, effectiveness at the community level, and management of residuals. In another case, for treating oil and mining wastewater, plants such as vetiver and bulrush have proven highly effective in absorbing heavy metals and organic compounds. These plants are suitable for phytoremediation in complex environments, including mining sites or oil-contaminated land. Pilot projects can be initiated by planting these species in polluted areas or wastewater retention ponds to evaluate their effectiveness under field conditions. While large-scale application at mining sites or oil industries may be feasible using constructed wetland systems, it necessitates close monitoring, as oil-polluted environments can hinder plant growth and absorption capabilities. Well-designed and properly managed constructed wetlands have great potential to enhance biodiversity and strengthen their ability to provide sustainable and environmentally friendly wastewater treatment solutions (Hsu et al. 2011). Wetlands’ effectiveness in treating industrial wastewater relies on the complex interactions between plants and microbial communities, which play a crucial role in biodiversity. Choosing the right plants and using strategies like bacterial inoculation and co-planting certain species can enhance treatment efficiency, resulting in environmentally friendly and sustainable solutions (Mao et al. 2023).

Plant materials such as coconut fiber, rice husk, and kapok fiber, which are used for filtration membranes, have significant potential for water filtration. Research has demonstrated that these materials reduce TDS, BOD, COD, and dyes at the laboratory scale. For pilot projects, these plant-based membranes can be evaluated in facilities with low waste volumes, such as workshops or small laboratories, to assess the durability of the materials. On a larger scale, producing plant-based filtration membranes requires technical adjustments concerning the material’s service life and regeneration capabilities. However, these membranes can offer a practical solution in resource-limited areas, particularly where modern or expensive filtration technologies are unavailable.

Keeping plant biodiversity can play a vital role in sustainable water and wastewater treatment. Jain et al. (2023) indicated that biomaterials from different sources have high adsorption capacity and regeneration potential, which support water treatment with minimal ecological impact. Koul et al. (2022) also highlighted that environmentally friendly bio-based natural coagulants can strengthen sustainability principles in water treatment, support the circular economy, and improve public health. In addition, Tripti et al. (2023) revealed that using carbon dot-based photocatalysts derived from biomass shows the potential of bio-materials in offering more economical and non-toxic water treatment solutions. While early research shows promise, more field trials are necessary to confirm the effectiveness of using local plant material for wastewater treatment on a larger scale. With the support of local regulations and infrastructure, implementing plant-based solutions can offer a cost-effective and environmentally friendly option for managing water and industrial wastewater, particularly in communities seeking sustainable alternatives. Each plant species has unique capabilities to remove or break down specific substances found in wastewater, highlighting the value of plants in pursuing environmental sustainability and clean water solutions.

Conclusion

Using local plants in water and wastewater treatment has the potential to provide effective and sustainable solutions for removing pollutants. Different types of plants, such as aquatic and wetland plants, fruit and fiber plants, grains, medicinal and ornamental plants, and timber trees, offer mechanisms like adsorption, coagulation, and phytoremediation. These mechanisms can help reduce contaminants such as heavy metals, organic compounds, pathogens, and dyes.

Plants are utilized across different water types, including peat water, agricultural runoff, and both industrial and domestic wastewater. This illustrates their adaptability and effectiveness in improving water quality. However, although laboratory results indicate significant potential for using local plants in water and wastewater treatment, the large-scale implementation of this method faces several challenges. For instance, these include the need for improved infrastructure for domestic water treatment at the household level, along with the complexities of industrial waste management.

Plant-based water and wastewater treatment has inherent limitations, including efficiency variations, dependency on environmental conditions, and the potential generation of secondary pollutants. To move forward, it is essential to develop larger, community-based pilot projects that integrate plant-based water treatment within specific socio-ecological contexts. Further research is necessary to evaluate the effectiveness of various local plants in addressing complex and diverse types of water pollution on a larger scale. Additionally, challenges related to plant material regeneration, system maintenance, and the management of treatment residues must be addressed to ensure that plant-based solutions can be implemented sustainably. With appropriate regulatory and infrastructure support, plant-based water treatment solutions can serve as a cost-effective and environmentally friendly alternative, contributing to the sustainability of water resources in Indonesia.

Limitation

This study has three main limitations. First, it focuses solely on English-language publications, potentially underrepresenting contributions from non-English-speaking countries and Indonesian water treatment research published in other languages. Second, it only includes journal articles, book chapters, and conference proceedings, excluding other publication types. Third, no additional data searches were conducted beyond those in the three databases (Scopus, WoS, and Google Scholar).