## 1 Introduction  
In recent years, various factors such as population growth, urbanization, industrialization, and shifts in societal behaviors have led to the introduction of numerous potentially hazardous substances into the environment [1]. This influx of pollutants, particularly into aquatic ecosystems, poses serious threats to both ecological health and human safety. Among these pollutants are the emerging contaminants (ECs), which represent a diverse range of chemicals not yet fully integrated into standard monitoring practices at the national or European Union level, including in the Republic of Serbia. Despite their increasing prevalence, the behavior, fate, and toxicity of these contaminants remain poorly understood [2, 3]. One of the critical categories of ECs includes organic UV filters, such as those found in personal care products, pharmaceuticals, and industrial additives. These compounds are widely used in sunscreens and cosmetics due to their ability to protect the skin from harmful UV radiation. Among them, 3-(4-methylbenzylidene) camphor (4-MBC), a camphor derivative, stands out as a common and potent UV-B absorber. However, 4-MBC has been detected in numerous environmental matrices, including rivers, lakes, sediments, and even drinking water sources. Studies have shown that it exhibits estrogenic, antiestrogenic,androgenic, and antiandrogenic activities, affecting aquatic organisms and acting as an endocrine disruptor. Due to its chemical stability and poor biodegradability, 4-MBC accumulates in aquatic environments and sediments, contributing to long-term environmental contamination [4; 5; 6; 7]. Alongside organic micropollutants, microplastics are labeled as emerging contaminants in wastewater, with a significant capacity for the adsorption of other micropollutants, acting as a novel carrier in aquatic environments. Plastics have become essential in modern society due to their versatility, durability, and lightweight nature, but their widespread use and improper disposal have led to significant pollution of terrestrial and aquatic ecosystems [8; 9]. A major environmental challenge is posed by microplastics (MPs), classified as particles smaller than 5 mm [10]. These MPs are prevalent in marine sediments, continental waters, and agricultural environments [11; 12; 13], and they frequently interact with organic and inorganic pollutants such as polycyclic aromatic hydrocarbons (PAHs), pesticides, and pharmaceuticals [14; 15; 16; 17; 18; 19]. While research has extensively studied the impact of MPs on marine environments [20], there is still limited data on their effects in inland water bodies and drinking water sources, particularly their interactions with other pollutants like 4-MBC. In response to the challenges posed by these pollutants, various water and wastewater treatment technologies have been developed, including biological digestion, chemical oxidation, and adsorption [21; 22]. Among these, adsorption stands out as an environmentally friendly solution due to its minimal energy requirements and avoidance of secondary pollution. Carbon-based adsorbents, particularly biochar derived from biomass, have garnered attention for their potential in water remediation [23; 24]. Biochar is produced through pyrolysis, a process that thermally decomposes organic material in an oxygen-free environment, transforming agricultural biomass waste into a stable carbon material [25; 26; 27; 28]. This process not only mitigates environmental problems associated with biomass waste but also contributes to reducing carbon emissions by sequestering carbon in a slower biological cycle [29; 30]. Biochar has demonstrated significant potential as an adsorbent due to its high surface area, functional groups, cation-exchange capacity, and aromatic carbon structure [31; 32; 33; 34]. Previous investigations indicate that, when present together, biochar and microplastics may exhibit greater synergistic adsorption of certain organic pollutants than each material separately [15].