## Abstract
The major sources of such contaminants are the refining industry, batteries, naneries, and the paint industry. Lead is one of the most significant environmental pollutants, due to its effects on health, causing damage to the central nervous system, gastrointestinal diseases, headaches, dizziness, diarrhea, and vomiting [5]. The toxic effects of lead have been investigated in several contributions, e.g., a Microtox asasy(r) was employed to determine the toxicity levels of lead compared to three other metals, reported the following order: mercury \(>\) lead \(>\) cadmium \(>\) arsenic [6]. According to the World Health Organization, the maximum concentration of lead allowed in drinking water is 0.01 mg/L [7]. To reach lower concentrations than the limit, it is necessary to apply treatment methods such as adsorption, ion exchange, coagulation, and chemical precipitation, among others. The wide range of alternatives for the removal of heavy metals is limited by high cost, low efficiency, low selectivity, or complexity [8]. The adsorption technique is known as one of the most effective methods to uptake heavy metal ions because of the availability of several high-efficient and low-cost materials with adsorption properties [9]. The selection of an adsorbent is the most important aspect during such a technique, according to the desired removal yields. Novel adsorbents have been tested to improve the selectivity, adsorption capacity, and reusability for large-scale application of traditional adsorbents [10; 11]. To date, different types of agricultural biomasses have been prepared as bioadsorbents for the treatment of residual water, such as peanut shells, shrimp exoskeleton, fruit peels, and sugarcane bagasse [12; 13]. The valorization of such biomasses by synthetizing adsorbent materials represents an attractive solution to solve disposal problems of agricultural residues [14]. [PERSON] et al. [15] performed a literature review on the use of agricultural biomasses as bioadsorbents to decontaminate aqueous solutions. Such a contribution identified adsorption capacities from 0.38 to 820 mg/g, which is highly affected by the biosorbent nature and the system metal-biosorbent. Different materials have been also tested for the removal of lead from water using adsorption technology. [PERSON] et al. [16] prepared amorphous titanium hydroxide and boron-doped (B-doped) sodium titanates hydrates for the removal of Pb(II) from water, and achieved an adsorption efficiency of 99.9%. [PERSON] et al. [17] synthesized titanate nanoflowers and evaluated their adsorption mechanism for lead uptake using isotherm and kinetic modelling. The authors reported that the Langmuir isotherm and pseudo-second order kinetic best fit the experimental data. [PERSON] and [PERSON] [18] used regenerated TiO\({}_{2}\) nanoparticles (which are released during water treatment processes) to remove heavy metal ions such as lead, and observed adsorption efficiencies greater than 94% after four cycles of regeneration using pH 2. These authors also evaluated the desorption process of lead, copper, and zinc from commercially-prepared TiO\({}_{2}\) nanoparticles, obtaining yields at pH 4 of 49, 85, and 88%, respectively [19]. Other contributions select agricultural materials as the main source of adsorbents for lead removal; for example, [PERSON] et al. [20] prepared adsorbents from the biomass of avocado seeds to remove lead and chromium ions from aqueous solution. They tested the adsorbent in its natural form (NB), in a chemically activated (AB) form, and with activated carbon (AC), and reported removal yields of up 80% at pH = 5 and T = 25 \({}^{\circ}\)C. [PERSON] et al. [21] used biochar derived from date palm waste biomass to evaluate the adsorption performance for lead and copper removal. The maximum adsorption capacity of lead (98.9 mg/g) was reached at pH = 4.5, and the Freundlich-Langmuir model best fit the adsorption data for Pb(II). [PERSON] et al.