This study contributes to the current state of knowledge by highlighting the physical–chemical interactions between biochar and dyes. The removal of Acid Orange 7 (AO7) dye by a modified biochar obtained from the wastes of mandarin peels (MPs) has been investigated in this work. A dehydration procedure with 80% H₂SO₄ under reflux was applied to produce an innovative biochar from MPs and then boiled with H₂O₂ and followed by boiling with triethylenetetramine to make mandarin biochar-C-TETA (MBCT). FTIR, SEM, EDX, BJH, BET, TGA, and DTA analyses were applied to investigate the MBCT. FTIR analysis showed an additional peak that confirmed the addition of the NH₂ group to the MBCT structure. An amorphous carbon structure was also confirmed by XRD analysis. The AO7 dye solution pH was proved to give the best absorption at pH 2.0. Significant removal of AO7 dye 99.07% using an initial concentration of 100 mg/L of AO7 dye and a 0.75 g/L MBCT. The Langmuir (LNR) and Freundlich (FRH) isotherm models investigated the experimental results. The LNR was best suited to handle the working MBCT data. The maximum adsorption capacity (Q_m) calculated for the MBCT was 312.5 mg/g using 0.25 g/L of the MBCT. Kinetic studies were conducted using the intraparticle diffusion (IND), film diffusion (FD), pseudo-first-order (PFOR), and pseudo-second-order (PSOR) models. The absorption rate was calculated using the ultimate value of the linear regression coefficient (R² > 0.99), and the PSOR rate model was found to ideally describe the absorption process. The point of zero charge (pHPZC) was found to be 10.17. The electrostatic attractive-forces between the sorbent surface positively charged sites and negatively charged anionic dye molecules were the primary mechanism of the MBCT sorption of the AO7 dye’s anion absorption. The results indicate that the manufactured MBCT adsorbent may be useful for removing the AO7 dye from wastewater. MBCT can be used repeatedly for up to six cycles without dropping its absorption efficiency.

Gas flaring (GasF) is an important aspect of the combustion mechanisms in the burning of related, undesirable, or surplus fluids (gases in particular) that are released during the ordinary or unexpected overpressuring process in several industrial activities, specifically in the petroleum resource (PTR) industries. It is also one of the major sources of greenhouse gas emissions which cause climate change (CMC). In addition to the generation of noise and heat, it makes substantial adjacent areas uninhabitable and, hence, causes detrimental consequences to the entire ecosystem as well as waste energy and results in economic losses. Reducing GasF is a critical issue due to its ensuing complications; consequently, there is a tenacious need to measure GasF via the study of its composition, distribution, and capacity, as well as the utilization of appropriate GasF recovery/removal procedures. The present review study will, thus, attempt to assess the impacts of GasF on the environment vis-à-vis the possible nexus between GasF/CMC using the perspective of the Niger Delta region of Nigeria which is rich in PTR, with relevant information drawn from existing publications. The roles of government, policymakers, and relevant stakeholders as well as suggestions and recommendations that will assist in the extenuation approaches and technologies of the influence of GasF on the environment are also discussed.