## 1 Introduction  
The global sustainable fabrics market report mentions a compound annual growth rate of 11.4%, valued at USD 58.3 billion [1]. However, manufacturing textures by material enterprises appallingly affect the climate because of the tremendous exhaustion of engineered colors; most of them increment BOD and COD., disable photosynthesis, upset plant development, give hard-headedness, and advance the cancer-causing nature and mutagenicity [2]. Additionally, unquenchable water utilization hurrying by trillions of gallons for every annum and a lot of handled color effluents containing a large number of huge loads of unconsumed colors represent a critical danger to nature and the climate [3; 4]. Notwithstanding the rigid guidelines forced on the material ventures in wastewater treatment, the results have been horrifyingly baffling [5; 6]. One of the essential reasons is the shortfall of an economical remediation strategy technique and the methodology for eliminating poisonous colors. Supportability as a framework resolves financial matters, climate, and, thus, social concerns [7]. The various techniques and methods reported in the literature may be broadly classified into four types--namely, biological [8; 9], chemical [10; 11; 12], physicochemical [13; 14], and physical methods [15; 16; 17]. The methods described above have severe limitations: the time of completion of the remediation process, the cost of the technique and/or method; the fall-out of chemical, electrochemical, and photochemical degradation processes, resulting in toxic substances [18]. Besides, one of the major problems associated with all the reported techniques is the disposal of sludge. Adsorption as a technique addresses many of the problems described above with substantial answers for the remediation of colors from modern effluents [19]. Notwithstanding, this technique also falls short of the disposal of \"sludge\" produced after the adsorption of the adsorbate onto the adsorbent. Hence, address the issue to give an amicable answer for ooze removal [20]. One of the options is to utilize an inorganic class of adsorbents which will affect less the climate and environment [21]. The textile industry requires an enormous quantity of adsorbent for the process of remediation of dyes and allied materials for the treatment of effluents. Thus, the adsorbent must have the following characteristics: availability in abundance, cost-effective, environmentally friendly, prepared to use with no pretreatment, and ought to have a pore structure. The latter assumes importance, as the adsorption technique is a physical method and requires an enormous surface region for the cooperation of the adsorbent with the adsorbate [22]. Halloysite nanotube (HNT) as an adsorbent qualifies as a candidate to meet the above requirements. Moreover, the tubular structure of HNT with different chemistries inside the pore and on the surface suits our present study. Additionally, HNT has been extensively used as filler material providing strength to the composites fabricated [23]. This information helps us to address the issue of disposal of the sludge as a reinforcement material. Brilliant green (B.G.) is the triarylmethane class of dyes. It is widely utilized in the paper industry to dye wool, biological staining, and dermatological agents. However, it is a hazardous contaminant that causes diarrhea, eye irritation, nausea, and vomiting [24]. Besides, scant literature is available to remove the triarylmethane class of compounds using HNT [25]. There are about a dozen research articles described in review studies relevant to imbibing inorganic materials. However, none of the papers have used nanomaterials and addressed the adsorption of brilliant green dye. The present research work is oriented towards the experimental optimization of the state of the features influencing the process of adsorption, model studies for better understanding, and carry out RSM studies based on a fractional factorial experimental design (FFED) for possible commercialization.