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A rapidly growing problem for life on earth is contamination of fresh water which is addressed in this article. By taking a glimpse on the causes of contaminations, persistent organic pollutants, especially synthetic dyes got prominent role. Here, out of commonly used techniques, adsorption using plant wastes was chosen for phytofiltration of such dyes. A natural adsorbent from plant source was selected and processed with acid, characterized with FTIR and SEM and then checked the efficacy on cationic dye brilliant green. Phytofiltration of dye was done to check the effectivity of both untreated (OA) and acid treated (OA-AC) form of Acacia concinna biowaste. Results were obtained, evaluated and presented here, giving maximum adsorption capacities (Qm) of AC and OA-AC 95.24 and 909.09 mg.g−1, respectively following Langmuir, pseudo second order kinetics and spontaneous exothermic nature, indicating their suitability to adopt on larger scale wastewater treatment effectively using green technology. NOVELTY STATEMENT: In this work, Acacia concinna both in untreated and acid treated form is used as an efficient adsorbent for the removal of Brilliant green dye from waste water, as not reported earlier, which proves its novelty. The values of adsorption capacities of both the adsorbent types are compared with different natural and synthetic adsorbents reported earlier, this comparison elaborate the efficacy of AC to be used as adsorbent and consider it as one of the efficient adsorbent materials naturally available. [ABSTRACT FROM AUTHOR]

Water pollution is a grave risk to mankind. Water pollutants including organic toxins, dyes effluents, and heavy metals have posed great stress on water quality in recent years. This has necessitated the search for an affordable, eco-friendly, inexpensive, stable, and effective strategy for wastewater remediation. In this work, a pollyoxometallate K6[H2AlBW11O40].9H2O (KAB) was impregnated on kaolin clay to synthesize a clay-based nanocomposite KAB-K which was then evaluated for adsorptive removal of brilliant green dye (BG) from wastewater. The prepared composite was characterized by different techniques such as FTIR, SEM, and EDX analysis. The characterization results indicated the fine distribution of KAB on kaolin's surface. The adsorption studies of BG involved evaluation of optimum parameters such as time contact (30 min), quantity of adsorbent (20 mg), pH (5), temperature (40 °C), and agitation speed (125 rpm). 99.5% of BG was removed by KAB-K within 30 min. The assessment of kinetic data was performed via Langmuir, Freundlich, and Temkin models. The experimental data was found to be in good agreement with the Langmuir model (R2 > 0.9965) as compared to other models. Qmax value of KAB-K (144.92 ± 0.005 mg/g) was much higher than simple kaolin (33.22 ± 0.01 mg/g). The applicability of the pseudo-second-order kinetic model suggested that the process was predominately chemisorption. KAB-K was easier to recycle and efficiently removed up to 68.7% dye in 3 subsequent cycles. Thus rapid adsorption rate, high adsorption capacity, efficient recovery, and reusability of KAB-K endorses that the synthesized composite is an effective adsorbent for wastewater pollutants. [ABSTRACT FROM AUTHOR]

Pakistan is an agricultural country producing plenty of fruits, like: mango, banana, apple, peaches, grapes, plums, variety of citrus fruits including lemon, grapefruit, and oranges. So far the peels of most of the fruits are usually wasted and not properly utilized anywhere. In this work, the peels of banana and grapefruit are converted into biochar by slow pyrolysis under controlled supply of air and used for sequestering cyanide ions from aqueous medium after chemical modification with ZnCl2 and sodium dodecyl sulfate (SDS). The modified biochar was characterized by various instrumental techniques, like: SEM, FTIR, TGA, and CHNS. Different parameters, like: time, temperature, pH, and dose of adsorbent affecting the adsorption of cyanide ions, onto prepared biochar were optimized and to understand the adsorption phenomenon, kinetic and thermodynamic studies were performed. Concentration of cyanide ions was estimated by employing standard ion selective electrode system and it is found that Sodium Dodecyl Sulfate treated biochar of banana peels shown more adsorption capacity, i.e.,: 17.080 mg/g as compared to all samples. Present work revealed that the biochar produced from the fruit waste has sufficient potential to eliminate trace quantities of cyanide from water, especially after treatment with sodium dodecyl sulfate. An industrial area in Asian and African countries where mining is done using traditional techniques is the major cause of cyanide toxicity in wastewater streams. So, here chemically fabricated biochar made by peels of banana and grape fruit is employed for removal of cyanide ion for controlling aquatic pollution using local resources in green way. Favorable results indicated the feasibility of this process, which is cost effective, convenient, ecofriendly, and sustainable. [ABSTRACT FROM AUTHOR]

Textile industries use large amounts of water as well as dyes. These dyes containing water are then discharged into the water bodies causing a significant role in water pollution. Brilliant Green dye contributes to many harmful diseases related to the respiratory and gastrointestinal tract. In this study, Symplocos racemosa (SR) agro-waste was chemically treated with acid (SR-HCl) and base (SR-NaOH) and then used for removing Brilliant Green Dye (BGD) on the batch scale. They were characterized by SEM, EDX, FTIR, XRD, TGA and DSC. Optimized conditions were 30 °C temperature, pH 6, adsorbent dose of 0.10 g/25 ml dye solution, shaking speed of 100 revolutions per minute, initial dye concentration of 50 ppm and 35 min time for shaking adsorbent and dye solution. Adsorption data obtained were analyzed using isotherms. The experimental data was found to fit well with the Langmuir model and the maximum adsorption capacity (qmax) of BGD on the SR, SR-HCl, and SR-NaOH was revealed to be 62.90, 65.40, and 71 mg/g respectively. Kinetic data (pseudo-first-order and pseudo-second-order) were evaluated and adsorption tends to follow the pseudo-2nd-order, which indicated the chemisorption mechanism. The results revealed that Symplocos racemosa agro-waste can be considered as the potential biosorbent. [ABSTRACT FROM AUTHOR]