Effluent from the textile industry is a major source of water pollution. Textile effluents contain a high amount of color, turbidity, BOD, and COD, which are highly toxic and affect aquatic organisms as well as human beings. Physical and chemical treatments of these effluents are difficult and costly. Adsorption is an effective method to treat textile industry effluent. In the present study, chitosan is selected as an adsorbent, derived from the exoskeleton of marine crustaceans like shrimp and crab by chemical processing. The color was removed using chitosan from shrimp and crab shells separately. On the sixth day of treatment, shrimp shell chitosan removed 100% of color from textile industry effluent and proved to be a better adsorbent.

Mesoporous clay-starch ceramic pellets have been prepared using silica-rich low fire clay and potato starch as a pore-forming agent. The ceramic pellets prepared using 30% starch, showed the highest porosity and lowest compressive strength among all the different pellets. Batch mode studies using the pellets showed higher methylene blue adsorption capacity with an increase in time and increased initial dye concentration. The adsorption capacity was found to decrease with increasing pellet dose, while pH had a negligible effect on methylene blue removal which makes them a suitable adsorbent in both acidic and basic mediums. Adsorption isotherm analysis of the process was followed by the Langmuir adsorption isotherm whereas the kinetics analysis fitted well with the pseudo-second-order kinetic model. A low-cost, simple device was made from a stainless-steel wire mesh with mesoporous ceramic pellets enclosed in it, which can easily be dipped and taken out of an aquarium and can remove methylene blue from water.

This paper investigated the adsorption properties of boron nitride materials for La(III), and the possible action mechanism was put forward based on experiments. Then the boron nitride materials were characterized by SEM, TEM, XRD, and FT-IR before and after adsorption. In addition, the effects of pH, the amount of adsorbent, the concentration of La(III) solution, and adsorption time on the adsorption efficiency were also investigated. It is found that under a certain amount of adsorbent when the pH is 7.0 and the concentration of La(III) is 40 mg.L-1, the adsorption ability of La(III) is the best. The maximum adsorption capacity is 201.45 mg.g-1. The adsorption kinetic data are in good agreement with the pseudo-second-order and intra-particle diffusion models. These results show that boron nitride has a good application prospect for removing and recovering La(III) in water and has a certain practical application value.

This paper aims to emphasize heavy metals’ impact on water and its removal mechanism with a focus on adsorption. Furthermore, factors affecting bio adsorption, such as temperature, pH, RPM, and initial heavy metal concentration, have been studied for different heavy metals and bioadsorbents. A comparison of their adsorption capacities and efficiencies has been made. This review reviewed different bioadsorbents for their suitability in removing cadmium, lead, and copper ions from water and wastewater, typically by using adsorption as a methodology. A suitable summary compares various heavy metal removal techniques and their advantages and limitations. For adsorption, the characteristics of bioadsorbents and their activation steps have been consolidated. Furthermore, the effects of operational parameters and adsorption mechanisms have been discussed in the review. Apart from assessing the suitability of bioadsorbent, a novel bioadsorbent has been suggested for copper ions removal. The findings shall be significantly useful in applying bioadsorbent in water/wastewater treatment fields to reduce heavy metal pollution. Thorough and well-planned research in this field can facilitate the creation of sustainable and durable technology for wastewater treatment, addressing the increasing demand for safe and dependable water resources, focusing on making it cost-effective and recyclable.

Various wastes can be utilized to produce activated carbon, one of the wastes that can be utilized is nutmeg shell (Myristica fragrans). Activated carbon from nutmeg shells (Myristica fragrans) was used in this study to reduce the content of Pb(II) and Cu(II) ions in liquid waste. This research utilized the adsorption method with the batch system to determine the optimum contact time, optimum pH, and adsorption capacity. The characterization of activated carbon was done by Scanning Electron Microscopy (SEM) and Surface Area Analyzers (SAA). The content of Pb(II) and Cu(II) ions in the filtrate after adsorption was analyzed using an atomic absorption spectrophotometer (AAS). The results of SEM analysis showed that the carbon surface was cleaner and had more open pores after the activation process than before activation. The carbon surface area is 19.6243 m2.g-1. From the results of AAS analysis, the optimum time and pH for Pb(II) and Cu(II) ions was 40 min at pH 5 and 70 min at pH 4. With the Freundlich isotherm method, the adsorption capacity of the adsorbent for Pb(II) ions was 9.6028 mg.g-1 and Cu(II) ions was 0.035 mg.g-1, and the adsorption effectiveness on liquid waste for Pb and Cu metals was 1.9454 mg.g-1 and 0.4251 mg.g-1, respectively. The results showed that activated carbon from the nutmeg shell (Myristica fragrans) was able to reduce the levels of Pb(II) and Cu(II) ions in liquid waste.

For many years, especially in emerging nations like India, the environment has been threatened by the increased output of industrial wastes and heavy metal toxicity. The usage of inexpensive adsorbents has recently attracted a lot of attention in studies on the removal of heavy metals like nickel from industrial wastewater. The use of agro-based adsorbent is an alternative to conventionally used activated charcoal. In this research, adsorption experiments were carried out using agro-based adsorbent prepared from rice husk, wheat husk, and soybean husk to reduce nickel from industrial wastewater. The adsorption process is simple, economical, and effective is the most preferred method used for the removal of toxic metals like nickel from industrial wastewater. Adsorbents prepared from these husks can be effectively used for adsorption due to low cost & high availability. Characterization of agricultural material by various tests like XRF, proximate analysis, bulk density, and iodine number was conducted on agro-based adsorbents to know the co-relation between removal efficiency and adsorption capacity. The effect of turbidity and pH parameters on Ni removal efficiency is also studied. Results indicated that wheat husk adsorbent appeared to be the most effective for the adsorption of Ni from wastewater as compared to soybean husk and rice husk adsorbent. Wheat husk, soybean husk, and rice husk have removal efficiency in the range of 62.50 to 73.33. Composite absorbents CA-2 with the proportion of 50% wheat husk, 33% soybean husk, and 17% rice husk have 82.50% efficiency, and CA-3 has 80.83% efficiency in removing Nickel. Wheat husk adsorbent, CA-2, and CA-3 are more effectively and sustainably used for the treatment of industrial wastewater to remove heavy metals.

Unavoidably, the expansion of industry causes the release of numerous heavy metals, radionuclides, and organic pollutants into the environment. Due to these pollutants, the extremely toxic, highly carcinogenic chemicals provide a serious risk to people and aquatic life. Wastewater pollutants must be removed to safeguard the ecology. A huge specific surface area, multiple binding sites, a plethora of functional groups, variable pore size, and simplicity of surface modification are just a few advantages of porous materials. They are considered viable candidate materials for the efficient and selective removal of contaminants from aqueous solutions in a range of difficult circumstances due to their benefits. This work reviews the characteristics, methods of functionalization, and ways of modification of many novel porous materials in recent years. The use of these porous materials in the treatment of wastewater was examined. The development potential of porous materials is finally summed up.

In this study, Fe3O4/GO nanocomposite was synthesized by hydrothermal method and tested for its efficiency in removing methylene blue (MB) and congo red (CR) from water. The synthesized nanocomposite was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The optimal values for MB and CR removal were determined to be pH 6.0, an adsorbent weight of 50.0 mg, and a contact time of 10 min. The adsorption isotherms of the contaminants on the nanocomposite were analyzed using the Freundlich model, indicating a heterogeneous distribution of active sites on the adsorbent surface. The highest adsorption capacity of MB and CR is 135.1 and 285.7 mg.g-1, respectively. Moreover, Fe3O4/GO nanocomposite recycled five cycles with proper adsorption capacity. Overall, the Fe3O4/GO nanocomposite holds great promise for efficient and sustainable water treatment, providing safe and clean water globally.