Magnetic activated carbon (MAC) is found to be effective for the adsorption of methylene blue due to its physico-chemical properties such as strong adsorption of magnetization. The use of activated carbon (AC) for methylene blue adsorption was ineffective compared to MAC. MAC was prepared by incorporating different types of iron powder and chemicals [sodium dodecyl sulphate (SDS), citric acid (CA), dimethicone (D350), and epichlorohydrin (C3H5ClO)] to strengthen the magnetism and stabilize the MAC. The methylene blue test and iodine test were tested on different samples. Characterization test on physical and chemical properties was carried out using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). The yield of MAC was higher because of the addition of magnetic particles. The incorporation of magnetic particles had been proven by the SEM and XRD analysis that showed the presence of iron compound. The performance study of the adsorbent sample showed that MAC_A3II presented better qualities with highest removal percentage (98.81 % of removal) in methylene blue adsorption and low magnetic contact time that showed strong magnetism. MAC_A3II was prepared by incorporating iron powder and treated by using sodium dodecyl sulphate (SDS). Among all the adsorbent sample, MAC_B2III performed the weakest quality because the dye removal percentage was low, and the preparation process was complicated compared with others.

Untreated effluents from the textile industry containing colorant dyes are harmful to the environment, aquatic organisms, and human health. Among these effluents, Rhodamine 6G is known as a corrosive and irritant dye. A coconut shell-derived nanomagnetic adsorbent composite (CS-NMAC) was developed to remove Rhodamine 6G from aqueous solution. Physical and adsorption properties of CS-NMAC were characterized via Brunauer–Emmett–Teller (BET) surface area analysis (SBET: 1092.17 m2/g; total pore volume: 0.6715 cm3/g), X-ray diffraction (Fe3O4 [θ=35.522], Fe2O3 [θ=35.720] and FeO [θ=41.724]) and Fourier transform infrared spectroscopy (Fe–O, C–H, asymmetric C=C=C, CN and O–H). CS-NMAC was found to be electropositive within a broad pH range of 3–10) owing to the presence of nanoscale iron oxides on the surface of the coconut shell-derived adsorbent that enhanced the chemical and electrochemical outputs. Isotherm study revealed that the adsorption process of Rhodamine 6G followed a multilayer type of adsorption onto a heterogeneous surface. Freundlich model fitted better (R2 = 0.981) than the other models (Langmuir, Temkin and BET). The maximum adsorption capacity was 32.02 mg/g. Rhodamine 6G removal by CS-NMAC obeyed the pseudo-second-order reaction (R2 = 0.9995) as opposed to other kinetic models. CS-NMAC has the potential to become an effective treatment for dye pollution.

Issues of water quality in Kelantan are often debated by various parties and have gained widespread media coverage. A study is carried out to assess behaviour of users in consuming water, their perceptions and willingness to pay for obtaining better water quality unit at home. Three districts in Kelantan namely; Pasir Mas, Tanah Merah, and Jeli were selected for the study. Questionnaire for 43 respondents in selected districts, interviewing local people, taking water samples, and sending for laboratory analysis were conducted. Shapiro-Wilk test and Spearman test were applied to analyse the results. It was shown that 46.5 % of the users for all drink have more than one source of water at home. Treated water supplied by Air Kelantan Sendirian Berhad was chosen by users as their main source for drinking. A closer look on users’ perception regarding water quality reveals that users were neutral about water quality from tap water (treated water supplied by local management) but they express optimistic on water’s quality from tube well. However, laboratory analysis of water from alternative sources proved otherwise. 83.7 % of 43 respondents willing to have water filter at home, and the willingness is proportional to the income of the user. These findings are essentials for household water management when multiple sources of water were used. This highlight the need study for water treatment industrial players to provide an efficient yet affordable water solution for the consumers.

The usage of groundwater as drinking water source in many parts of Kelantan encourages the research and development of various cost-effective alternative adsorbent material for turbidity reduction and drinking water purification. The preparation, characterization, and use of a magnetic biocarbon adsorbent composite (MBAC) is introduced in this study as an option to treat turbid groundwater. In contrast to commercial activated carbon (CAC), peak shifts and peaks denoting Fe-O bending were observed in the FTIR spectrum of MBAC. The adsorption process for turbidity reduction by MBAC and CAC was investigated. A factorial design matrix consisting of four parameters were tabulated, namely, adsorbent dosage (0.02, 0.04, and 0.06 g), agitation time (15, 30, and 60 min), agitation rate (150, 200, and 250 rpm), and two adsorbent particle size ranges (M: 300 < x ≤ 500, and Q: ≤ 45 μm). The predictive model was validated with 0.04 g MBAC of ≤ 45 μm in particle size, agitated at 150 rpm, for 48 min, that attained 98.46% turbidity removal efficiency with a final NTU reading of 0.40. Conversely, CAC removed 88.19% for a final NTU reading of 3.07. Overall, the iron oxide impregnated biocarbon composite showed better turbidity reduction capability compared to CAC. The findings of this work support the potential application of MBAC as an alternative adsorbent for the treatment of groundwater sourced drinking water.

In this study a simple and rapid harvesting method using electro conductive polymer coated saw dust has been presented as a new coagulant for separating Chlorella vulgaris from a diluted suspension. Polypyrrole (PPy) coated saw dust as a novel coagulant was prepared via in-situ polymerization of pyrrole (Py) monomer using FeCl3 oxidant in aqueous medium in which saw dust particles were suspended. The zeta potential of coagulant and C. vulgaris and X-ray photoelectron spectroscopic (XPS) analysis of coagulant were characterized. PPy maintain predominantly positive charge over a wide pH range (2-10) with an isoelectric point 10.4 while, C. vulgaris maintained negative surface charge from pH 5 and onward with isoelectric point 3.8. The microalgae showed the highest separation efficiency at pH 10. The maximal recovery efficiency reached more than 90% for microalgae at a stirring speed of 120 rpm within 7 min. The maximal adsorption capacity of C. vulgaris was 28.8 mg dry biomass/mg-saw dust coated PPy. The concentration factor obtained is higher than 32 which save energy and time associated with microalgal harvesting and allows a reduction in the equipment size necessary for biomass dewatering and improves the feasibility of using these microorganisms in biofuel or wastewater processes.