Cutting fluid effluent removal by adsorption on chitosan and sds-modified chitosan

Abstract

This study examined the adsorption of a synthetic cutting fluid and cutting fluid effluent on chitosan and SDS-modified chitosan. Chitosan and SDS-modified chitosan were prepared in form of beads and fibers. A series of batch experiments were carried out as a function of the initial concentration of cutting fluid, contact time and pH of the fluid. The contact angle study suggested that the SDS-modified chitosan was more hydrophobic than chitosan. The Zeta potential study showed that chitosan, SDS-modified chitosan and synthetic cutting fluid had a point of zero charge (PZC) at pH 7.8, 9 and 3.2, respectively. SDS-modified chitosan has a greater adsorption capacity than chitosan. The experimental results show that adsorption capacity of the cutting fluid on 1.0 g of SDS-modified chitosan at pH 3 and for a contact time of 120 min was approximately 2,500 g/kg. The adsorption capacity of chitosan and SDS-modified chitosan increased with decreasing pH. The Langmuir, Freundlich, and Brunauer Emmett and Teller (BET) adsorption models were used to explain the adsorption isotherm. The Langmuir isotherm fitted well with the experimental data of chitosan while the BET isotherm fitted well with the SDS-modified chitosan data. Pseudo first-and second-order kinetic models and intraparticle diffusion model were used to examine the kinetic data. The experimental data was fitted well to a pseudo second-order kinetic model. The significant uptake of cutting fluid on chitosan and SDS-modified chitosan were demonstrated by FT-IR spectroscopy, SEM and heat of combustion.

Recovery of oil from oil-in-water emulsion using biopolymers by adsorptive method

“…log q e = log k F + (1/n) log C e (2) Where C e is the equilibrium concentration of the adsorbate (mg/L) and q e is the amount of adsorbate adsorbed per unit weight of adsorbent, k F and n are Freundlich constants with n giving an indication of how favorable the adsorption process. Table 2 presents the values of Freundlich isotherm constants for chitin that was calculated from the linear plot of log q e vs. log C e which is shown in Fig.…”

“…The water-based fluids are soluble oil, which may be synthetic and semisynthetic and are mixed with water to form oil-in-water emulsion. A Material used as a lubrication matter in soluble oil, synthetic and semisynthetic cutting fluid is mineral oil, organic compounds of poly-alpha-olefins and the mixture of mineral oil and organic compounds, respectively [2]. Typical additives in the water-based cutting fluid is emulsifiers, surfactants, corrosion inhibitors and biocides.…”

“…The adsorption capacity was calculated as {(weight of the adsorbed adsorbate/weight of the adsorbent) × 100}. Hydrophobic index was then computed as the adsorption capacity of cutting fluid/adsorption capacity of deionized water[2].…”

“…Conventional treatment methods of oil-in-water emulsions are skimming, gravity setting, emulsion breaking [12], chemical de-emulsification [13], the combination of destabilization and flotation [14] and membrane [15]. Adsorption is a far and wide accepted technology for both organic and inorganic contaminants such as cutting fluid [2], dyes [16], fluoride [17], nitrate [18], phosphate [19], perchlorate [20] etc. It is a promising technology to remove oil from oil-in-water emulsion using adsorbents such as peat [21], mixture of Ca and Mg oxides [22] activated carbon, etc.…”

Treatment of emulsified oil using biopolymer assisted materials

“…It is clear that the calorific value of CS/LZMO composite was less than that observed for oil adsorbed CS/LZMO composite. This may be a good agreement to use oil sorbed CS/LZMO composite as a solid fuel in order to get energy in return .…”