The threat of oil pollution increases with the expansion of oil exploration and production activities, as well as the industrial growth around the world. The study on the treatment of oily wastewater is a critical issue to the environmental protection as oil caused problems to the wastewater treatment facilities. Although oil particles can efficiently be removed by advanced technologies, the treatments are usually expensive and difficult to maintain. Adsorption and coalescence filtration are promising choice of treatment for its simplicity, effectiveness, and feasibility when appropriate sorbent is used. This review discusses the recent papers on the use of natural fibrous sorbent for removal of oil from wastewater, and its current development. With their excellent oil removal properties, environmental friendliness, easy availability, and feasibility, natural fibrous sorbents are an attractive alternative for oily wastewater treatment.

exhibiting a characteristic of high adsorption capacity. The high adsorption capacity suggests that the activated carbon produced using this pyrolysis approach could act as an adsorbent to adsorb metal ions, therefore it shows great potential to be used as a catalyst-support material-the base material to which catalytically active substance such as metal binds to form a heterogeneous catalyst. The activated carbon also demonstrated high thermal stability in N 2 atmospheres, representing a durable material to be synthesized into a catalyst for use in thermal process. Our results show that the activated carbon produced from microwave pyrolysis of orange peel shows exceptional promise as a catalyst-support material.

With oil and grease content of 4000-8000 mg/l in palm oil mill effluent (POME), the commonly used ponding system often fails to produce treated effluent that meets the minimum standard of treated effluent. The present study investigates the efficiency of sago bark (SB) and esterified sago bark (ESB) for removal of emulsified oil from POME. Oil removal experiments were conducted at different batch experimental conditions: namely adsorbent dosage, contact time, temperature and pH. In overall, the oil removal efficiency of both SB and ESB increased with the increasing of sorbent dosage and contact time. 24-h oil adsorption test afforded oil removal efficiency of 57.77% (SB) and 80.23% (ESB).On the other hand, the oil removal efficiency of both SB and ESB decreased with the increasing temperature. Acidic pH was favorable pH condition for high oil removal efficiency in POME. There was a good correlation (R2 > 9.5) between experimental data and the intra-particle diffusion model for both SB and ESB. The adsorption of oil in POME using SB was best described by Freundlich isotherm (R2 = 0.998), indicating heterolayer adsorption of oil on SB. The adsorption of oil in POME using ESB was better represented using Langmuir isotherm (R2 = 0.992), indicating a monolayer adsorption of oil onto the ESB surface. In conclusion, ESB showed better potential for use as sorbent for removing emulsified oil from wastewater, particularly POME.

a b s t r a c tBiochar, a carbon-rich material, can be produced via microwave pyrolysis, as a more energy and cost saving method compared to conventional externally heated pyrolysis. Biochar has versatile applications, for example, for soil amendment purpose and pollutant removal from wastewater. Chemical treatment has been proven to improve the physical and chemical properties of biochar for better applicability. Thus, extensive amount of research has been conducted on chemical treatment of conventional biochar, and several review articles have discussed published works on the chemically treated conventional biochar. However, there has been no review on works involving the chemically treated microwave-derived biochar, by far. This paper presents an overview of the current development and improvement on chemical treatment methods and applications of microwave-derived biochar.