Membrane processes have been extensively employed in diverse applications, specifically in industrial wastewater treatment. The technological development in membrane processes has rapidly advanced and accelerated beyond its common principle and operation. Tremendous efforts have been made in the advancement of membrane materials, fabrication method, membrane modification and integration with other technologies that can augment the existing membrane processes to another level. This review presents the recent development of hollow fiber membranes applied in wastewater treatment and resource recovery. The membrane working principles and treatment mechanism were discussed thoroughly, with the recent development of these hollow fiber membranes highlighted based on several types of membrane application. The current challenges and limitations which may hinder this technology from expanding were critically described to offer a better perspective for this technology to be adopted in various potential applications.

The chemical coagulants used in the process of wastewater treatment causes negative implications on environment and human health. Exploration on natural coagulants as environmental friendly solution has been widely carried out. In present research, Artocarpus heterophyllus (jackfruit) peel is used as coagulant in treating domestic wastewater. This study aimed to assess optimum pH of wastewater and coagulant dosage by varying them to achieve the maximum removal rate of total suspended solid (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD) and turbidity. The studied range for pH of wastewater was pH 1-3 and dosage of coagulant within 50–70 mg/L. Response surface methodology (RSM) based on central composite design (CCD) implied in optimization of this coagulation process. Treatment using this natural coagulant enabled maximum reduction of turbidity, TSS, BOD and COD up to 80.7 %, 77.5 %, 34.3 % and 34.6 % respectively under optimum condition of pH 2.1 and dosage of 58 mg/L. These findings revealed higher reduction in turbidity and TSS. Thus, this study indicates the promising potential of the Artocarpus heterophyllus peel extract as an alternative bio-based coagulating agent for effective pre-treatment of wastewater.

The application of chemical coagulants which is damaging to environment and human health has triggered to the exploration of new coagulants from natural based sources. This study emphasized on the performance of a treatment process to remove particles in the synthetic domestic wastewater by coagulation using Artocarpus heterophyllus (jackfruit) peel extract and evaluation of zeta potential (ζ). The measurement of zeta potential which is the criteria defining the electrostatic interaction between pollutants and natural coagulant agent is used in proposing mechanism of coagulation. The jar test experiment was carried out and the treated wastewater was analysed to determine reduction in turbidity, BOD, COD and TSS. The coagulant extracts were characterized in terms of surface charge. The best operating conditions were: pH 2 and dosage 60 mg/L. The corresponding removal efficiencies for turbidity, TSS, COD and BOD were 80 %, 70 %, 46 % and 20 % respectively. The measured zeta potential of the coagulant was -25.2 mV at its original pH, 6.95. On the other hand, the surface charge of synthetic wastewater was positive at pH 2 and later turned to be negative as the pH is increased up to pH 12. This best describes that jackfruit peel coagulant possessed the characteristic of anionic polyelectrolytes which involves bridging mechanism. The results obtained here suggest that coagulation using Artocarpus heterophyllus peel extract can be employed as an effective and low-cost preliminary technique in wastewater treatment process.

Solar thermal energy plays a vital role in the industrial sector, especially for water heating applications. Further research to improve the efficiency of flat plate solar collectors by focusing on collector design modification is imperative. This research aimed to carry out an experimental investigation on comparative designs and fabrication approaches that deal with the analysis of flat plate solar collector thermal performance, thermal efficiency, the effect of various mass flow rates, and pressure drop analyses. In this paper, a different design modification of pipe collector with serpentine-shaped was established with different tube diameters (3/4-inch and 3/8-inch), and different pipe spacing (18.5 cm and 27.0 cm). Under the same heat radiation intensity and constant mass flow rate, a pipe collector with a tube diameter of 3/4-inch achieved 3.5% and 9.4% higher thermal performance and collector efficiency respectively compared to the tube diameter of 3/8-inch. Furthermore, the pipe collector with pipe spacing of 18.5 cm exhibited 4.3% and 12.6% higher thermal performance and collector efficiency respectively compared to pipe spacing of 27 cm. The relationship between collector efficiency and temperature difference was also investigated. Moreover, the effect of different mass flow rates was studied upon and it was found that a flow rate of 0.03 kg/s exhibited optimum thermal performance for the pipe collector. Additionally, a pressure drop was observed with the increase in flow rate, while decreases when the fluid temperature increases.