Optimum design and analysis study of stand-alone residential solar PV microgrid

Today’s power system network has become more complex and it has more responsibilities and challenges to provide secure, reliable and quality energysupply to the communities. A small entity of electrical network known as Microgrid (MG) is more popular nowadays to enhance reliablity and secure level of energy supply, in case of any energy crisis in the utility network. The MG can also provide clean energy supply by integrating renewable energy sources effectively. TheMG with small scale solar photovoltaic (PV) power system is more suitable to provide reliable and clean energy supply for remote or urban communities in residential level. This paper presents the basic analysis study of stand-alone solar photovoltaic (PV) MG power system which has been developed with the aid of Matlab - Simulink software, on the basis of residential load profile and solar exposure level in a particular area of Geelong, Victoria State. The simulation result depicts the control behavior of MG power system with optimum sizing of PV (4.385 kW)and battery storage (480Ah/48V) facility, fulfills daily energy needs in residential load level. This study provides a good platform to develop an effective and reliable stand-alone MG power system for the remote communities in the near future.

Adsorption kinetics and optimum conditions for Cr(VI) removal by activated carbon prepared from luffa sponge

Activated carbon (AC) prepared from luffa sponge was firstly used as an adsorbent to remove Cr(VI) from aqueous solution. The Cr(VI) adsorption behaviors of AC under different conditions, including initial Cr(VI) concentration, quantity of AC, solution pH, and temperature were investigated. The optimal conditions for adsorption of Cr(VI) by AC were pH = 1, initial Cr(VI) concentration = 80 mg/L, T = 303 K, and AC content = 1.6 g/L. The adsorption kinetics could be described by the pseudo-second-order model. Fourier transform infrared spectroscopy was used to investigate the sorption mechanism. Some functional groups such as C–O and O–H were formed on the carbon surface, which could then react with Cr(VI). The surface structure of AC before and after adsorption was analyzed by scanning electronic microscopy. Adsorbed ions choked some of the pores in AC after adsorption. The Brunauer–Emmett–Teller surface area and average pore size of the AC were 834.13 m2/g and 5.17 nm, respectively. The maximum adsorption of Cr(VI) by AC was 149.06 mg/g, which makes AC prepared from luffa sponge promising for removing Cr(VI) from wastewater.