introduction: the powdered activated carbon treatment (pact) has been proposed as an alternative in wastewater treatment and wastewater biomass protection against toxic substances. this study aims to evaluate pact performance in treating dyes, acid orange, and remazol brilliant reactive blue. methods: this empirical- applied research was carried out in pilot scale in which different dye removal...

background: contamination of water with arsenic has attracted the researchers’ attention as a global problem in recent years and has been observed in some parts of iran. the purpose of this study is to assess the efficiency of welding iron waste in removing arsenic from aqueous solutions.   methods: in this study, the effects of different parameters, such as ph (3-9), initial concentration of a...

in the present study, the treatment of tannery wastewater was performed by electrocoagulationmethod (ec) using aluminium and steel electrodes. response surface methodology (rsm) with three factors; current density (i), electrolysis time (t) and ph, with each factor at five levels, was used to optimize the factors for higher chemical oxygen demand (cod) and total suspended solids (tss) removal. ...

background: the effective size of the end grain of horizontal roughing filters (hrfs) is larger than 2 mm. this study aimed to examine the efficiency of hrfs in removing nitrate, phosphate, and chemical oxygen demand (cod) from effluent of a wastewater stabilization pond. methods: this experimental study was conducted in 2013. the pilot project was transferred to the karaj wastewater treatment ...

Mistrust of science has seeped into public perception of the most fundamental aspect of conservation-extinction. The term ought to be straightforward, and yet, there is a disconnect between scientific discussion and public views. This is not a mere semantic issue, rather one of communication. Within a population dynamics context, we say that a species went locally extinct, later to document its...

Exploitation can modify the characteristics of fish populations through the selective harvesting of individuals, with this potentially leading to rapid ecological and evolutionary changes. Despite the well-known effects of invasive fishes on aquatic ecosystems generally, the potential effects of their selective removal through angling, a strategy commonly used to manage invasive fish, are poorl...