The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolt...The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolting and grouting lining have been also listed. Bolting and grouting lining can increase the integrity and load-carrying capacity of supporting framework and it can assure the stability of supporting framework. It possesses not only the flexible and yielding capacity of bolting and shotcrete lining, but also the effect of rigid support such as metal support and brickwork, forming many kinds of support system, maintaining the stability of roadway together.展开更多
The purpose of this study is to develop low cost adsorbing materials to remove the heavy metals from waste waters. The outer covering of coconut, coconut shell, is the most abundant in the countries of its plantation ...The purpose of this study is to develop low cost adsorbing materials to remove the heavy metals from waste waters. The outer covering of coconut, coconut shell, is the most abundant in the countries of its plantation and enormous use. Utilization of agricultural waste （coconut shell） in the production of activated carbon potentially leads to produce a highly effective adsorbent generated from low cost raw materials that are available in huge quantity as renewable resources. At present coconut shell is not in use as valuable entity due to which disposal and ultimate environmental problems are faced. In this study coconut shells were impregnated with phosphoric acid and chemically activated at 450 C. The potential to remove chromium （VI） from aqueous solution by using activated coconut shells was investigated by batch experiment. The various sorption parameters i.e pH, sorbent dose, sorbate concentration, agitation time and agitation speed were optimized. The sorption of Cr （VI） onto activated carbon, developed from coconut shell, at pH 2 was achieved 81.25%. The best optimum conditions were obtained when 0.75 gm of sorbent was agitated at 150 rpm with 60 mg/L of sorbate for 40 min. Activated coconut shells has potential to be a good resource material for effective removal of chromium （VI） of low concentration from wastewater.展开更多
文摘The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolting and grouting lining have been also listed. Bolting and grouting lining can increase the integrity and load-carrying capacity of supporting framework and it can assure the stability of supporting framework. It possesses not only the flexible and yielding capacity of bolting and shotcrete lining, but also the effect of rigid support such as metal support and brickwork, forming many kinds of support system, maintaining the stability of roadway together.
文摘The purpose of this study is to develop low cost adsorbing materials to remove the heavy metals from waste waters. The outer covering of coconut, coconut shell, is the most abundant in the countries of its plantation and enormous use. Utilization of agricultural waste （coconut shell） in the production of activated carbon potentially leads to produce a highly effective adsorbent generated from low cost raw materials that are available in huge quantity as renewable resources. At present coconut shell is not in use as valuable entity due to which disposal and ultimate environmental problems are faced. In this study coconut shells were impregnated with phosphoric acid and chemically activated at 450 C. The potential to remove chromium （VI） from aqueous solution by using activated coconut shells was investigated by batch experiment. The various sorption parameters i.e pH, sorbent dose, sorbate concentration, agitation time and agitation speed were optimized. The sorption of Cr （VI） onto activated carbon, developed from coconut shell, at pH 2 was achieved 81.25%. The best optimum conditions were obtained when 0.75 gm of sorbent was agitated at 150 rpm with 60 mg/L of sorbate for 40 min. Activated coconut shells has potential to be a good resource material for effective removal of chromium （VI） of low concentration from wastewater.
