The existence of pH optima for proteolysis was early established, primarily through measurements of the initial rate of reaction as a function of pH. When synthetic substrates for proteolytic enzymes were discovered, it was found that the rate of digestion depended upon the amino acids of the peptide and their arrangement in the chain. We have investigated the effect of pH upon the hydrolysis o...

IIn this study, the Electro Coagulation (EC) was used for the removal of acid orange 5 from synthetic wastewater in a batch electrochemical reactor. The impact of the operational variables such as current density, initial pH, time of electrolysis, and initial concentration of the dye was investigated. The results showed that the optimum conditions were obtained at initial pH of 7, curre...

Adsorption capacity of 4-chloro-2-nitrophenol (4C2NP) onto nano-Ti02 from aqueous solutions wasinvestigated in a batch system by considering the effects of various parameters like contact time, nano-TiO2 dosage, initial pH and initial 4C2NP concentration. Optimum conditions for 4C2NP adsorptionwere found to be initial pH z 2, nano-TiO2 closer- 0.01 g and equilibrium time 1 h. The adsorptionkine...

The removal of Cd2+ and Pb2+ ions from wastewater using p-tert-butyl-calix[4] arene was investigated in terms of initial pH, initial concentration, adsorbent dosage, contact time and temperature. The maximum adsorption occurred at the pH value of 6. The adsorbent studied exhibits high efficiency for Cd (II)and Pb (II) adsorption and the equilibrium states could be achieved in 10 min. Adsorption...

The photo-degradation of organic dye C.I. Acid Red 213 (AR-213) was achieved by 207 nm UV radiation emitted from a planar KrBr* excimer lamp without addition of oxidants at varying initial pH values. Precipitates were found to be generated when the irradiated solution of initial acid pH was adjusted to alkaline pH and they would disappear again when the solution was readjusted to acidic conditi...

In this research, a response surface methodology (RSM) was used to investigate the effects of independent parameters (pH, contact time, temperature, adsorbent dosage, and initial concentration of pollutant), their simultaneous interactions, and quadratic effects on crystal violet adsorption onto two starch based materials in the form of batch experiments. The characterizing results indicated th...

background & aims of the study: toluene-2, 4-diamine (tda) is a famous carcinogenic aromatic amine that is mostly employed as an intermediate in the production of dyes and toluene diisocyanate. in this study, degradation and mineralization of tda were investigated by uv/h2o2 process. materials & methods: this study is an experimental investigation on a laboratory scale. the study performed on s...

Experimental data on cadmium (II) and nickel (II) ion sorption on deactivated protonated yeast over a wide range of sorbent and initial metal concentrations, were analyzed by an equilibrium model based on a thermodynamics approach. Model describes relationships between the equilibrium concentration of metal, metal sorption per unit biomass dosage and concentration of sorbent and initial metal c...

The effects of solution pH and initial concentration on adsorption and coprecipitation of As(V) from aqueous solutions by manganese dioxide [MnO2] for 50d and 1120d were studied. The XRD, FT-IR and SEM results indicated that there was only slight difference between the MnO2 adsorbents before and after adsorption, but their crystal structure had not changed. For the initial As(V) concentration C...