Peanut shell plating wastewater treatment

Use of peanut shells in the treatment of electroplating wastewater

peanut shell contains a lot of carbohydrate and crude fiber, and tannin compounds [ 12] 。 It is a kind of polyphenol compounds, and many metal ions formed by the strong coordination stable five membered ring structure, so it is extremely effective ion exchange material, easy substitution reaction with heavy metal ions in order to achieve the purpose of the precipitation of heavy metal ions.

GuYaXin [ 13] Clean the peanut shells, drying, crushing, peanut shell powder, peanut shell powder as the main raw material is studied, and the of Cd2 +, Pb2 + waste water adsorption experiment was carried out. Experimental results show that the pH value, Cd2 + and Pb2 + in waste water quality concentration, adsorption time factors can influence the peanut shell powder of Cd2 +, Pb2 + adsorption effect; In Cd2 +, Pb2 + mass concentration are 30 mg/L, pH value of 6, 2 h, the quality of peanut shell powder is 0. Under the condition of 25 g, Cd2 +, Pb2 + removal rate reached 92 respectively. 2% and 90. 0%.

Gary tong, etc. [ 14] Will deal with good peanut shell powder 50 g put in 250 mL of the round bottom flask, add a certain amount of acid formaldehyde solution ( The volume of formaldehyde with sulfuric acid ratio is 1:5, the concentration of sulfuric acid is 0. 1 mol/L, the volume fraction of formaldehyde is 37%) , under 80 ℃ water bath pot heating reflux after 3 h, peanut shell powder to the suction filter to remove the solvent and residual slag powder with distilled water to wash to the pH value & gt; 5, the final drying 3 h under 50 ℃, the modification of peanut shell. The heavy metal in wastewater treatment using modified peanut shell, reaction time, amount of treatment agent to join, pH and reaction temperature on the influence of acidic waste water of heavy metal ions adsorption performance. The results show that the acid formaldehyde solution to appropriate modification of peanut shells, and the modified products used to remove heavy metal ions in the water is feasible. Heavy metal wastewater treatment, the better technology conditions as follows: control the pH value of 7, add 2 in every 100 ml water. 5 g modified peanut shell, stir under 40 ℃ to 60 min. In this condition, the removal rate can reach more than 90%.

li [ 15] With peanut shell as raw material, HNO3 as modifier, to modified adsorbent preparation of peanut shells, and studied the adsorption of Pb2 + in water performance. The results showed that in 2. 0 g peanut shells add 25 mL volume fraction of 10% HNO3 solution, the temperature control at 80 ℃, stirring 3 h, the modification of peanut shell. Using modified peanut shell adsorption Pb2 + the best conditions for: modified peanut shell 0. 2 g, contains mass concentration for 97. 5 mg/L of Pb2 + 25 mL of solution, pH 5. 0, stir 60 min. In this condition, the removal rate can reach 97%; After the adsorption of peanut shells with 0. 5 mol/L HCl solution regeneration, repeat use 2 times, to Pb2 + removal rate over 92%; Compared with the unmodified peanut shells on the removal rate of Pb2 + ( 87%) Which has obvious improvement. By HNO3 to modified adsorbent preparation of peanut shells, preparation method is simple, high adsorption performance, easy regeneration and can be reused, expanded the adsorbent material source, for the comprehensive utilization of peanut shell provides an effective way.