Study On Treatment Of Storage Battery Acid-Lead Wastewater With Zeolite And Its Modified Materials

Lead is a kind of heavy metal with great toxic. While it was broadly used in industry and agriculture production, wastes including lead into environment have overlap the capacity of environment and cause serious environmental problem, of all the industy discharging lead, lead-acid accumulator production is one of the most important pollution source.ANJ.SIC is an effective material with adsoption and ion exchange capacity, which is modified from zeolite, cheap and easy to regenerate. it has been testified that ANJ.SIC could remove Iron and Manganese from groundwater efficiently. This paper take wastewater of the Guangyu lead-acid accumulator production industy as the object. Put zeolite, and two kinds of modified zeolite (ANJ.SIC) into dealing with the manual wastewater, optimize the factor that could effect the treatment efficiency and discuss the regeneration effect of the saturated material. Comparing the change of material before and after adsorption and make sure its mechanism of lead removal. Then, study on the treatment of the lead-acid accumulator wastewater with a serial of process in which adsorption was the main procedure.After the optimization of the factor, the three material all can treat the wasterwater bearing lead at a high removal rate. By comparison, the first modified material was the best. To the wasterwater 100ml with lead at 10mg/L, it can reach the steady removal rate over 98% at 25℃with the dosage of 0.5g, pH>4.62. By conducting orthogonal experiment, we can find that pH is the most influencial factor, the impact of adsorbent dosage, temperature and adsorption time varied with the adsorbents. Reasearch the Thermodynamics and Kinetics of the adsoption, Langmuir and Freundlich Adsorption isotherm both well fitted. The adsoption is a endotherrmic and spontaneous reaction, Pseudo second order kinetics model can fit the process well.Good absorbent should be durable, so we investigate their regeneration ability . if adopting NaOH in 1M as the regenerant, with the ratio to adsorbent at 20ml:1g, regerate for 1h at the room temperatue, three adsorbents all could regenerate well, while the first modified zeolite was the best. Its capacity after the first regeneration can reach 31mg/g, even larger than the raw zeolite. Add NaCl into NaOH could improve the regeneration effect. Adopting NaOH and NaOH with NaCl as regenerant to regerate for five time. The first modified zeolite was the best, its saturated capacity was 23mg/g after five regeration. Analysis the change of the material before and after the adsoption, we found that the structure and contents of the material did not change much. lead removal with zeotile mainly through lead involved into the framework, while the modified zeolite react with lead at the surface to remove lead from the wastewater. Observing the ion change in the wastewater to decide the contribute ratio of adsoprion and ion exchange in lead removal. In the wastewater with lead in low concentration, ion exchange and adsoption both important in lead removal, with Na+ and Ca2+ as the main ion to exchange. The role of adsoprion in lead removal strengthen with the concentration of lead increased and the adsoption time prolonged.The acidity, lead and Sulfate concentration of Wastewater from lead-acid storage battery production industy was quite large, so we choose the first modified material as the adsorbent, take lime- sand filter- adsorption to remove lead from the wastewater. To the filtration column with the first modified zeolite of 70cm3, adjust the filtration rate to make the HRT at 5min, 10min and 20min, the column could run for 10d, 18d and 32d respectively. After the material saturated, we take different regenration mode, of which with NaOH and NaCl of 1M as the regererant, adjust regereration flow rate at 750ml/h for 2h could get the best regeneration effect. After regeneration the lead removal capacity only reduce at 8%, Adopting this regeneration mode to operate for five times, the capacity reduce to 59%, while the attenuation of lead removal capacity is only 27% in the first four regeneration.