Lead removal from aqueous solutions at ph 3 by peat sorption

Abstract

Within the European Community, the eleven elements of highest concern are arsenic, cadmium, cobalt, chromium, copper, mercury, manganese, nickel, lead, tin and thallium. Some of these chemical elements are actually necessary for humans in small amounts (cobalt, copper, chromium, manganese, nickel) while others are carcinogenic or toxic, affecting, among others, the central nervous system (manganese, mercury, lead, arsenic), the kidneys or liver (mercury, lead, cadmium, copper) or skin, bones, and teeth (nickel, cadmium, copper, chromium).Experiments focus specifically on lead, a pollutant that is present in wastewater and may have a negative impact on human health. Removal of heavy metals from water by sorption is an effective method because many metals are chemically or biologically persistent. In this article, peat has been investigated as a sorbent for elimination of lead from water at pH 3. Peat was selected for experimental research because it is plentiful and inexpensive and has several characteristics that make it effective for the removal of heavy metals from water. The influence of adsorption time to adsorption capacity of lead by peat at 0.5 mg/l, 25 mg/l, 50 mg/l and 75 mg/l Pb concentrations was evaluated. The biggest adsorption capacity was recorded for 360 min adsorption time.

Europoje didžiausia susirupinima kelia vienuolika cheminiu elementu – arsenas, kadmis, kobaltas, chromas, varis, gyvsidabris, manganas, nikelis, švinas, alavas ir talis. Dalis iš šiu cheminiu elementu yra butini žmonBms mažais kiekiais (kobaltas, varis, chromas, manganas, nikelis), o kiti pasižymi toksišku, kancerogeniniu ar centrinei nervu sistemai neigiamu poveikiu (manganas, gyvsidabris, švinas, arsenas). Neigiamai veikia inkstus arba kepenis – gyvsidabris, švinas, kadmis ir varis; kaulus, oda arba dantis neigiamai veikia – nikelis, kadmis, varis ir chromas. Straipsnyje pagrindinis dBmesys skirtas nuotekose aptinkamam sunkiajam metalui – švinui, turinciam neigiama poveiki žmogui. Sunkiuju metalu šalinimas iš vandens sorbcijos budu yra efektyvus, nes dauguma metalu yra chemiškai arba biologiškai patvarus. Tirtas durpiu panaudojimas švino šalinimui iš vandens prie pH = 3. Eksperimentiniams tyrimams pasirinktos durpBs, nes jos yra nebrangios ir ju gausu, taip pat jos turi savybiu, veiksmingai šalinanciu iš vandens sunkiuosius metalus. Buvo ivertinta adsorbcijos laiko itaka švino adsorbcijos durpBmis adsorbcijos gebai, kai švino koncentracija buvo 0,5 mg/l, 25 mg/l, 50 mg/l ir 75 mg/l. Didžiausia adsorbcijos geba gauta, kai adsorbcijos laikas buvo 360 min.