實(shí)驗(yàn)室污水處理英文版(共3頁)

1、精選優(yōu)質(zhì)文檔-傾情為你奉上Laboratory Wastewater disposal (Read 748 times)Here the chemical used in every test performed.1. Chloride content of cementConc.Nitric aciddilute Nitric acid(1+2) & (1+100)silver nitrate(8.494g/L)AmmniumThiocyante(3.8g/LAmmonium iron sulphate - saturated solution2.Insoluble residueConc.

2、 Hydrochloric acid & (1+19)sodium carbonate(50g/L03.sulphate contentconc HCl & (1+19)Naoh(1+16)Barium chloride(100g/L)4.SilicaAmmonium chloride(0.5g add to 250 ml waterHClSulpuric acid hydrofluric acidsulpuric and hydroflouric are added to the precipiate in a crucible and then ignited(so its not add

3、ed to waste water)filtrate soln is kept for total oxide determination4.total oxidesmethy red(2g/l in ethanol)conc nitric acidammonia soln(1:1)ammonium nitrate soln(2%)filtrate solution is kept for calcium oxide determination5.calcium oxideDilute Ammnia(1:4)dilute HCl(1:4)ammnium Oxalate(1g/L)Oxalic

4、acidfiltrate solution is reserved for Magnesia determination6.Magnesia testconc nitricdilute HClDiammnium hydrogen phosphate(saturated)conc ammoniadilute(25ml/L) & (1:3)ammonium nitrate(2g/L)7.Ferric oxide determinationstannous chloride soln - 5 g added to 10 ml HCl and dilute to 100mlbarium dipheny

5、lamoine sulphonate -0.3g in 100ml waterpotassium dichromate - 2.457g/Lstaurated soln of mercuric chlorideMostly the test is carried out by heating/boiling,washing with acid ,filtering. precipiate burn at furnace 1000C then weigh.The filtrate is dipose directly into the sink then at the drainage and

6、eventually to the sea.pH normally is acidic. but we neutralise it with dilute ammonium hydroxide. Is this sufficient enough? I bought a plastic water tank so I can collect all the filtrates and flush it large volume of water before I dispose it to the drainage The filtrates after each test is less t

7、han 4 liters.Please help.Can you please suggest what is the best way and easiest way to treat this smll amount of wastewater in the lab.THE PROCESS The Faculty of Science through their research activities and their Award Programs produce a significant quantity of chemical wastewater. Prior to the ad

8、option of their cleaner production initiative, the chemical wastewater was collected, treated and disposed of by a waste contract service. Given the significant quantities of wastewater produced, this option for collection and disposal proved to be extremely costly. Direct discharge to sewer provide

9、s the most economically viable option for the laboratory wastewater of an acceptable of standard. Despite the Faculty of Science抯 wastewater undergoing minimal pre-treatment within the laboratories prior to disposal it did not attain the acceptable pH standard for direct discharge to the Power and W

10、ater Authority (PAWA) sewer. For wastewater effluent to be discharged directly to the sewer, the pH should generally not be lower than 6.5 and not higher than 11. The acid and alkali waste streams that do not occur within this range have the potential to seriously affect the pH value of the receivin

11、g water if they are discharged directly without acceptable pre-treatment. The acid wastewater reacts with the alkalinity of the receiving water by:Ca (HCO3)2 + 2HCl = CaCl2 + 2H2O + 2CO2Alkalis react with free carbon dioxide dissolved in the receiving water and increase its alkalinity by:2NaOH + CO2

12、 = Na2CO3 + H2OIf the Faculty of Science had discharged their wastewater directly to sewer and had not adjusted the reaction of the pH, then the following problems would have occurred:1Biocoensis as both animal and plant organisms perish in excessively acid and excessively alkaline media. 2Damage to

13、 PAWA sewer lines and plant structures from untreated effluent that would corrode both concrete and metals. 3Alkalis have the potential to cause serious difficulties in the operation of the receiving treatment plant. Sealants used in conduits may be attacked by alkalis, causing leakage and damage in

14、 the network as well as causing precipitation of various deposits and hence choking of the pipes. 4.Increased demand for excessive chemicals necessary for coagulation when employed as a treatment method; 5.Insufficient provision for optimum bacterial activity in the biological treatment of wastes; 6

15、.Production of noxious odours which may emitted at low or high pH values; 7.Damage to the receiving Darwin waters and environs due to the detrimental effects of the Laboratory wastewater. Conscious of the possible detrimental impacts of the untreated wastewater and the increasing cost of employing a waste contract service, the Faculty of Science identified the need to install their own treatment system which could be utilise