B- PH Influence chemical and biological processes of precipitation, redox, sorption, methanogenesis Controlled by volatile acids during acid phase After methanogenesis begins, controlled by carbonates and ammonia Major factor in controlling metal solubility
C- Effluent Limitations & Permitting Process Case-by-case basis based on: Type of receiving water body Aquatic life present in receiving water body Concentration of toxic chemicals based on pH, hardness, temperature, etc. ParameterUnitsAverage Standard BOD 5 mg/L30 Total Suspended Solidsmg/L30 NH 3 \N (May-October)mg/L3 NH 3 \N (November-April)mg/L6 Dissolved Oxygenmg/L4 (minimum) PHS.U
Equalization Tanks Remove heavy metals and solids (optional) Remove biodegradable organics, ammonia, nitrite/nitrate, some heavy metals, and toxic compounds Air diffuser UV disinfection to remove pathogens Sludge wasting Lined reed bed for polishing treatment Discharge to local sewer system 2 SBRs with 24 hr cycle; gal. capacity NaOH to increase pH H 3 PO 4 to bring pH down and add phosphate Air stripping tower to remove ammonia (optional) Na 3 PO 4 to add phosphorous without changing pH Example for Leachate Treatment
Sequencing Batch Reactor(SBR) A variation of the activated sludge process which incorporates equalization, aeration, and clarification.
Reed Bed Removal of heavy metals, BOD, TSS, Nitrogen, & Phosphorus
Heavy Metals Removal
Ultraviolet radiation (UV) Disinfection Removes pathogens Contact time only 5 seconds No disinfection by- products O&M Costs Low Simple Operation
Optional Components Chemical Addition Phosphorus Addition Achieve optimum BOD:N:P ratio of 100:5:1 pH Adjustment Control pH levels to optimize performance Processes Metals Precipitation When metals concentration gets too high to meet effluent standards Ammonia Stripping When concentration of Ammonia is over 1000 mg/L