Application and Considerations of Activated Carbon in Membrane Water Treatment

In membrane-based water treatment systems (such as ultrafiltration UF, nanofiltration NF, and reverse osmosis RO), activated carbon typically does not serve as the core component for desalination or sterilisation. However, it plays an irreplaceable role as a crucial ‘pre-treatment guardian’ and ‘protective deity’. Its application is primarily manifested in the following aspects: Thoroughly remove residual chlorine Reverse osmosis and nanofiltration polyamide membranes are highly sensitive to oxidants. Even at residual chlorine concentrations as low as 0.1ppm (mg/L) in feedwater, prolonged exposure can cause polymer chain breakage within the membrane, typically resulting in a permanent reduction in the membrane element’s salt rejection rate within hours to days. Activated carbon filters can reduce residual chlorine concentrations to below the safe threshold of <0.01ppm through highly efficient surface reduction reactions, thereby completely eliminating the oxidative threat to membranes. effective adsorption of organic matter, reducing membrane fouling activated carbon possesses an immense specific area, typically ranging between 700–1500 m²/g. this enables it efficiently adsorb natural matter (nom) in water, incoming uv254 value (characterising compounds containing conjugated double bonds and benzene rings) by 60–90% removing total (toc) 20–50%. directly reduces colloidal loads that cause fouling. improved pollution index: effectively pre-treatment significantly subsequent sdi (silt density index) values, providing qualified feedwater for reverse osmosis membranes (sdi15 < 5, ideal 3). biological (bac) effect under suitable temperature conditions (>15°C) and nutrient levels, biological activated carbon filters can achieve ammonia nitrogen (NH₃-N) removal rates exceeding 80%. Removal efficiency for biodegradable dissolved organic carbon (BDOC) can be enhanced to 50%-70%, significantly surpassing the 20%-40% rates achievable through physical adsorption alone. Precautions and Key Operating Points: Selection and Parameters of Activated Carbon Types Coconut shell carbon: Possesses an exceptionally well-developed microporous structure (pore size <2nm), typically exhibiting an iodine adsorption value exceeding 1000mg/g. it demonstrates rapid rates and high capacity for residual chlorine small-molecule organic compounds. coal-based activated carbon: possessing both microporous mesoporous structures (pore size 2–50 nm), exhibits methylene blue values of 150–250 mg/g. this material superior removal efficiency larger molecules (such as humic acids) colour in water. when procuring, addition to value, attention should also be paid strength ≥95% (to minimise fragmentation pulverisation during operation) moisture content ≤8%. preventing carbon powder leakage new flushing: newly installed must undergo forward reverse flushing. the flushing duration requires 1-2 hours or longer, until effluent turbidity is <1.0 ntu. security filter: a filter with precision 5μm downstream, ensuring differential pressure rise rate remains within normal parameters. element darken excessively rapidly, indicates severe leakage. microbial growth control uncontrolled filters may produce total bacterial counts 10 100 times higher than influent. regular disinfection: recommended rinse hot water at ≥80°c 30 minutes more every 1-3 months, administer shock dose non-oxidising disinfectant dbnpa). design optimisation: prevent prolonged retention, system shall ensure that ≥10% periodic backwashing washing operations daily. saturation replacement cycle core monitoring indicator: from monitored continuously least daily mg/l. any detection occur, immediate investigation undertaken. estimated cycle: (t) preliminarily using following formula: t (hours)=[Activated loading (kg) × unit (mg cl₂/g carbon)] / [inlet flow (m³/h) concentration (mg/l)] where taken 10–15 mg (conservative value). example: containing 500kg carbon, treating influent 1.5mg/l 50m³/h, has theoretical retention time approximately (500 1000 10) (50 1.5) ≈ 666 (approximately 28 days). represents period only. considering adsorption, actual set between 6 24 subject data. hydraulic operating parameters effective bed contact (ebct) critical parameter. matter removal, ebct designed 10-15 minutes. backwash velocity: 12-15 m³/(m²·h) (equivalent m/h), lasting air wash intensity: combined air-water backwashing, intensity 50–60 m³/(m²·h). frequency once 24–48 hours, inlet increases by 0.5–1.0 bar. The main products of flocculant manufacturer Xinhuan Water Treatment are: White polyaluminium chloride (food grade), drinking grade polyaluminium chloride, industrial grade polyaluminium chloride, anionic polyacrylamide, cationic polyacrylamide, nonionic polyacrylamide, petroleum recycling polyacrylamide, oil recovery polyacrylamide, polyacrylamide, polymer flocculant polymer flocculation coagulant, polymeric ferrous sulphate, polymerized iron and aluminium chloride, and other water treatment chemicals. Welcome customers to write to us to negotiate business! Tel/WhatsApp：86 19139972558 Email：Sunny@xhwtm.com Contact:Sunny