Landfill Leachate Treatment Plant (LTP)

Leachate is the liquid that drains through a landfill or dumpsite as rain and waste moisture percolate through decomposing refuse. It carries everything the waste releases: dissolved and colloidal organics (COD 2,000–60,000 mg/L), ammoniacal nitrogen (500–3,000 mg/L), chlorides and total dissolved solids often above 10,000 mg/L, heavy metals, colour and refractory humic compounds that biology alone cannot break down.

Its character changes with the age of the landfill: young leachate is acidic and highly biodegradable (BOD/COD > 0.5); old, stabilised leachate is alkaline, dark and refractory (BOD/COD < 0.1) with most of the COD locked in humic acids. A leachate treatment plant therefore has to be designed for the specific site, its age and its monsoon flow variation — not from a catalogue.

KK Enviro Engineers designs and builds leachate treatment plants (LTP) for municipal solid-waste landfills, legacy dumpsite bio-mining and capping projects, waste-to-energy plants, compost yards, and secured landfills for hazardous industrial waste (TSDF).

1. Collection, equalisation and storageLeachate ponds or HDPE-lined tanks sized for monsoon peaks; mixing to average out quality; oil and floating debris removed.
2. Pre-treatment and pH correctionLime or caustic dosing, coagulation with ferric or PAC to strip colour, colloids and part of the COD; primary clarification or DAF.
3. Ammonia stripping or removalAir stripping at high pH, or biological nitrification–denitrification in an anoxic–aerobic reactor when ammonia is 500–3,000 mg/L.
4. Anaerobic treatment (young leachate)UASB or anaerobic contact reactors for high-BOD leachate, producing biogas and cutting aeration power.
5. Aerobic biological treatment — MBRMembrane bioreactor with extended sludge age handles slowly-degradable organics and gives a solids-free permeate ready for membranes.
6. Advanced oxidation (refractory COD)Fenton, ozone or electro-oxidation to break humic compounds that survive biology — used where old leachate must meet tight COD limits.
7. Membrane polishing — NF / RONanofiltration and two-stage reverse osmosis, often disc-tube RO (DTRO) built for high fouling, remove salts, residual COD and heavy metals to reuse or discharge quality.
8. Concentrate managementRO reject to evaporator (MEE / MVR) and crystalliser for zero liquid discharge, or recirculated to the landfill where the licence permits.
9. Sludge handlingChemical and biological sludge thickened, dewatered on a filter press or decanter, and sent to the secured landfill.

Municipal solid-waste landfills

Engineered sanitary landfills with leachate collection systems under Solid Waste Management Rules; treatment to discharge or reuse for dust suppression and green belt.

Legacy dumpsite remediation

Bio-mining and capping projects release large, variable leachate flows for two to five years; mobile or containerised plants suit these contracts.

Waste-to-energy and compost plants

Pit and floor leachate from refuse storage and windrows — high BOD, oil and odour; often combined with plant process water.

Hazardous-waste TSDF

Secured landfill leachate with heavy metals, high salts and toxic organics — chemical precipitation, MBR, RO and evaporation to ZLD.

Mining and ash ponds

Acidic or high-sulphate seepage with dissolved metals; neutralisation, precipitation and membrane recovery.

Inlet characterisation and sampling plan → process selection and mass balance → PFD, P&ID, hydraulic and equipment sizing → civil and mechanical drawings → BOQ, vendor RFQs and procurement → erection supervision → commissioning, performance guarantee test and operator training → operation & maintenance. Delivered as a containerised or skid-mounted package for small and remote sites, or as a site-built turnkey plant for large capacities. Documentation to refinery-grade standards: datasheets, interlock lists, cause-and-effect matrices and O&M manuals your team can actually run the plant from.