Wednesday, October 12, 2011

Ultrafiltration and Reverse Osmosis for Landfill Leachate Treatment - Environmental Expert

Lanchester Landfill serves Eastern Lancaster County and Western Chester County in PA for disposal of household and construction waste. The facility produces around 10,000 gals per day of  leachate.




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The Problem


The facility ran a single basin sequential batch reactor (SBR) and a filter press to dewater the solids for many years, but found that they first, could not sustain a good biomass, and second, in winter could not nitrify the ammonia. The facility therefore could not reliably sustain the average monthly discharge requirements:


Evaluation


The purpose of the new system is was meet the discharge requirements consistently. Ultrafiltration and Reverse Osmosis technology was selected since this offers the best performance possible in the smallest footprint with a low capital cost.
The Solution


The existing SBR basin was converted to an equalization basin, and Dynatec provided and installed a prefilter to remove larger solids, an ultrafiltration system to remove fine colloidal solids and oils, a reverse osmosis system to remove TDS, and ammonia and the other dissolved components of concern.


Several tanks already in place were utilized as process and buffer tanks between the various treatment stages.


Final ph control and chlorination was also provided.


The Process

The leachate is equalized in an equalization basin. A filter removes large solids before it enters the UF process.The leachate is processed with ultrafiltration to remove particles and oils.The UF permeate is processed with Reverse Osmosis to remove dissolved materials.

Operation


The system has operated successfully for over five years, allowing the plant to meet its discharge permit on all parameters. The influent and effluent data are provided below.


Conclusion


Dynatec Systems has built on its water treatment experience that began in the 1970's using membranes with rugged industrial reliability to produce UF and RO systems wrapped in a compact package. This made Dynatec the right choice for this project. The successful implementation of this system allows this landfill to continue to discharge to the local POTW and for use for dust control on the facility’s roads.


View the original article here

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