Potential for using constructed wetlands to treat landfill leachate: Literature review and pilot study design (Special report series)

This digital document is a journal article from Ecological Engineering, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Four surface-flow mesocosm wetlands were operated at different hydraulic retention times during two periods to treat diluted woodwaste leachate that was acidic, of very high oxygen demand, and toxic. Temperature, dissolved oxygen, and redox potential decreased with increasing water depth. However, there was no significant vertical variation in microbial biomass. No significant development in biomass of planktonic microorganisms was found over 6 weeks of initial operation. It took <1-6 weeks for maturation of the biofilm on submerged plant surfaces and the sedimentary microbial community. Mass reduction efficiencies of chemical oxygen demand, and tannin and lignin increased significantly with hydraulic retention time when 10% leachate was fed with tap water. When a more recalcitrant influent was fed, there was a slight increase of reduction efficiency with increasing hydraulic retention time. Reduction rates increased linearly with mass loading rates up to 0.4kgm^-^3d^-^1 chemical oxygen demand and 0.13kgm^-^3d^-^1 tannin and lignin. Precipitation and evapotranspiration had profound impacts on the overall performance and its variability. Mass balance-based operating data of wetlands with a mature microbial community are required for proper performance assessment. formance assessment.

Price:

Click here to buy from Amazon

The Characteristics and impacts of landfill leachate

Disposing of solids waste to landfill is regarded as one of the most economical means of handling waste though landfills pose pollution threat to both ground and surface water resources. However, landfill liners and good landfill management practices may reduce the impact of water contamination by landfills. Chemical analysis of groundwater beneath and near two landfills from New Zealand and Lesotho (in Southern Africa) showed that there are higher concentrations of chemicals such as Chlorides, TDS and COD than average. The water was also found to contain higher amounts of heavy metals. High concentrations of chemical constituents, such as those found in leachate contaminated water may cause various health complications in humans if consumed. To minimize possible hazards due to landfill leachate, future landfills must be lined at the base and sides by a combination of clay, geosynthetic clay and high-density polyethylene liners.

Price: $114.00

Click here to buy from Amazon

Fulton continues to work on landfill violations - Fulton Sun

He said the city also has completed supplemental environmental performance projects, which he described as "essentially an additional penalty designed to improve the situation, including a methane capture system. Slivka also addressed a concern from Ready regarding what happens when the landfill closes in May 2011.

"We will have a financial assurance instrument in place," he said.

"Essentially saying 'Here's this money to fix violation issues if it happens."

Fulton Director of Administration Bill Johnson said the city actually has been subject to more inspections since announcing its intention to close the landfill.

"DNR has an interest in ensuring we close it properly," Johnson said.

Regarding odor issues, Slivka said the Department of Natural Resources has been out to test air quality on a number of occasions -- as recently as the week of Sept. 6 -- and never found a problem.

"On odor violations, our litmus test is 7 to 1 dissolution," Slivka said. "We've gone out there a number of times and it's never been higher than 2 to 1."

Johnson addressed the most recent violations for exposed litter.

"This is not an excuse, but we are approaching our closure date, and there was an attempt to spread trash thinner over a wider area to even out the land," Johnson said, noting that process also included having to haul in more dirt. "The idea sounded good to use the trash to fill in, but it just didn't work out the way we thought.

"We did it, it was wrong, and we won't be doing it anymore."

As for methane levels, he said one supplemental environmental performance project currently in the works involves putting in a 10,000 gallon tank to pump water that flows down into the methane collection wells out of the landfill.

"This will allow our methane extraction wells to function better," Johnson said. "Hopefully by drawing the methane down into the wells it will stop it from migrating."

Another just-completed project is a storm water sediment pond "that will give sediment in the storm water time to settle out before water leaves the site."

Although Slivka said he could not give a number regarding how much the city has been fined for these violations, he did say DNR recently sent an agreement in principal regarding settlement.

"We're certainly sympathetic to Mrs. Ready, but we feel like we have been out there and we have been on the city's back," Slivka said.

Johnson acknowledged the city has received that agreement, noting DNR is proposing a fine of $10,000 as well as an additional $5,403 to pay for investigative costs.

Johnson said he is scheduled to meet with Department of Natural Resources officials later this week, and noted the agreement in principle will be presented to the Fulton City Council at its Sept. 28 meeting.

View the original article here