Variations in the chemical properties of landfill leachate

Abstract

ABSTRACT/Landfill leachates were collected and their chemical properties analyzed once every two months over a ten-month period from the Gin Drinkers' Bay (GDB) and Junk Bay (JB) landfills. The contents of solids, and inorganic and organic components fluctuated considerably with time. In general, the chemical properties of the two leachates correlated negatively (P < 0.05) with the amounts of rainfall prior to the sampling periods. However, magnesium and pH of the leachates remained relatively constant with respect to sampling time. The JB leachate contained higher average contents of solids and inorganic and organic matter than those of GDB with the exception of trace metals. Trace metals were present in the two leachates in trace quantities (<1.0 mg/liter). The concentrations of average ammoniacal nitrogen were 1040 and 549 mg/liter, while chemical oxygen demand (COD) values were 767 and 695 mg/liter for JB and GDB leachates, respectively. These results suggest that the leachates need further treatment before they can be discharged to the coastal waters.One of the constaints of successful treatment of landfill leachate is the difficulty in identifying and quantifying its typical characteristics. The chemical properties of leachate samples from different sanitary landfills vary widely and are affected by the amount, composition, and moisture content of the refuse; hydrogeology and climate of the site; age and height of the landfill; and season of the year (Chian and DeWalle 1976, Uloth andMavinic 1977). Furthermore, leachate composition is influenced by sampling methods and factors affecting leachate flow, such as dilution with rainfall or groundwater, and decontamination of leachate during passage through soil (Boyle and Ham 1974). The design of a leachate treatment system for a particular landfill site may require extensive characterization for the leachate. For instance, an activated sludge plant for a small landfill in Dorset, England, which was designed for leachate with a biochemical oxygen demand (BOD) up to 1900 mg/liter and ammonia (NH3) up to 250 mg/liter, treated leachate with a BOD of about 150 mg/liter and NH3 con-

Characterization of the leachate produced in the closed cells of a landfill site at Alhendín (Granada, Spain)

“…In contrast, during the wet period, leachate was diluted with rainfall water, and thus, a higher volume of lower-strength leachate was produced. Such seasonal changes in leachate quality have also been documented by other researchers in landfill leachate samples [15,[23][24][25]. Evidently, this is another factor that must be considered in the design of any leachate treatment plant.…”

Assessment of heavy metal contamination in soil due to leachate migration from an open dumping site

“…The Fe concentration in the leachate sample indicates that Fe and steel scrap are also dumped in the landfill. The dark brown color of the leachate is mainly attributed to the oxidation of ferrous to ferric form and the formation of ferric hydroxide colloids and complexes with fulvic/humic substance (Chu et al 1994). …”

Evaluating pollution potential of leachate from landfill site, from the Pune metropolitan city and its impact on shallow basaltic aquifers

“…The high range of iron (Table 1) is an indicative of the dumping of metal scrap and tin-based garbage at the dumping site. The dark brown color of the leachate is attributable to the oxidation of ferrous to ferric form and the formation of ferric hydroxide colloids and complexes with fulvic and humic substances (Chu and Cheung 1994).…”