Effects of alum coagulation on speciation and distribution of trihalomethanes (THMs) and haloacetic acids (HAAs).

The impacts of alum coagulation on the distribution of disinfection by-products (DBPs), trihalomethanes (THMs), and haloacetic acids (HAAs) were evaluated under controlled chlorination conditions using four surface waters. Among the nine HAAs found in waters, dihaloacetic acids (X2AAs) have been found to be the dominant species in all of the raw and alum treated waters. Alum coagulation tends to remove more monohaloacetic acids (XAAs) and trihaloacetic acids (X3AAs) precursors than that of dihaloacetic acids (X2AAs).

Characterization of solid waste disposed at Columbia Sanitary Landfill in Missouri.

Waste sorts were conducted during each of the four quarters (or seasons) of 1996 at the City of Columbia Sanitary Landfill. A detailed physical sampling protocol was outlined. Weight fractions of 32 waste components were quantified from all geographic areas that contribute to the Columbia Sanitary Landfill using a two-way stratification method, which accounted for variations in geographical regions and seasons.

Relationship of chlorine decay and THMs formation to NOM size.

Because of increasing concern about balancing health risks for pathogen control and disinfection by-product (DBP) formation in water supplies, utilities are forced to closely examine and optimize their disinfection practices. A better understanding of the relationship between the molecular weights of the natural organic matter (NOM), chlorine decay kinetics and THMs formation can help the utilities to minimize the DBP concentrations, providing healthier and microbially safer water. The authors present data on chlorine decay kinetics and total trihalomethanes (TTHM) formation kinetics and modeling with different molecular weights NOM fractions of Mississippi River water.

Feasibility of metal recovery from soil using DTPA and its biostability.

Removal of heavy metals from contaminated soil by chelation can be a valid remediation method. Important properties of the chelating agent used are: strength of the chelation bonding, reusability, and biostability during the remediation operation. This work tested the extraction, recovery, and biostability of diethylenetriaminepentaacetate (DTPA) as a remediation agent for soils contaminated with metals.