Taenia saginata, Ascaris suum, current research on inactivation of ova in sewage sludge by means of heated anaerobic digestion: United Kingdom

Taenia saginata and other pathogens likely to cause problems resulting from agricultural use of sewage sludge, laboratory and field trials testing efficacy of DF 955 (formalin based compound) as a means of chemical destruction

"Collection of essays based on lectures delivered during a course on "Aquatic Ecology" organised by C.K. Varshney at the School of Environmental Sciences, Jawaharlal Nehru University, New Delhi ..."--Foreword.

The effect of a surface application of urea on the transport of N in surface runoff from permanent pasture in New Zealand was investigated under natural rainfall conditions. Maximum concentrations of NH4- N(3.6 mg l-1) and NO3-N(4.5 mg l-1) in surface runoff were attained 3 and 1 week, respectively, following urea application (60 kg N ha-1). Amounts of NH4-N, NO3-N, and total N transported in surface runoff from unfertilized (1.58, 0.52, and 4.73 kg ha-1 yr-1, respectively) and fertilized pasture (1.74, 1.09, and 8.96 kg ha-1 yr-1)were less than inputs in precipitation (2.09, 3.63, and 10.9 kg ha-1 yr-1), respectively. Amounts of NH4-N, NO3-N, and total N transported in surface runoff were only 0.3, 1.0, and 7.1 % of that applied. The mean annual concentration of NH4-N (0.9 mg l-1) in surface runoff from unfertilized pasture was above the recommended levels for drinking water (0.5 mg l-1) and the mean concentration of NO3-N (0.5 mg l-1) was greater than levels associated with accelerated cutrophication (0.3 mg l-1 ). The practicality of attaining or maintaining N concentrations in surface runoff from fertilized agricultural land below recommended levels is questioned.