Effect of the application of various wastewater sludges on the properties of sandy soil Barış Bülent Asik & Cumhur Aydinalp & Ali Vahap Katkat & Fatma Olcay Topaç Sagban Received: 20 October 2014 /Accepted: 12 January 2015 /Published online: 30 January 2015 # Springer International Publishing Switzerland 2015 Abstract This research was conducted to determine the effect of various wastewater sludge (domestic type (B), mixture of industry and domestic type (L), aero- bic food industry (P), anaerobic food industry (M)) levels on the properties of sandy soil, including pH, electrical conductivity (EC), and the levels of avail- able N (NH 4 and NO 3 ) and P, diethylenetriamine pentaaceticacid (DTPA)-extractable microelements and heavy metals. An incubation experiment was performed in which sludges were applied at rates of 0, 40, 80, 120, and 160 tons ha -1 , and the effects on the soil properties were measured over a period of 150 days. Soil pH decreased and electrical conductiv- ity increased with increasing levels of sludge applica- tion. The levels of NH 4 -N, NO 3 -N, available P, and DTPA-extractable heavy metals also increased with the application rate of the sludge. NO 3 -N content increased and NH 4 -N content decreased over time. The most unfavorable effects on soil properties were observed with the B sludge. Other soil characteristics changed according to the sludge properties. Keywords Heavy metals . Incubation . Wastewater sludge . Soil properties Introduction Wastewater treatment plants produce millions of tons of residual sludge worldwide every year. Wastewater sludge obtained as a by-product reflects the chemical composition of the treated wastewater, but the compo- sition of the sludge is determined by the industrial wastewater inflow to the treatment plant. The composi- tion of sewage sludge is very complicated, both quanti- tatively and qualitatively. Wastewater sludges almost always contain a large number of pathogens, such as bacteria, viruses, protozoa, and parasitic worms, and are usually attractive for disease vectors, which may threat- en human health (Anonymous 1983). Sludge also con- tains heavy metals that are harmful to humans and plants. The highest potential for environmental damage from sludge derives from possible contamination by toxic metals and the potential for pathogen transfer. Application of sludge to soil is a widely accepted disposal method throughout the world because of its agricultural value. Wastewater sludge can provide a significant proportion of the nutrient requirements of plants. When applied to agricultural soil in suitable concentrations, sludge is known to improve the physical properties of soil, soil structure, water-holding capacity, and soil water transmission characteristics due to its high nutrient and organic matter content. Sludge con- tains agronomically valuable amounts of plant nutrients Environ Monit Assess (2015) 187: 30 DOI 10.1007/s10661-015-4300-5 B. B. Asik (*) : C. Aydinalp : A. V. Katkat Department of Soil Science and Plant Nutrition, Uludag University Faculty of Agriculture, Bursa 16059, Turkey e-mail: bbasik@uludag.edu.tr F. O. T. Sagban Department of Environmental Engineering, Uludag University Faculty of Engineering and Architecture, Bursa 16059, Turkey