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The aim of the present study was to develop structurally stable, nutrient-rich and environmentally safe growing media by combining waste material: crop residue hazelnut husk (HH) and municipal sewage sludge. In order to achieve this goal, lignocellulosic HH residue was mixed with nutrient-rich sewage sludge (S) in various proportions: HH 100%; HH + S1 87.5% : 12.5%; HH + S2 75% : 2 5%; HH + S3 50% : 5 0%. Following composting, the key physical, chemical and microbiological properties of the growing media were characterized for long-term ornamental nursery crops. The addition of S to the mixture had both significant detrimental and remedial effects on physical properties such as reduced total porosity and water-holding capacity, whilst improved the air capacity, wettability and shrinkage. S content of growing media significantly enriched the plant nutrients, especially the most desired soluble and organic nitrogen fractions and micro nutrients. Germination tests and microbiological analysis confirmed the products as environmentally safe ornamental growing media. We conclude that composting of HH with S is a viable alternative for the development of nutrient-rich growing media and recycling of such waste in the ornamental industry could be a beneficial method in order to sustain waste management and crop production.

The effect of solarization on bacterial inactivation in sewage sludge was studied using thermotolerant coliforms, enterococci and Escherichia coli (E. coli) as the indicator organisms. Solarization significantly increased the sludge temperature. The maximum temperatures were achieved at the beginning of the second week, reaching 65, 58, 55 and 50 degrees C at depths of 0-10, 10-20, 20-30 and 30-40 cm, respectively. E. coli was found to be the most sensitive microorganism and was reduced to undetectable levels after 9 d at all monitored sludge depths. Thermotolerant coliforms were rapidly inactivated but were not reduced to below the detection limit. The inactivation curves of enterococci showed both shoulders and tailing, indicating a larger heat resistant fraction than with E. coli and the thermotolerant coliforms. Overall, the results suggest that the temperature regime produced by solarization was sufficient to reduce bacterial indicators to an acceptable level, meeting the pathogen regulation limit, in two weeks.

In this study, wastewater formed in marble mines operated as open mines with the aid of a cutting slope in the soil clarification tanks, which were made impermeable by using membranes and similar impermeable elements, was collected after the sedimentation process. The reusability of the water during the process was also investigated. In the marble mines where the study was carried out, an average of 25 m3/day of water is used as the process water for cutting operations. It is thought that ~ 10 m3/day of this water is evaporated or remains between the marble blocks. However, in the facility, 15 m3/day of wastewater was collected in the clarification tank that was made impermeable with a plastic cover. The initial (I) and final (F) values for the suspended solid (SS), pH, colour (C), oil and grease (OG) and Cr6+ were determined as SSI = 106.5 mg/l, SSF = 58.3 mg/l, pHI = 8.06, pHF = 7.93, CI = 83.5 (Pt–Co), CF = 47.5 (Pt–Co), (Cr6+)I = < 0.05 mg/l, (Cr6+)F = < 0.05 mg/l, OGI = 8.7 mg/l and OGF = 2.3 mg/l. The fact that these values are below the required limits in the Water Pollution Control Regulation applied in Turkey indicates that the treatment is successful and that the clarification tank is working effectively. Therefore, this method can be used successfully in marble mines. [ABSTRACT FROM AUTHOR]