جستجوی مقالات مرتبط با کلیدواژه « عوامل حجیم کننده » در نشریات گروه « پزشکی »

Due to the adverse effects of sewage sludge and environmental problems of organic waste, today, composting is proposed as a new method for the reuse of sludge to safely dispose of sludge and organic waste. The purpose of this study was to review the co-composting of wastewater treatment plant sludge and various organic wastes, as a strategy to reduce environmental and agricultural pollution.

In the present study, articles from Scopus, Springer, Web of Science, and PubMed databases in English, and google scholar in Persian, were searched and parameters such as pH, carbon to nitrogen ratio, moisture content, and process time were studied. The keywords included "co-compost", "wastewater treatment sludge", "organic wastes", "environmental pollution", "agricultural", and "agriculture".

From 2011 to 2020, 14 articles were found with the mentioned keywords. However, 24 items that did not have the keywords “wastewater treatment sludge”, as well as five books and six items related to wastewater, were excluded from the study. To improve the composting process, we can increase the quality of the product by reducing the size of the raw material and using bulking materials to reduce the processing time, as well as measuring and controlling the pH, carbon to nitrogen ratio, and daily moisture content.

In most previous studies, bulking agents and particle size reduction were used to increase compost aeration and reduce the processing time. The most important parameter influencing the co-composting process was the adjustment of pH and temperature. The composting process, with reducing environmental adverse effects of the sludge produced by the treatment plant and organic waste, as an environmentally friendly process, increases the health and well-being of the community.

Dewatered sewage sludge is a by-product of wastewater treatment process which can cause health and environmental problems if not properly managed. The aim of this study was to determine the feasibility of composting of Yazd WWT dewatered sludge with windrow method using different treatments.
In this study, the dewatered sewage sludge was mixed with two treatments of agricultural wastes (straw) and green waste (leaves), respectively. The mixture was done based on weight ratio of 20:1 and 10:1 (agricultural waste: dewatered sludge, and green waste: dewatered sludge) to achieve a ratio of C/N:20. The windrows were built with a length of 2 m, width of 75 cm and height of 1.5 m. Composting process was controlled by measuring the temperature, humidity, volatile solids, ash, pH, EC, organic carbon and estimating the C/N ratio. The results were compared with those of the Institute of Standards and Industrial Research of Iran.
After 100 days of composting, C/N ratio was 13.08±6.25 in the treatment with green waste and reached to 15.46±5.35 in the treatment with agricultural waste. The amount of volatile solids decreased to 19.8±14.01% and 20.71±16.06% in the treatments with green waste and agricultural waste, respectively. The amount of EC had an increasing trend in both treatments.
composting with both treatments was led to an improvement in indicators of organic fertilizers in dewatered sewage. However, the windrow containing green waste reached to the mature compost standards sooner than the windrow containing agricultural waste.