ورمی کمپوست

Cutting and drilling mud contains significant amounts of petroleum hydrocarbons that are detrimental to both the environment and public health. The objective of this study was to remove the hazardous components of drill cutting mud using the two biological processes of sewage sludge vermicomposting and biocomposting. In an experimental laboratory research, two pilot composting and vermicomposting processes, each over a period of two months with 2 repetitions, were conducted using the the same biological sludge mixed with drill cuttings contaminated with total petroleum hydrocarbon (TPH) along with sawdust and yard waste. The GC-FID unit was used to determine the residual total petroleum hydrocarbon concentrations. Results showed that the vermicomposting pilot had a higher TPH removal efficiency than did the composting one so that TPH concentration in the mixed waste mass declined after 60 days from its original value of 42.004 g/kg to 11.316 g/kg. In other words, TPH removal in the pilots A (vermicomposting) and B (biocomposting) were 73/06% and 55/3%, respectively. Moreover, the TPH levels in the two composting and vermicomposting pilots on the 45th and 60th days showed significant differences (p

In this experiment, active sewage sludge was inoculated in organic waste. The objective was to study its effect on nutrient dynamics during vermicomposting. Active sewage sludge, as a source of nitrogen fixing and phosphorous solubilizing bacteria, was added in four combinations to the vermicomposting substrate. Prior to inoculation with active sludge, the treatments were precomposted for 30 days and finally vermicomposted for 40 days. Results showed that inoculation of microorganisms in the substrate accompanied by earthworms’ activity enhances the organic waste biodegradation rate. Increasing sludge concentration from 0 to 6000 mg/l led to reduced Total Organic Carbon from 32.76 to 29.91%, Total Volatile Solids from 49.85 to 48/02%, and C/N ratio from 19.59 to 16.06 but increased Total Kjeldahl Nitrogen from 1.68 to 1.87%, nitrate from 1476.75 to 1699.60 mg/kg, Total Phosphorous from 1.66 to 1.77 g/kg, and Electrical Conductivity from 3.10 to 3.48 mS/cm. By increasing the concentration of sewage sludge, heavy metals content also increased significantly due to the enhanced organic matter biodegradation. Finally, the results showed that, among the treatments, the one with an active sewage sludge concentration of 6000 mg/l had more desirable effects on the final vermicompost quality. Based on the reproducibility of the process and the quality of the final products, this experimental procedure may be proposed for studies requiring a mass reduction in the initial composted waste mixtures.

Using of organic waste resources especially municipal wastewater sludges for improvement of agricultural soils’ fertility is increasing, but in order to decrease environmental and health risks sludge must be stabilized before using in farms. Nowadays, vermicomposting process has been considered for stabilizing organic wastes. As, there is contravercial reports about concentration of nutrients (P,.K.N), organic matters and C/N ratio in vermicomposts, this research study is performed to determine concentration of nutrients organic matters and C/N ratio in vermicomposts derived from municipal wastewater sludge The concentration of nutrients in manure and vermicompost was compared with each other.Eighty five percent of dewatered raw sewage sludge and %15 bulking agent were mixed to provide earhworms’ food for a one month period. Concentrations of volatile orgainic matters, total nitrogen, total phosphorous, total potassium, Ash and pH in initial substrate and vermicomposted sludge were determined by dry agitation., macrokageldal, colorimetery, flamephotometery, Gotas, modifled Burian and Erhart methods, respectively. Concentrations of organic matter, nitrogen phosphorous, potassium, pH and C/N ratio in vermicomposted sludge were %36.42, %1.04, %0.11, %0.62, 7.5 and 22.62 respectively. The obtained vermiocompost is a suitable organic amender for fertilizing of agricultural soils.