TREATMENT OF PARBOILED RICE MANUFACTURING WASTEWATER USINGANAEROBIC FIXED FILM FIXED BED REACTOR PACKED WITH SPECIAL MEDIA
Studies on bench scale reactors packed with two different media matrix – Biopac media and Fugino spirals were undertaken to determine the performance at various organic loading rate (OLR) and on one day hydraulic retention time (HRT). Parboiled rice mill wastewater depicted a COD/BOD ratio of 1.6 indicating good degradable nature of the wastewater. Four different organic loadings of 0.8, 1.6, 2.4 and 3.2 kg COD/m3/day were studied in detail. The results indicated BOD and COD removals in the range of 83.0-92.7% and 80.2-89.0% respectively with respect to Biopac media while it ranged between 79.4–90.6% and 76.7–86.1% respectively in case of Fugino spiral media. It is very clear from the results that, Biopac media packed fixed film reactor gave efficient removals compared to Fugino spiral media packed reactor. Volatile acid concentration was well within the congenial range in both the reactors and volatile acid to alkalinity ratio remained well below 0.8 indicating good performance of the reactors. pH of the treated effluent was in the range of 7.1–7.3 indicating good buffering in the system. Daily gas production was measured. This paper discusses in detail the feasibility of upflow anaerobic fixed film fixed bed reactors packed with special media matrix in treating the parboiled rice manufacturing wastewater. Comparative performance of two special media matrix i.e. Fugino Spirals and Special Ultraviolet Stabilized Biopac media in the treatment of parboiled rice manufacturing wastewater has been studied in detail.
An experimental study on biogas production by anaerobic digestion of rice mill wastewater
Abstract With the rising interest for renewable power source and ecological security, anaerobic digestion of biogas technology has attracted a considerable attention among researchers. This study proposed a new technique for producing biogas from rice mill wastewater (RMW) by utilizing an anaerobic digester. An anaerobic digester was packed with RMW and distillery anaerobic sludge at a mesophilic temperature for 15 days for stabilization. After that the effect of the organic loading rate (OLR) and hydraulic retention time (HRT) on the mesophilic anaerobic digestion of RMW was examined. The OLR of the anaerobic reactor was increased stepwise from 0.25 to 3.91 kg COD/m 3 /day, and the HRT was varied from 1 to 32 days. The total chemical oxygen demand utilized was >75%, and the CH 4 percentage of the biogas was 62% – 63% for the OLRs studied. The efficient working volume of the digeste rwas maintained as 25% of the distillery anaerobic sludge and 75% of RMW loaded at a mesophilic temperature for the study purpose. By changing the conditions of the OLR and HRT, biogas production, methane yield, and percentage of chemical oxygen demand (COD) reduction were examined. This enhanced the biological treatment of the effluent with the anaerobic sludge in a continuous activity mode. The observed results showed that the proposed technique exhibited in prominent biogas production with maximum COD reduction when compared with existing approaches.
Cross talk between redox signalling and metabolic activity of osteoblasts and fibroblasts in the presence of hydroxyapatite-based biomaterials influences bone regeneration
Regeneration of bone tissue defects that result from metabolic disorders, including periodontal diseases, can be supported by biomaterials based on hydroxyapatite. Despite of good biocompatibility of biomaterials they can cause oxidative stress and inflammatory processes as a result of mechanical interaction with surrounding tissues. Because osteoblasts are responsible for bone regeneration process in which gingival fibroblasts may also participate, the aim of the work was to investigate the influence of hydroxyapatite-based biomaterials (allogeneic and xenogeneic) and biomaterials combined with enamel matrix derivative (Emdogain) on osteoblast and fibroblast redox balance in the context of osteoblast proliferation and differentiation.
The results showed that examined substitutes were not cytotoxic in vitro, but affected redox balance of osteoblasts and fibroblasts (ROS level increase and GSH level decrease) which led to oxidative stress (MDA and protein carbonyl groups level increase) resulting in an increase of the Nrf2 and NFκB expression. The consequence of these changes was partial inhibition of proliferation and osteoblast differentiation. Emdogain alone and combined with biomaterials decreased ROS generation and increased GSH level in both osteoblasts and fibroblasts leading to reduction of transcription factors expression especially proinflammatory NFκB, which promoted osteoblast differentiation and mineralization process.