Micro and macro analysis of restaurant wastewater containing fat, oil, grease (FOG): An approach based on prevention, control, and sustainable management.

The number of restaurants is increasing day by day in almost all the developing countries, causing the increase in the generation of restaurant wastewater. Various activities (i.e., cleaning, washing, and cooking) going on in the restaurant kitchen lead to restaurant wastewater (RWW). RWW has high concentrations of chemical oxygen demand (COD), biochemical oxygen demand (BOD), nutrients such as potassium, phosphorus, and nitrogen, and solids. RWW also contains fats, oil, and grease (FOG) in alarmingly high concentration, which after congealing can constrict the sewer lines, leading to blockages, backups, and sanitatry sewer overflows (SSOs). The paper provides an insight to the details of RWW containing FOG collected from a gravity grease interceptor at a specific site in Malaysia, and its expected consequences and the sustainable management plan as prevention, control, and mitigation (PCM) approach. The results showed that the concentrations of pollutants are very high as compared to the discharge standards given by Department of Environment, Malaysia. Maximum values for COD, BOD and FOG in the restaurant wastewater samples were found to be 9948, 3170, and 1640 mg/l, respectively. FAME and FESEM analysis are done on the RWW containing FOG. In the FOG, palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9c), linoleic acid (C18:2n6c) are the dominant lipid acids with a maximum of 41, 8.4, 43.2, and 11.5%, respectively. FESEM analysis showed formation of whitish layers fprmed due to the deposition of calcium salts. Furthermore, a novel design of indoor hydromechanical grease interceptor (HGI) was proposed in the study based on the Malaysian conditions of restaurant. The HGI was designed for a maximum flow rate of 132 L per minute and a maximum FOG capacity of 60 kg.

The role of restaurant wastewater for producing bioenergy towards a circular bioeconomy: A review on composition, environmental impacts, and sustainable integrated management.

Population inflation has led to the unprecedented increase in urbanization, thus causing negative impacts on environmental sustainability. Recently, there is an upsurge in the number of restaurants due to the changing lifestyles of the people round the globe. For instance, there were 167,490 food and beverage establishments in 2015, representing an annual growth rate of 5.1% since 2010 in Malaysia. The rapid growth of restaurants has implicated a negative impact due to the generation of highly polluted restaurant wastewater (RWW). RWW is mainly generated during the cooking, washing, and cleaning operations. RWW typically contain fat, oil, and grease (FOG) resulting from residues of meat, deep-fried food, baked items and butter, and has caused serious blockages of sewer due to clogging and eventually sewage backup. This has increased the required frequency of cleaning and sanitary sewer overflows (SSOs). Results from the previous studies have shown that FOG can be treated using physical, chemical, and biological processes. Different technologies have been applied for the treatment of FOG and other pollutants (COD, BOD, SS and NH4-N) present in RWW. Therefore, this review aims to provide an in-depth understanding of the characteristics of RWW, chemical and physical characteristics of FOG with the mechanism of its formation and utilization for biocomposites, biogas and biodiesel productions for circular bioeconomy. Besides, this review has discussed the potential treatment technologies comprehensively for RWW which is currently remain understudied. Integrated sustainable management of FOG with technoeconomic analysis of bioproducts, sustainable management with international initiatives and previous studies are also summarized. Hence, this review aims towards providing better alternatives in managing RWW at sources, including its treatment and potential of its biorefinery, therefore eventually contributing towards environmental sustainability.

Long-term follow-up of 83 limbs treated by femoropopliteal bypass / 日本心臓血管外科学会雑誌

We did a retrospective review of 83 femoropopliteal bypasses with grafting of saphenous vein performed for two groups of limbs: those with arteriosclerosis obliterans (<i>n</i>=71) and thromboangiitis obliterans (<i>n</i>=12) over the past 15 years. The purpose of the study is to assess factors that influence long-term graft patency. We also examined methods used for reoperation. After a mean follow-up of 35 months (ranges, 1-164), the cumulative patency rate was 79% at 5 years and again 79% at 8 years, which was better than the patency of PTFE grafts or other prosthetics reported by other authors. The two groups were compared for the severity of ischemia, condition of the outflow tract, and whether anastomosis was above or below the knee. These factors were different between the two groups, but the difference in patency was statistically not significant. Two reoperations for claudication were needed. One was carried out with use of the bilateral saphenous veins from below the portions used earlier. The other was done for obstruction of a PTFE graft; anastomosis was done at the mid portion with the use of Vitagraft.