Failure Analysis of a Dissolved Air Flotation Treatment Plant in a Dairy Industry

Environmental pollution in Nigeria presents an urgent need to assess wastewater treatment facilities in various industries. This article presents an assessment of dissolved air flotation (DAF) operation in a dairy industry. The industry was visited, wastewater treatment facilities were assessed (based only on efficacy to remove selected environmental health-related pollutants) and measurements of essential design and characterization parameters were taken. The study revealed that the averages of flow rate, biochemical oxygen demand at 5 days (BOD₅), chemical oxygen demand (COD), suspended solids (SS) and total solids (TS) of the influent wastewater into the plant (DAF) were 3.45 L/s, 1652.37, 3304.67, 2333.82, and 4396.10 mg/L compared to effluent quality of 560.37, 1127.33, 172.33, and 1866.67 mg/L for BOD₅, COD, SS, and TS, respectively. The pH of the wastewater is being adjusted by addition of lime before the effluent equalization tank and individual efficacies of the system were 66.09, 65.89, 65.89, 57.54, 8.68, and 94.49% for BOD₅, COD, SS, TS, DS, and total nitrogen, respectively, with overall efficacy of 38.10%. It was concluded that failure (lower overall efficacy) of the system can be attributed to setting of lime in the oversized equalization tank (50 m³ instead of 16.82 m³ per 8 h shift), the lack of application of standardized engineering code and practices (provision of underground tank in the process, lack of complete coagulation processes, coagulation and flocculation units), lack of adequate aeration unit and lack of reliable systems for automatically adjusting dosage of coagulant and flocculant. Although, DAF unit is the centerpiece of a DAF-based system design, there are several other supporting systems important to optimal DAF operation. These observations, coupled with the analysis in this report, demonstrate that the facilities necessary to minimize continuous environmental pollution are lacking. Pollution will become an increasing problem unless pollution preventing codes and standards are developed; incorporated into government regulations and the regulations are enforced.     

RS Codes with Filtered-OFDM: A Waveform Contender for 5G Mobile Communication Systems

In recent years, the proportion of elderly population in various countries has gradually increased. Increasing with age, it can entail illness. When these diseases are sudden, the elderly often die because there is no immediate treatment. Elderly care has become an important issue. According to this issue, we want to monitor the physiological data of the elderly, such as heartbeat, blood pressure, etc., through wearable devices. Once an abnormal condition is detected, the wearable device can be used to immediately request treatment from a nearby clinic or hospital. In order to improve the network quality of this service, we use the architecture of the mobile edge computing. The mobile edge computing provides features such as immediacy, low latency, proximity etc. However, the process of data transmission on the mobile edge computing has the risk of being stolen and identity authentication is also an important issue. Therefore, we propose a secure protocol based on cryptography to protect personal information with lightweight authentication. The proposed scheme aims to achieve mutual authentication, non-repudiation, integrity, user privacy, and defend against known attacks.