The study was undertaken to determine the performance evaluation of locally made anaerobic, easily portable and cleanable biogas digester using a Polyvinyl Chloride (PVC) water tank available in Bangladesh. Cow manure, kitchen waste and anaerobically digested slurry were used as a source of biomass. This study was conducted at ambient temperature in two different feeding practices (daily and 4^th-day interval feedings) to investigate biogas production variation. The biogas' composition, pH and Total Volatile Fatty Acid (TVFA) were measured daily and weekly basis. The cumulative biogas and CH₄ produced during daily feeding were 59.6 Nm³ and 33.8 Nm³. The average CH₄ content was 57%, the TVFA and pH were ranged 163–356 mg/L and pH 6.8–7.5, respectively. In contrast, the cumulative biogas and CH₄ produced at 4^th-day interval feeding was 54.2 Nm³ and 30.62 Nm³. The average CH₄ content was 56% and the TVFA and pH were 194-340 mg/L and 7.1–7.6, respectively. Before and after anaerobic digestion, the microbial load comparison was reduced by 2 logs. The biogas yield per ton of feedstock in daily and 4^th-day interval feeding was 54.30 Nm³t^-1 and 44.21 Nm³t^-1 and overall digester performances 0.43 Nm³_BG/m³_DG and 0.34Nm³_BG/m³_DG, respectively. Daily feeding was found 28% higher in biogas yield and 22% higher in the digester performance. The performance of locally made digester (3000 L) was satisfactory and good enough to fulfill the demand for biogas production in Bangladesh's urban and rural areas.

In this paper, we investigated the wave reflected from the perforated breakwater caisson. The study is for physical models and laboratory. Wave reflection from the breakwater can cause many problems for vessels so to reduce wave reflection from breakwater, perforated caisson can be used. This is a test case that wave reflection when a perforated wall is in front of the main wall and two perforated wall is in front of the main wall is to be measured and the impact of the perforated walls on wave reflection checked. The perforated walls are slot and the porosity is 1/2 and 1/3. Tombak port was used for modeling and the size of breakwater and the waves information related to Tombak port breakwater. The experiments conducted in wave flume of the Soil Conservation and Watershed Management Research Center

The food security in Cameroon is well stated on manufactured and imported products. What is the case about food produced in Cameroon that does not go through industrial transformation in general and sea products in particular? The impact of the presence of companies at the sea side on aquatic organisms had to be assessed on hydrocarbons pollution due to the fact that some of them are carcinogenic. The evaluation of four of the most consumed species of fishes (Tarphops oligolepis, Pseudotolithus senegalensis, Ethmalosa fimbriata, and Lepidopus caudatus) revealed that PAHs are accumulated in these organisms. The Pseudotolithus senegalensis is the most dangerous specie consumed by the population living around the sampling sites since it has the highest concentration of Chrysene (1472.792 µg/kg), followed by Benzo(a)Pyrene (164.054 µg/kg) in Bobende coastal beach samples, and 3757.150 µg/kg and 154.519 µg/kg respectively for Chrysene and Benzo(a)Pyrene in Down-beach samples.

A Two (2) weeks practical survey of Karu Abattoir was carried out to determine the state of facilities and management system obtainable to ensuring regulated practices and better production of quality hides and skins. The abattoir is situated in a boundary area of the Federal Capital Territory (FCT) and Nasarawa State of Nigeria. It is presently in the middle of a busy part of the town which houses residential areas, schools and various business outfits and the road network leading thro and fro the abattoir is accessible and in good state. The abattoir facilities including the available lairage, slaughter, condemned meat rooms, hides and skins preservation room, veterinary laboratory, water supply system, waste discharge system and the hoisting equipment where assessed. The current man power, and the management system adopted were also observed. The following observations were made; The site lacked proper sanitation and hygiene standards were not properly adhered to. Handling, proper preservation and drainage to manage waste water were also a challenge. Workers were not properly kitted with boots, aprons, hand gloves and scarf. However, flies and offensive odour were minimal because the premise was fumigated on daily basis (putting Hazard Analysis Critical Control Point, HACCP into consideration) and sources of maggots and odour were identified and arrested using de-odorizing agents and readily available chemicals. It was also observed that, the management order in the abattoir was from, The Government-The Livestock Director-The Manager (a Veterinarian)-The Assistant Manager-The Meat Inspectors. Animal by-products such as bones, horns, hooves, blood where duly utilised. The Hides and skins were cured and taken to Kano and sold on request to the Tanneries. The nearby stream served as a drainage channel for the abattoir and we recommend that the management of the Federal Capital Territory Administration should provide adequate source of waste collection point for treatment before discharging it into the nearby stream to protect the public health. Other recommendations are; to increase the capacity of the site in terms of labor and structure to meet rising demands as the population of the area have increased over time. Optimal implementation of National Leather and Leather Products Policy is recommended. In general, factors such as animal husbandry and disease management, slaughter facilities and practices, handling and preservation methods as observed in Karu abattoir, may affect the quality of hides and skin which are leather economic source if serious attention are not taken to providing suitable services, facilities and infrastructure.">">

Industrial effluents treatment is the most important target for researchers in the present era as it contains hazardous pollutants which lead to serious environmental problems and it also affects human health and aquatic systems. In this research work an attempt has been made to determine the efficiency of low cost bio-sorbent derived from Lantana Camara Plant for the removal of heavy metal ions such as Cu(II). The biosorbent was characterized by FTIR Spectroscopy and Scanning Electron Microscopy (SEM) methods. The effect of various experimental parameters such as pH, adsorbent dosage, contact time and initial metal concentration on the biosorption process were investigated. The equilibrium adsorption data were interpreted by Freundlich and Langmuir Adsorption Isotherm Models.       ">">">">