This study investigated the possibilities of improving methane yield production from, the anaerobic co-digestion of wheat straw (WS) and primary sludge (PS). The batch experiment was conducted under mesophilic conditions. Different mixtures of WS and PS depending on its C/N ratio were carried out to investigate the optimum C/N ratio for effective methane production. The cumulative methane yields (CMYs) for co-digestion of PS with WS at C/N ratios of 35, 25, 20, 15 and 10 were 1.29, 1.62, 1.33, 2.44 and 2.16 time than digesting PS alone, respectively. The maximum CMYS was observed at C/N ratio of 15 with an increase of 89 %, 50.93 %, 83.61 % and 13.12 % compared with the other C/N ratio of 35, 25, 20 and 10 respectively. This result showed the positive synergy of co-digesting of PS and WS for methane production caused by improving the C/N ratio of the feed stock.

Simplification is an important design step of water supply and irrigation pipes networks. It is recognized by making the original network easier to be understood and analyzed. Water hammer in water-supply networks may give rise to high and low pressures, due to the superposition of reflected pressure waves. The effect of pipes networks’ simplification on water hammer phenomenon is investigated. This study uses a simple two loops pipes network composed of 12 high density polyethylenes (HDPE) pipes with different diameters, thicknesses, and roughness coefficients representing of a general parallel/series system. The network is fed from a boundary head reservoir and loaded by either distributed or concentrated boundary water demands. According to both hydraulic and hydraulic plus water quality equivalence, three levels of simplifications on the original network are performed. Also, the effect of water demands’ concentration on the transient flow is checked. The transient flow in the network is initialized by either concentrated or distributed boundary water demands which are suddenly shut-off or released. Water hammer and mass oscillation (WHAMO) software which uses the implicit finite difference scheme for solving the momentum and continuity equations at unsteady-state case is used in the simulation. All scenarios produced results showed that both hydraulic equivalence and demands’ concentration simplifications increase the transient pressure and flow rate in the simplified network compared with the original one. However, hydraulic plus water quality equivalence simplification results in an adverse effect. It was found that, as the degree of simplification increases the transient pressure head and flow rate of the simplified network deviate more from those of the original network. Therefore, simplifications of the distribution networks should be done with very careful caution.

Certain complaints about building water supply systems (BWSSs) arise from their oversizing or undersizing. It is essential to improve their efficiency by way of minimizing their cost and maximizing the benefit accrued from them. This work introduces practical guidelines for BWSSs design, which deal not only with the cost optimization but also with water availability during high demands. A head-dependent analysis function, which takes into consideration the pressure dependency of nodal outflows, is presented. A resilience index, minimum surplus head, and failure index are used to express the capability of BWSSs of overcoming peak demand conditions. The proposed approach was applied on a direct BWSS within three identical residential floors at different levels. It was found that, the internal pipes are preferable to have the same diameter while the main riser of each floor must be increased as the height of the floor increases.

Previous studies on water treatment processes confirmed that preoxidation of the surface water improves the coagulation and filtration processes. However, only few studies focused on its effects on algae and their toxins. In this study, the variability of microcystins through conventional treatment processes was investigated within a full-scale plant, which is challenged with a high level of cyanotoxins and where surface water is pre-chlorinated. Treatment trials were conducted with and without prechlorination. The water characteristics, algal count, and microcystins were compared. The results revealed that, prechlorination causes lysis of Cyanophyta cells, consequently releasing cell bound toxins and other compounds that lead to the formation of harmful disinfection by-products (DBPs). Laboratory jar tests were performed to evaluate potassium permanganate effectiveness as an alternative preoxidant. Unlike prechlorination, permanganate preserved the algal cells integrity, allowing for removal of intact cells with their toxins and provided better controls of DBPs.

Wastewater production is a serious problem in Egypt, which increases as the population grows and the demand on fresh water increases. The lack of water used in agriculture in arid and semi-arid regions is being an important reason to use wastewater in agriculture. In this research, a wastewater stabilization ponds (WSPs) system with a design flow of 40000 m3/day in El-Qusiyyah city located in Upper Egypt is evaluated to make sure that the effluent from this system is inconformity with Egyptian and Food and Agriculture Organization of the United Nations (FAO) quality standards for wastewater reuse in agriculture. Monthly samples were collected from the inlet, anaerobic ponds, facultative ponds, and maturation ponds. Some physicochemical parameters as pH, biochemical oxygen demand (BOD), and total suspended solids (TSS) were measured. In addition, levels of some heavy metals were taken into consideration. Concentrations of copper (Cu), chromium (Cr), and zinc (Zn) were measured. Results showed a moderate efficiency of the system and the effluent did not match the recommended characteristics to be reused in agricultural purposes. Increasing in pH, and TSS values above the permissible limits prevent the agricultural reuse of the effluent from El-Qusiyyah wastewater treatment plant.

Wastewater production is a serious problem in Egypt, which increases as the population grows and the demand on fresh water increases. The lack of water used in agriculture in arid and semi-arid regions is being an important reason to use wastewater in agriculture. In this research, a wastewater stabilization ponds (WSPs) system with a design flow of 40000 m3/day in El-Qusiyyah city located in Upper Egypt is evaluated to make sure that the effluent from this system is inconformity with Egyptian and Food and Agriculture Organization of the United Nations (FAO) quality standards for wastewater reuse in agriculture. Monthly samples were collected from the inlet, anaerobic ponds, facultative ponds, and maturation ponds. Some physicochemical parameters as pH, biochemical oxygen demand (BOD), and total suspended solids (TSS) were measured. In addition, levels of some heavy metals were taken into consideration. Concentrations of copper (Cu), chromium (Cr), and zinc (Zn) were measured. Results showed a moderate efficiency of the system and the effluent did not match the recommended characteristics to be reused in agricultural purposes. Increasing in pH, and TSS values above the permissible limits prevent the agricultural reuse of the effluent from El-Qusiyyah wastewater treatment plant.

In this study, a series of reinforced concrete beams were carried out to determine the size effect of the beams strengthened with different types of fiber reinforced polymer sheets (FRP). Two types of FRP sheets were considered in this study; Carbon and Glass fiber reinforced polymer sheets (CFRP and GFRP). FRP sheets were bonded to the soffit of the beams using a two-part Epoxy. These two types of FRP sheets were used to allow a variety of fabric stiffnesses and strengths to be studied. Also, this study introduced a new type of anchor to improve the efficiency of the FRP-strengthened beams and to prevent the anchor delamination of the FRP sheets. The results show that the strengthening system increases the ultimate capacity of the FRP-strengthened beams. Also, this increase depends on many parameters such as the type of the FRP sheets and size of the tested beams. Moreover, the beam size has significantly effected on the ductility of testing beams which increases as the size of beams decreases.

In this study, a series of reinforced concrete beams were carried out to determine the size effect of the beams strengthened with different types of fiber reinforced polymer sheets (FRP). Two types of FRP sheets were considered in this study; Carbon and Glass fiber reinforced polymer sheets (CFRP and GFRP). FRP sheets were bonded to the soffit of the beams using a two-part Epoxy. These two types of FRP sheets were used to allow a variety of fabric stiffnesses and strengths to be studied. Also, this study introduced a new type of anchor to improve the efficiency of the FRP-strengthened beams and to prevent the anchor delamination of the FRP sheets. The results show that the strengthening system increases the ultimate capacity of the FRP-strengthened beams. Also, this increase depends on many parameters such as the type of the FRP sheets and size of the tested beams. Moreover, the beam size has significantly effected on the ductility of testing beams which increases as the size of beams decreases.

In this study, a series of reinforced concrete beams were carried out to determine the size effect of the beams strengthened with different types of fiber reinforced polymer sheets (FRP). Two types of FRP sheets were considered in this study; Carbon and Glass fiber reinforced polymer sheets (CFRP and GFRP). FRP sheets were bonded to the soffit of the beams using a two-part Epoxy. These two types of FRP sheets were used to allow a variety of fabric stiffnesses and strengths to be studied. Also, this study introduced a new type of anchor to improve the efficiency of the FRP-strengthened beams and to prevent the anchor delamination of the FRP sheets. The results show that the strengthening system increases the ultimate capacity of the FRP-strengthened beams. Also, this increase depends on many parameters such as the type of the FRP sheets and size of the tested beams. Moreover, the beam size has significantly effected on the ductility of testing beams which increases as the size of beams decreases.

NULL