Flocculation kinetics using dual coagulants: effects of temperature, addition sequence, rapid mixing, and sulfate

The effects of temperature, rapid mixing time and intensity, sulfate, and coagulant addition sequence of dual coagulants on the flocculation kinetics were studied. Either ferric nitrate alone or a cationic polymer alone or in combination as dual coagulants were used. The flocculation kinetics were monitored using mainly a Photometric Dispersion Analyzer (PDA). An Automatic Image Analyzer was also used in a limited number of experiments to monitor the flocculation kinetics. Kaolinite clay (with four concentrations: 5, 25, 50, and 100 mg/L) suspended in distilled water with added salinity was used at two temperatures (5 or 23°C) and two pH values (6.0 or 7.8) to simulate natural water. Sulfate effects were also studied using either zero concentration or 0.001 M concentration. The following conclusions were drawn from this work: (1) Extended rapid mixing is an important step for particle growth when inorganic coagulants or dual coagulants were used, but not when cationic polymers alone were used. The optimum extended rapid mixing time is a function of the suspended matter concentration. (2) Rapid mixing at a low mixing intensity (G ≅ 450 s[superscript]-1) and longer mixing times gave better flocculation kinetics than high mixing intensity (G ≅ 900 s[superscript]-1) with shorter mixing times for the same Gt product value. (3) Dual coagulants outperformed the sole use of each coagulant alone when the inorganic coagulant dose was high enough to form metal hydroxide precipitate. When the mechanism of coagulation of the inorganic coagulant was completely charge neutralization, the use of dual coagulants was inferior to the use of the cationic polymer alone. (4) The cationic polymer should be added simultaneously with the inorganic coagulant. Simultaneous addition was found to produce the strongest flocs. (5) Low temperature has a detrimental effect on the flocculation process for low turbidity waters regardless of the coagulant type. This detrimental effect is reduced (for inorganic coagulants) and almost eliminated (for cationic polymers alone or for dual coagulants) for higher turbidity waters

Nutrients requirements in biological industrial wastewater treatment

Wastewaters from olive mills and pulp and paper mill industries in Jordan have been characterized and treated using laboratory scale anaerobic and aerobic sequencing batch reactors, respectively. Nutrient requirements for these two industrial wastewaters were found to be less than what is usually reported in the literature for C:N:P ratio of 100:5:1 for aerobic treatment and 250:5:1 for anaerobic treatment. This was ascribed to the low biomass observed yield coefficients and relatively low removal efficiencies in these wastewaters. It was found that for anaerobic treatment of olive mills wastewater COD:N:P ratio of about 900:5:1.7 was able to achieve more than 80% COD removal. The observed biomass yield was about 0.06 kg VSS per kg of COD degraded. For extended aeration aerobic treatment of pulp and paper mill wastewater COD:N:P ratio of about 170:5:1.5 was able to achieve more than 75% COD removal. The observed biomass yield was about 0.31 kg VSS per kg of COD degraded. In both these wastewaters nutrients were not added. A simple formula is introduced to calculate nutrient requirements based on removal efficiency and observed biomass yield coefficient. Key Words: Olive mill wastewater; anaerobic treatment; aerobic treatment; sequencing batch reactor; biomass yield; nutrient requirement. African Journal of Biotechnology Vol. 3 (4), 2004: 236-23

Modified ureterosigmoidostomy for management of malignant and non-malignant conditions

Objective: To investigate the outcome of Mainz Pouch II urinary diversion for both malignant and non-malignant diseases. Design: A retrospective analysis. Setting: Kilimanjaro Christian Medical Centre, Institute of Urology, Moshi, Tanzania from April 1995 to May 2007. Patients: Mainz Pouch II was created in 83 patients of which, 38 were females and 45 were males (M:F 1.2:1). Results: Early complications were seen in 11 (13.2%) patients, as follows: one (1.2%) prolonged ileus, 1(1.2%) wound dehiscence, two (2.4%) perioperative deaths among the malignant group, seven (8.4%) superficial wound sepsis. Long term complications were seen in 14 (16.9%) patients, as follows: one (1.2%) patient developed an incision hernia, one (1.2%) patient developed unilateral pyelonephritis, one (1.2%) patient developed unilateral ureteral stenosis, two (2.4%) patients had deterioration of renal function, three (3.6%) patients developed mild to moderate unilateral hydronephrosis, three (3.6%) patients developed mucoceles. Among the 83 patients in this series, three (3.6%) patients developed metabolic acidosis, two (2.4%) of which, required oral bicarbonate supplementation. All (100%) patients had daytime continence while three (3.6%) patients had occasional night time incontinence. Overall total continence was achieved in 80 (96.4%) of the patients. Conclusion: The Mainz Pouch II is a safe and reproducible method of urinary diversion and serves as a satisfying method of continent urinary diversion in all age groups. This reconstructive surgery enabled the afflicted to achieve personal goals, hopes and aspirations, positively influencing their quality of life. The follow up show low complication rate with good results in terms of continence and quality of life, however, long term results remain to be evaluated. East African Medical Journal Vol. 85 (7) 2008: pp. 334-34

Etude qualitative de la relation entre les Pratiques de Management du Capital Humain et l’Engagement Organisationnel : cas des Professionnels de la Santé Publique

L’objectif de cette réflexion est de proposer un inventaire des variables explicatives de l’engagement organisationnel en termes de pratiques de Management du Capital Humain offertes, ainsi que de ceux dont le personnel soignant souhaiterait disposer dans leur organisation. Dans ce sens, une étude qualitative exploratoire a été réalisée auprès de 23 professionnels de la santé publique pour présenter un modèle des pratiques du management de capital humain susceptibles d’influencer l’engagement organisationnel. Le traitement des entretiens semi-directifs a été réalisé sous le logiciel Nvivo 10, à travers une analyse de contenu thématique. Compte tenu des résultats, la caractéristique la plus marquante de cette étude est l’apparition du climat d’éthique comme un antécédent de l’engagement organisationnel.   This paper focuses on proposing an inventory of the explanatory variables of organizational commitment in terms of Human Capital Management practices offered, as well as those that the nursing staff would like to have in their organization. An exploratory qualitative study was carried out with 23 public health professionals. This study presented the main human capital management practices likely to influence organizational commitment. The processing of the semi-directive interviews was carried out using the Nvivo 10 software through a thematic content analysis. Considering the results, the most striking feature of this study is the appearance of ethical climate as an antecedent of organizational commitment

Dewaterability of sludge digested in extended aeration plants using conventional sand drying beds

Dewaterability of unconditioned sludge digested in full scale and lab scale experiments using either extended aeration (EA) or anaerobic digestion were compared on full and lab scale sand drying beds. Sludge digested in EA plants resulted in improvement in sludge dewaterability compared to  sludge digested anaerobically. This was demonstrated by comparing capillary suction time, time to filter a specific amount of water, the sludge volume index and the dry solids content. In addition, sieve analysis results from both types of sludge after drying in sand drying beds clearly shows that the grain portions in the fine range in case of anaerobically digested sludge are more than that in case of EA sludge. This was also clear in microscopic photos of samples. The microscopic photos of EA stabilized sludge are characterized by larger colonies of flocs and more open structure than anaerobically digested sludge

Surgery for ureteral complications of bilharziasis

OBJECTIVE: To review our experience with reconstructions of ureteral complications of Schistosoma haematobium, in a centre situated in an endemic zone. PATIENTS: Fifty one patients operated for bilharzial complications of the ureters. METHODS: A retrospective analysis of patients operated upon, at the Coast Province General Hospital, Mombasa, Kenya between 1996 and 2008. All patients had obstructive ureteral complications. Data abstracted included demographics, level and nature of complication, surgical options utilized and follow-up. RESULTS: Endoscopic visual internal ureterotomy (VIU) was performed in 21 (41%) patients, resection and ureteroneocystostomy in 27 (49% of 55 procedures done), resection and ureteroureterostomy in one, nephrectomy in two and ileal replacements in two. Nephrostomy was performed in two patients who presented with anuria. Two patients restenosed after VIU and were offered resection and ureteroneocystostomy. One patient restenosed after ureteroneocystostomy and underwent a revision with psoas hitch. One patient with nephrostomy had bilateral ureteric replacement with ileum to skin. The two patients with anuria who had nephrostomy done eventually died of progressive renal failure. CONCLUSION: Schistosoma haematobium is associated with severe complications of the upper urinary tracts. Once established these complications are amenable to surgical correction, by both open and endoscopic techniques as long as renal function is not irretrievably impaired

Surgical Aspects of Genitourinary Bilharzia

The blood fluke Schistosoma haematobium mainly affects the lower genitourinary tract, where the pathological effects are a result of the reaction to the schistosome ova. The chronic effects cause damage to the musculature of the urinary tract resulting in scarring and fibrosis. The ureters dilate and or stricture. Contracture of the bladder and or detrussor failure may occur. Secondary calculi in the upper tracts and bladder are common. There is strong association with bladder cancer development of the squamous cell type. Emphasis is on the prevention of the infestation

Dismal salvage of testicular torsion: A call to action!

Background: Testicular ischaemia and infarction in cases of torsion depend on the duration and degree of twisting. Early evaluation and treatment are associated with high salvage reports.Objective: To determine the salvage rates of testicular torsion in selected hospitals at the Coast Province of KenyaDesign: A retrospective study of patients managed for testicular torsion and related conditions between 1999 and 2011.Setting: Coast Province General Hospital, Mombasa (1999 - 2008) and Moi District Hospital, Voi (2009 - 2011).Patients and Methods: Case records of 44 patients were reviewed. Forty two underwent scrotal explorations while two patients with bilateral  testicular loss due to torsion had no surgery. Patients were reviewed for age, operative diagnoses, testicular salvage, surgical procedures  performed and recurrence of symptoms.Results: Of 29 patients operated for acute testicular torsion, four had viable testes (salvage rate of 14%). Seven patients had bilateral orchidopexyfor intermittent testicular torsion. Three patients who had missed torsions with resultant total testicular atrophy, had orchidopexy of the contralateral testes. At scrotal exploration 2 patients with epididymorchitis and one patient with a torsion of appendix testis that was excised, were not subjected to orchidopexy. There was no occurrence of torsion after orchidopexy.Conclusion: Testicular torsions were associated with low salvage rates. Increased public awareness coupled with clinician, parental, teacher,  teenage and adult male education with respect to the consequences of acute scrotal pain is warranted

Product Innovation and Process Innovation of Madura Batik Entrepreneurs in Surabaya

Innovation must be done by entrepreneurs to be able to survive in the midst of business competition. This study examines the product innovation and process innovation of Madura batik on Madura batik entrepreneurs in Surabaya because there have not been many studies on this topic. Data collection method in this research are interviews and observations. Observations were done at the place of business owned by informants who are Madura batik entrepreneurs. The results showed that product innovation in Madura batik were patterns, motifs, colors, and product diversification. While the innovation processes on Madura batik are manufacturing techniques and equipment. Madura batik entrepreneurship innovation sources come from two sources, there were internal sources and external sources. Internal source comes from entrepreneur. While external source comes from customer or market, social change, internet, and the environment. Innovation barriers that faced by Madura batik entrepreneur were lack of innovation structure, resistance of change, shortage of resources, and lack of collaboration. Product innovation and process innovation implemented by Madura batik entrepreneur is entrepreneur centric because employees who work in Madura batik entrepreneur business place have not been fully involved in the innovation process. The conclusion of this research is that entrepreneurship as an aspect of human resources in the Madura batik industry is the main foundation for the success and sustainability of Madura batik product innovation and process innovation. To achieve sustainable innovation the entrepreneur must optimize all the resources, including human resources, that is employees. So, it is important for entrepreneur to involve their employees to such training to improve their skill and knowledge in batik for the sake innovation in entrepreneur’s business