Treatment of wastewater using response surface methodology: a brief review

Response surface methodology (RSM) is widely applied to gathering knowledge on the interactions among parameters that require optimization during the treatment of wastewater. It can be used to optimize parameters during the process of treating wastewater, e.g., landfill leachate. The experimental design methods are useful to evaluate the parameters involved in a treatment with the minimum number of experiments. This will reduce the need for reagents and materials for experiments, which finally causes both time and expense to be increased. Anaerobic digestion of wastewater technologies escalated depending on the design configuration of the reactor. Several important parameters are taken into consideration in designing an anaerobic reactor such as operating conditions, seed sludge, wastewater composition and mixing. To construct a highly efficient degradation system, it is necessary to optimize such effective parameters. As a result, the advanced statistical design is used for process characterization, optimization and modelling. In this paper, the fundamentals of RSM and its application in the anaerobic treatment of wastewater was discussed in brief. The various works done in an anaerobic reactor using RSM for prediction and optimization are given

The effects of bracing on sagittal spinopelvic parameters and Cobb angle in adolescents with idiopathic scoliosis: A before-after clinical study

Objectives: This study aims to evaluate the effects of bracing on the Cobb angle and sagittal spinopelvic parameters in adolescent idiopathic scoliosis (AIS) patients. Patients and methods: A total of 25 adolescents (2 males, 23 females; mean age 12.7±1.6; range, 10-15 years) with AIS who received bracing between January 2000 and June 2017 were retrospectively analyzed. The initial and final out-of-brace radiographs of 25 AIS patients were analyzed with regard to the spinopelvic parameters. The pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), Cobb angle, thoracic kyphosis (TK), and lumbar lordosis (LL) were measured. Results: The mean age at the initiation of bracing was 12.7±1.6 years. The mean initial Cobb angle was 31.8°±5.9°. There were no statistically significant differences between the baseline and the final measurements of the PI, PT, and SS. However, there were statistically significant differences between the baseline and the final measurements of the TK, LL, and Cobb angle. A significant correlation was observed between the PI and Cobb angle and TK and between the LL and SS. Conclusion: Our study results show significant associations between the sagittal pelvic parameters and the spinal parameters during the brace treatment of adolescents with idiopathic scoliosis. © 2020 All right reserved by the Turkish Society of Physical Medicine and Rehabilitation This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes (http://creativecommons.org/licenses/by-nc/4.0/)

The Immediate Effect of Lateral Wedge Insoles, With and Without a Subtalar Strap, on the Lateral Trunk Lean Motion in Patients With Knee Osteoarthritis

Background: Orthotic interventions for knee osteoarthritis (OA) aim to reduce mechanical loading on the medial compartment of the knee and may lessen the lateral trunk lean as the most important compensatory gait strategy. The lateral wedge insole is a known orthotic intervention for knee OA. However, the question whether the addition of a subtalar strap to the wedge improves its effect has not been addressed in the literature. Objective: To compare the effects of lateral wedge insoles, with and without a subtalar strap, on the lateral trunk lean in patients with knee OA. Methods: Twenty-three patients aged over 40 years, with grade I or II OA of the medial compartment of one knee, based on the American College of Rheumatology criteria, were included in this study. The patients were diagnosed with OA based on a clinical examination, and the diagnosis was confirmed with radiographs. A 3-dimensional motion measurement system was used to collect the gait data for 3 different conditions: (1) with no insole, (2) with a lateral wedge insole, and (3) with a lateral wedge insole and a subtalar strap. The immediate effect of the 3 test conditions on the lateral trunk lean was compared during a gait cycle a stance phase and at the point of midstance. Results: Based on the laboratory coordinate system, the 3 conditions had no significant effect on the lateral trunk lean during a gait cycle and a stance phase and at the point of midstance in patients with knee OA. Conclusion: The results of this study demonstrated that the lateral wedge insoles, with and without a subtalar strap, had no immediate effect on the lateral trunk lean in patients with knee OA. However, the long-term effect of lateral wedge insoles on the lateral trunk lean in these patients requires further investigation. © The Author(s) 2013

Success rate of brace treatment for juvenile-onset idiopathic scoliosis up to skeletal maturity

Background: Natural history studies have reported that the progression rate of juvenile idiopathic scoliosis (JIS) curves larger than 208 is high and tends to progress. The aim of this study was to investigate the outcome of bracing on JIS and to determine the prognostic factors on the success rate of brace treatment. Methods: From March 1985 to February 2015, the clinical data of all JIS patients with referral age from 4 to 10 years who received brace treatment were reviewed. Those patients with a prebrace Cobb angle.208 and a Risser sign of 0 to 2 were included and followed up a minimum of 2 years after discontinuation of the brace or time of spinal fusion. The Cobb angle was recorded at the time of diagnosis, before initiation of bracing, weaning time, brace discontinuation, and final follow-up. Results: From 297 patients with JIS, a total of 75 cases (18 boys, 57 girls) with an average curve magnitude of 31.98 at the time of diagnosis met the inclusion criteria of the study. For successfully treated patients, the average best in-brace correction was 55 for Lenke I curves, 59 for Lenke II curves, 41 for Lenke III curves, and 62 for Lenke V curves. For a total of 27 patients (36), the brace treatment failed. Of these, 21 patients (78) reached spinal fusion, and curves of 6 patients (22) increased to �508. The progression rate was highest in patients with Lenke type III curves (67), and also in those with a curve magnitude of �468 (94). Conclusions: Brace treatment is an effective strategy for controlling the curve progression and avoiding spinal fusion in JIS. © International Society for the Advancement of Spine Surger

Prediction and optimization of the Fenton process for the treatment of landfill leachate using an artificial neural network

In this study, the artificial neural network (ANN) technique was employed to derive an empirical model to predict and optimize landfill leachate treatment. The impacts of H2O2:Fe2+ ratio, Fe2+ concentration, pH and process reaction time were studied closely. The results showed that the highest and lowest predicted chemical oxygen demand (COD) removal efficiency were 78.9% and 9.3%, respectively. The overall prediction error using the developed ANN model was within -0.625%. The derived model was adequate in predicting responses (R2 = 0.9896 and prediction R2 = 0.6954). The initial pH, H2O2:Fe2+ ratio and Fe2+ concentrations had positive effects, whereas coagulation pH had no direct effect on COD removal. Optimized conditions under specified constraints were obtained at pH = 3, Fe2+ concentration = 781.25 mg/L, reaction time = 28.04 min and H2O2:Fe2+ ratio = 2. Under these optimized conditions, 100% COD removal was predicted. To confirm the accuracy of the predicted model and the reliability of the optimum combination, one additional experiment was carried out under optimum conditions. The experimental values were found to agree well with those predicted, with a mean COD removal efficiency of 97.83%

A review on microalgae as potential lipid container with wastewater treating functions

Abstract Microalgae are reported as potential source to produce lipids from their biomass cells. Lipid as a group of organic compound is a primary raw material used in biofuel production as well as component for foods, cosmetic products, fertilizers and animal feed. As the resources of manufacturing lipid from synthetic media are costly, the derivation of inexpensive carbon and nutritional sources from wastewater such as palm oil mill effluent (POME) is useful in massive scale. Furthermore, unique characteristic of microalgae as alternative agents to treat POME wastewater is another encouraging aspect of its application. In addition, biodiesel production from algae can produce 5,000 -15,000 gallons of biodiesel per acre/year. However, high yield production of high-lipid-content-algae biomass, determination of effective techniques in order to harvest grown algae, algal oil extraction and trans-esterification of extracted oil for converting into biodiesel are challenging issues need deep investigation. This review is focused on previous studies on POME as possible carbon and nutritional source used to treat environmental pollution caused by POME discharges and to increase the growth rate of microalgae in order to high-lipid content production

A comparative study on the equine and camelid antivenoms upon cardiovascular changes induced with Hemiscorpius lepturus venom in rats

Objective(s): In this study, the neutralizing abilities of the equine and the recently introduced camelid antivenoms on the hemodynamic parameters (inotropism, chronotropism, and arrhythmogenicity) were assessed following envenomation by Hemiscorpius lepturus venom in rats. Materials and Methods: At first, the electrophoretic profiles of both products were obtained by using the SDS-PAGE method (12.5%) and stained with Coomassie blue and silver nitrate. Secondly, different doses of the camelid antivenom (10, 50, and 100 μl) were given intravenously in 10 min before venom injection (400 μg/rat). The neutralizing potencies of camelid and equine antivenoms were measured by preincubation (100 μl) with H. lepturus venom for 30 min at room temperature. Finally, equal amounts of the antivenoms were injected intravenously to observe the hemodynamic changes. Results: Based on the electrophoretic profile, it was evident that undesired proteins significantly decreased in equine antivenom, owing to impurities. Pretreatment with the camelid antivenom (100 μl), neutralized the elevation of the mean arterial pressure evoked with scorpion venom injection (88.15±4.56 versus 10.2±1.23 percent at the 8th min). The Incubation of the venom and the camelid antivenom counteracted the hemodynamic changes, but the equine product had no effect. The intravascular injection of the equine antivenom transiently increased the mean arterial pressure as compared to the control (108.67±8.63 mmHg versus 52.67±1.93 mmHg at the 10th min). Conclusion: The most obvious finding emerging from this study was that the camelid antivenom neutralized the hemodynamic changes in rats significantly, but in comparison, the equine antivenom had just a minor ability

Experimental Evaluation of Mouse Hind Paw Edema Induced by Iranian Naja oxiana Venom

Iranian Naja oxiana (the Elapidae family) known as cobra snake inhabits in the northwestern part of Iran. This study aimed to evaluate the edematogenic potency of the crude venom with intraplantar injection into mice. Additionally, the inhibitory effects of three different drugs (i.e., promethazine, dexamethasone, and piroxicam) on paw edema were examined. Moreover, the gelatinase activity of this venom was assessed using the zymography method. Paw edema was induced by the intraplantar injection of different concentrations of the venom (0.5-5 μg dissolved in 50 μl of normal saline) into the mice (six in each group). It was estimated through the measurement of the increase in the paw thickness (%) with a digital caliper. The paws were pretreated and the rate of changes was measured after the venom injection. Pathological findings in the treated paws were evaluated with hematoxylin and eosin staining. Paw thickness reached its maximum amount within 5 min and resolved after 1 h. This venom had no gelatinase activity using the zymography method ruling out its role in edema. It caused non-hemorrhagic diffuse edema with the infiltration of inflammatory cells (i.e., leukocytes and lymphocytes) in the dermis. Intraperitoneal pretreatment with drugs significantly inhibited the venom-induced (1 μg/paw) edema; however, all the mice died unexpectedly a day after piroxicam injection. This in vitro and in vivo preliminary study demonstrated for the first time that N. oxiana venom-induced non-hemorrhagic edema in a short time. Dexamethasone (phospholipase A2 inhibitor; 1 mg/kg) and promethazine (H1 inhibitor; 5 mg/kg) decreased the venom-induced edema (p <0.001). It is suggested to carry out further studies to identify different mediators in venom-induced edema formation

Effects of nonantibiotic feed additives on performance, nutrient retention, gut pH, and intestinal morphology of broilers fed different levels of energy.

An experiment was conducted to determine the effects of different feed additives on performance, nutrient retention, gut pH, and intestinal morphology of broilers fed different levels of energy. This study was a 4 × 2 factorial arrangement of 4 feed additive programs (a basal diet without any feed additive as the control, the basal diet with added organic acid, the basal diet with added prebiotic, and the basal diet with added probiotic) with recommended levels (3,150 and 3,200 kcal of ME/kg of diet for the starter and finisher diets, respectively) or low levels (90% of recommended) of energy. A total of 640 one-day-old male and female broiler chicks were randomly assigned to 8 treatments. Each treatment consisted of 4 replicate floor pens of 20 birds each. Starter and finisher diets were fed from 1 to 21 d and 21 to 42 d of age, respectively. Dietary levels of other nutrients, housing, and general management practices were similar for all treatments. Dietary inclusion of additives had no significant effects on broiler performance, intestinal villus height, crypt depth, gut pH, and dietary AME. Birds fed the low-energy diets were heavier but had inferior FCR compared with those fed the recommended-energy diets. Prebiotic and organic acid significantly (P < 0.05) improved protein digestibility. The recommended-energy diets significantly (P < 0.05) increased AME and protein digestibility. No interactions were observed for the measured parameters