Operation of an activated sludge plant for fellmongery wastewater treatment : a thesis submitted in partial fulfilment of the requirements of the degree of Master of Technology in Environmental Engineering at Massey University, Palmerston North, New Zealand

Activated sludge is one of the most common wastewater-treatment processes used to reduce pollutant loads on the receiving environment. For efficient operation, there must be an effective process control and operation strategy in place to ensure that process problems are avoided. This research is a case study into the process control and operation of an activated sludge plant used for fellmongery wastewater treatment. Analysis of the pretreated fellmongery wastewater showed that it is characterised by high total and volatile suspended solids concentrations, and high organic nitrogen concentrations. The plant was experiencing frequent problems that were attributed to the high influent suspended solids load coupled with ineffective solids management. Operation of bench-scale simulations showed that solids retention time (SRT) control at 5 or 10 days will produce acceptable effluent suspended solids concentrations and soluble chemical oxygen demand (COD) removal. Soluble COD removal for both 5 and 10 days was high at 85 and 80 % respectively at a hydraulic retention time of 6.4 days. Effluent suspended solids concentrations were 100 and 157 g/m 3 respectively. A steady state control model was developed based on, mass balances of biochemical oxygen demand (BOD) and volatile suspended solids (VSS), process performance equations, and the solids retention time (SRT). The model used three control points, the clarifier underflow pump, the clarifier influent pump and the waste sludge pump. The model was incorporated into an off-line Activated Sludge Operation Program (ASOP) to provide a user-friendly interface between the plant and operator. The main output from ASOP includes values for the three control points and suggestions to help avoid problems. A process control and operation strategy was developed using ASOP, the knowledge gained in this research, and an operation manual developed from accepted operation practises

Antioxidant and biochemical content in Brazilian guava germplasm with white, red and pink pulps.

Guava is considered to be an excellent source of antioxidant compounds due to the high content of lycopene and vitamin C. The international guava market is dominated mainly by white pulp fruit, differing from the Brazilian market, which pays a high price for guava cultivars with dark red pulp fruit. The goal of the present study was to analyze the content of Brazilian guava accessions contrasting for pulp colors to support the breeding program of guava, focusing on cultivars producing fruits with a high content of functional impounds. Sixty guava accessions established in a field germplasm bank, at Embrapa Tropical Semi-Arid, Petrolina, Pernambuco State, Brazil, were evaluated for total antioxidant activity, phenolic compounds, ascorbic acid, flavonoids, lycopene and beta-carotene, titrable acidity, soluble solids and total soluble sugars. The accessions, including guavas of white (n=10), red (n=23) and pink pulp (n=27), were grown in a block design experiment, with two replications/ accession. An ANOVA was performed, decomposing the degrees of freedom for the three pulp color groups in order to test the contrast to the nine evaluated compounds. The accessions presented high variability (p<0.01) for all compounds. Guava white pulp did not presented variability for the majority of compounds, except soluble solids, while guava red and pink pulps presented high variability (p <0.01) for most compounds, except flavonoids in pink pulp guava and flavonoids, beta-carotene, soluble solids and total sugars in red pulp fruit. The white*red and pink pulp contrast was significant (p<0.01) for most compounds, except for titrable acidity and soluble solids, with the greater mean values found in the accessions of pink red pulp, except for total soluble sugars. The red*pink contrast was also significant (p<0.01), except for titrable acidity and soluble solids, with greater values found in the accessions of red pulp fruit, except for lycopene and total soluble sugars. The compounds mean values were, approximately, 1.5, 1.4, 1.7, 1.8, 2.7 and 3.1 times greater for antioxidant activity, phenolic compounds, ascorbic acid, flavonoids, lycopene and beta-carotene, respectively, quantified in the pink and red pulp guava accessions when compared to white pulp. These results indicated that pink and red pulp guavas have a potential of greater beneficial contribution to the human diet than white pulp guava

Evaluation of solvent extraction of Amaranth betacyanins using multivariate analysis

The present study was aimed at assessing the effect of solvents on the yield and the color properties of amaranth extract. Two species of amaranth namely Amaranthus gangeticus and Amaranthus blitum were extracted with water, methanol and ethanol. Seven parameters like betacyanin content, total soluble solids, lightness (L* ), redness (a* ), yellowness (b* ), hue angle (h* ) and chroma (c* ) were analyzed to assess extraction efficiency. Correlation analysis was carried out to assess the linear association among the analytical variables. Principal component analysis was used to establish the relationships between the different analytical variables and to detect the most important factors of variability. Among the two varieties, Amaranthus gangeticus extract contained about two and half time more betacyanin with half of total soluble solids compared to Amaranthus blitum. Water is the best as solvent for extracting betacyanin from Amaranthus gangeticus and ethanol in case of Amaranthus blitum. Among the analytical parameters, a* and c* were perfectly correlated. Three principal components were found among the seven analytical variables accounting 88% of total variability. The first principal components mostly reflected the redness (a* ), whereas the second principal components reflected the betacyanin content, total soluble solids and lightness (L* value)

Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

Optimizing conditions for hot water extraction of banana juice using response surface methodology(RSM).

A response surface methodology (RSM) was used for the determination of optimum extraction temperature and time to produce an acceptable banana juice extract. Banana juice was extracted using hot water extraction method at different extraction temperature (35–95 C) and time (30–120 min). The effects of the extraction conditions on juice yield, total soluble solids (Brix), banana odour and taste were studied by employing a second-order central composite design. The coefficient of determination, R2, for juice yield, total soluble solids (Brix), banana odour and taste were greater than 0.900. Analysis of the regression coefficients showed that temperature was the most important factor that affected characteristics of the banana juice extract as it exerted a highly significant influence (p < 0.001) on all the dependent variables. An increase in extraction time and temperature of hot water extraction resulted in an increase in juice yield, total soluble solids, banana odour and taste of the banana extract. Based on surface and contour plots, optimum conditions for hot water extraction of banana juice were 95 C for 120 min

Effect of cooking time on physical properties of almond milk-based lemak cili api gravy

One of the crucial elements in developing or reformulating product is to maintain the quality throughout its entire shelf life. This study aims to determine the effect of different cooking time on the almond milk-based of lemak cili api gravy. Various cooking times of 5, 10, 15, 20, 25 and 30 minutes were employed to the almond milk-based lemak cili api gravy followed by determination of their effects on physical properties such as total soluble solids content, pH and colour. pH was determined by using a pH meter. Refractometer was used to evaluate the total soluble solids content of almond milk-based lemak cili api gravy. The colours were determined by using spectrophotometer which expressed as L*, a* and b* values. Results showed that almond milk-based lemak cili api gravy has constant values of total soluble solids with pH range of 5 to 6, which can be classified as low acid food. Colour analysis showed that the lightness (L*) and yellowness (b*) are significantly increased while redness (a*) decreased. In conclusion, this study shows that physical properties of almond milk-based lemak cili api gravy changes by increasing the cooking time

QUALITY EVALUATION OF 'SUNBURST' CHERRIES HARVESTED AT DIFFERENT RIPENESS STAGES .

The sweet cherry ‘Sunburst’ is highly appreciated by consumers due to its organoleptic traits. Regional producers tend to harvest cherries sooner in order to increase their profits. With the aim of understanding the consequences of this we have tested the effect of different ripeness stages at the moment of harvesting on fruit quality. Quality parameters tested included external colour (L*, a*, b*), fruit texture, total soluble solids (TSS), and titratable acidity (TA). To evaluate nutritional quality total antioxidant activity was measured too. Once again, and in agreement with results obtained in previous studies, we conclude that there is no advantage in picking less ripe cherries

Effects of different levels of preharvest shading on the storage quality of strawberry (Fragariax ananassaDuchesne) cv. Ostara II. chemical characteristics

To study the effects of different levels of preharvest shading (74, 58, 48, 38 and 5% of light penetration which were denoted by So' SI' S2' 53 and S4 respectively) on developing strawberry (Fragaria X ananassa Duchesne) cv. Ostara fruits, some chemical tests (pH, total soluble solids and titratable acidity) associated with fruit quality were carried out. Results showed that although the different levels of preharvest shading were found to demonstrate a significant effect on the chemical parameters studied, this could only be detected in fruits shaded by S4 and S3. However, for total soluble solids, significant interactions were observed between location of fruit and fruit type and also between storage day and fruit type

Study of physico-chemical parameters of orange (Citrus reticulate Blanco) for the development of orange wine

Physico-chemical properties are an essential factor during processing and preservation of food. The retention and changes in physico-chemical properties depends upon the processing technique. In this work, physicochemical parameters of orange like vitamin C (ascorbic acid), pH, total soluble solids (TSS), % acidity, temperature and color were studied with all the optimized conditions of fermentations for the development of orange wine. The fermentation of the fruit juice was completed within 7 days period at temperature 27oC, pH 4.5 and total soluble solids of 24oBrix with an inoculum level of 10% (v/v). Thus, orange wine with ethanol content of 8.5% (v/v) was prepared from the orange variety ‘Nagpur Santra’ (Citrus Reticulata Blanco) in controlled physico-chemical parameters

A note on the effect of calcium alginate coating on quality of refrigerated strawberries.

peer-reviewedAn alginate-based edible coating was investigated for the preservation of the quality of strawberries during cold storage (5 °C). Strawberries were immersed, successively, in sodium alginate and calcium chloride solutions to generate a surface coating of calcium alginate. The quality of coated and non-coated strawberries was evaluated by weight loss, visible decay, titratable acidity, total soluble solids and reducing sugar concentration over a 14-day storage period. Results showed that coating with calcium alginate had no significant effects on weight loss or physicochemical parameters when compared to control fruit, but it did result in the postponement of visible decay during refrigerated storage