Modeling Escherichia Coli Concentration in Surface Runoff: the ECOLI Model.

A biological model, ECOLI, is developed that is capable of continuously simulating E. coli concentration in surface runoff from agricultural land applied with manure. The model was calibrated and validated by using data from field-scale studies at Franklinton, Louisiana. During validation the model was interfaced with GLEAMS-SWT model to obtain the necessary hydrologic and erosion variables as input to the ECOLI model. The ECOLI model was found to perform best when simulating runoff concentration following the first application of waste. For reapplication of waste within 50 days, the trend of decrease over time was well-simulated but simulated E. coli concentrations were lower than the observed concentrations. The correlation coefficient of the simulated E. coli concentration versus the observed concentration was found to be 0.85. The regression intercept is significantly different from zero. The regression slope is 1.06 and is not significantly different from 1.0. The ECOLI model is not recommended for reapplied waste until more research is done on the effect of applied waste on subsequent E. coli density and decay. The ECOLI model is also not recommended for use in simulating fecal coliform concentration unless methods of enumerating fecal coliforms that exclude false positive counts are used. Two experiments were carried out to investigate E. coli adsorption in soil-water system of Tangi Silt Loam and Commerce Clay Loam. The adsorption of E. coli in Tangi Silt Loam was found to be significantly lower than that of Commerce Clay Loam. The distribution coefficient of loose adsorption of E. coli in Tangi soil water system was found to be significantly lower than that of tight adsorption. The distribution coefficient of loose adsorption of E. coli in Commerce soil-water system was found to be significantly higher than that of tight adsorption. Soil with higher clay content was found to adsorb significantly more E. coli than soil with lowerer clay content. Together with literature data, a high correlation (R2 = 0.89) was found between adsorption and clay content. Significant correlation (R2 = 0.67) was found between distribution coefficient and clay content. The relationships developed may be used in modeling purposes

Elementary statistic for sciences with SPSS

With the widespread of availability of computers and statistical software and the application of quantitative methods in many fields of studies, introductory statistical course now emphasizes statistical reasoning more than computational skill development. Questions of how have given way to questions of why, when and what? The goal of this book is to enable users to work independently, learning software skills while coming to understand the underlying statistical concepts and techniques

Ethnic identity of young Malaysian adolescents in Sarawak

The study examined the ethnic identity of young Malaysian adolescents living in Sarawak from the aspects of their identification with their own ethnic group and their tolerance of ethnic diversity. The ethnic groups focused on were the Malay, Chinese and Indigenous groups of Sarawak. The development of ethnic identity of the adolescents was measured by means of Phinney’s (1992) multigroup ethnic identity measure. The data for the study were obtained from 1181 participants aged 13 to 17 in three urban and three rural localities in Sarawak. The results showed positive ethnic identity development for the group of adolescents under study, with frequent reports of affective behaviour towards their own ethnic group. However, this was not backed by up an equally strong display of ethnic behaviour such as using the ethnic language, practicing the life style of the ethnic group and interaction with members of the same ethnic group. A comparison by ethnic group revealed that the Indigenous participants had the strongest affiliation with their ethnic group, followed by the Malay participants, and the lowest was shown by the Chinese participants. The results suggest that the close proximity in social space for the adolescent Malaysians generates the conditions for them to construct notions of an ethnic identity that is hinged on the distinctiveness of their own ethnic group and interlaced with cultural elements of other ethnic groups

Phosphorus in batang ai hydroelectric dam Reservoir, Sarawak, Malaysia

Phosphorus is the nutrient that is responsible for eutrophication in reservoirs and lakes. Batang Ai Hydroelectric Dam Reservoir has been used for aquaculture for 20 years. However, little information is available on phosphorus concentration in the reservoir. Therefore, in this study, different forms of phosphorus were determined at six stations. Results shows that concentrations of total phosphorus depends on the season whereby rainy season and high water level showed lower concentrations (24.90-38.59 μg/L) than dry season and low water level (45.94-67.28 μg/L). In addition, during dry season, near the aquaculture station in the reservoir, higher total phosphorus (67.3 μg/L) but lower dissolved total phosphorus (23.90 μg/L) and higher organic fraction (25.55 μg/L) and lower dissolved organic fractions (9.74 μg/L) were observed. The second highest total phosphorus was located upstream in Batang Ai during wet season and it was high in organic form attributable to grey and black water and domestic animal waste. Outflow total phosphorus showed higher concentration during dry than wet season and it was much higher in dissolved organic form than dissolved reactive form. During dry season, outflow total organic phosphorus was twice the inflow but during wet season, the opposite was observe

Assessing water quality of Murum Reservoir halfway through impoundment

This paper reports the water quality of Murum Hydroelectric Reservoir, eight months after impoundment of the dam. A total of nine stations were selected in the reservoir. Temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD5), chlorophyll-a and total suspended solids (TSS) were studied. The results showed that the water was warmer at 0.5 m depth. As the depth increased, temperature in the reservoir decreased in the range of 4.40°C to 7.35°C from 0.5 to 20 m depth. The concentration of DO dropped to zero at 4 - 6 m depth leading to anoxic level. pH at 0.5 m depth ranged from 6.40 to 7.20 and they were significantly higher (p<0.05) than those at 10 and 20 m. Chlorophyll-a at 0.5 m were in the range of 4.61 to 20.50 mg/L, relatively higher compared to 10 m and 20 m depths. The results obtained indicates that impoundment of Murum River generally caused water quality deterioration. In addition, this could be due to anthropogenic activities such as plantation and logging activities that are still going on within the catchment during the impoundment. Therefore, further continuous monitoring and investigation is required to determine the long-term water quality condition and identify factors that influence water quality in Murum Reservoir

Treatment of domestic wastewater in Kuching City - ecological sanitation

In Kuching, partially treated black water from septic tanks and grey water are discharged into stonn water drains and subsequently into the rivers. Discharge from households was the main pollution source of the Sarawak River. The option of urban ecological sanitation was explored by the Sarawak Government. Ecological sanitation involves separating wastewater at source and recycling of the nutrients. A pilot project of ecological sanitation was implemented. Grey water from selected households were clmmeled to a grease trap and then pumped to biofilters before flowing through a constructed wetland with two species of ornamental plants before discharge. The objective of this study was to deternline the efficiency of the biofilters and the constructed wetland. Results of six months of sampling indicated that there was significant improvement in water quality in terms of dissolved oxygen (DO), total suspended solids (TSS), reactivephosphorus (RP), total-phosphorus (TP), anunonia-nitrogen (AN), total nitrogen (TN), biochemical oxygen demand (BODs), chemical oxygen demand (COD) and fecal coliform counts. The influent DO of below 1 mg/L improved to 3.4 - 4.6 mglL in the effluent. Removals of BODs and COD were the highest .with means of 99 and 95% respectively. Removal of nitrogen were also high, 86% (AN) and 81 % (TN) respectively. Total removal of TSS was 81 %. Removal of phosphorus, though not as high were 64 (RP) and 61 % (TP). The biofilter contributed most of the total removal especially organic matter (97% for BODs and 92% for COD) followed by nitrogen (78% for AN, 62% for TN) and then phosphorus (66% for RP and 61 % for TP). The wetland contributed 53% of total removal ofTSS and 22-41 % of nutrients and 46% of the total increase in DO. The fecal coliform count in the influent was reduced by 99 % after the biofilter treatment. In teffilS of BODs, COD and TSS, the effluent complied with the effluent standard A of Environmental Quality Act 1974 (Sewage and Industrial Effluents). Furthermore, WQI indicated that the effluent quality of water improved from Class V to Class II. Therefore, this cost effective method of urban sanitation is highly recommended

Hydrodynamic Modeling of a Tropical Tidal River Using the Dynamic Estuary Model (DYNHYD5): A Case Study in Sibu Laut River, Sarawak, Malaysia

Application of the Dynamic Estuary Model (DYNHYD5) in a tropical tidal river is limited. The successfully calibrated and validated hydrodynamic model is valuable in subsequent water quality simulation for environmental management. Hence, a hydrodynamic modeling approach using the DYNHYD5 was conducted in a tropical tidal river in Malaysia. Samplings were conducted in the Sibu Laut River to collect the hydrology data for model simulation. The model was calibrated and validated by comparing the simulated flow and mean depth with the field data at different simulation periods of time. The results showed that the model DYNHYD5 was successfully calibrated with channel flows and mean depths and then reproduced with good agreement in validation. The observed and simulated data were linearly correlated (R2 > 0.8) with values of slope γ ranging from 0.891 to 1.204 in both calibration and validation. The Nash–Sutcliffe coefficient of efficiency (NSE) of more than 0.7 in both calibration and validation also indicated satisfactory comparison between the observed and simulated data. The result indicated that the application of the DYNHYD5 is feasible in a tropical tidal river in Malaysia

Assessment of the characteristic of nutrients, total metals, and fecal coliform in Sibu Laut River, Sarawak, Malaysia

The concentrations of nutrients (nitrogen and phosphorus), total metals, and fecal coliform (FC) coupling with chlorophyll-a (chl-a), 5-day biochemical oxygen demand (BOD5) and other general environmental parameters were evaluated at the sub-surface and near-bottom water columns of 13 stations in the Sibu Laut River during low and high slack waters. The results indicated that inorganic nitrogen (mainly nitrate) was the primary form of nitrogen whereas organic phosphorus was the major form of phosphorus. The abundance of total heavy metals in Sibu Laut River and its tributaries was in the order of Pb\Cu\Zn\Cd. Fecal coliform concentration was relatively low along Sibu Laut River. The shrimp farm effluents contributed a substantial amount of chl-a, BOD5, nutrients, and FC to the receiving creek except for total metals. Nevertheless, the influence was merely noticeable in the intake creek and amended rapidly along Selang Sibu River and brought minimal effects on the Sibu Laut River. Besides, the domestic sewage effluents from villages nearby also contributed a substantial amount of pollutants