Modelling the Effects of Nanomaterial Addition on the Permeability of the Compacted Clay Soil Using Machine Learning-Based Flow Resistance Analysis

Impermeable base layers that are made of materials with low permeability, such as clay soil, are necessary to prevent leachate in landfills from harming the environment. However, over time, the permeability of the clay soil changes. Therefore, to reduce and minimize the risk, the permeability-related characteristics of the base layers must be improved. Thus, this study aims to serve this purpose by experimentally investigating the effects of nanomaterial addition (aluminum oxide, iron oxide) into kaolin samples. The obtained samples are prepared by applying standard compaction, and the permeability of the soil sample is experimentally investigated by passing leachate from the reactors, in which these samples are placed. Therefore, Flow Resistance (FR) analysis is conducted and the obtained results show that the Al additives are more successful than the Fe additive in reducing leachate permeability. Besides, the concentration values of some polluting parameters (Chemical Oxygen Demand (COD), Total Kjeldahl Nitrogen (TKN), and Total Phosphorus (TP)) at the inlet and outlet of the reactors are analyzed. Three different models (Artificial Neural Networks (ANN), Multiple Linear Regression (MLR), Support Vector Machine (SVM)) are applied to the data obtained from the experimental study. The results have shown that polluting parameters produce high FR regression similarity rates (>75%), TKN, TP, and COD features are highly correlated with the FR value (>60%) and the most successful method is found to be the SVM model.

Post-Treatment of Kennel Wastewater With Different Aeration Strategies

The objective of this study was to evaluate the effect of the introduction of a complementary aerobic treatment composed of a submerged aerated biological filter (SABF) with a secondary clarifier (SC), followed by horizontal subsurface flow constructed wetlands (CWs), after anaerobic units, on the ability to remove pollutants in different aeration phases (Ph1, Ph2, and Ph3) at the effluent treatment station of the Parque Francisco de Assis (PFA) dog shelter. Ph1 and Ph2 had 7 and 5 hours of daily aeration, respectively, and Ph3 had intermittent aeration every 2 hours. The phases were monitored regarding the removal efficiency of organic matter, solids, nutrients (N, P), coliforms, and detection of Giardia and Cryptosporidium. It was found that post-treatment provided greater removal efficiencies and that the aeration strategy of Ph3 showed mean efficiencies of 71% for COD removal and 77% for BOD removal, being similar or statistically higher, even with less biodegradable effluent, than those of Ph1 and Ph2. The SABF and SC removed N by nitrification and denitrification, leaving a total Kjeldahl nitrogen (TKN) concentration in the effluent of 18 mg L−1. The CW showed potential for simultaneous nitrification and denitrification (SND), in addition to solid filtration. The system did not satisfactorily remove thermotolerant coliforms (ThermC) (1 ± 0 log). PCR suggested the presence of the pathogens Giardia and Cryptosporidium in all post-treatment units in Ph1 and Ph2.

The Effectiveness of Seaweeds as Biofilter for Reducing Wastewater Nutrient and Preventing Water Pollution from Hybrid Grouper Culture

Highlight ResearchWastewater in hybrid grouper culture should be maintain before resirculate and dispose to aquatic environment to avoid eutrophication.Seaweed that is used for biofilter must be observed for its suitability, performance and effectivity.Ulva sp. has the best effectiveness to reduce nutrient in wastewater of hybrid grouper aquaculture by absorbing then stored into thallus.Ulva sp. is proven has the best SGR and adaptability in wastewater of hybrid grouper culture.AbstractWastewater generated from hybrid grouper culture needs to be managed to improve water quality before being recirculated, or discharged in the aquatic environment. Seaweed biofilter has been proposed in wastewater treatment technology for marine fish farming. This study aimed at comparing which of these species i.e. Ulva sp., Sargassum sp., Gelidium sp., and Dictyota sp. work best to absorb nutrient wastewater hybrid grouper culture. This research utilized these seaweed as treatments and controls with three replications using Completely Randomized Design. A statistical analysis was conducted to investigate the significant differences in the nutrient absorptions among various seaweed species by using ANOVA and least significant difference. Non-parametric tests namely Kruskal-Walis, Mann-Whitney, and t-test were used with confidence interval of 95%. The results revealed that Ulva sp. has the best ability to reduce the Nitrogen 80%, while Dictyota able to reduce Phosphor 88% by Dictyota sp. generated from wastewater of hybrid grouper culture. While the highest absorbtion of Total Kjeldahl Nitrogen (104%) and phosphate (182%) that stored in thallus were performed by Ulva sp. Ulva sp. had the best performance and highest growth rate (1.9% d-1) as biofilter in hybrid grouper cultivation than other species.

Multi-Scale Analysis of the Dependence of Water Quality on Land Use Using Linear and Mixed Models

Land use influences water quality in streams at different spatial scales and varies in time and space. Water quality has long been associated with agricultural and urban land uses in catchments. The effects of developed, forest, pasture, and agricultural land use on nitrogen, nitrate, and nitrite (NNN); total phosphorus (TP); total suspended solids (TSS); chemical oxygen demand (COD); dissolved oxygen (DO) and total Kjeldahl nitrogen (TKN) concentrations and their sensitivity were quantified to spatial pattern differences. The linear mixed modeling framework was used to examine the importance of spatial extent on models with water quality parameters as the response variable and land use types as the predictor variable. The results indicated that land use categories on different water quality parameters were significant and dependent on the selected spatial scales. Land use exhibited a strong association with total phosphorus and total suspended solids for close reach distances. Phosphorus is not highly soluble, and it binds strongly to fine soil particles, which are transported by water via runoff. Nitrogen, nitrate, and nitrite, dissolved oxygen, chemical oxygen demand, and total Kjeldahl nitrogen concentrations were better predicted for further reach distances, such as 45 or 50 km, where the best model of nitrogen, nitrate, and nitrite is consistent with the high mobility of NO3−.

Effects of Partial Saturation on Nitrogen Removal and Bacterial Community in Vertical-Flow Constructed Wetlands

The laboratory-scale pilot of constructed wetlands has been in operation for six months; (1) an unsaturated vertical flow constructed wetland (UVF-CW), this system was used to represent the classic vertical constructed wetlands, (2) a saturated vertical flow constructed wetland (SVF-CW), to evaluate the effects of the saturated condition on nitrogen removal and composition of the microbial community. The results showed that the saturation condition positiveley influenced the removal efficiencies of the nitrogen,, the aeverage removal rate of the total kjeldahl nitrogen increased from 56% in unsaturated vertical flow constructed wetland (UVF-CW) to 63% in saturated vertical flow constructed wetland ( SVF-CW). In addition, the microbial communities also was affected by the saturation condition, the relative abundances of nitrifying bacterium in UVF-CW are 13.8% (Nitrosomonas), 7.2% (Nitrosospira), 18.1% (Nitrospira) and 15.3% (Nitrobacter). In contrast, in SVF-CW, Nitrosomonas, Nitrosospira, Nitrospira and Nitrobacter only accounted for 6.8%, 5.6%, 7.4% and 10.6% respectively. However, the saturation condition seemed to increase denitrifying bacterium more than three times, in unsaturated vertical flow constructed wetland, only Pseudomonas (6.5%) and Paracoccus (4.85%) were detected, but in saturated vertical flow constructed wetland (SVF-CW), the abundance of Pseudomonas (13.08%) and Paracoccus (9.74%) were increased, and three other groups of denitrifying bacteria were also detected as Zoogloea (3.32%), Thauera (5.41%) and Thiobacillus (3).

PENCIRIAN TEMPORAL SKALA KECIL AIR SISA DOMESTIK PERBANDARAN

Sewage treatment plants (STP) in Malaysia are designed to treat a load of contaminants according to the level of concentration for chemical oxygen demand (COD) and nitrogen ammonia (NH3-N) of 250 mg/L and 30 mg/L, respectively. However, studies show that the organic load of Malaysian wastewater is low and even temporarily fluctuates resulting in the low effectiveness of treatment especially in ammonia removal and consequently cause effluents that do not undergo proper treatment to be released into the environment. Therefore, this study aims to identify concentrations of COD and NH3-N in the influent of urban domestic wastewater along with other physico-chemical characteristics. Two locations of the STP were chosen based on the urban area with different catchment sizes for a population equivalent (PE) 60,000 for the first STP (LRK#1), and 150,000 for the second STP (LRK#2). These parameters include pH, temperature, conductivity, turbidity, total suspended solids (TSS), nitrogen nitrate (NO3-N), total Kjeldahl nitrogen (TKN) as well as heavy metals such as Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), and Zinc (Zn). The sampling and analysis methods used the guidelines recommended in the American Public Health Association (APHA). The results give the highest average COD concentrations for the LRK#1 and LRK#2 are 180.5 mg/L and 380.9 mg/L, respectively. The highest NH3-N concentrations were 33.53 mg/L for LRK#1 and 31.63 mg/L for LRK#2. Overall, the wastewater physico-chemical characteristics of both treatment plants show wastewater in the medium and low concentration categories.

Reducing Pollution of Stabilized Landfill Leachate by Mixing of Coagulants and Flocculants: A Comparative Study

The physico-chemical process of coagulation-flocculation is very efficient and economical for the treatment of leachate. The latter can have considerable impacts on the environment. The leachate from the landfill of the city of Mohammedia is characterized by a high COD content which varies between 2200 and 2700 mg/l, a total Kjeldahl nitrogen concentration varying from 1080 to 1405 mg/l while the ammonium content has a concentration varying between 587 and 1410 mg/l. Organic matter is not readily biodegradable (BOD5/COD: 0.2 to 0.13). Metal concentrations ranged from 0.1 to 4.2 mg/l for Cr, 40 to 5 mg/l for Cd, and 0.3 to 0.8 mg/l for lead. For monitoring the leachate treatment, several coagulants and flocculants were used (FeCl3, Al2(SO4)3, Alginate, cationic flocculants, anionic flocculants). In parallel with the monitoring of the physicochemical parameters we followed the production of the volume of the settled sludge over time. Treatment with all coagulants and flocculants used is pH dependent. Ferric Chloride has been shown to be effective at a pH of 6.5 while for Aluminum Sulfate the optimum pH is 5.3. The results showed that coagulation-flocculation by Ferric Chloride and Aluminum Sulfate is very effective in reducing turbidity. This reduction reaches 95 and 98% respectively for FeCl3 and Al2(SO4)3, while the reduction in COD for the two coagulants is around 60%. Organic flocculants alone do not lead to a significant reduction in turbidity and COD, while their combination with coagulants marks a good reduction in pollution. Hydrated iron hydroxides precipitate more easily than flocs formed by aluminum, resulting in more efficient removal of pollutants than that obtained at lower pH values. The order of introduction strongly influences the coagulation flocculation. The optimal doses of the various coagulants and flocculants chosen for the study vary from one reagent to another. FeCl3 remains the most suitable coagulant to further eliminate organic and metal pollution. The cost associated with the treatment using flocculants remains much higher when the flocculant is used in admixture with a coagulant.

Effects of Packing Media and the Insertion of Vegetation on the Performance of Biological Trickling Filters

The use of the plant Chrysopogon zizanioides (vetiver), able to develop under adverse conditions while removing a great number of pollutants, in constructed wetlands (CWs) is widely reported. Regarding the biological trickling filters (BTFs), the selection of the media is one of the most important factors in its performance. We investigated whether the addition of vegetation improves the efficiency of the basic parameters of BTFs with gravel. In addition, due to the properties of light expanded clay aggregate (LECA), we evaluated whether the support media composed of vetiver and LECA is able to increase the media’s oxygenation. The efficiencies were 39, 49, 56, and 49% for biochemical oxygen demand (BOD) and 27, 20, 12, and 31%, for total Kjeldahl nitrogen (TKN) in BTFLV (vetiver with LECA), BTFL (LECA only), BTFGV (vetiver with gravel) and BTFG (gravel only), respectively. LECA when associated with vetiver may have provided higher aeration of the filter, denoted by the higher nitrate effluent concentration (0.35, against 0.03, 0.06, and 0.10 mg L−1 for BTFL, BTFGV, and BTFG). Vetiver had no improvement on BTFs performance concerning BOD. However, associated with LECA, its use could be viable to remove dissolved forms of nitrogen.

Alteration of Spatial Pollution Compounds to Eutrophication Phenomenon of Small-Scale Area under Corona Virus Disease Circumstances

This research aims to study the alteration of spatial pollution compounds to the eutrophication phenomenon in water resources during the COVID-19 situation. Sixteen water resources were monitored to examine the impact of spatial pollution compound on eutrophication phenomenon discovered from the activities of the Valaya Alongkorn Rajabhat University under the Royal Patronage. The analytical parameters were DO, nitrite (NO2-), nitrate (NO3-), ammonia (NH3), phosphate (PO4-), and Total kjeldahl nitrogen (TKN) collected in three months (November 2020, January 2021, and March 2021). This research has presented the differences in water resource characters in three months and the positive impact of the COVID-19 lockdown on wastewater. The total nitrogen was highest in November 2020 when compared with that of in January and March 2021 because it was a ‘normal situation’ (no lockdown) in November. The student, officer, lecturer, and government visitors came to use the facilities of the university. The results of total kjeldahl nitrogen showed a high range during the working period. The effect of P was higher on the water bodies in November than January and March because in November was a normal situation (no lockdown). The N:P ratio showed different trends to the eutrophication phenomenon with nitrogen and phosphate. Therefore, a comparison between a situation with lockdown and no lockdown showed that the lockdown situation was environment friendly. Finally, the results also confirm an improvement in environmental quality, which happened when humans were absent, especially in coronavirus circumstances.

Nutrient Concentrations in Macrophytes from Lotic and Lentic Environments of the Middle Parana River, Argentina

Objectives: The purpose of this work was to compare nutrient concentrations in water, sediment, and in plant tissues of Eichhornia crassipes and Panicum elephantipes from lotic and lentic environments of the Middle Parana River floodplain (Argentina). Materials and Methods: The study was carried out over an 18-month period. Plants, water, and sediment were collected in a lake (lentic environment) and in a river (lotic environment) from the Middle Parana River floodplain. Water and sediment were sampled in sites where P. elephantipes or E. crassipes were predominant and in sites without vegetation. Results and Discussion: The lentic and lotic environments dominated by E. crassipes showed the highest ammonium concentrations. The sediment from the lotic environment showed total phosphorus (TP) and total Kjeldahl nitrogen (TKN) concentrations significantly lower than those found in the sediment from the lentic environment. In the lentic environment, the sediment from the lake with the dominance of E. crassipes showed the highest TKN concentration, while the sediment from the lake dominated by P. elephantipes showed the highest TP concentration. For both plant species and for both environments, TKN and TP tissue concentrations were significantly higher in leaves in comparison with roots. Conclusions: Our results could be used to optimize the efficiency of treatment wetlands. Additionally, the use of locally available macrophytes as contaminant bioaccumulators in the Middle Parana River floodplain is completely feasible.