Ablation with a Large Fractionof Solid Removal

Treatment of dairy wastewater with two-stage anaerobic sequencing batch reactor systems — thermophilic versus mesophilic operations

This research focused on the solid and nitrate removal efficiency in a solid digestion-denitrification column. The 20 L up-flow column consisted of 18 L acrylic column with 2 L down-comer inlet tube located in the middle. In the first part, the wastewater with high suspended solids from the Tilapia fish tank was applied into the sedimentation unit at 5 variable flow rates i.e., 11.25, 25.71, 60, 105.88 and 360 L/h. The results indicated that the flow rate of 11.25 L/h (0.57 m/h) gave the highest solid removal efficiency of 72.72% ± 8.24%. However, the total suspended solids removal was highest at 360 L/h (18.13 m/h). In the second part, methanol was added as an external organic carbon source for denitrification process in a hybrid column containing settled solids. The COD:N ratios of 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1 and 6:1 were investigated and compared with control without methanol addition. This experiment was operated at the HRT of 1 h with 450 L wastewater from recirculating aquaculture pond containing 100 mg-N/L sodium nitrate. The results indicated that the COD:N ratio of 3:1 gave the highest nitrate removal efficiency of 33.32% ± 21.18% with the denitrification rate of 5,102.88 mg-N/day.

Pollutants in aquaculture system effluent mostly originated from solid wastes including uneaten feed and excreta of cultured species. In this research, DAF(Dissolved Air Flotation) unit is suggested as an integrated solid control unit especially as a form of IIBG(Inline Injection Bubble Generation) process in aquaculture system. Solid removal performance of DAF unit was examined under various operation and salinity conditions with turbidity and suspended solid. Solid waste removal efficiencies were found to be affected by operation conditions including saturator pressure, recycle ratio, coagulant concentration. Solid removal efficiency was higher under higher saturator pressure and recycle ratio under which condition larger number of bubbles is generated. Coagulant is thought to have important role in creating bubble-particle aggregate by showing better removal efficiency with higher concentration. However higher saline water showed less effectiveness in removing solids by DAF(IIBG). Application of DAF(IIBG) process also showed additional effect in phosphate removal and DO(Dissolved Oxygen) supply. Phosphate existed in polluted water was removed up to 46% after treatment, which is thought to attribute to aluminium phosphate precipitation. And DO concentration was found to increase over 50% of initial saturation concentration after the injection of micro-bubbles. Through experiments on solid removal from aquaculture effluent, DAF(IIBG) process is estimated to be effective solid control method. This property can help aquaculture system being installed and operated simply and effectively.

Effluents generated in landfills are difficult to treat and require different forms of treatment to reach the necessary polishing for disposal. Leachate is usually treated in stabilization ponds where pollutants are significantly removed, but it might not be enough for disposal. Thus, we aimed at evaluating the applicability of the natural coagulant Tanfloc SG and the chemical coagulant PAC, with the addition of the anionic flocculation auxiliary polymer (PA), in the coagulation / flocculation processes as a post-treatment of landfill effluents. The tests were carried out by means of a jar test, with coagulant dosage ranging from 0 - 1,250 mg.L-1 and pH values ranging from 5 - 9, in three decantation times. The results showed that both Tanfloc SG and PAC are efficient in clarifying the effluents, even though they act well in different dosage values of coagulants and pH. The polymer dosage did not generate significant improvements in the variations of the variables studied, however, in some experiments it was shown to expand removal range in regards to some variables. The PAC coagulant showed to be efficient in the removal of suspended solids, dissolved materials, colloidals and humic substances, and Tanfloc SG acted mainly in the removal of solids.

Population growth has contributed to increasing poultry production, entailing a high waste loading, mainly poultry litter. One of the alternatives to treat such residues is anaerobic digestion, in which digester startup and generated-digestate quality are related to the material to be digested and to operation conditions, wherein inoculum use is one of the factors. This study therefore aimed to investigate how digestates, such as inocula, influence poultry litter (PL) anaerobic digestion, as well the reduction of solids and chemical oxygen demand (COD). For this, two inocula (bovine and swine digestates) were tested in the digestion process. The inocula were added at loads of 0.67, 1.00 and 1.67 gVS.L-1day-1. A split-plot design was developed and data underwent analysis of variance with means compared by the Tukey's test at 5% significance. Concerning bovine and swine inocula, it was concluded that both are indicated in the process. However, swine inoculum is better indicated because it had a better removal of total solids (TS), volatile solids (VS) and COD.

The 340 Complex is a less-than-90-day storage unit for mixed waste generated on the Hanford Site. The 340 Complex receives liquid waste from various buildings in the 300 Area via underground transfer lines, or by containers from generators supporting Hanford Site programs. The tanks used for waste storage at the 340 Complex include two 57 kiloliter tanks within the 340 Underground Storage Vault and six 30 kiloliter tanks within the 340A building. The two underground vault tanks provide primary waste storage while the six tanks in the 340A building provide reserve storage capacity. The 340A Building tanks are not equipped with agitation devices and/or equipment. Consequently, past usage of the tanks has resulted in the formation, deposition, and settling of waste water solids. The deposited tank solids contain radioactive material that represent a source of radiation exposure to workers. For as low as reasonably achievable (ALARA) purposes, the solids must be removed periodically from the tanks. The most recent tank solids removal effort occurred in the early 1980s. The removal of solids from the 340A building tanks constitutes a modification, in accordance with WAC 173-460-020(14), and, in accordance with WAC 173-460-040, the proposed activities are subject to New Source Review. In accordance with WAC 173-460 and WAC 173-400, this document serves as a Notice of Construction (NOC) for periodically removing solids from the 340A Building tanks.

Performance and bacterial diversity of bioreactors used for simultaneous removal of sulfide, solids and organic matter from UASB reactor effluents.

Chapter 20 - Gas-Solid Separations

A substantial part of urban surfaces is to some extent impermeable. Rainfall on these areas turns into runoff, which mobilises solids present on these surfaces. This runoff is removed from urban built areas by different type of drainage systems via gully pots. The objective of a gully pot is twofold, namely 1) to convey runoff to the drainage system with minimal hydraulic losses, while 2) to remove entrained solids to protect the downstream system. The continuous removal of suspended solids results in a growing sediment bed in the gully pot. This sediment bed can eventually reduce the hydraulic capacity of the gully pot and increase the probability of urban flooding due to rainfall. The increasing sediment bed also reduces the removal efficiency, which implies that more solids are transported to the downstream drainage system. Therefore, the objective of this study is to quantify the related processes, which are the build-up of solids on the street, the transport of solids to gully pots, and the removal of solids in gully pots. Which would assist the decision of the optimal cleaning interval of the sand trap. Four research questions have been formulated to meet the study objective: 1. What is the solids loading to gully pots in terms of mass and composition? 2. Does street sweeping reduce the solids loading to gully pots? 3. What is the removal efficiency of solids of a gully pot? 4. How do the in-gully-pot hydraulics influence the removal efficiency?

Floating faeces: Effects on solid removal and particle size distribution in RAS

Phosphorus contamination in water bodies is a major contributor to eutrophication, leading to algal overgrowth, oxygen depletion, and ecological imbalance. Conventional treatment methods, including chemical precipitation and synthetic adsorbents, are often limited by high operational costs, low biodegradability, and secondary pollutant generation. In this study, a cationic starch was synthesized through free radical graft polymerization of 3-methacrylamoylaminopropyl trimethyl ammonium chloride (MAPTAC) onto corn starch. The modified polymer exhibited a high degree of substitution (DS = 1.24), indicating successful functionalization with quaternary ammonium groups. Theoretical calculations using zDensity Functional Theory (DFT) at the B3LYP/6-311+G(d,p) level revealed a decrease in chemical hardness (from 0.10442 eV to 0.04386 eV) and a lower ionization potential (from 0.24911 eV to 0.15611 eV) in the modified starch, indicating enhanced electronic reactivity. HOMO-LUMO analysis and molecular electrostatic potential (MEP) maps confirmed increased electron-accepting capacity and the formation of new electrophilic sites. Experimentally, the cationic starch showed stable zeta potential values averaging +15.3 mV across pH 5.0–10.0, outperforming aluminum sulfate (Alum), which reversed its charge above pH 7.5. In coagulation-flocculation trials, the modified starch achieved 87% total suspended solids (TSS) removal at a low coagulant-to-biomass ratio of 0.0601 (w/w) using Scenedesmus obliquus, and 78% TSS removal in real wastewater at a 1.5:1 ratio. Additionally, it removed 30% of total phosphorus (TP) under environmentally benign conditions, comparable to Alum but with lower chemical input. The integration of computational and experimental approaches demonstrates that MAPTAC-modified starch is an efficient, eco-friendly, and low-cost alternative for nutrient and solids removal in wastewater treatment.

Practical implications of lowering dietary starch content on waste management in recirculating aquaculture systems operated with drum filtration or sedimentation in yellowtail kingfish (Seriola lalandi)

The evaluation of different alternatives for effective solids capture and removal in fish culture tanks of recirculating systems becomes important as the first mechanism to guarantee an appropriate wastewater treatment and their subsequent dumping or reuse. The main objective of this research was to evaluate during a month the apparent solids removal performance on 12 fish culture tanks of 250 L in a recirculating aquaculture system with four different drainage systems: D1-bottom perforated tube with lateral outlet and external stand pipe, D2-external stand pipe, D3-internal stand pipe, D4-double drainage, and three hydraulic detention time Q1, Q2 and Q3 equivalents to one exchange each 25, 50 and 82 minutes. The experiment was done with rainbow trout fries for an initial biomass of 1,6 kg/m3 feed daily at a rate of 3% of living weight, the parameters dissolved oxygen, temperature and pH were monitored. There were significant differences between tanks for drainages and hydraulic retention times, the best results were obtained for the D3-Q1, which combination reported an average solids removal efficiency of 88,02%, followed by the D1-Q1; the treatment with the lower efficiency was the made up by the D2-Q3.

Fenugreek mucilage for solid removal from tannery effluent

This research details the effects of ozone pretreatment on flux of a reverse osmosis membrane. Initial tests were conducted to determine the effects of ozonation on solids removal, turbidity, and chemical oxygen demand concentrations using various doses on a simulated surface water. These initial tests showed that the best reduction of solids in the 2–5 microns range was at 0.30 mg/L of ozone. Next, a series of bench scale tests was run for 62.5 hours using a standard reverse osmosis system under constant pressure with three pre-ozonation doses and a no ozone baseline dose. Temporal models were developed using the flux data from these tests to determine the effects of operating hours and ozone dosage on flux. It was found that the laboratory data were not linear and followed power law models. Statistical analysis was used to determine the significance of each ozone dose on the four developed models. The change in flux over the 62.5 operating hours with an ozone dosage of 0.30 mg/L showed the lowest flux change. Last, the models were tested using Hermia's filtration models and resistance versus time data to determine the type of membrane fouling that existed. It was concluded that the major fouling was pore blockage. This work demonstrated that ozone pretreatment is effective prior to use with reverse osmosis since it shows a better solid and organic removal rate as well as decreased flux and resistance changes over time.