Amount Of Suspended Solids Research Articles

Improving energy efficiency of electrochemical blackwater disinfection through sequential reduction of suspended solids and chemical oxygen demand

Onsite reuse of blackwater requires removal of considerable amounts of suspended solids and organic material in addition to inactivation of pathogens. Previously, we showed that electrochemical treatment could be used for effective pathogen inactivation in blackwater, but was inadequate to remove solids and organics to emerging industry standards. Further, we found that as solids and organics accumulate with repeated recycling, electrochemical treatment becomes less energetically sustainable. Here, we describe a pilot study in which concentrated blackwater is pretreated with ultrafiltration and granular activated carbon prior to electrochemical disinfection, and show that this combination of treatments removes 75-99% of chemical oxygen demand, 92-100% of total suspended solids, and improves the energy efficiency of electrochemical blackwater treatment by an order of magnitude.

Improving energy efficiency of electrochemical blackwater disinfection through sequential reduction of suspended solids and chemical oxygen demand.

Onsite reuse of blackwater requires removal of considerable amounts of suspended solids and organic material in addition to inactivation of pathogens. Previously, we showed that electrochemical treatment could be used for effective pathogen inactivation in blackwater, but was inadequate to remove solids and organics to emerging industry standards. Further, we found that as solids and organics accumulate with repeated recycling, electrochemical treatment becomes less energetically sustainable. Here, we describe a pilot study in which concentrated blackwater is pretreated with ultrafiltration and granular activated carbon prior to electrochemical disinfection, and show that this combination of treatments removes 75-99% of chemical oxygen demand, 92-100% of total suspended solids, and improves the energy efficiency of electrochemical blackwater treatment by an order of magnitude.

Why are Lake Abaya and Lake Chamo so different? A limnological comparison of two neighboring major Ethiopian Rift Valley lakes

Lake Abaya and Lake Chamo are the two largest Ethiopian Rift Valley lakes; they are located close to each other, but have a strikingly different water transparency. We explain key differences in the structure and the functioning of the food web with variation in limnological variables and major pelagic food web compartments within and across both lakes. Data from a detailed comparative investigation of physical and chemical variables and zooplankton community characteristics during the wet and dry season from two consecutive years revealed major differences in key limnological variables between Lake Abaya and Lake Chamo. The most pronounced differences were related to water transparency and the amount of suspended solids in the water column. Lake Abaya is much more turbid, has lower phyto- and zooplankton biomass, and has considerably lower primary production than Lake Chamo. Based on our results, we infer that the profound differences in food web structure between both lakes probably result from differences in sediment load. Finally, our results indicate that conservation programs should focus on reducing sediment inflow from the catchments into the lakes.

The characteristics of pollution in thebig industrial cities of Kazakhstan by the example of Almaty.

BackgroundEnvironmental pollution is a problem in the most industrial cities, including Almaty. These cities are frequently overpopulated and hazardous industrial facilities often have a negative impact on public health. The purpose of this study was to determine the characteristics of pollution in Almaty city and assess possible impact on a human by comparing obtained results with sanitary and hygienic standards. (Hygienic standards (HS) 2.1.7.2042–06. AAC of chemical substances in soil Russia). We used both local standards, such as ST RK 2011–2010 "Water, Food, Stern and Tobacco Products. Determination of Chlororganic Pesticides" and International Standards (Customs Union) Sanitary Regulations and Norms number 4630–88.MethodsThe study was conducted by sampling air, water, and soil and subsequently analyzing them via laboratory and instrumental methods.ResultsHeavy metals were detected via a high-precision method of atomic absorption spectroscopy. Noise was measured on location. Geographic regions with characteristic types of pollution were discovered. It was found that the main polluting factors were as follows: air pollution – carbon monoxide, suspended solids in the form of dust, lead, and noise; water – ammonium compounds, organic substances (assessed based on the chemical oxygen demand (COD) parameter), polychlorinated biphenyl (PCB); soil – lead and PCB. The amount of suspended solids in the air exceeded standard levels by as much as 13.6 times.ConclusionsWe visualized obtained data (using StatSoft Statistica v6.0 Rus and Exhibit 3.0 (MIT Simile Project) Softwares) for three districts of Almaty, which allowed us to compare the results efficiently. The results show the need for a detailed study on the optimization of the state of the environment and public health. Plans for further studies include development of a system that would enable reducing the negative impact of industrial facilities on public health and the environment in general.

Hydrothermal liquefaction of kraft lignin in sub-critical water: the influence of the sodium and potassium fraction

As a part of developing a hydrothermal liquefaction (HTL) process to valorise lignin, it is important to consider integration possibilities with existing infrastructures in order to obtain an overall positive economic impact. One obvious example is to integrate the HTL process with the kraft pulp mill: transport and storage costs is reduced, the temperature levels on process streams can be matched (energy integration) and the recovery/use of alkali can be made efficient. In this study, softwood kraft lignin was depolymerised using sub-critical water (623 K; 25 MPa) in a continuous, small pilot unit with a flow rate of 2 kg/h. ZrO2, K2CO3/KOH and Na2CO3/NaOH were used as catalytic system, and phenol as the capping agent. The influence of the ratio between sodium and potassium in the feed on the yield and composition of the product stream was investigated. The results showed that bio-oil, water-soluble organics (WSO) and char yields were not remarkably influenced by shifting the catalytic system from potassium to sodium. Moreover, the yields of most phenolic compounds did not change significantly when the sodium fraction was varied in the feed. The amounts of suspended solids in the bio-oil produced showed, however, a diminishing trend, (decrease from 10.8 to 3.8%) when the sodium fraction was increased in the feed, whilst the opposite trend was observed for the heavy oil, which increased from 24.6 to 37.6%.

ARSENIC AND TRACE METALS IN WATER AND SEDIMENT OF THE VELHAS RIVER, SOUTHEASTERN IRON QUADRANGLE REGION, MINAS GERAIS, BRAZIL

This work was undertaken in the Velhas River Basin, in the municipalities of Rio Acima, Nova Lima, Raposos and Sabara, upstream of the city of Belo Horizonte in Minas Gerais State, Brazil. Velhas River provides the public water supply for much of this region. The gold and iron mining activities in the Velhas River yield considerable amounts of suspended solids as well as metals to the hydrological system of the region. Thus, the present study sought to evaluate the concentrations of arsenic and trace metals in the waters and their distribution and mobility in sediment by BCR sequential extraction. Arsenic concentrations in the water samples were between 78.1 and 85.3 μg L-1, which exceeded 10 μg L-1 (maximum limit permitted by Brazilian environmental regulations for water destined to human consumption, CONAMA Resolution 357/2005). The sequential extraction of the sediment showed considerable amounts of As (20%), Cd (55%), Co (56%), Cr (16%), Cu (23%), Ni (29%), Pb (47%) and Zn (71%) associated with the geochemical fractions considered potentially available for the remobilization to the aquatic environment. The presence of the elements in these fractions indicated high ecotoxicological risk and potential harm to the health of the local population.

Response of suspended solids and dissolved nutrients in littoral zone of Lake Taihu under wind-wave disturbances

为研究风浪扰动下沉积物起悬过程中悬浮物浓度的分布特征和水体营养盐时空分布状况，以太湖西北湖滨带为例，选择代表4种不同生境的6个点位进行了连续12 d的野外观测.利用高精度分层同步采样装置，采用重量法计算悬浮量，并对悬浮过程中总磷（TP）、总氮（TN）、铵态氮（NH₄⁺-N）和硝态氮（NO₃^--N）浓度进行分析.结果表明：风速是引起太湖西北湖滨带水体悬浮物增加的主要因素，沉积物悬浮的临界风速为3.6 m/s.各点位悬浮物浓度的均值差异明显，表现为：无植被区 > 植被区 > 河口区 > 湖心区.太湖西北湖滨带水体氮、磷浓度日变化幅度较大，TN浓度为1.82~4.96 mg/L，TP浓度为0.10~1.47 mg/L.NH₄⁺-N和NO₃^--N浓度分别在0.09~2.83和1.05~3.69 mg/L之间波动.近岸无植被区水柱的总悬浮量与风速的相关性最好，相关系数达到0.722；而远岸湖心区与风速的相关系数仅为0.039.悬浮物浓度除了受风情（风向和风速）的影响外，同样受水深、地形特征和水生植被的影响.;To understand the spatiotemporal characteristics of suspended solid concentration and nutrients under different wind-wave conditions in the northwestern littoral zone, Lake Taihu, six sites representing four biotopes were investigated for twelve days. The quantity of suspended solids were calculated by gravimetric method and the contents of total phousphorus, total nitrogen, nitrate nitrogen and ammonium nitrogen were analyzed by the high-accuracy layered sampling apparatus. The results showed that the wind speeds were the major factor leading to the increase of the suspended solids in the western Lake Taihu littoral zone and the critical wind speed was 3.6 m/s. The mean concentration of suspended solids in each site was obviously different:non-vegetation areas > vegetation areas > estuary areas > open water areas. The diurnal variation of nitrogen and phosphorous contents were significant, with the total nitrogen of 1.82-4.86 mg/L and the total phosphors of 0.10-1.47 mg/L. The content of ammonium nitrogen was changed between 0.09-2.83 mg/L and nitrate nitrogen was 1.05-3.69 mg/L. In the nearshore non-vegetated areas, the correlation between the total suspended solids and the wind speeds was the strongest with the correlation coefficient of 0.722, while it was only 0.039 in the offshore areas. In addition to the influence of wind speeds, the concentration of suspended solids was also affected by the water depth, topography and aquatic vegetation.

Dissolved and suspended solids in aquaculture.

Abstract A few major ions contribute most of the weight of dissolved solids in water. Direct determination of total dissolved solids (TDS) concentration is tedious, and the electrical conductivity of freshwater and the salinity of saline water are common surrogates for TDS in aquaculture. The primary concern over dissolved solids is maintaining TDS concentration within a range that allows effective osmoregulation by culture species. There is usually more concern over TDS concentration in inland, saline water or brackishwater aquaculture than in freshwater aquaculture. The handheld salinity refractometer is used almost exclusively to measure the salinity of saline waters for aquaculture. Suspended solids comprise mineral soil particles, living microorganisms (especially phytoplankton) and decaying organic matter cause turbidity, and amount of suspended solids is usually assessed from water clarity as determined with a Secchi disk. Turbidity limits light penetration and restricts the depth to which photosynthesis may occur. Turbidity from suspended soil particles usually is a negative factor while plankton turbidity normally is a positive factor in fertilized ponds. Nevertheless, in fertilized ponds or un-aerated ponds with feeding, excessive plankton turbidity causes low nighttime dissolved oxygen concentrations. Turbidity from suspended soil particles may be beneficial by reducing light penetration for phytoplankton growth in mechanically-aerated ponds with feeding, but soil particles suspended by aeration settle creating zones of organically-enriched sediment. Such sediment may result in anaerobic areas from which microbial respiration releases toxic metabolites. Methods of managing dissolved and suspended solids and sediment are summarized.

Fabrication and Evaluation of Rotary Separator of Sesame Oil

Sesame seeds is one of the most important and oldest oily seeds used today in various industries. Sesame oil is also rich in protein substances, which is why it is considered as a quality and valuable oil. In this research, the effect of two angular velocity factors on three levels of 3500, 4500 and 5500 rpm and two levels of the radius, 175 and 125 mm was investigated in order to investigate on the quality of extracted sesame oil. In this experiment, the cylinder's time was selected for a constant test and equal to 5 minutes. The quality of the oil output from the device was evaluated by a pectometer method and the results were analyzed. The lowest and highest amount of suspended solids was obtained at a speed of 5500 rpm with a cylindrical radius of 175 mm and a velocity of 3500 rpm with a cylinder with a radius of 125 mm, respectively. The radius of the rotation and cylinder's angular momentum on the gross particles in the refined oil was significant at 1% level, but the effect of repetition on them was not affected. Also, the interaction between the angular velocity of the cylinder and the radius of cylinder are non-significant.

Aluminum electrocoagulation followed by forward osmosis for treating hydraulic fracturing produced waters

Forward osmosis is an emerging membrane based separation technology that could find niche applications in the treatment of oil and gas produced water. Here, the feasibility of treating hydraulic fracturing produced waters using a combined electrocoagulation (EC) and forward osmosis (FO) process has been investigated. EC is shown to be effective in removing suspended solids and organic compounds which foul the membrane during FO. The amount of suspended solids and organic compounds that are removed depends on the EC reaction time. By accounting for internal and external concentration polarization as well as fouling due to deposition on the feed side barrier surface of the FO membrane, the expected flux may be determined. The effectiveness of removal of suspended solids and organic compounds may be modeled as changes in the permeability of the foulant layer that develops on the feed side of the membrane. The results obtained for real produced waters from Southwestern Energy operations in the Fayetteville Shale indicate that combined EC and FO could be an effective method for water recovery from hydraulic fracturing produced waters.

Peculiarities of clarifiers’ reconstruction at waste water treatment plants

The article reveals the ways in which the reconstruction of clarifiers for wastewater treatment plant can be performed. One of the most common method is bioflocculation that means use of corresponding properties of excess activated sludge or biofilm, which both have in its composition so called extracellular biopolymers that determine the spatial structuring and bioflocculation of cell formations. Multiple researches showed that use of surplus sludge as bioflocculant provides increased efficiency of sedimentation in any waste water up to 85–90% and reduce biochemical oxygen demand (BOD) in the clarified water by 40–50%. The other method to be implemented for reconstruction of clarifying facilities is thin-layer modules to raise the efficiency of settling. Thin-layer modules can be used in a wide range of capacity of sewage works. The possibility of application depends on the structural size and condition of building structures, the amount of suspended solids and other parameters.

Removal of Dyes of Textile Rejects by Activated Carbon

The composition of wastewater from the textile industry varies enormously from one moment to another depending on the nature of the dyes used, the type of tissue, methods used and the concentration of added chemicals. In most cases the dye effluents are characterized by strong color, high temperatures, high and random values of pH, amounts of suspended solids and COD-concentrations close to the limit values set by the draft Moroccan standards.The study of turbidity indicates a variation between 120 and 190 NTU for the three samples. As for their conductivity varies between 5,2 and 20 mS.cm-1. Moreover their pH varies in the field of basic pH. Measuring the temperature of these three samples showed values varying between 25 and 30 ° C. The levels of suspended solids range between 146,8 and 514,7 mg L-1.The results show that the measured absorbance at 436 nm decreased to 2,020 A and it stabilizes at this value. To the absorbance of the color measured at 525 nm decreases to 3,072 A and it stabilizes. The absorbance measured at the wavelength 620 nm decreases and reaches a minimum value of 1, 918 A after ten hours.

Zirconium and chitosan coagulants for drinking water treatment – a pilot study

Scientists continuously search for alternative coagulants that would be able to outperform traditionally used aluminium (Al) and iron (Fe). Use of a novel metal coagulant zirconium (Zr) has been associated with enhanced organic matter reduction. On the other hand, eco-friendly non-metal solutions, such as chitosan, can provide non-toxic sludge and water with no metal residue. In fact, Zr and chitosan have been utilized in full-scale operation by several water plants in Norway providing over 50,000 recipients in small and large municipalities with drinking water. However, the use of these two agents is limited in other parts of the world. In the present work, Zr and chitosan coagulants were tested together with Al for drinking water production in both pilot and laboratory trials. All coagulants provided high quality effluents. However, the metals showed higher efficiencies in terms of reduction of humic substances, with better performance of Zr than Al. On the other hand, the amount of suspended solids in sludge produced with chitosan was 25% of the amount produced with metal salts. Chitosan also functioned over a broad pH range without affecting the pH of the treated water.

Effect of increasing organic loading rates on the performance of moving-bed biofilm reactors filled with different support media: Assessing the activity of suspended and attached biomass fractions

In this study, two moving-bed biofilm reactors (MBBR1 and MBBR2) filled with different carrier media (Kaldnes K1 and Mutag Biochip, respectively) were subjected to increasing organic loading rates for 700 days. Regardless of the carrier used, both systems could withstand high organic loads up to 3.2kgCOD/(m3d), condition under which complete ammonium removal was achieved. However, the type of media influenced the quantity and distribution of attached biomass in the support, which in turn affected the activity of specific microbial functional groups in the biofilm. As the chemical oxygen demand (COD) input was gradually increased, the biofilm got thicker and the surface detachment rates were enhanced. Consequently, the amount of suspended solids has increased considerably to levels commonly found in hybrid bioreactors. Activity batch tests have shown that the contribution of the bulk phase biomass to the overall nitrification was very significant, being more relevant as the biofilm sloughing events became more intense. At constant organic loading rate, the hydraulic retention time (HRT) had a noticeable impact on the nitrification process, as it directly influenced the fraction of ammonium oxidized either by the attached or suspended biomass. Total nitrogen removal amounted up to 86 and 73% in MBBR1 and MBBR2, respectively.

Characteristics of free cells and aggregated flocs for the flocculation and sedimentation of activated sludge

Laboratory experiments were conducted to investigate the correlation of the free cells/aggregated flocs characteristics and the sludge flocculation and separation behavior during the activated sludge process. Activated sludge was cultured in three laboratory-scale batch reactors with same carbon sources of glucose but different sludge retention times (SRTs) of 5, 10 and 20 days. The variation in the operation condition produced sludge with different flocculation and separation characteristics. The reactor performance in terms of bioflocculation as measured by the amount of suspended solids in the effluent, sludge sedimentation and compression as measured by the sludge value index improved considerably as the SRT lengthened. The higher SRT was related to less negatively charged surface of free cells and more hydrophobic of aggregated flocs. The negative zeta potential of aggregated flocs (11–13 mV) was smaller than that of free cells (15–23 mV), and free cells carrying lesser negative surface charges resulted in effluent clarification. Hydrophobicity of aggregated flocs (10–17 %) in each reactor was higher than that of free cells (5–8 %). The increase in hydrophobicity of aggregated flocs had positive effect on settleability. Floc strength measured by breakage/erosion index was closely related to hydrophobicity of aggregated flocs, but no correlation could be established with zeta potential of aggregated flocs. In addition, different bacterial species existed in free cells and aggregated flocs. Microbial similarity between free cells and aggregated flocs increased with shorter SRT and was closely related to effluent clarification.

Megacities Land Drainage and Land Runoff Features and Treatment

The land runoff of major cities is a significant factor in pollution of the hydrosphere. Sorption-filtration treatment technology of large volumes of water runoff most cost-effective, it is as deep purification technology. Their application in the complex composition of runoff from urban areas gives the best results in combination with the technology pre-separation main quantity of suspended solids and emulsified oil products in different kinds of traps and sumps.

SEDIMENTOS DE FUNDO E EM SUSPENSÃO NO CORREDOR FLUVIAL DO RIO PARAGUAI, PANTANAL NORTE MATO-GROSSENSE, BRASIL

To understand the variation of solid and liquid discharges during flood and drought periods, the present study aimed to analyze the types of sediments transported on the Paraguay River - the upstream in the city of Caceres (MT). The methodology consisted of collections of bottom and suspended sediments, flow monitoring and laboratory analysis with pipetting/screening and evaporation. The flow values ranged from 615,12 m³/s-1 to 135,74 m³/s-1 on the Paraguay River and from 62,28 m³/s-1 to 0,71 m³/s-1 at the entrance of the Long Bay with 56,61 m³/s-1at the exit of the Long Bay. Concerning to the average depth it was recorded a maximum of 4.73 and minimum of 0.10m. The bottom sediments showed higher sand volume (concentration above 70 %) with the presence of silt and clay. The volume of suspended solids on the Paraguay River ranged from 15412.44 tons/ day and 2111.02 tons/day. It was registered 1076.08 tons/day and 978.22 tons/day of suspended solids at the entrance and the exit of the channel of the morphological feature in the rainy season. It should be emphasized that the results of flow were higher than the historical average (1966-2002) and the values of the bottom sediments were similar to those obtained by Silva et al. (2008). The study proved relevance for the particle size characterization of the bottom sediments, and estimate of the quantity of suspended solids carried by the Paraguay River to morphological features of the floodplain. Key words: seasonality, siltation, channel abandonment.

Dynamics of metal ions in suspended sediments in Hugli estuary, India and its importance towards sustainable monitoring program

Summary Metal contamination in a river has often been assessed based on total metal ion concentrations without relating them with the amount of suspended solids. This approach masks lot of important dynamics of metal ions in water. This is first time in India, a study has been undertaken to present how the level of metal ions in river water is influenced by suspended solids in response to spatial and seasonal conditions in Hugli estuary, India and to focus necessity of harmonizing science and policy. This study presented extent of metal pollution and distribution pattern over the stations, seasons, tides and depth. Major fraction of metal ions is associated with suspended sediments and discharges into the largest alluvial fan, Bengal fan, in the world. Enrichment factors indicated that major source of metal contamination is large influx of sediment due to strong natural activities and moderate anthropogenic activities over the years strong seasonal change, variable tidal energy level and irregular estuarine geometry play crucial role in maintaining metal concentrations in water column. Findings of this study would help to refine existing monitoring practice and to understand its importance in water quality management.

Integrated Membrane Bioreactor for Water Quality Control in Marine Recirculating Aquaculture Systems

The aquaculture live feed organisms Acartia tonsa (a calanoid copepod, experiment 1) and Brachionus “Cayman” (a rotifer, experiment 2) were cultivated in marine recirculating aquaculture systems (RAS), respectively. The pilot plant was built as a combination of conventional RAS (cRAS) and as a modified RAS which implemented an ultrafiltration membrane bioreactor (MBR) for the removal of fine suspended solids and colloidal particles as part of the treatment system (mRAS). The two treatment schemes were connected to the same biofilter (a moving bed bioreactor). In the first experiment, the membrane was operated with no extraction of concentrate, and hydraulic retention time (HRT) of 6 hours (i.e., water exchange in the cultivation tanks of 4 times per day). In the second experiment, the membrane was operated with daily extraction of concentrate, and HRT of 12 hours. Results show that the MBR option is more efficient in removing particles from the recycle stream than conventional RAS. However, the impact this has on the number of particles in the live feed cultivation tanks is not readily apparent based on particle analysis. The amount of suspended solids added during feeding exceeds the amount removed in the recycle system. This requires a higher recirculation rate and different membrane operating conditions.

Properties of Heat Treatment Alkaline Pulping Black Liquor with Aluminum Chloride

The black liquor contains a large amount of suspended solids, organic pollutants and toxic substances, the black liquor discharged directly into water bodies will lead to serious pollution. So we regards the alkaline pulping black liquor as a research object, using autoclave to heat the mixture of aluminum chloride and soda black liquor lignin. By changing the heating temperature and the pH before the heat treatment, we analyze the lignin and carbohydrates in the cooking liquid to study cleavage situation and the corresponding structural changes. The results show that the lignin content accompanied the increase in temperature, organic matter content decreased and part of the decomposition of organic matter. Without adjusting pH, the lignin content is small and ash (inorganic) content is higher.