All posts by simiecoind

Abstract:

Modern requirements to electroplating waste treatment necessitate development of technologies that would allow on-site recycle and reuse of both treated water and residuals of water processing. The most prospective option for introduction of recourse-saving wastewater purification is associated with application the method of ferritisation. In this connection, the paper presents an advanced ferritisation process for reduction of initial concentrations of heavy metals (HM) in exhausted nickel electroplating electrolytes from 100 mg/L to 0.3 mg/L. Effects of main technological parameters of such wastewater treatment at thermal and electromagnetic pulse methods of activation of the ferritisation process were determined experimentally. Kinetics of removal of nickel and iron ions from aqueous solutions was investigated. Phase compositions and properties of sediments from wastewater treated were studied. The sediments are predominantly characterised by crystalline nanostructures, ferromagnetic properties and chemical stability, supporting opportunities for their environmentally sound utilisation. Proposed comprehensive process for treatment of liquid industrial waste flows would prevent contamination by toxic effluents; ensure rational use of water, raw materials and energy inputs.

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Abstract:

In this research capability of biological treatment method via active sludge and aquatic fern evaluated in different operating conditions and they were optimized in order to remove Zn (II). A simple reactor performance for treatment of model and real wastewater on laboratory and semi-industrial scale was investigated. This refining process proceeded with special attention to the effect of solution pH-value, pollutant concentration, absorbent concentration and reaction time. The batch semi-industrial scale reactor represented over 90 % removal efficiency under pH-value of 6 and 5-5.5 for aquatic ferns and active sludge, respectively. Effective reaction times represented various durations for aquatic ferns and active sludge with respect of 120 minutes and 90 minutes. The two biological masses had the best performances with 6 g/l for aquatic ferns and 5 g/l for active sludge. In the presence of 5 ppm of Zn (II) as the objective heavy metal, both absorbents had over 93.2 % removal efficiencies. While obviously laboratory-scale attempts introduced higher acceptable reduction efficiencies via this economic applicable treatment method. Additionally, economic considerations clarified feasibility of this recommended simple method.

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Abstract:

Prior to discharge, high-loads wastewater needs intensive treatment, that can be carried out by physical, chemical or biological means towards discharge water quality. Extensive research has been carried out to identify solutions with reduced costs and high efficiencies. The paper presents the lab scale performance efficiencies of an innovative biological complex product obtained for the treatment of several samples (municipal wastewater, pig farm wastewater, wastewater from a restaurant’s grease removal tank). The experiments were carried out in laboratory bioreactors, the sample volume considered ranging from 1.5L to 4L depending on the waste water load and the number of simultaneous samples. Each sample was tested in parallel under similar conditions, the only varied parameter being the dissolved oxygen concentration. The results have shown that, under the tested conditions, the product contributes to pollutants degradation, with good efficiency for nitrogen ammonium and Kjeldahl nitrogen removal, managing to partially reduce the organic load. However, after 42 days of experiment, the effluent does not meet the sewage discharge conditions imposed by NTPA 002-H.G.352.

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Abstract:

Collagen production is generating wastewater with high organic loading. This type of wastewater is still containing valuable compounds that can be reused in other applications. In order to investigate the possibility to recover and reuse these compounds the membrane based processes were investigated. Four types of commercial available membranes were characterised and then used to recover the proteins. The results proved that membrane based processes represent a viable alternative to treatment of wastewater generated by collagen production facilities when recovery of valuable compounds is envisaged. It has to be stressed that on the other hand only membrane processes do not assure too reach the quality norms imposed by the legislation for treated wastewater discharge into sewerage systems or natural receivers. Therefore, when proteins recovery and reuse is wanted, the membrane processes represent only the first step of wastewater treatment and should be followed by biological processes in order to obtain the organic loading quality indicators required for wastewater treatment plants discharges.

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Abstract:

Mine water treatment scope is to produce an effluent which satisfies the discharge limits according to permits. However, the production of metal-rich sludge is a consequence of the mine water treatment and its disposal as a waste raises the cost of the whole operation, so ways to convert the sludge into marketable products are desirable. For example, mine water treatment sludge can be used for adsorbents or pigments production or some of the sludge components can be extracted and utilized as coagulants. Coagulants were obtained from mine water after partial precipitation of metal species or after conventional treatment, by leaching the sludge with acid. The effectiveness of coagulants considering phosphate, chemical oxygen demand and turbidity is presented in this paper, alongside with some of the drawbacks as observed.

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Abstract:

The piers can be placed on the spillway crest to hold the sluice gate for controlling the flow or support a service bridge. In addition, these piers to be placed on spillway body provide air entry to prevent negative pressure on the crest and eliminate the risk of cavitation. However, piers and abutments reduce the flow section area and it may cause increasing in reservoir water level. This contraction in the section varies depending on the thickness of the piers besides shape of the cross section. There are some theoretical methods in literature to calculate reduce in effective length of crest. In this study, experimental studies have been done on circular and square section bridge legs in laboratory environment. The results obtained from the studies showed that there are serious differences between experimental and theoretical calculations.

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Abstract:

Reducing the costs of wastewater treatment plants in the food industry is a necessity. Thus, it is necessary to find solutions to make their operation more efficient. The use of biogas obtained in the production process is a variant that leads to the increase of the profit at the whole plant level. This is how the Balance Scorecard model was used. The use of this model was based on non-financial indicators. These were: biogas quality and wastewater indicators from the UASB reactor that ensures biogas quality.

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Abstract:

This study presents an introduction in air revitalisation practice by using a microalgae-based biosystem. Althrough the study is developed in the light of space applications, it opens new horisons for implementing such systems for terestrial applications as well, where biotechnologies for addresing climate change and other issues associated with air pollution is in high demand. The experiments have been performed at laboratory-scale by using Arthrospira (spirulina) platensis as microalgae model. Influence of culture and illumination conditions, as well initial gas composition and other factors/techniques such culture filtration on the biosystem performance were investigated and the relevant results are presented and discussed. Based on the actual findings, future research needs are addressed.

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Abstract:

Classical methods used to remove pollutants from groundwater are known to be generally expensive and with a high potential to generate by-products or waste. In this respect, an increasing attention has been paid to obtaining, characterization and testing of new environment-friendly materials and technologies that can be successfully applied in groundwater treatment without a negative impact on them. The removal of nitrate, manganese and iron from groundwater using clean technologies is an example in this area. 

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Abstract:

Inventory of pesticide polluted sites in Republic of Moldova showed a huge number of high polluted sites and large pollution spectrum. The identified sites need effective remediation actions in order to diminish the risks for environment and public health. Some demonstration projects on the remediation technologies have been tested in the country.

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Abstract:

Climatic changes displayed through extremes (thermic or hydric) correlated with uncontrolled anthropic interventions exercised over time on land usages are the main factors that emphasize ecological and hydric disequilibrium from the South, East part of Romania. Specific of our country, the torrential precipitation regime generates rapid floods in mountain and hill areas. Torrential and land degrading processes occur on slopes and on the main hydrographic network as a result of torrential runoffs. Their consequences extend on a larger area than the one on which they occur. This happens especially as a consequence of perturbing the hydrological regime of water courses, generating floods in downstream areas or the cogging of accumulation lakes in periods with rain redundancies.
Forest protection cultures (forest vegetation) installed on degraded or overexploited agricultural lands from the hill and mountain areas represent the most efficient solution for attenuating the negative effects of climatic changes. This happens by steadily re-establishing the hydrological equilibrium, together with creating an ecological equilibrium that has positive effects on the soil and waters.
This paper emphasized the results of investigations realized in 2017 concerning the characteristics of forest protection cultures created on strongly and excessively degraded lands, followed by their hydrological and anti-erosion effects in the context of extreme meteorological phenomenon. As such, the runoff coefficient had values lower than 6.5% (from the total volume of precipitations in 24 hours), while the specific erosion was under 0.24 t/ha/an. The maximum charge of alluvium (erosion) produced by rain is of over 40 mm; their frequency and intensity has increased lately.

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Abstract:

The present study considered the use of a by-product from winemaking for the treatment of wastewater from hemp retting process. To evaluate if different obtained extracts of grape marc (BRE-extract of refrigerated grape marc, BUE-extract of dried grape marc, BLE-extracted of lyophilised grape marc, BLM-ultrasound soaked lyophilised grape marc, BLM fUS-soaked lyophilised grape marc, no ultrasound treatment) are feasible to be used for the wastewater treatment. The chosen parameters (pH, turbidity, dissolved oxygen and conductivity) were monitored over 14 days and it was observed that starting with day 8 the measured values for all parameters remained constant.

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Abstract:

The present paper presents the results obtained in the attempt of valorisation of the natural pigments obtained from vegetable wastes by considering the principles of the circular economy. For this purpose, was used the waste from different technological steps of food preparation (outer leaves, spine with seeds). The extracted pigments were used for the dyeing of cotton fabric that firstly was bioscoured and bleached. The results showed that the treated cotton fabric presents good properties (weight loss, hydrophilicity, whiteness and colour intensity K/S, etc.). This paper also addressed to the monitoring of the parameters for the wastewater resulted after the treatment of cotton fabrics with the studied pigments. The results showed that the wastewater from the dyeing proved to comply with the imposed limits for the wastewater according to the environmental standards.

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