Correction to: Biochar efficiency in copper removal from Haplic soils The articles listed above were initially published with incorrect copyright information.

Handling different types of environmental monitoring fraud in multiple ways Abstract Environmental monitoring fraud has become a serious issue all over the world, in both developed and developing countries. A very different and more pernicious type of fraud was exposed in China. This is the first time that government officials but not enterprise managers and employees have been sentenced for environmental monitoring fraud. This event revealed that the types of environmental monitoring fraud are very different and complex in China, and the challenge to handling such frauds is more difficult and serious. The main drivers behind the frauds were analyzed. To avoid manipulation of monitoring data, it is necessary to develop and combine multiple strategies of administration, judiciary, and technology. More than anything, the management of the monitoring networks should be changed from the current “not only the referee but also the athletes” model. The issue of pollution cannot be fully addressed in a short period of time. However, it is necessary and reasonable to handle the monitoring data fraud immediately. The emphasis here should be on the authenticity of monitoring data, which is prerequisite to winning the war against heavy smog as well as other types of pollution.

Iron nanoparticle-modified water treatment residues for adsorption of As(III) and As(V) and their cement-based solidification/stabilization Abstract Sludge of tap water production was modified by iron nanoparticles via borohydride reduction in ferric chloride as an adsorbent for arsenic removal from contaminated water. Factors affecting the adsorption of As(III) and As(V) were studied. The maximum adsorption capacity was 24.2 and 35.7 mg/g for As(III) and As(V), respectively. The modified sludge with 10% (w/w) iron was effective for As(III) and As(V) removal from wastewater, surface water, and groundwater. The arsenic-contaminated sludge was stabilized/solidified using cement. The leaching study of arsenic by the dynamic monolithic leaching test (DMLT) showed that arsenic was mildly leached from the solidified adsorbent.

Optimization of process variables by the application of response surface methodology for dye removal using nanoscale zero-valent iron Abstract The study investigated the degradation and removal of Acid Red 114 (AR-114) and Basic Blue 41 (BB-41) as a model of azo dyes of aqueous solutions by using nanoscale zero-valent iron (NZVI). Both the size and the surface morphology of NZVI particles were specified by XRD and SEM techniques. The removals of AR-114 and BB-41 were studied at different experimental conditions, including catalyst amount, dye concentration, solution pH and the contact time. The removal parameters were modeled by response surface methodology. Given the low P value (< 0.0001), high F value (more than 85 for both dyes), R2 = 98.76% and Adj-R2 = 97.61% for AR-114 and R2 = 99.50% and Adj-R2 = 99.04% for BB-41 and nonsignificant lack of fit for both dyes. Given the ANOVA results, there is a positive relationship between the experimental and predicted values of the response. The results indicated that NZVI particles had removed more than 94% of both dyes under the optimum operational conditions. The optimum catalyst amount, dye concentration, pH of the solution and contact time were found to be 0.40 g, 4.00 mgL−1, 5.00 and 106.00 s, respectively, for AR-114 and those for BB-41 were 0.80 g, 9.00 mgL−1, 9.00 and 205.00 s, respectively.

Lignocellulose resources for the Myrothecium roridum laccase production and their integrated application for dyes removal Abstract In this study, the extracts of lignocellulosic materials such as sawdust, hay, and rapeseed press cake were used as medium for the production of laccase of the non-ligninolytic fungus Myrothecium roridum. Media prepared from hay extract and rapeseed press cake extract contributed to the highest quantity of the enzyme produced (ranging from 465 to 728 U/L after 24 h of cultivation). It could have resulted from the high content of reducing sugars and phenolic compounds such as gallic or ferulic acid identified in media by liquid chromatography coupled with tandem mass spectrometry. The enzyme was found to be stable in the pH ranging from 2 to 8 and decolorized up to 90% of Amaranth (400 mg/L) after 24-h incubation in the presence of a selected redox mediator. After 24 h of incubation, laccase almost completely (97%) decolorized the simulated dye effluent containing several dyes, metal ions, reducing agents, and detergents. An environment-friendly approach for dyes removal by laccase immobilized together with rapeseed press cake was proposed. After 24-h incubation of a dye (acid orange 7, trypan blue, and Amaranth) with laccase–rapeseed press cake alginate beads, more than 70% decolorization was obtained. The rate of Amaranth removal was found to be about 50% after five successive batches. Low-cost production and high decolorization efficiency in the presence of additional compounds make M. roridum laccase and its newly developed immobilization technique a promising option as a green catalyst for azo dyes containing wastewater treatment.

Novel reusable renewable resource-based iron oxides nanocomposites for removal and recovery of phosphate from contaminated waters Abstract Water pollution and purification are significant issues currently facing the world. Phosphorous is one of the pollutants which degrades water quality and is a cause of concern for eutrophication of water. This paper discusses the synthesis of a novel renewable resource-based nanocomposite, its use in phosphorus remediation, and its regeneration. The nanocomposite is synthesized from waste pine wood chips with stepwise chemical treatment. The synthetic method is environmental friendly and economically viable. Harmful chemicals are not used in the synthesis of the nanocomposite, which represents a significant shift from existing technologies. These nanocomposites are found to be useful for the removal of phosphate from contaminated waters, mainly agricultural wastes, mine drainage, and seawater. The superiority of using nanocomposites for adsorption is mainly associated with the positive charge as well as the presence of iron oxide nanoparticles on the surface of the media. Scanning electron microscopy and X-ray photoelectron spectroscopy were performed to determine the size and the elements present on the surface of the nanocomposite. Kinetic studies and adsorption isotherm were conducted which helped in proposing a mechanism for adsorption of phosphate on the media. Results indicate that phosphorus levels can be brought down from 1000 parts per billion to at least 10 parts per billion from stock solutions. The phosphorus could also be desorbed and the media regenerated for reuse at least 100 times without loss of phosphorus removal efficiency.

Removing toxic contaminants from groundwater by graphene oxide nanocomposite in a membrane module under response surface optimization Abstract A novel graphene oxide nanocomposite was investigated in a flat membrane module with cross-flow pattern for decontamination of water on optimization of the operating conditions. Response surface optimization methodology was followed in arriving at the best operating conditions. The best module performance in terms of flux and rejection was obtained at the optimum set of operating conditions comprising a pH of 8.0, operating pressure of 14 bars and an hourly cross-flow of 800 L. At the end of a 96-h run, the observed drop in flux was a negligible 3.4%. On rinsing and backwashing at the end of this period, the net drop could be limited to within 2%. The module succeeded in selectively removing 98.5% of arsenic, 96.7% of fluoride, 96–97% of iron and suspended solids from contaminated groundwater while permeating more than 79–81% of the useful calcium and 87–90% of magnesium minerals as desired in potable water. The study shows that if run under properly optimized conditions, a flat membrane module with cross-flow pattern and equipped with the graphene oxide nanocomposite can be a potential technology in producing healthy, tasty and non-toxic drinking water from contaminated groundwater even in the remote areas.

Biodegradation of 17-β-estradiol in water Abstract This study reports a potential biotechnical method of 17-β-estradiol removal in aquatic systems. The different bacterial strains isolated from sewage water samples were Bacillus sp., Enterobacter sp. I, Enterobacter sp. II, Klebsiellasp., Aeromonas veronii and Aeromonas punctate. These isolates were characterized on the basis of a single PCR reaction from the 5′ end of the PCR fragment to obtain > 700 bp of high-quality sequence. The adjoining lineages of each organism were obtained by BLAST searches. The identified bacterial species were incubated in a saline media under different concentrations of 17-β-estradiol in both aerobic and anaerobic conditions. The concentrations of CO2and 17-β-estradiol were measured by GC and HPLC, respectively. The percentage degradations of 17-β-estradiol in aerobic and anaerobic conditions were 100 and 91.56%, respectively, using Klebsiella and Bacillus species. The developed and reported method is an inexpensive, selective and economic. This method may be used to remove 17-β-estradiol in any water resource.

Biochar efficiency in copper removal from Haplic soils Abstract The main aim of the study was to examine the biochar efficiency in copper (Cu) ion removal from Haplic (Luvisol, Podzol) soils. In other words, the most effective biochar dose and the most favorable environment pH value were proposed. The copper removal was carried out based on the adsorption process. The results of kinetics measurements were modeled using Richie equation, whereas the adsorption isotherms using Langmuir–Freundlich and Dubinin–Radushkevich equations. The copper removal is a strongly pH-dependent process which is associated with variability of chemical Cu forms and various reactivities of organic molecules. The Cu adsorption amount was higher on silty Haplic Luvisol than on sandy Haplic Podzol mainly due to higher content of organic carbon, functional groups, clay and silt fractions as well as larger surface area. Moreover, the biochar addition increased linearly the soil surface charge and contributed to higher copper adsorption in the whole range of investigated ion concentrations. The higher the biochar dose added, the more Cu ions were adsorbed.

Application of low-density electric current to performance improvement of membrane bioreactor treating raw municipal wastewater Abstract The main objective of this study was to investigate the effect of low-density electrical current application on the performance of a laboratory-scale membrane bioreactor (MBR) treating municipal wastewater. The MBR operation was divided in two experimental runs: without (run I) and with electrocoagulation process (run II). The results demonstrated that the use of electrocoagulation process was beneficial for organic matter and nutrient removal, enabling the average removal efficiencies for COD, NH4+–N and PO43−–P of 98.5, 99.8 and 99.2%, respectively. Despite the decreasing of MLVSS/MLSS ratio during the period with electrocoagulation, both autotrophic and heterotrophic biomass activities have increased. Data from the 16S RNA genetic sequencing showed that the electric current application affected the nitrifying bacteria population, specially the genre Nitrospira, which exhibited a significant increase in its relative abundance. Such behavior probably occurred due to electrostimulation phenomenon that can improve microbial metabolism and increase cell growth. These results demonstrate that the electric currents application can improve the MBRs performance on wastewater treatment.