Removal of Different NOM Fractions from Spent Filter Backwash Water by Polyaluminum Ferric Chloride and Ferric Chloride

Advances on removal of organophosphorus pesticides with electrochemical technology

Widespread use of organophosphorus pesticides (OPs), especially superfluous and unreasonable use, had brought huge harm to the environment and food chain. It is because only a small part of the pesticides sprayed reached the target, and the rest slid across the soil, causing pollution of groundwater and surface water resources. These pesticides accumulate in the environment, causing environmental pollution. Therefore, in recent years, the control and degradation of OPs have become a public spotlight and research hotspot. Due to its unique advantages such as versatility, environmental compatibility, controllability, and cost-effectiveness compatibility, electrochemical technology has become one of the most promising methods for degradation of OPs. The fundamental knowledge about electrochemical degradation on OPs was introduced in this review. Then, a comprehensive overview of four main types of practical electrochemical technologies to degrade pesticides were presented and evaluated. The knowledge contained herein should conduce to better understand the degradation of pesticides by electrochemical technology, and better exploit the degradation of pesticides in the environment and food. Overall, the objective of this review is to provide comprehensive guidance for rational design and application of electrochemical technology in the degradation of OPs for the safety of the environment and food chain in the future.

A review on electrocoagulation process for the removal of emerging contaminants: theory, fundamentals, and applications

Electrocoagulation (EC) is an excellent and promising technology in wastewater treatment, as it combines the benefits of coagulation, flotation, and electrochemistry. During the last decade, extensive researches have focused on removal of emerging contaminants by using electrocoagualtion, due to its several advantages like compactness, cost-effectiveness, efficiency, low sludge production, and eco-friendness. Emerging contaminants (ECs) are micropollutants found in trace amounts that discharging into conventional wastewater treatment (WWT) plants entering surface waters and imposing a high threat to human and aquatic life. Various studies reveal that about 90% of emerging contaminants are disposed unscientifically into water bodies, creating problems to public health and environment. The studies on removal of emerging contaminants from wastewater are by global researchers are critically reviewed. The core findings proved that still more research required into optimization of parameters, system design, and economic feasibility to explore the potential of EC combined systems. This review has introduced an innovative collection of current knowledge on electro-coagulation for the removal of emerging contaminants.

Non-thermal plasma irradiated polyaluminum chloride for the heterogeneous adsorption enhancement of Cs+ and Sr2+ in a binary system

The natural ecosystem will continually deteriorate for decades by the leakage of Cs and Sr isotopes. The exploration of the new materials or techniques for the efficient treatment of radioactive wastewater is critically important. In this study, a dielectric barrier discharge (DBD) configuration was constructed to operate the non-thermal plasma (NTP). The NTP was incorporated into the synthesis of polyaluminum chloride (PAC) in two different procedures to intensify the synthesis of PAC (NTP-PAC) and enhance the further removal of Cs and Sr from wastewater. The employment of NTP in two procedures both had significantly changed the physicochemical characteristics of PAC materials, which facilitated the further adsorption application of NTP-PAC on the treatment of Cs⁺ and Sr²⁺. Different molecular, morphological, and adsorption characteristics were confirmed to the NTP-PAC materials. The heterogeneous adsorption of the NTP-PAC can be appropriately fitted by both the pseudo-first-order kinetic model and the Elovich model. Both physisorption and chemisorption reaction mechanisms were ensured for the heterogeneous adsorption of the NTP-PAC material towards Cs⁺ and Sr²⁺, which guaranteed the excellent adsorption performance of NTP-PAC materials compared to PAC. The electron collisions caused by NTP with alum pulp created highly reactive growth precursors and intensified the nucleation and hydrolysis polymerization of PAC. The employment of NTP explicitly broadens the reaction pathways between PAC and cationic contaminants in the aqueous environment, which expands the application area of PAC materials in environmental sustainability.

Effects of coagulant morphology and chemical properties on soluble reactive phosphate removal in corn ethanol wastewater

As ethanol production continues to rise around the world, and wastewater discharge requirements for phosphorus become more stringent, it is important that phosphorus removal technologies are evaluated on ethanol wastewater streams. In this study, five coagulating agents with distinct characteristics were evaluated for their soluble reactive phosphate (SRP) removal performance on both a synthetic wastewater sample and a wastewater sample collected from a corn ethanol manufacturer. All coagulants demonstrated a positive correlation between coagulant dose and percent removal of SRP on both samples. Alum and ferric chloride produced the highest SRP removal efficiencies on both the ethanol and synthetic wastewater, indicating that prepolymerized, high-basicity coagulants (e.g., aluminum chlorohydrate, poly-aluminum ferric chloride) are less effective for SRP removal than nonpolymerized coagulants. The background matrix analysis combined with the pH studies revealed that the high alkalinity in the ethanol wastewater has a substantial inhibitory effect on SRP removal capacity that supersedes pH effects. These experimental results suggest that the Al-Al and Al-OH bonds in the heavily hydroxylated and polymerized structure of high-basicity coagulants are very rigid, which could prevent inner-sphere complexation and drive a less effective outer-sphere interaction, thus hindering SRP removal efficiency. PRACTITIONER POINTS: Five different coagulants are evaluated for reactive phosphate removal from wastewater. Alum and ferric chloride show higher removal efficiency than prepolymerized and high-basicity coagulants. Optimal removal pH increases with increasing coagulant basicity.

Recent advances in thin film composites membranes for brackish groundwater treatment with critical focus on Saskatchewan water sources

Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations (pesticides, herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their sources. It is followed by a discussion of Saskatchewan's groundwater status and various issues. Furthermore, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented.

Experimental data for aluminum removal from aqueous solution by raw and iron-modified granular activated carbon

This dataset deals with the modification of granular activated carbon (GAC) with FeCl₃ under basic conditions (pH ≈ 12) for removal of aluminium (Al) from aqueous solution. The structural properties and operational parameters including Al ion concentration (2.15 and 10.3 mg/L), pH solution (2–10), adsorbent dosage (0.1–5 g/L), and contact time (0–10 h) was investigated for raw and modified GAC. This dataset provides information about Al removal by GAC and modified GAC at conditions including: pH = 8, contact time = 6 h, initial Al concentration = 2.15 mg/L. The characterization data of the adsorbents was analysed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) test. The data showed that Freundlich isotherm with and Pseudo second order kinetic model were the best models for describing the Al adsorption reactions. The acquired data indicated that the maximum adsorption capacity of GAC and modified GAC to uptake Al (C₀ = 10.3 mg/L) was 3 and 4.37 mg/g respectively.

Dataset on the cost estimation for spent filter backwash water (SFBW) treatment

The dataset presented in this article are related to the research article entitled “Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl₃ as a pre-treatment” (Ebrahimi et al., 2017) [1]. This article reports the cost estimation for treating produced spent filter backwash water (SFBW) during water treatment in Isfahan- Iran by various methods including primary sedimentation, coagulation & flocculation, second clarification, ultra filtration (UF) and recirculation of settled SFBW to water treatment plant (WTP) entrance. Coagulation conducted by PAFCl and FeCl₃ as pre polymerized and traditional coagulants. Cost estimation showed that contrary to expectations, the recirculation of settled SFBW to WTP entrance is more expensive than other method and it costs about $ 37,814,817.6. Versus the cheapest option related to separate primary sedimentation, coagulation & flocculation in WTP. This option cost about $ 4,757,200 and $ 950,213 when FeCl3 and PAFCl used as coagulant, respectively.

Dataset on the spent filter backwash water treatment by sedimentation, coagulation and ultra filtration

During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2–10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl₃) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCl used as coagulant).