Use of reclaimed municipal wastewater in agriculture: Comparison of present practice versus an emerging paradigm of anaerobic membrane bioreactor treatment coupled with hydroponic controlled environment agriculture.

Advancements in anaerobic membrane bioreactor (AnMBR) technology have opened up exciting possibilities for sustaining precise water quality control in wastewater treatment and reuse. This approach not only presents an opportunity for energy generation and recovery but also produces an effluent that can serve as a valuable nutrient source for crop cultivation in hydroponic controlled environment agriculture (CEA). In this perspective article, we undertake a comparative analysis of two approaches to municipal wastewater utilization in agriculture.

Lead (Pb) deposition onto new and biofilm-laden potable water pipes.

Heavy metals' interactions with plumbing materials are complicated due to the differential formation of biofilms within pipes that can modulate, transform, and/or sequester heavy metals. This research aims to elucidate the mechanistic role of biofilm presence on Lead (Pb) accumulation onto crosslinked polyethylene (PEX-A), high-density polyethylene (HDPE), and copper potable water pipes. For this purpose, biofilms were grown on new pipes for three months.

Managing and treating per- and polyfluoroalkyl substances (PFAS) in membrane concentrates.

Per- and polyfluoroalkyl substances (PFAS), which are present in many waters, have detrimental impacts on human health and the environment. Reverse osmosis (RO) and nanofiltration (NF) have shown excellent PFAS separation performance in water treatment; however, these membrane systems do not destroy PFAS but produce concentrated residual streams that need to be managed. Complete destruction of PFAS in RO and NF concentrate streams is ideal, but long-term sequestration strategies are also employed.

Dynamic Modeling of Fouling in Reverse Osmosis Membranes.

During reverse osmosis (RO) membrane filtration, performance is dramatically affected by fouling, which concurrently decreases the permeate flux while increasing the energy required to operate the system. Comprehensive design and optimization of RO systems are best served by an understanding of the coupling between membrane shape, local flow field, and fouling; however, current studies focus exclusively on simplified steady-state models that ignore the dynamic coupling between fluid flow, solute transport, and foulant accumulation. We developed a customized solver (SUMs: Stanford University Membrane Solver) under the open source finite volume simulator OpenFOAM to solve transient Navier-Stokes, advection-diffusion, and adsorption-desorption equations for foulant accumulation.

Understanding the Role of Pattern Geometry on Nanofiltration Threshold Flux.

Colloidal fouling can be mitigated by membrane surface patterning. This contribution identifies the effect of different pattern geometries on fouling behavior. Nanoscale line-and-groove patterns with different feature sizes were applied by thermal embossing on commercial nanofiltration membranes.

Membrane adsorption with polyacrylonitrile prepared with superfine powder-activated carbon, case study: separation process applied in water treatment containing diclofenac.

Polyacrylonitrile membranes (PAN) have high stability against chemical agents, making them suitable for a wide range of applications as such Ultrafiltration processes. Ultrafiltration membranes composed of PAN/Superfine powder activated carbon (S-PAC) mixtures can be a good research route, aiming the development of a new separation processes for water treatment. The association of materials to form a single product can have technological and economic advantages in separation processes.

Adsorption kinetics of synthetic organic contaminants onto superfine powdered activated carbon.

Superfine powdered activated carbon (S-PAC) is an adsorbent material with the promise of properties that allow for rapid adsorption of small molecule contaminants. To explore the potential for rapid adsorption among varying activated carbon types, seven commercially available activated carbons were obtained and pulverized to produce S-PAC particles less than 1 μm in diameter. The carbons were chosen to include several types of common carbons produced from coal precursors as well as a wood-based carbon and a coconut shell-based carbon.

Role of Nanocomposite Support Stiffness on TFC Membrane Water Permeance.

This paper discusses the role played by the mechanical stiffness of porous nanocomposite supports on thin-film composite (TFC) membrane water permeance. Helically coiled and multiwall carbon nanotubes (CNTs) were studied as additives in the nanocomposite supports. Mechanical stiffness was evaluated using tensile tests and penetration tests.

Crude oil contamination of plastic and copper drinking water pipes.

This study was conducted to determine the susceptibility of plastic (i.e., PEX, HDPE and CPVC) and copper pipes to short-term contamination by crude oil.

Impact of dispersant on early life stages of the water flea Daphnia magna and the eastern oyster Crassostrea virginica.

In response to the 2010 Deepwater Horizon oil spill, over 1 million gallons of dispersant were applied in Gulf of Mexico offshore waters; Corexit 9500 was the most applied dispersant. The impact on organisms in nearshore and freshwaters has received little scrutiny. Acute 48 h toxicity of Corexit 9500 and a new hyperbranched polyethylenimine (HPEI) dispersant-like compound were evaluated for the freshwater indicator organism, Daphnia magna and for larval and early spat stages of the Eastern oyster, Crassostrea virginica.

Superfine powdered activated carbon incorporated into electrospun polystyrene fibers preserve adsorption capacity.

A composite material consisted of superfine powdered activated carbon (SPAC) and fibrous polystyrene (PS) was fabricated for the first time by electrospinning. SPAC is produced by pulverizing powdered activated carbon. The diameter of SPAC (100-400nm) is more than one hundred times smaller than conventional powdered activated carbon, but it maintains the internal pore structure based on organic micropollutant adsorption isotherms and specific surface area measurements.

Bacteria Inactivation via X-ray-Induced UVC Radioluminescence: Toward in Situ Biofouling Prevention in Membrane Modules.

Germicidal UVC radiation is a highly effective, chemical-free tool for bacteria inactivation, but its application is limited to reactors and open areas that can accommodate lamps/LEDs and wiring. A relevant example of problematic bacterial colonization within UV-inaccessible confines where chemical techniques have found only limited success is biofouling of feed channels in high-pressure membrane elements for water treatment. Herein we demonstrate a unique method of generating UV internally using embedded radioluminescent (RL) particles excited by an external X-ray source.

The control of N-nitrosodimethylamine, Halonitromethane, and Trihalomethane precursors by Nanofiltration.

Nanofiltration (NF) is a promising technology for removing precursors of disinfection byproducts (DBPs) from source waters prior to oxidant addition in water treatment. The aims of this study were to investigate (i) the removal efficiencies of N-nitrosodimethylamine (NDMA), halonitromethane (HNM), and trihalomethane (THM) precursors by NF membranes from different source water types (i.e.

Superfine powdered activated carbon (S-PAC) coatings on microfiltration membranes: Effects of milling time on contaminant removal and flux.

In microfiltration processes for drinking water treatment, one method of removing trace contaminants is to add powdered activated carbon (PAC). Recently, a version of PAC called superfine PAC (S-PAC) has been under development. S-PAC has a smaller particle size and thus faster adsorption kinetics than conventionally sized PAC.

Effect of bead milling on chemical and physical characteristics of activated carbons pulverized to superfine sizes.

Superfine powdered activated carbon (S-PAC) is an adsorbent material with particle size between roughly 0.1-1 μm. This is about an order of magnitude smaller than conventional powdered activated carbon (PAC), typically 10-50 μm.

Structure-function relationship of PAMAM dendrimers as robust oil dispersants.

PAMAM dendrimers have recently been investigated as efficient and biocompatible oil dispersants utilizing their encapsulation capacity; however, their high cationic charge density has been shown to be cytotoxic. It is therefore imperative to mitigate cationic charge-induced toxicity and understand the effects of such changes. Presented here is a synergistic experimental and computational approach to examine the effects of varying terminal surface charge on the capacity of dendrimers to disperse model liner, polycyclic aromatic, and hybrid hydrocarbons.

Integrating algaculture into small wastewater treatment plants: process flow options and life cycle impacts.

Algaculture has the potential to be a sustainable option for nutrient removal at wastewater treatment plants. The purpose of this study was to compare the environmental impacts of three likely algaculture integration strategies to a conventional nutrient removal strategy. Process modeling was used to determine life cycle inventory data and a comparative life cycle assessment was used to determine environmental impacts.

Comparing graphene, carbon nanotubes, and superfine powdered activated carbon as adsorptive coating materials for microfiltration membranes.

Multi-walled carbon nanotubes (MWCNTs), nano-graphene platelets (NGPs), and superfine powdered activated carbon (S-PAC) were comparatively evaluated for their applicability as adsorptive coatings on microfiltration membranes. The objective was to determine which materials were capable of contaminant removal while causing minimal flux reduction. Methylene blue and atrazine were the model contaminants.

Nanomaterial transformation and association with fresh and freeze-dried wastewater activated sludge: implications for testing protocol and environmental fate.

Engineered nanomaterials (ENMs) are an emerging class of contaminants entering wastewater treatment plants (WWTPs), and standardized testing protocols are needed by industry and regulators to assess the potential removal of ENMs during wastewater treatment. A United States Environmental Protection Agency (USEPA) standard method (OPPTS 835.1110) for estimating soluble pollutant removal during wastewater treatment using freeze-dried, heat-treated (FDH) activated sludge (AS) has been recently proposed for predicting ENM fate in WWTPs.

Solubility of nano-zinc oxide in environmentally and biologically important matrices.

Increasing manufacture and use of engineered nanoparticles is leading to a greater probability for release of engineered nanoparticles into the environment and exposure to organisms. In particular, zinc oxide (ZnO) is toxic, although it is unclear whether this toxicity is due to the zinc oxide nanoparticles, dissolution to Zn(2+) , or some combination thereof. The goal of this study was to determine the relative solubilities of both commercially available and in-house synthesized ZnO in matrices used for environmental fate and transport or biological toxicity studies.

Indanylacetic acids as PPAR-delta activator insulin sensitizers.

A series of indane acetic acid derivatives were prepared which show a spectrum of activity as insulin sensitizers and PPAR-alpha and PPAR-delta ligands. In vivo data are presented for insulin sensitizers with selectivity for PPAR-delta over PPAR-alpha.