Potential of acid activated clays in the clarification of menhaden stickwater

Abstract

The primary objective of this investigation was to determine the feasibility of using acid activated clays to clarify menhaden stickwater effluent. Experiments, such as physical and chemical properties determinations, effect of changes in pH and temperature and coagulation, and coagulation followed by clay treatment were also performed to study the separation of solids in stickwater.

Analysis of the stickwater showed that it contained 4.5% crude protein, 1.4% crude fat, 6.5% total solids, 1.13% ash and 93.1% water. At a wavelength of 575 um, the sample absorbed all the light and the percent transmittance was zero. When diluted 1:100 the percent transmittance was 0.39 at the same wavelength. Measured at 25°C the sample had a viscosity of 9.0 centipoises.

The results showed that the precipitation of fat increased with increasing temperatures, while the reverse was true for protein. A pH of 4.0 gave the maximum clarification at all temperatures employed. The viscosity decreased at pH values above and below the original pH of the sample.

Among the four different acid activated clays used in this study (trade names Supact‐150, Impact‐150, Impact‐12 and Impact‐1OORR), Impact‐150 was the most effective in protein and fat precipitation, and the degree of separation of these components increased by treating stickwater with a coagulant (aluminum sulfate) prior to treatment with acid activated clay.     

Hazardous Waste Minimization: Part Vii (B) Hazardous Waste Minimization within the Department of Defense

This article is a series of representative case studies of Department of Defense hazardous waste minimization. Each Military Department and the Defense Logistics Agency describe actual accomplishments. Areas covered range from production line modification to product specification change. These efforts are part of a Department of Defense plan composed of individual programs executed independently by each military service and defense agency.

Part VII of the hazardous waste minimization series appears in two separate installments: the first installment, Part VII (A), dealt with Department of Defense waste minimization efforts in vehicle repair operations, explosives manufacturing, and abrasive blasting processes; Part VII (B) covers shipboard mercury wastes, industrial chemical control, solvent reclamation, and hazardous property sales efforts.     

Ambient Air Monitoring for Sulfur Compounds

The role of sulfur compounds in our environment has been the subject of much speculation during the past two decades. An evaluation of the effect of man-made contributions to the biogeochemical sulfur cycle requires a comprehensive examination of source magnitudes, atmospheric concentrations and removal processes. Many voids exist in our present knowledge of these parameters despite the contributions of numerous researchers. Adequate information is needed concerning the various forms of sulfur as well as other critical constituents which exist in our biosphere so that their interrelationship and role in the mechanisms of the sulfur cycle may be more fully understood.     

Validation of a dynamic model of hydrogen permeation through Pd-based membranes

Pd-based membranes have been studied for pure hydrogen separation from syngas: in particular, a mathematical model of a Pd membrane for hydrogen separation has been developed.This model can be used in process and assessment studies of the parameters which characterize the mass transfer phenomena (such as: hydrogen permeability, surface coverage and limiting step). By coupling the permeation and water gas shift reaction kinetics, it can also be used to evaluate the performances of the membrane reactor. Further, it can be helpful to evaluate the best assembly and sizing of a H₂/CO₂ separation system.The model takes into account the kinetics of H₂ adsorption/desorption on Pd surface, the H₂ permeation into the palladium bulk and in the porous layer, and the kinetics of CO, CO₂, H₂O, O₂, H₂S competitive adsorption/desorption on Pd surface. It is also comprehensive of flux equations and bulk mass, momentum and energy balance.The results released by the model were compared to the experimental data during both the transient phase and the steady state conditions. A satisfactory agreement between model and experimental data was found.     

Reductive dehalogenation: A subsurface bioremediation process

Introduction and large-scale production of synthetic halogenated organic chemicals over the last fifty years has resulted in a group of contaminants that tend to persist in the environment and resist both biotic and abiotic degradation. The low solubility of these types of contaminants, along with their toxicity and tendency to accumulate in food chains, make them particularly relevant targets for remediation activities. Among the mechanisms that result in dehalogenation of some classes of organic contaminants are stimulation of metabolic sequences through introduction of electron donor and acceptor combinations; addition of nutrients to meet the needs of dehalogenating microorganisms; possible use of engineered microorganisms; and use of enzyme systems capable of catalyzing reductive dehalogenation. The current state of research and development in the area of reductive dehalogenation is discussed along with possible technological application of relevant processes and mechanisms to remediation of soil and groundwater contaminated with chlorinated organics. In addition, an overview of research needs is suggested, which might be of interest for development of in-situ systems to reduce the mass of halogenated organic contaminants in soil and groundwater.     

The object of environmental ethics

Since the term environmental ethics began to be used a generation ago, it has covered many different kinds of environmental notions, problems, ethical systems, and forms of behavior. A variety of cases are presented and examined under two terms,environmental ethics andecological morality, in an effort to illustrate different kinds of ethical objectives. In order to understand the connections between various strands of environmental ethics, personal and social values and subcultural norms of environmental ethics are examined under Christopher Stone's concept of moral pluralism. G. J. Warnock's notion of the general object of morality is proposed to integrate the variegated purposes of environmental ethics.     

THE REGULATED RIPARIAN VERSION OF THE ASCE MODEL WATER CODE: THE THIRD WAY TO ALLOCATE WATER1

ABSTRACT: Lawyers, engineers, and hydrologists are accustomed to thinking of water law as falling into one of two incompatible models: riparian rights (under which water is allocated by courts according to the relative reasonableness of the competing uses) and appropriative rights (under which water is allocated according to the temporal priority of the competing uses, largely by the action of the water users themselves but perfected by the issuance of an administrative permit). Usually unnoticed is the existence of a third approach, which I have dubbed “regulated riparianism.” Under regulated riparianism, water is allocated by water permits issued after an administrative determination of the reasonableness of the proposed use before the use is commenced. This system, now in place in about half of the states east of Kansas City (plus Hawaii), thus is fundamentally different from either the traditional ripanan rights that it replaces or the appropriative rights found in western states.     

Measuring environmental performance at niagara mohawk power

A system for measuring environmental performance is important to the success of a company's environmental excellence program. In 1991, Niagara Mohawk Power Corporation (NMPC) unveiled a new corporate policy on protection of the environment. To measure and communicate progress in achieving the goals and objectives embodied in the new policy, an environmental performance index (EPI) was developed. In this article the author shows how the EPI utilizes a weight and rating scheme to reflect environmental performance in three categories: emissions/wastes, regulatory compliance, and environmental enhancements. Performance goals have been established for the period 1992–1995, and actual performance data has been compiled for 1992 and 1993. While the EPI is designed to measure changes in NMPC's environmental performance over time, it does not provide information on how the company's performance compares to that of other electric utilities. Accordingly, NMPC is developing an environmental benchmarking program with a group of Northeast electric utilities that will allow comparisons of environmental performance between utilities.     

Metrics,decisions, and strategies: Environmental performance measurement in the electric utility industry

The twin challenges of increased competition and environmental consciousness are causing companies in the utility industry to re-examine their methods for measuring environmental performance. A new paradigm is emerging which has already appeared in other industries—treating environmental quality as a potential source of profitability and competitive advantage. This article discusses how utilities and industrial companies can develop an environmental performance measurement framework, integrate it into their strategic and operating business practices, and use it for evaluation of alternative environmental strategies.