About Us
Experience You Can Count On
With nearly 40 years of delivering innovative solutions for clients around the world pH2O Consulting is your trusted partner for the development of innovative, cost effective and robust solution for your water and wastewater needs.
Peter Hillis, the founder of our business, has worked globally on projects including research and development, strategic planning, feasibility and concept design, detailed design and commissioning and operational optimisation.
We aim to deliver bespoke solutions, working with you and we work in a collaborative and engaging manner. Our aim is to make the experience of working with us enjoyable and rewarding, with a commitment to knowledge sharing and transfer.
We have access to a global network of world leading independent experts, if we don't know it you can rest assured we will know somebody who does.
Let us bring global knowledge to meet your local need.
Some of our clients in 2020:
Napier City Council, New Zealand
Hawkesbury City Council, NSW, Australia
Watercare, Auckland, New Zealand
Hunter Water Corporation, NSW, Australia
Melbourne Water, Australia
South East Water, Australia
Utilitas Group, Queensland, Australia
AECOM Australia
Pattle Delamore Partners, Auckland, New Zealand
Spiire Property and Infrastructure Consultants, Australia
Tessele Consultants, Perth, Australia
Learn More
Our breadth of process knowledge is available to assist you in the delivery of what you need to succeed. Talk to us today about how we can support your goals and put you on a solid track to success.
Publications, articles and books
Membrane Technology in Water and Wastewater Treatment
Presenting a useful reference to the current state of membrane technology and its likely future growth, this book covers all aspects of the technology and its applications in the water industry. Drawing on the experience of international experts, Membrane Technology in Water and Wastewater Treatment encompasses many practical applications of specific membranes, including MF, UF, NF, RO and EDR, in the treatment of ground and surface water, backwash water, seawater, and industrial and domestic wastewater. Novel applications, process enhancements and the latest systems are also discussed. This book is an excellent guide to membrane technology and will be of great interest to water companies, industrialists, legislative bodies and anyone with an interest in the technology or its applications.
Infrastructure Financing in the Water Industry
Private investment in the water industry is not new, here we discuss the history and future of private finance in the water industry.
Comparing International Water Regulations
The Australian Drinking Water Guidelines
(ADWG) directs efforts expended by
Australian utilities to provide safe,
reliable water. It provides guidance in
determining the health of supplies, proper
treatment for purification and potable
needs, and maintenance of water quality
through regional and council reticulation
schemes. It is also a living document,
as evidenced by the recently published
revision (NHMRC, NRMMC 2011). Future
ADWG revisions are expected to follow
patterns similar to other governmental
and international guidance and regulatory
documents. This manuscript investigates
evolutionary changes to non-Australian
regulatory practices to help provide an
assessment of ADWG’s future, and what
utilities can do to prepare
Phosphate treatment to reduce plumbosolvency of drinking water also reduces discharges of copper into environmental surface waters
This paper provides an analysis of the impact of phosphatedosing of drinking water on the metal concentrations in drinking water andsewage work effluents and the potential impacts in relation to the Water Frame-work Directive. Phosphate treatment the reduced average copper concentrationsin drinking water by around 40% from 65 to 35
m
g/L; the reduction is propor-tional to the phosphate dose. A corresponding 30% decrease in wastewatertreatment work effluent concentrations is observed. No significant changes areevident in the zinc and nickel concentrations
Reducing Organics and its Water Quality Impact
Over the last five years United Utilities has undertaken major capital investment to further reduce the risk from Cryptosporidium and trihalomethanes in more than half the supplies in the north west of England. The majority of the supplies in the region come from upland surface sources which historically have had minimal treatment and in consequence high organic concentrations. The factors influencing the integration of new treatment processes with existing, the choice of process and the challenges arising are discussed; as is their impact on the water quality. In particular, the benefit to the two measures driving the investment. The consequences extend beyond that achieved at the water treatment works. The reduced organic input into the distribution network has resulted in chlorine persisting a lot further into the distribution system. As a result of this, and the lower organic input, bacteriological activity has fallen substantially with consequent reduction in the presence of coliform bacteria. The lower concentration of organics has contributed to a substantial reduction in lead concentrations. This has been clearly illustrated by lead concentrations observed at lead pipe rigs situated within the distribution network.
Numerical modelling of fixed-cavity plate-and-frame filtration: Formulation, validation and optimisation
A model of fixed-cavity plate-and-frame filter presses is developed based on the theoretical framework developed by Buscall and White (1987. The consolidation of concentrated suspensions. Part 1. The theory of sedimentation. Journal of the Chemical Society. Faraday Transactions. I, Physical Chemistry in Condensed Phases 83, 873–891) and the piston-driven filtration model of Landman et al. (1991. Dewatering of flocculated suspensions by pressure filtration. Physics of Fluids. A, Fluid Dynamics 3(6), 1495–1509). The model properly accounts for compression of the suspension network structure within a filter cake in one dimension over a fixed cavity and allows for the effect of membrane resistance and ramping pressures. The model is validated by comparing on-site measurements of actual process performance at two water treatment plants with model predictions based on fundamental material properties of the feed slurries, the operating conditions and the press dimensions. The material properties are measured using laboratory based filtration tests. The model is then used to investigate the optimisation of press throughput and cake solids for a ferric water treatment slurry.
Optimisation of combined coagulation and microfiltration for water treatment
The effect of upstream coagulant dosing for full-flow microfiltration of an upland-reservoir water has been investigated. The process, run under conditions of constant flux and pH and based on a ferric salt, is compared with a published study of another full-flow process based on alum dosing and operated at constant pressure and coagulant concentration. The current study includes data for the residual deposit remaining following backflushing by reverse flow. Results are presented in terms of the specific-cake resistance as a function of pH or coagulant dose. Reasonable correlation with classical cake filtration theory was obtained, such that R′c was assumed to be independent of run time and cake thickness. The following trends have been noted:
Microfiltration membrane plant start up: A case study with autopsy and permeability recovery analysis
A potable water treatment plant, supplied from a low NOM (natural organic matter), low turbidity source with precoagulation and two-stage pressure sand filtration, had a MF (microfiltration) membrane process added to meet UK Water Regulations. An autopsy of the membrane modules showed that despite upstream coagulation/filtration with chlorination, a biofilm of EPS (extracellular polymeric substances) and inorganic particulates had developed. Backwashing under laboratory conditions yielded an almost full recovery. Laboratory-scale modules of fouled fibres from pre-commissioning and post-commissioning were assembled and cleaned. The recovery was modelled and optimized with a response surface experiment using variables of concentration, soak period and temperature. The pre-commissioning fibres were more recovered by longer chemical soak times at higher cleanant concentrations than the post-commissioning fibres. Comparative tests on post-commissioning fibres indicated that full recovery was possible with organic acids. It was concluded that start-up of new membrane plants may involve fouling conditions not necessarily representative of those under routine operating conditions, such that modification to prescribed cleaning operations may be required.
Fate and removal of permethrin by conventional activated sludge treatment
The fate and removal of permethrin during conventional wastewater treatment were evaluated at pilot-plant scale at different concentrations of mixed liquor suspended solids (MLSS) and, hence, different solids retention times (SRT). At feed concentrations of 0.26-0.86 microg L(-1), the permethrin was removed by primary treatment at an efficiency rate of 37%, similar to previously reported data, and from 40% to 83% for secondary treatment, decreasing with decreasing SRT. Comparable ranges, from 37% up to 98%, have been reported for micropollutants with similar physicochemical properties to permethrin, such as galaxolide and tonalide. Little difference in removal was noted between the medium and low MLSS concentrations trials, the main difference in treated effluent permethrin concentration arising on changing from high to medium MLSS levels. This was attributed to the limited acclimatization period employed in these two trials, leading to higher levels of soluble organic matter in the treated water, with which the permethrin appeared to be associated.
Fate and behaviour of copper and zinc in secondary biological wastewater treatment processes: I Evaluation of biomass adsorption capacity
The current sources of copper and zinc in municipal wastewaters have been considered, and the changes in the concentrations and quantities of these two elements entering sewage treatment works over the last three decades have been calculated. The concentrations and quantities of the heavy metals cadmium, chromium, copper, mercury, nickel, lead and zinc, entering UK sewage treatment works, have been reduced by between 50% and 90% during this period. However, the reductions in copper and zinc appear to be at the lower end of these ranges and thus remain a cause for concern, particularly their concentrations in sewage effluents and their potential environmental impacts on receiving waters. Bench studies have been undertaken to predict removals by three types of biological wastewater treatment plants: trickling filters, conventional activated sludge and membrane bioreactors, to determine if any of these processes are more efficacious for the removal of these metals. These results suggest that, despite membrane bioreactor biomass achieving the lowest effluent suspended solids concentration and having the lowest effluent chemical oxygen demand, which is accepted as a surrogate measure of organic chemical chelating ability of the aqueous phase, they produce the highest effluent values for the two metals in this study (copper and zinc). Removals of zinc and copper in biological wastewater treatment processes are probably primarily determined by those factors influencing metal solubility in the biomass matrix.
The MBR Site Guest blog
The ‘circularisation’ of the economy – where maximum value is drawn from resources at the same time as minimising waste – has been all the rage in many industries and communities, and especially so in the water industry.
The water industry has in many ways been at the forefront of sustainability for over 100 years. This is evident in the very concept of treating raw sewage to the benefit of the receiving environment to which the treated effluent is discharged. It is also evident in the production of biogas from the anaerobic digestion of biosolids for renewable energy.